Home

INT - Isaac Newton Group of Telescopes

1. 41 INT TCS 1 issue 3 1 INT TCS User Manual oO O Oo 0 O Declination Equinox Mean pre IAU76 B post I AU76 J or apparent Differential tracking rates blank if not specified Proper motions and epoch blank if not specified Parallax and radial velocity blank if not specified e Apertures and offsets O O O Positional offset currently enabled blank if zero If the POSITION command was used then the offset number 1 to 20 is given in the first field this is left blank if the OFFSET command was used instead The next two fields give the offset components in the RA and Dec directions For an offset specified in tangent plane coodinates by ENTER ARC the values are labelled XI and ETA and given in arcseconds For an incremental offset ENTER TIME they are given in seconds of time and seconds of arc respectively and are called RA and DEC For a tangent plane offset the origin of the offset may be displayed after the offset components if a nominal offset had been set up The total offset applied to the target position is the sum of the offset and the offset origin Aperture offset currently enabled blank if zero If the APERTURE command was used then the first field gives the aperture number 1 to 20 if BEAMSWITCH was used instead then the field is left blank The next two fields give the x4 and y4 components of the offset in arcsec Reference positio
2. None Examples PROPER_MOTION 1 54 0 675 Comments The synonym PM can also be used 4 50 RA Enter a right ascension in the edit source block Format RA lt ra_hours gt lt ra_minutes gt lt ra_seconds gt Defaults None 28 INT TCS 1 issue 3 1 INT TCS User Manual Parameters Keywords Examples The right ascension in hours minutes and seconds of time The right ascension is rejected if the any of the components lie outside the following ranges ra_hours 0 to 23 inclusive ra_minutes 0 to 59 inclusive ra_seconds 0 0 to 59 99 inclusive None RA 12 34 56 789 4 51 RADIAL_VEL Enter a radial velocity in the edit source block Format Defaults Parameters Keywords Examples Comments RADIAL_VEL lt radial_velocity gt Unspecified radial velocities are assumed to be 0 The radial velocity in km s A positive velocity implies a receding source None RADIAL_VEL 98 The synonym RV can also be used 4 52 RECALL Recall a previous command This command is not allowed from DRAMA Format Parameters Qualifiers Defaults Examples Comments RECALL lt n gt RECALL lt string gt or RECALL ALL lt n gt refers to the mth last command lt string gt is a character string forming the first part of a command to be recalled ALL causes the entire command buffer to be listed Last command RECALL 2 RECALL SOURCE RECALL ALL This command is essentially ident
3. The System Catalogue INT TCS User Manual 33 34 34 34 35 35 35 35 36 36 38 38 39 40 41 41 41 43 45 46 48 48 48 INT TCS 1 issue 3 1 INT TCS User Manual 1 INTRODUCTION 1 1 Purpose This document is the User Manual for the Telescope Control Software TCS at the Isaac Newton Telescope INT 1 2 Scope This document applies only to the TCS User Interface use of the TCS via the DRAMA interface is not covered 1 3 Definitions Right ascension Declination parallactic angle sky position angle mount position angle XK Bo D E RQA a lt 3 Cartesian coordinates in the tangent plane parallel to a and respectively Cartesian coordinates in the tangent plane along mount position angle 0 and 90 respectively in the input coordinate system X4 VA Cartesian coordinate system fixed in the focal plane 1 4 Overview The TCS runs on an Alphastation under the VMS operating system Some commands are not available via the DRAMA interface this is noted in the command descriptions and in the command summary INT TCS 1 issue 3 1 INT TCS User Manual 2 STARTING AND STOPPING THE TCS 2 1 Startup To start the TCS log in to LPAS2 either from the X terminal in the INT control desk or from a terminal window on the Instrument Control computer The username and password are displayed on the X terminal If the TCS is not running you will be presented with a START menu similar to
4. 20 INT TCS 1 issue 3 1 INT TCS User Manual Comments The focus is normally adjusted to compensate for changes in tube temperature The input to FOCUS is a virtual position which should be independent of these corrections It should not therefore vary from night to night Use the DFOCUS command to compensate for known changes of optical path e g filters If focus tracking is enabled the default state the displayed focus is the virtual position if not the raw encoder reading is displayed 4 25 GOCAT Retrieve the entry for the named source from the user catalogue and then send the telescope to track that source Format Defaults Parameters Keywords Comments GOCAT lt source_name gt None The name of the target object None The user catalogue is searched first followed by the system catalogue 4 26 GOMOON Move the telescope to point at the moon and then track it Format GOMOON Defaults None Parameters None Keywords None Comments If you stop the telescope while tracking the moon and then wish to continue tracking it use the GOMOON command again Do not use the NEXT command as then the differential track rates will stay constant and will not vary as they should for accurate tracking 4 27 GOTO Move the telescope to a new source and track it Format GOTO lt source_name gt lt right_ascension gt lt declination gt lt equinox gt Defaults None Parameters lt source
5. Manual e LIMITOFFSET Change the limits of the Cass rotator forbidden zone e TRACK Turn focus dome rotator or telescope tracking on or off e ZEROSET Determine incremental encoder zero points 3 10 Change of focal station and instrument Note that Select in this context means set up software and drive the correct rotator Both allowed in engineering mode e STATION Select focal station e INSTRUMENT Tell the TCS which instrument is in use 3 11 Display functions All allowed in engineering mode MOON and SHOW are not allowed from DRAMA e DISPLAY Change the coordinate system of the displayed telescope position e MOON Give the current right ascension and declination of the Moon e PAGE Switch to another information display page e SHOW Display information about the system state 3 12 Logging of test data All allowed in engineering mode e LOG Log encoders tracking errors and associated data e POINT Write encoder coordinates to a data file e RMS Calculate and display mean and rms servo errors e SNAPSHOT Record the current information display page 3 13 Meteorological and Earth rotation data All allowed in engineering mode e HUMIDITY Input relative humidity used in refraction calculation e POLE Input values of polar motion e PRESSURE Input barometric pressure used in refraction calculation e TEMPERATURE Input temperature used in refraction calculati
6. Set the limit that determines whether the guidestar is in position Format Defaults Parameters Limits Examples Comments AGLIMIT lt limit gt None The limit in arcseconds 0 to 5 arcseconds AGLIMIT 2 5 This command is useful in conditions of bad seeing when the default limit of 0 5 arcseconds is too small 4 4 AGSELECT Select which autoguider to use Format AGSELECT lt autoguider_name gt Defaults None The prime focus autoguider is selected on startup Parameters None Keywords Valid autoguider names are CASSEGRAIN the Cassegrain off axis autoguider PRIME the prime focus Wide Field Camera autoguider Examples AGSELECT CASS Comments The TCS needs to know which autoguider is currently in use in order to perform the conversion between guide star pixel position and drive corrections 4 5 AGVIEW Perform an aperture offset to move an image onto the autoguider CCD Format AGVIEW Defaults None Parameters None Keywords None Comments This command allows a field to be viewed using the autoguider An offset is applied to move the image from the nominal aperture usually the rotator centre to the centre of the autoguider field It is essential to tell the TCS which autoguider is in use and to define its position in the focal plane use the AGSELECT and PROBE commands as necessary 4 6 APERTURE Offset the telescope so that an object moves by
7. be prompted for The user can accept the default or can enter a new duration The required duration of the log in minutes the maximum duration is 80 minutes for continuous logging or 30 minutes for saved encoder data lt system gt valid keywords are AUTOGUIDER pixel coordinates produced by one of the CCD autoguiders ENCODERS encoder readings servo errors and drive demands for the telescope axes current rotator and auxiliary mechanisms TV pixel coordinates produced by a TV system not normally connected does not work with the Grinnell but retained for test purposes lt state gt valid keywords are ON turn logging on OFF turn logging off and display the filename KEEP only used with the ENCODERS keyword This will save the previous lt duration gt minutes of encoder data to a log file LOG AUTO ON 15 LOG ENC ON 5 LOG ENC KEEP 10 If TV or autoguider logging is turned on when it is already enabled the log file is closed and a new one is opened If encoder logging is turned on when it is already enabled the log will continue to be written to the current file if the new duration is equal to or greater than the previous duration otherwise the file will be closed A LOG ENC KEEP command can only save data starting from the last time a LOG ENC KEEP command was issued or for the last 30 minutes whichever is the shorter time Any of the logging functions may be run simultan
8. heads on the HA axis and two Heidenhain heads on the Dec axis these are read in quick and slow motion In addition the high resolution Baldwin encoders are used only in slow motion The usual combination for HA is the mean of all three Ferranti heads in quick motion and the Baldwin in slow motion For Dec the mean of the two Heidenhain heads is normally used in both quick and slow motion The command will be rejected if an ENCODER OFF command removes the last enabled encoder for that mechanism 18 INT TCS 1 issue 3 1 INT TCS User Manual 4 18 ENGINEERING Put the telescope into engineering mode Format ENGINEERING Defaults None Parameters None Keywords None Comments This command should be used as part of the normal shutdown procedure at the end of the night to return to engineering mode at any time or in an emergency to remove power from the drives and put on the brakes It is equivalent to pressing the COMP ENG button on the control desk To return to computer mode turn the COMP ENG key to the right and let it spring back 4 19 ENTER Set up aperture and positional offsets for repeated use Format ENTER APERTURE lt aperture_number gt lt x_offset gt lt y_offset gt ENTER ARC_POSITION lt pos_number gt lt xi gt lt eta gt ENTER TIME POSITION lt pos_number gt lt ra_offset gt lt dec_offset gt Defaults None Parameters lt aperture_number gt is an integer in the range
9. offset this change is not retained when the TCS is restarted SHOW LIMITS displays the current value of offset The Prime focus rotator is no longer controlled by the TCS its default position on startup is defined in the TCS as 180 If the Prime focus rotator is not at 180 the ROTATOR command must be used to inform the TCS of the true position otherwise autoguiding will not work 4 56 RV Synonym for RADIAL VELOCITY q v _ 30 INT TCS 1 issue 3 1 4 57 SHOW Display data on the topic indicated by the keyword This command is not allowed from DRAMA Format Defaults Parameters Keywords INT TCS User Manual SHOW lt show_topic gt None None lt show_topic gt The following keywords are valid show topics APERTURES ASTROMETRY AUTOGUID El wa CALIBRAT GI CATALOGUES CLONES EDIT ENCODERS FOCAL_STATION LIMITS LOGGING MECHANISMS Displays the x4 and y4 coordinates of apertures 0 to 20 and the currently selected aperture See APERTURE BEAMSWITCH ENTER and STORE Displays the user modifiable astrometric parameters wavelength pressure temperature relative humidity all used to calculate refraction UT1 UTC and polar motion TDT UTC is also shown as a check on the insertion of leap seconds TDT TAI 32 184 s TAI UTC is an integral number of seconds compare with IERS Bulletin
10. or may be imported from the instrumentation computer using INCLUDE Catalogues are simply lists of source parameters in free format with spaces separating the fields All data for an entry should be on one line of the file Anything following an asterisk or an exclamation mark is treated as a comment and is ignored by the TCS Do not use tab control or other peculiar characters The parameters must be in the order Name RA Declination Equinox RA proper motion Dec proper motion Epoch parallax radial velocity The first four parameters are mandatory and the remainder are optional with sensible defaults The formats and units of the necessary parameters are as follows Name up to 20 characters Embedded spaces are allowed but if they are used then the name must be enclosed in double quotes Right ascension hours minutes seconds separated by spaces Declination degrees minutes seconds separated by spaces Equinox For mean places the equinox must have two components a leading letter indicating the system of the coordinates and a number indicating the epoch of the mean equator and equinox of that system The format is lt letter year gt e g B1950 J2000 B denotes the pre I AU76 loosely FK4 system J implies post AU76 FK5 The year must lie in the range 1800 0 to 2100 0 Geocentric apparent coordinates of the date of observation are denoted APPARENT abbreviable to A No year is required or accepted for appar
11. see LOG displays the status of all of the main mechanisms The main drives are said to be following during a sidereal track For the dome following means that it is tracking the telescope and for the focus that it is being adjusted to compensate for temperature changes see TRACK The software and hardware limit status for the mechanism is shown next The mechanism is moving if it is being driven under computer control otherwise stopped The next field reads in position if the mechanism is either tracking or stopped within a defined position error depending on its requested 3 gt INT TCS 1 issue 3 1 INT TCS User Manual state The final field shows whether the mechanism can be driven under computer control if not the status shown is Manual override or Engineering mode POSITIONS Lists the type and size of positional offsets 0 to 20 currently defined and any offset in use See OFFSET POSITION ENTER and STORE TV gives the TV camera currently selected by the TCS This option is only useful under special circumstances for the INT a suitable TV system is not normally connected to the TCS VERSION Displays the version of TCS software in use 4 58 SLOWOFF Apply a tangent plane offset at a rate defined by the user Format Defaults Parameters Keywords Examples Comments SLOWOFF lt xi gt lt eta gt lt rate gt lt offset_type gt lt off
12. see below Examples OUTPUT PRINTER OUTPUT TERMINAL as 5 ges INT TCS 1 issue 3 1 INT TCS User Manual Comments 4 40 PAGE OUTPUT FILI OUTPUT FILI The catalogue can be saved in the default catalogue area on the TCS computer or on the ICS computer use int cat filename cat in the OUTPUT command to store the catalogue file in int cat filename cat whence it may be recovered on a subsequent night with the INPUT command Old catalogues will be deleted periodically The CAT extension is mandatory any other extension will be removed and CAT substituted TABBY CAT int cat my cat G Py F Pi Display the next page in the cycle of information and status displays Format Defaults Parameters Keywords Examples Comments PAGE lt display_screen gt PAGE NEXT the next display screen in the cycle The information display appears on startup None The various displays in the cycle are in order INFO Top level information display appears on startup ENCODERS Encoder readings LIMITS Limit indicators STATUS Status information PAGE ENC PAGE See Section 6 for more details 4 41 PARALLAX Enter a parallax into the edit source block Format Defaults Parameters Limits Keywords Examples 4 42 PARK PARALLAX lt parallax_arcsecs gt None Unspecified parallaxes are assumed to be zero The parallax in arcseconds The par
13. 0 to 20 0 being the reference position the default on source change lt pos_number gt is an integer in the range 0 to 20 Position 0 is the nominal offset and can only be used with tangent plane offsets ENTER ARC_POSITION lt x_offset gt lt y_offset gt lt xi gt lt eta gt and lt dec_offset gt are in arcseconds lt ra_offset gt is in seconds of time Keywords Valid offset modes are APERTURE set up an aperture offset in the focal plane ARC_POSITION setup a tangent plane offset 7 TIME_POSITION setup an incremental offset Examples ENTER APERTURE 3 1 5 20 3 ENTER ARC_POSITION 3 3 0 12 0 ENTER TIME POSITION 1 0 33 11 Comments ENTER APERTURE sets up an aperture offset which can be applied using the APERTURE command ENTER ARC_POSITION and ENTER TIME_POSITION set up a positional offset which can be added to the telescope demand position using the POSITION command 4 20 EPOCH Enter a value for the epoch of the position into the edit source block Format EPOCH lt date gt Defaults None Parameters The epoch in years Keywords None Limits The year must be in the range 1800 0 to 2100 0 Examples EPOCH 1967 35 Comments The epoch is used in conjunction with the proper motions to compute the position of date 19 INT TCS 1 issue 3 1 INT TCS User M
14. 6 ROTATOR mode ROTATOR mode is not currently implemented 5 3 Sign conventions For the modes which cause the image to move in the focal plane the sense of motion for the keys has been set so that the image moves in the obvious way The displayed cumulative totals for each mode refer to the motion of the telescope This coupled with the variety of different hand conventions of astronomical coordinate systems requires the sign conventions summarised below e RA_DEC mode o Image moves east right ascension displayed o Image moves west right ascension displayed o ft Image moves north declination displayed o Image moves south declination displayed e X_Y mode The sign convention has been used to be consistent with that used for apertures set up with the BEAMSWITCH and ENTER APERTURE commands o lt Image moves left on TV x displayed o Image moves right on TV x displayed o Image moves up on TV y displayed o Image moves down on TV y displayed e OFFSET mode As for X_Y e APOFF mode As for X_Y e FOCUS mode o Focus o Focus If the image appears to move in a direction opposite to that expected check that the TV scan switches are in their correct positions for the optical configuration in use 40 INT TCS 1 issue 3 1 INT TCS User Manual 6 THE TCS DISPLAY 6 1 General The display has four screens arranged as follows e Source and t
15. A See WAVELENGTH PRESSURE TEMPERATURE HUMIDITY UT1UTC and POL EJ gives the autoguider currently selected by the TCS see AGSELECT the associated probe position if relevant see PROBI the guiding pixel coordinates and the state of the guiding loop unlocked locked or suspended see AUTOGUIDE GI wm displays the values of declination index error HA index error and HA collimation together with their rms errors and the sky sigma for the last CALIBRATE at the current focal station The corresponding parameters for the default pointing model are also given gives a directory of user catalogues Only the first 50 user catalogues are listed lists the address of each device that is displaying a copy of the display screen displays the parameters of the edit source which will be selected by the NEXT command lists the encoders currently being used by the TCS to control the telescope See ENCODER for information on how to change the configuration gives the current software selection of focal station This option is intended to allow the user to check that the combination of TCS selection of focal station autoguider and instrument is self consistent See STATION INSTRUMENT and AGSELECT lists the software position limits for the main drives rotation both focal stations and focus shows the current status of data logging
16. Particle Physics and Astronomy Research Council Isaac Newton Group INT TCS 1 Isaac Newton Telescope Telescope Control System USER MANUAL Marion Fisher Issue 3 1 7 September 2007 Isaac Newton Group Apartado 321 38780 S C La Palma Tenerife Canary Islands Telephone 34 922 425400 Fax 34 922 425401 Internet mpf ing iac es INT TCS l1 issue 3 1 Table of Contents 1 INTRODUCTION 1 1 Purpose 1 2 Scope 1 3 Definitions 14 Overview 2 STARTING AND STOPPING THE TCS 2 1 Startup 2 2 Stopping the TCS 3 TCS USER INTERFACE COMMANDS SUMMARY 3 1 General TCS commands 3 2 Source data entry 3 3 Catalogue handling 3 4 Source change 3 5 Positional and Aperture offsets 3 6 Autoguiding 3 7 Calibration procedures 3 8 Mechanism control 3 9 Mechanism configuration 3 10 Change of focal station and instrument 3 11 Display functions 3 12 Logging of test data 3 13 Meteorological and Earth rotation data 4 TCS USER INTERFACE COMMAND LIST 41 ACKNOWLEDGE 4 2 ADD 4 3 AGLIMIT INT TCS User Manual 10 10 10 10 10 11 11 11 11 12 12 12 13 INT TCS 1 issue 3 1 4 4 4 5 4 6 4 7 4 8 4 9 4 10 4 11 4 12 4 13 4 14 4 15 4 16 4 17 4 18 4 19 4 20 4 21 4 22 4 23 4 24 4 25 4 26 4 27 4 28 4 29 4 30 4 31 4 32 AGSELECT AGVIEW APERTURE AUTOGUIDE BEAMSWITCH BLIND_OFFSET CALIBRATE CLONE DEC DFOCUS DIFF_RATES DISPLA
17. Stop the TCS TELD Start the TELD task NFSMOUNT Mount the ICS Unix partition EXIT Exit this menu and log out Option gt INT TCS 1 issue 3 1 INT TCS User Manual STOP will stop the running TCS then after waiting for 20 seconds for the sub processes to die the START menu will be displayed TELD will start TELD the task which communicates between the TCS and the ICS via DRAMA If TELD is already running it will be stopped and restarted NFSMOUNT will dismount all NFS mounts and remount the ICS Unix partition which is used by the TCS to write the FITS header and also to access user catalogues TELD and NFSMOUNT are not present on the START menu as both actions are part of the TCS startup procedure 2 2 Stopping the TCS Always zenith park the telescope and switch to engineering mode first Under normal circumstances the TCS should be closed down using the TCSEXIT command at the user interface see command list If the user interface is not working e g its window has disappeared or has been accidentally deleted then the system can be stopped from another login session Log in as described in the previous sub section and type STOP at the Opt ion gt prompt INT TCS 1 issue 3 1 INT TCS User Manual 3 TCS USER INTERFACE COMMANDS SUMMARY This section contains a summary of the commands available at the user interface of the telescope control system classified into functional groups Details o
18. This is the INT TELESCOPE CONTROL SYSTEM The TCS is not running Please enter an option START Start the TCS version 120 1 0 Info display on l1px22 ing iac es USER window on l1px22 ing iac es SIMULATE Run the TCS version I20 1 0 in simulation mode Info display on lpas2 USER window on Ilpas2 VERSION Select a different TCS version DISPLAY Select different display devices EXIT Exit this menu and log out Option gt START runs the displayed TCS version The login window disappears then the Display and User windows appear The User window displays a few lines of information followed by the USER gt prompt VERSION allows the user to choose a different version of the TCS A list of the available versions is displayed enter the version required or press RETURN to keep the default value DISPLAY is used to select a different device for the Display and User windows Enter the IP name or address of the new device for the Display window and again for the User window Pressing RETURN will keep the default value It is possible for the Display and User windows to be on different devices If the TCS is already running the following menu will be displayed This is the INT TELESCOPE CONTROL SYSTEM The TCS is running using version 123 0 0 Please enter an option STOP
19. Y DOME ENCODER ENGINEERING ENTER EPOCH EQUINOX ERASE FIND FOCUS GOCAT GOMOON GOTO HANDSET HELP HUMIDITY INCLUDE INSTRUMENT INT TCS User Manual 13 13 13 14 14 15 15 16 16 17 17 17 18 18 19 19 19 20 20 20 20 21 21 21 22 22 22 23 23 INT TCS 1 issue 3 1 4 33 4 34 4 35 4 36 4 37 4 38 4 39 4 40 4 41 4 42 4 43 4 44 4 45 4 46 4 47 4 48 4 49 4 50 4 51 4 52 4 53 4 54 4 55 4 56 4 57 4 58 4 59 4 60 4 61 LIMITOFFSET LOG MARK MOON NEXT OFFSET OUTPUT PAGE PARALLAX PARK PM POINT POLE POSITION PRESSURE PROBE PROPER_MOTION RA RADIAL_VEL RECALL REMOVE RMS ROTATOR RV SHOW SLOWOFF SNAPSHOT SOURCE STATION INT TCS User Manual 23 24 24 24 25 25 25 26 26 26 26 27 27 27 28 28 28 28 29 29 29 30 30 30 31 32 32 32 33 INT TCS 1 issue 3 1 4 62 4 63 4 64 4 65 4 66 4 67 4 68 4 69 4 70 4 71 5 5 1 5 2 5 3 6 1 6 2 6 3 6 4 6 5 7 1 7 2 STOP STORE TCSEXIT TEMPERATURE TRACK TRANSFER TWEAK UTIUTC WAVELENGTH ZEROSET THE TCS HANDSET General Handset modes Sign conventions THE TCS DISPLAY General Source and telescope information Encoder display Limit page Dome status and manual overrides page CATALOGUES Catalogue format
20. _name gt The name of the new source It must be a string of up to 20 characters extra characters are lost To include spaces the whole string should be enclosed within double quotes lt right_ascension gt Specifies the right ascension of the new source in three fields separated by spaces Format lt ra_hours gt lt ra_minutes gt lt ra_seconds gt The right ascension is rejected if any of the components lie outside the following ranges lt ra_hours gt 0 to 23 inclusive lt ra_minutes gt 0 to 59 inclusive lt ra_seconds gt 0 0 to 59 99 inclusive lt declination gt Specifies the declination of the new source in three fields separated by spaces The lt dec_degrees gt field may be signed If not signed the default is Format lt dec_degrees gt lt dec_minutes gt lt dec_seconds gt The declination is rejected if any of the components lie outside the following ranges lt dec_degrees gt 0 to 89 inclusive lt dec_minutes gt 0 to 59 inclusive oe S INT TCS 1 issue 3 1 INT TCS User Manual lt dec_seconds gt 0 0 to 59 99 inclusive lt equinox gt Specifies the equinox of the source coordinates A valid equinox must have two components a leading letter indicating the system of the coordinates and a number indicating the epoch of the mean equator and equinox of that system Format lt letter year gt e g B1950 J20000r APPARENT for which no number is required Note that only B J or A are acceptable as
21. a Ad STORE POSITION 0 will store the current 7 offset as the nominal offset a Aa Ad offset cannot be stored in position 0 4 64 TCSEXIT Initiate an orderly shutdown of the telescope control system Format TCSEXIT Defaults None Parameters None Keywords None Comments This command stops the telescope before shutting down the control system 4 65 TEMPERATURE Enter the value of the outside air temperature used in the calculation of refraction Format TEMPERATURE lt temperature gt Defaults None A temperature of 5 C is assumed on startup Parameters The outside air temperature in degrees Centigrade Limits 10 to 30 C Keywords None Examples TEMPERATURE 7 5 Comments An error of 10 C gives a pointing error of 1 7 arcseconds at an elevation of 45 34 INT TCS 1 issue 3 1 INT TCS User Manual 4 66 TRACK Turn the focus dome or telescope tracking on or off Format Defaults Parameters Keywords Examples TRACK lt mechanism gt lt state gt None None The lt mechanism gt keyword selects the mechanism which is to have its tracking state changed The allowed mechanisms are DOME FOCUS TELESCOPE The lt state gt keyword sets the tracking either ON or OFF TRACK FOCUS OFF 4 67 TRANSFER Control the operational state of rem
22. a vector fixed in the focal plane Format Defaults Parameters APERTURE lt aperture_number gt None The reference position aperture 0 is selected on startup This is usually also the rotator centre 0 0 The aperture number is in the range 0 to 20 The corresponding x4 y4 displacement must have been set up previously by using the ENTER or STORE commands APERTURE is the referen ition l ey ie INT TCS 1 issue 3 1 INT TCS User Manual Keywords Examples Comments None APERTURE 2 An x4 ya shift in the focal plane is divided into two parts the reference position which is unaltered on source change and an aperture offset which is reset to zero on source change The APERTURE command provides a means of switching between the reference position and previously defined aperture offsets 4 7 AUTOGUIDE Lock or unlock the CCD autoguider loop Format Defaults Parameters Keywords Examples Comments AUTOGUIDE lt state gt lt x gt lt y gt WAIT None The optional parameters x and y are the desired pixel coordinates for the guide star and are used with the ON keyword If they are not specified the system will adopt the most recent autoguider coordinates sent to the TCS WAIT is designed for use when the AUTOGUIDE command is sent via DRAMA The command will not complete until the guidestar is in position The in posit
23. allax is rejected if it lies outside the range 0 0 to 10 0 arcseconds None PARALLAX 0 023 Move the telescope to a defined park position and stop it Format Defaults Keywords Examples 4 43 PM PARK lt park_position gt None The valid park positions are ZENITH The zenith park position HA 0 declination latitude AP1 Access Park 1 HA 0 declination 95 PARK ZE Synonym for PROPER_MOTION q v 26 INT TCS 1 issue 3 1 INT TCS User Manual 4 44 POINT Log in TPOINT format the present position of the telescope as read on the encoders Format Defaults Parameters Keywords Examples Comments 4 45 POLE POINT lt file_status gt POINT OLD None NEW opens a new set of log files in the POINTING directory and logs the telescope position CALIBRATE opens a new set of log files in the CALIBRATE directory and logs the telescope position OLD appends to the latest set of log files unless none exist in which case a new set of pointing files are opened in the POINTING directory POINT POINT NEW The data are logged to pointing data files in a format suitable for input to the TRPOINT analysis package The following pointing files are created in INT DATA POINTING TRACKyymmdd DAT the encoder combination used for telescope tracking DEMANDyymmdd DAT the demand position calculated by the TCS Used for internal consistency tests only FERRlyymmdd DAT HA F
24. anual 4 21 EQUINOX Enter a value for the equinox of the position into the edit source block Format EQUINOX lt equinox gt Defaults None Parameters A code for the coordinate system followed for mean coordinates by the equinox in years The allowed systems are APPARENT Geocentric apparent coordinates J lt year gt Mean coordinates FK5 system B lt year gt Mean coordinates FK4 system Keywords None Limits The year must be in the range 1800 0 to 2100 0 Examples EQUINOX B1950 EQUINOX J1992 5 EQUINOX APP 4 22 ERASE Erase all entries from the current user catalogue Format ERASE Defaults None Parameters None Keywords None 4 23 FIND Retrieve data for the named source from the user or system catalogues see Section 7 and place them in the edit source block Format FIND lt source_name gt Defaults None Parameters The name of the the source to be retrieved It can be a string of up to 20 characters extra characters are lost To include spaces the whole string should be enclosed within double quotes Keywords None Examples FIND HD123456 FIND NGC_4151 FIND Supernova in LMC Comments The user catalogue is searched first followed by the system catalogue 4 24 FOCUS Drive the focus to a specified setting and stop it Format FOCUS lt setting gt Defaults None Parameters The focus in mm Limits 10 to 50 mm Keywords None Examples FOCUS 29 1
25. ations of input and display coordinates as follows INPUT always allowed APPARENT always allowed J2000 not allowed for input in apparent coordinates B1950 not allowed for input in apparent or FK5 J coordinates HA_DEC always allowed 4 16 DOME Move the dome to the specified azimuth and stop Format DOME lt angle gt Defaults None Parameters The angle in degrees Limits The angle must be in the range 0 to 360 even though the dome has no mechanical limits Keywords None Examples DOME 275 34 T 4 17 ENCODER Set the combination of incremental encoders used for tracking Format ENCODER lt state gt lt mechanism gt lt encoder_name gt Defaults None The default combination on startup is set in the startup file Keywords Valid states are ON add an encoder to the tracking combination OFF remove an encoder from the tracking combination Valid mechanism encoder name combinations are HA FERR1 hour angle Ferranti head 1 HA FERR2 hour angle Ferranti head 2 HA FERR3 hour angle Ferranti head 3 HA BALDWIN hour angle Baldwin DEC HH1 declination Heidenhain tape head 1 DEC HH2 declination Heidenhain tape head 2 DEC BALDWIN declination Baldwin FOCUS ABS focus absolute encoder use when incremental is faulty FOCUS INC focus incremental encoder this is the default on startup Examples ENCODER OFF HA FERR1 Comments There are three Ferranti encoder
26. ay be lost Larger offsets can be split into successive smaller ones or autoguiding may be suspended whilst the CCD window is moved The TCS focal plane aperture coordinate system is used with position angle measured anticlockwise 4 69 UT1UTC Enter the value of the correction to Universal Time UT1 UTC used in the control system Format UT1UTIC lt correction gt 35 INT TCS 1 issue 3 1 INT TCS User Manual Defaults Parameters Limits Keywords Examples Comments None This command overrides the startup value of UT1 UTC which is determined from an interpolation formula supplied by the IERS Rapid Service Prediction Center The correction in seconds l to 1 s None UT1UTC 0 0222 The IERS bulletin is pinned up on a noticeboard in the control room it is also available on the TOs web pages or can be found on the Web at http maia usno navy mil ser7 ser7 dat The bulletin is updated weekly The predicted correction UT1 UTC for each night is listed in a table in the section headed PREDICTIONS 4 70 WAVELENGTH Enter the value of the effective wavelength of light used in the calculation of the refraction correction Format Defaults Parameters Limits Keywords Examples WAVELENGTH lt wavelength gt None The startup value is 0 4 um The wavelength in microns 0 3 to 35 um None WAVELENGTH 0 55 4 71 ZEROSET Set the zero points of incremental en
27. clamp OFF NOT OFF OFF l Figure 4 The limits screen e Emergency stop This shows the state of the red emergency stop buttons ACTUATED or RELEASED None of the drives will function unless all the buttons are out in which case the display shows RELEASED Mode selected COMPUTER or ENGINEER duplicated on the top level display Hour angle limits These are hardware limits and should not be encountered in normal computer controlled operation The pre limits are hit first and cause the system to revert to engineering mode The telescope can only be driven out of a main limit by hand The display should show CLEAR for all limits and pre limits in normal operation and SET with the message in reverse video if the limit has been hit The nominal hardware limit positions are o LIMIT 6 6 hrs o PRE LIMIT 6 2hrs o PRE LIMIT 6 2 hrs o LIMIT 6 6 hrs Declination limits As for hour angle except that the final positive limit refers to the Access Park 1 position which can only be reached under engineering mode control from the balcony The nominal positions are o LIMIT 139 o PRE LIMIT 2 o PRE LIMIT o LIMIT 34 25 45 INT TCS 1 issue 3 1 INT TCS User Manual Focus limits Hitting a limit stops the focus drive but does not cause a switch to engineering mode o LIMIT 54 5 mm o LIMIT 9 0 mm Horizon limit This is sensed by a mercury switch mounted in the telescope cube centre secti
28. coders by a variety of methods Format Defaults Keywords ZEROSET lt mechanism gt lt method gt lt position gt None lt mechanism gt The following mechanisms may be zeroset HA DEC FOCUS lt method gt Several different methods are provided to set the zero points of the incremental encoders in order to reduce the dependence on individual bits of electronics These are TARGET This method is in principle capable of the highest accuracy A mechanical target is used to provide a fixed reference point The targets are located at HA 0 and declination 28 45 respectively The mechanism is driven slowly through the standard position in engineering mode and the encoders are reset when the target is detected electronically in which case the user terminal will bleep and output a suitable message HA and Dec target zerosets may be active simultaneously There is no target zeroset for the focus CANCEL This is used to cancel a target zeroset request if for some reason it fails ABSOLUTE This method only applies to FOCUS It sets the incremental encoder equal to the absolute encoder TO Allows the current position of the mechanism to be input This would normally be derived from the engineering desk synchros and is corrected for known zero point errors This method provides a backup in case of failure of the target electronics 36 INT TCS 1 issue 3 1 Parameters Exampl
29. crements in each mode and the currently selected mode and increment value are remembered on exit to USER gt level and restored when the handset is next used They are reset on source change using the GOTO GOCAT GOMOON NEXT or BLIND_OFFSET commands 5 2 Handset modes There are six handset modes that can be used at the INT ALT AZ mode is not useful each of which can be selected using the key specified in the table above The six functions divide naturally into three groups RA_DEC and X_Y increment the demand position in the input coordinate system and differ only in the directions of the increments The increments displayed are therefore the accumulated values from both modes in the coordinate system of the current mode The tracking position on the information display also changes OFFSET and APOFF are used in conjunction with the STORE command to set up positional and aperture offsets interactively The tracking coordinates do not change FOCUS and ROTATOR move individual mechanisms Each handset mode is described in more detail below 5 2 1 RA_DEC mode Changes the demand position in right ascension and declination units are arcseconds The image is moved in the east west or north south direction Increments are defined in the tangent plane so their magnitudes do not depend on declination Image movement on the TV and detector will depend on the chosen sky position angle At a sky position angle of 0 the movement
30. e The name or IP address of the display device The allowed states are ON creates a copy of the display screen on the specified device OFF deletes all copies of the display screen from the specified device CLONE ON 1px31 CLONE OFF 161 72 6 108 If a window created by CLONE is closed other than by the CLONE OFF command e g by using the window buttons the command CLONE OFF device must be issued to clear internal variables Enter a declination in the edit source block Format Defaults DEC lt dec_degrees gt lt dec_minutes gt lt dec_seconds gt Value of declination None Sign of declination 16 INT TCS 1 issue 3 1 INT TCS User Manual Parameters Keywords Examples The declination in degrees minutes and seconds of arc The value is rejected if any of the components lie outside the following ranges dec_degrees 0 to 89 inclusive dec_minutes 0 to 59 inclusive dec_seconds 0 0 to 59 99 inclusive None DEC 12 34 56 78 4 13 DFOCUS Offset the focus to compensate for additional optical elements Format Defaults Parameters Keywords Limits Examples Comments DFOCUS lt focus_offset gt None Focus offset in mm None 10 to 10 mm DFOCUS 0 3 This command is intended to be used when the telescope focus has to be changed to compensate for the additional optical thickness of a filter The virtual focus reading is unchanged and the focus offset i
31. e This mode changes the aperture offset interactively It is intended to be used to shift an object to an instrument aperture away from the reference position The aperture coordinates may be recorded for 39 INT TCS 1 issue 3 1 INT TCS User Manual future use with the command STORE APERTURE The image moves in x and y on the TV and or detector To set up a new aperture move an object to the reference position using X_Y or RA_ DEC mode switch to APOFF move it to the new aperture spectrograph slit or whatever exit from the handset and type STORE APERTURE lt aperture_number gt where lt aperture_number gt is in the range 0 to 20 STORE APERTURE 0 redefines the reference position The APOFF mode may be used even when the autoguider loop is locked This is useful for making small corrections e g to optimise a target position on the spectrograph slit The telescope offset and the reference pixel coordinates on the autoguider are changed simultaneously in such a way that the guiding errors remain zero The image appears to move in the same way as in the X_Y mode Small increments lt 1 arcsec should be used in order to avoid losing the guide star 5 2 5 FOCUS mode Changes the telescope focus units are millimetres Always allow time for the focus to settle after an increment as the drive is a bit sticky It should eventually stop within 0 01 millimetres of the requested position 5 2
32. e most likely the TEM L system o Air mass relative to the zenith 6 3 Encoder display The second page displays the encoder readings for hour angle declination and both of the instrument rotators In addition the positions of the dome shutter and windshield are shown The layout is shown in Figure 3 43 INT TCS l1 issue 3 1 INT TCS User Manual FFF Dec Heidenhain 1 Dec Heidenhain 2 HA Ferranti 1 HA Ferranti 2 HA Ferranti 3 00 00 00 81 00 00 00 19 00 00 00 77 HA Baldvin Declination Baldwin HA worm gear phase 00 00 00 73 259 49 312 53 53 Prime Focus Rotator Cassegrain Rotator Dome 102 37 Shutter Windshield Focus Absolute 46 160 Top end ring Temp 14 5 Serrurier Truss Temp 14 6 Centre section Temp 13 3 Mirror cover Temp Autoguider packet Figure 3 The encoder display screen 105 20 02 39 105 19 37 97 028 58 01 00 180 00 00 143 18 063 30 0000 00 0000 00 0000 00 i In case of pointing difficulties it is particularly useful to compare the individual encoders on the same axis The values displayed are as follows e Hour angle units are hours minutes seconds The encoder combination used for tracking can be changed using the ENCODER command o HA Ferranti 1 HA Ferranti 2 HA Ferranti 3 HA Baldwin used only when driving in slow motion 0 calculate the worm error correction e Declination units are degrees minutes seconds o Declinatio
33. elescope information appears on startup Encoder and temperature readings Limit computer mode and emergency stop indicators and alarm indicators Manual overrides dome and mirror cover status interlocks and focal station information The first screen is intended for normal operation the rest for fault finding The user interface command PAGE q v is used to cycle through them The following sub sections describe the contents of the pages in more detail 6 2 Source and telescope information The layout of this the default screen is shown in Figure 2 E Er 1999 November 08 13 59 43 15 57 29 51490 5831 SOURCE BLANK2 RA 13 04 DEC 029 50 49 00 B1950 Offset XI 0 0 ETA 10 0 Aperture NOMINAL Reference X 251 0 Y 326 0 Topocentric AZ 281 58 56 91 EL 052 57 54 76 ENG MODE HA 00 00 00 73 DEC 105 19 50 18 Position Error HA 00 00 00 73 DEC 076 34 06 98 LIMITS Sets in 09 33 HA limit in 10 05 ENG MODE Prime focus Mount PA 180 00 00 Par Angle 080 35 46 FOCUS 46 80mm TC 0 79mm DF O 15mm DOME 102 37 Air Mass 4 229 i Figure 2 The telescope information display This is the first of the display screens and is the default on startup Its contents are as follows e Time o Date o UT Universal time UTC from the time service o ST Local apparent sidereal time o MJD Modified Julian date i e Julian date 2400000 5 in days e Input data for the current source o Name o Right ascension
34. ent coordinates The formats units and defaults of the optional parameters are as follows Proper motions in RA seconds of time per year and Dec seconds of arc per year They default to 0 if not specified Epoch of position year This should not be confused with the equinox The epoch of observation is used in conjunction with the proper motions to correct for the space motion of the object If the epoch is not specified it is assumed to be the same as the equinox Parallax arcsec Generally negligible Defaults to 0 if not specified Radial velocity km s lt 1 positive for a receding object Generally unimportant Defaults to 0 if not specified Differential tracking rates do not form part of a catalogue entry Examples of catalogue files are The simplest possible catalogue containing name RA Dec and equinox 3C567 12 34 45 67 01 23 34 56 B1950 NGC123 00 12 34 56 88 44 22 J2000 COMET 12 12 12 12 33 33 33 3 A A more complicated entry including proper motions SP003 1 124 00 31 22 2 12 24 21 B1950 0 011 17 G158 100 A complete entry S02 15 01 51 27 640 10 20 6 20 J2000 0 00276 0 0390 2000 038 9 3 7 KO 7 2 The System Catalogue The TCS has a standard catalogue which is searched automatically by the commands FIND GOCAT and BLIND It contains accurate positions and when available proper motions for a variety of astrometric photometric and spectrophotometric standards The ma
35. eously 4 35 MARK Store the current position of the telescope as a named catalogue entry Format MARK lt source_name gt Defaults None Parameters The name of the source Keywords None Examples MARK SUPERNOVA Comments This command stores the current position to allow return to an object at a later date The position is stored in the current input coordinate system 4 36 MOON Display the geocentric and topocentric apparent right ascension and declination of the Moon This command is not allowed from DRAMA Format Defaults Parameters MOON None None 94 INT TCS 1 issue 3 1 INT TCS User Manual Keywords None 4 37 NEXT Send the telescope to track the source whose data are in the edit source block Format NEXT Defaults None Parameters None Keywords None Comments The user catalogue is searched first followed by the system catalogue 4 38 OFFSET Offset the telescope by a given amount in right ascension and declination Format OFFSET lt offset_system gt lt offset_ra gt lt offset_dec gt Defaults None Offsets are reset to zero on source change e g GOTO or NEXT Parameters If the ARC keyword is specified see below the offsets in right ascension and declination must be in arcseconds If the TIME keyword is specified see below the offset in right ascension must be entered in seconds of time and offset in decl
36. erranti 1 Dec Heidenhain 1 FERR2yymmdd DAT HA Ferranti 2 Dec Heidenhain 2 FERR3yymmdd DAT HA Ferranti 3 Dec Heidenhain 1 The function key F10 is equivalent to the POINT command Input values of polar motion Format Defaults Parameters Limits Keywords Examples Comments POLE lt x_position gt lt y_position gt None See comments below The polar motion xy corrections in arcseconds 1 to 1 arcsec None POLE 0 10 0 23 This command overrides the initial values for polar motion which are derived from an interpolation formula supplied by the International Earth Rotation and Reference Systems Service It makes a very small difference to the pointing of the telescope and is too esoteric for normal use 4 46 POSITION Move the telescope by a previously stored 7 or Aa A offset Format Defaults Parameters POSITION lt position_number gt None POSITION 0 zero offset is automatically selected on startup or change of source The position number is an integer in the range 0 to 20 The offset values for a given position number must have been set up using the ENTER or STORE commands SI INT TCS 1 issue 3 1 INT TCS User Manual POSITION 0 is the nominal offset and is only used with tangent plane offsets POSITION 0 is zeroed on source change Keywords None Examples POSITION 2 Comments The offset may be tangent plane or incremental depending on the way i
37. erwise the telescope corrections will be in the wrong direction The function key F8 is equivalent to the AUTOGUIDE OFF command The function key F9 is equivalent to the AUTOGUIDE ON command If the autoguider is not sending packets or if the data is unreliable due to low signal then the AUTOGUIDE command is ignored 4 8 BEAMSWITCH Offset the telescope so that an image moves by a vector fixed in the focal plane Format Defaults Parameters BEAMSWITCH lt offset_x gt lt offset_y gt None On source change e g GOTO offsets are reset to the nominal values this can also be done with the BEAMSWITCH 0 0 or APERTURE 0 commands see APERTURE The aperture x4 y4 positions in arcseconds es Fs INT TCS 1 issue 3 1 INT TCS User Manual Keywords None Examples BEAMSWITCH 20 2 100 4 9 BLIND_OFFSET Offset between a reference object centred on the reference position and a faint target object Format BLIND_OFFSET lt source_name gt Defaults None Parameters The name of the faint target object Keywords None Examples BLIND 0512 22 Comments This is the standard method for locating very faint objects which are difficult or impossible to see on the acquisition TV or detector Accurate positions for a brightish star and the faint target object must be entered in the catalogue Slew to the bright star using GOCAT and centre it on the reference position wit
38. es Comments PARK INT TCS User Manual This is used to set the zero points in HA and or declination assuming that the telescope is at one of its two park positions This is a useful backup option when there is a problem with a target zeroset since the telescope can be moved to a reproducible position independently of the encoders The PARK and TO keywords both require additional parameters TO PARK HA TARGI GI T DEC PARK Z Zl Z Z Z Z K HA TO 02 0 HA CANCEL FOCUS ABS GI requires the position to be entered in the format lt hours gt lt minutes gt lt seconds gt in HA or lt degrees gt lt minutes gt lt seconds gt in declination requires lt position gt to be one of ZENITH the zenith park position at HA 0 and Dec 28 45 at which the yellow light will be lit on the synchro dials or AP1 the access park 1 position at HA 0 Dec 95 ENITH 0 00 It is important to cancel a target zeroset if it fails to complete Saye INT TCS 1 issue 3 1 INT TCS User Manual 5 THE TCS HANDSET 5 1 General The handset provides an interactive way of incrementing the position of the telescope in various coordinate systems setting apertures and offsets and altering the focus and rotator position angle The handset is selected by pressing F6 or typing HANDSET at the user interface Pre defined and user selectable increments may be used and the arrow keys are used to input the
39. f individual commands are given in the alphabetical list in the next section Commands which require the telescope or one of its mechanisms to be moved are forbidden in engineering mode 3 1 General TCS commands All allowed in engineering mode HANDSET HELP RECALL and TRANSFER are not allowed from DRAMA e ACKNOWLEDGE Turn off a limit or engineering mode alarm e CLONE Make a copy of the display window on another device e HANDSET Select handset mode e HELP Get help on a command e RECALL Recall a previous command e TCSEXIT Close down the control system e TRANSFER Transfer control to or from a remote terminal 3 2 Source data entry All allowed in engineering mode e DEC Enter declination of edit source e DIFF_RATES Enter non sidereal tracking rates for the edit source e EPOCH Enter epoch of position for edit source e EQUINOX Enter equinox for edit source e PARALLAX Enter parallax of edit source e PM Synonym for PROPER_MOTION q v e PROPER_MOTION Enter proper motions of edit source e RA Enter right ascension of edit source e RADIAL VEL Enter radial velocity of edit source e RV Synonym for RADIAL_VEL q v e SOURCE Enter name right ascension declination and equinox for edit source 3 3 Catalogue handling All allowed in engineering mode e ADD Add the contents of the edit source block to the catalogue as a na
40. for about 1 minute for SERVO sampling is at 20 Hz or for gt 50 autoguider samples AUTO and then type RMS SERVO OFF or RMS AUTO OFF as appropriate The results of RMS SERVO should be rms errors of lt 0 05 arcsec in HA and Dec and means whose absolute values are lt 0 001 arcsec The rotator values are not normally useful for the INT 4 55 ROTATOR Move the Cassegrain rotator to the specified position angle and stop it Format ROTATOR lt mode gt lt position_angle gt Defaults None Parameters lt position_angle gt position angle in degrees measured anticlockwise from North Limits The position angle must be in the range 0 to 360 Keywords lt mode gt is one of SKY The position angle is in the input coordinate system e g J2000 at the epoch of observation MOUNT The position angle is in the telescope mount coordinate system Examples ROTATOR SKY 275 ROT MOU 275 Comments At present mount and sky position angle are regarded as identical This is not quite correct because of the effects of precession and pointing errors but is the conventional approximation for equatorial telescopes Mount position angle is used for both MOUNT and SKY keywords The Cassegrain rotator is not allowed to move inside the zone defined as 140 offset where the default value of offset is 2 This prevents the rotator overshooting past the software limit of 140 The command LIMITOFFSET can be used to change the value of
41. h the handset keys Then type BLIND lt source_name gt for the faint object This offsets the telescope so that the faint object is accurately aligned with the reference position It can then be moved around the detector using the BEAMSWITCH or APERTURE commands BLIND_OFFSET performs a local correction to the pointing model assuming that the position of the reference object is accurate Subsequent executions of BLIND_OFFSET all use this correction so several faint objects can be observed using the same reference star The NEXT GOTO and GOCAT commands revert to the default global pointing solution GI 4 10 CALIBRATE Update pointing coefficients at the start of an observing session Format CALIBRATE lt solution gt Defaults CALIBRATE NEW Parameters None Keywords Valid keywords are LAST recalls the last pointing solution This may be useful if the running of the control program has been interrupted but does not ensure very accurate pointing because the encoder zero points may have changed DEFAULT reverts to the default pointing solution in the initialisation file This is a suitable course of action if the CALIBRATE command fails e g gives very large rms errors NEW packages a sequence of commands to do a short pointing calibration using bright FK5 stars FAINT does the same as NEW but with a grid of fainter V 9 stars ZEROPOINT logs the current encode
42. ical to its namesake in DCL RECALL lt n gt recalls the nth last command within a 50 line buffer and RECALL string recalls the last command beginning with string RECALL ALL lists the command buffer If no argument is given the last command is recalled but this is more conveniently done with the cursor key 4 53 REMOVE Remove the entry for the named source from the user catalogue Format Defaults Parameters Keywords Examples REMOVE lt Source_name gt None The name of the source to be deleted The name may be a string of up to 20 characters extra characters are lost To include spaces the whole string should be enclosed within double quotes None REMOVE NGC_4151 REMOVE Supernova in LMC 29 INT TCS 1 issue 3 1 INT TCS User Manual 4 54 RMS Turn calculation of mean and rms servo or guiding errors on or off and display the results Format RMS lt error gt lt state gt Defaults None Keywords lt error gt is the source of errors SERVO Main drive position errors AUTOGUIDER Autoguider guiding errors TV TV system guide errors not normally connected for the INT lt state gt is either ON Begin calculation of errors OFF End calculation of errors and display results Examples RMS SERVO ON Comments This command is used to check the performance of the main drives To start accumulating data type RMS SERVO ON or RMS AUTO ON Wait
43. ide the following ranges lt dec_degrees gt 0 to 89 inclusive lt dec_minutes gt 0 to 59 inclusive lt dec_seconds gt 0 0 to 59 99 inclusive lt equinox gt Specifies the equinox of the source coordinates A valid equinox must have two components a leading letter indicating the system of the coordinates and a number indicating the epoch of the mean equator and equinox of that system Format lt letter year gt e g B1950 J2000 or APPARENT for which no number is required Note that only B J or A are acceptable as leading letters The year must lie in the range 1800 0 to 2100 0 Keywords None Examples SOURCE HD123456 12 34 56 789 11 22 33 44 B1900 Comments SOURCE copies the user default values for all source values into the edit source entry and then takes the command line or prompted input for source name right ascension declination and equinox T 4 61 STATION Select a focal station Format STATION lt focal_station gt Defaults None Keywords Valid focal station names are CASSEGRAIN PRIMI GI Comments Applies the appropriate pointing model and configures the rotator 4 62 STOP Stop the named mechanism by ramping the velocity to zero Format STOP lt mechanism gt Defaults STOP ALL Parameters None Keywords Valid mechanism names are ALL HA DEC DOME FOCUS ROTATOR CASS PRIME Examples STOP ROT 33 GI INT TCS 1 issue 3 1 INT TCS User Manual STOP C
44. ill be lit when the mechanisms concerned are under engineering control either because the system as a whole is in engineering mode or as a result of overrides The display shows ENABLED when the mechanism is overridden DISABLED otherwise Mechanisms which may be overridden and their states in normal computer controlled operation are 46 INT TCS 1 issue 3 1 INT TCS User Manual Dome normally DISABLED Focus normally DISABLED HA normally DISABLED Dec normally DISABLED Cass turntable normally DISABLED O Ov Or O e Control locations These show the state of the remote local off keyswitches on the gallery control panel REMOTE means that the mechanism can be driven from the control room LOCAL that it must be driven from the balcony panels o Dome normally REMOTE o Shutter normally REMOTE o Windshield normally REMOTE e Power Normally ON alarm state OFF o Dome o Shutter o Windshield e Overtravel alarms Normally CLEAR alarm state SET o Shutter o Windshield e Primary mirror cover o CLOSED NOT CLOSED Reads CLOSED when the cover is fully shut NOT CLOSED otherwise o OPEN NOT OPEN Reads OPEN when the cover is fully open NOT OPEN otherwise e Declination tie If IN this disables motion in Declination Normally OUT s47 INT TCS 1 issue 3 1 INT TCS User Manual 7 CATALOGUES 7 1 Catalogue format Object catalogues may be created using the TCS ADD and OUTPUT commands
45. in groups of objects are 48 INT TCS 1 issue 3 1 INT TCS User Manual A grid of bright stars with accurately known positions selected from the FK5 catalogue and used to check the pointing of the telescope e g by CALIBRATE NEW There is a fairly wide range of magnitudes V 1 5 to 7 and spectral types A similar grid with stars having V 7 to 9 and a narrow range of spectral types These are more suitable for automatic pointing tests and are used by CALIBRATE FAINT A grid with stars having V 10 to 11 intended primarily for pointing calibrations with the Wide Field Camera Spectrophotometric standards selected from the literature All have accurate positions in many cases considerably more accurate than those tabulated elsewhere Two sets of Landolt UVBRI photometric standards Some sequences suitable for calibration of CCD photmetry Blank fields for sky flat fields Pairs of stars for testing telescope offsetting accuracy The central positions for pairs of stars which may be used to check the IDS slit rotation Bright infra red standards The complete catalogue can be viewed here 49
46. ination must be entered in arcseconds Keywords The valid offset systems are ARC offsets the telescope by given amounts parallel to right ascension and declination in the tangent plane Positive offsets imply that the right ascension and declination of the telescope both increase The magnitude of the offset is independent of position TIME offsets the telescope by given amounts in right ascension and declination The magnitude of the offset depends on declination Aa and Ao are assumed to be in the input coordinate system Examples OFFSET ARC 12 6 18 8 OFFSET TIME 0 32 13 4 Comments The origin for OFFSET ARC is the nominal offset stored in POSITION 0 see ENTER and STORE The nominal offset is zeroed on source change OFFSET TIME replaces any previously applied positional offsets 4 39 OUTPUT Write out the current user catalogue in text format to the printer TCS user interface or to a disk file Format OUTPUT lt output_device gt filename Defaults There is no default output device The defaults for the catalogue filename are Node LPAS2 telescope computer Directory device USER_CAT Extension CAT Keywords Valid output devices are PRINTER sends the output to the INT laser printer TERMINAL sends the output to the user input terminal FILE sends the output to a named file Parameters The full path for the output file if the FILE keyword is specified
47. ion limit can be changed with the AGLIMIT command Valid autoguider states are ON specifying that the telescope should be guided in response to guiding errors from the CCD autoguider OFF specifying that autoguiding should be switched off i e that any guiding errors from the CCD autoguider should be ignored SUSPEND put the TCS in a state where pixel coordinates are read from the autoguider and the current reference position is maintained but guiding errors are not applied RESUME Restart guiding if the loop has been suspended AUTOGUIDE ON AUTOGUIDE ON 122 5 63 5 The autoguider sends xy pixel coordinates of a guide star to the telescope control computer The TCS then adjusts the telescope drives to keep the star at a given location on the autoguider CCD If the intention is to maintain the current positioning of a field e g if acquisition onto a spectrograph slit has been verified then the command AUTOGUIDE ON should be used This takes the most recent position received from the autoguider when the command was issued and keeps the guide star there On the other hand if the autoguider coordinates are already known then the appropriate command is AUTOGUIDE ON x y This is likely to be useful when an observation is to be repeated and the field is to be positioned at the same place on the detector The guide probe and pixel positions should be repeated The TCS must know the autoguider in use see AGSELECT oth
48. leading letters The year must lie in the range 1800 0 to 2100 0 Keywords None Examples GOTO HD123456 12 34 56 78 76 54 32 10 J2000 4 28 HANDSET Place the TCS user interface in handset mode This command is not allowed from DRAMA Format HANDSET Defaults None Parameters None Keywords None Comments In handset mode the keypad may be used to guide the telescope set up offsets or apertures change the focus or move the rotator See The TCS Handset for a more detailed description This command is bound to the F6 key and to the Do key ona standard Digital keyboard To exit from the handset mode press the F6 key or the Do key on a standard Digital keyboard and control will return to the USER gt prompt 4 29 HELP Provide information about the commands available from the TCS user interface This command is not allowed from DRAMA Format HELP topic subtopic Defaults Lists all available commands Parameters The command you wish to receive help on Keywords None Examples HELP GOTO EQUINOX Comments Invoking the HELP command initiates an interactive dialogue with the user interface HELP library a normal VMS HELP library In response to a Topic or subtopic prompt you may Type the name of the command topic for which you need help Type a question mark to redisplay recently requested text Press the RETURN key one or more times to exit from HELP Press CTRL Z once to exi
49. m used to input the source data Any space motions have been removed so the position refers to the current epoch If proper motions parallax or radial velocity are specified then the position will differ from the input position even in the absence of offsets B1950 available for pre IAU76 mean input coordinates only Current epoch s INT TCS 1 issue 3 1 INT TCS User Manual o J2000 available for any mean input coordinates Current epoch o APPARENT geocentric apparent coordinates of the current date Always available o HA_TOPO topocentric hour angle and declination Always available e TV autoguider coordinates o Ifthe telescope is being autoguided using a TV camera or CCD autoguider then the pixel coordinates of the requested position of the guide star are displayed together with the latest guide errors converted to arcseconds e Limit information o Elevation limit information this refers to the software limit of 20 If the object is circumpolar the message displayed is No El limit If it is currently visible above the limit but will eventually set the message Sets in together with the sidereal time remaining is shown If the object has set the message is Rises in followed by the sidereal time interval until it becomes visible again Finally for objects which are too far South ever to be seen the message is Never rises o Hour angle limits The message gives the sidereal ti
50. me remaining until the positive hour angle limit 6 is reached or the time until the source becomes visible if it is currently outside the observable range of 6 to 6 Note that there is no entry for the southern declination limit since the telescope cannot encounter this in the course of normal tracking e Turntable information o The message STOPPED MOVING or ENG MODE is displayed o The focal station currently selected This means that the software has been configured for that focal station and that the appropriate turntable will be driven The options are Cassegrain and Prime focus o Mount position angle effectively identical to the sky position angle for an equatorial telescope although there are subtleties to do with the coordinate system o Parallactic angle e Miscellaneous o Focus position mm This is a virtual focus position which should not depend on temperature elevation or the presence of filters in the beam It should in theory remain constant for a given focal station o The focus offset TC mm applied to compensate for expansion of the structure o The focus offset DF mm used to correct for additional optical elements e g filters in the beam o Dome azimuth The label flashes if the dome is out of position This will occur during a slew and briefly during tracking If the flashing is continuous and the dome is not moving to the correct azimuth then there is likely to be a fault in the dome driv
51. med entry e ERASE Clear the user catalogue e FIND Get a named catalogue entry and put it in the edit source block e INCLUDE Append a text catalogue to the current user catalogue e MARK Store the current telescope position as a named catalogue entry e OUTPUT Output the current catalogue to an ASCII file terminal or line printer e REMOVE Delete a catalogue entry 3 4 Source change None allowed in engineering mode INT TCS 1 issue 3 1 e BLIND_OFFSET e GOCAT e GOMOON e GOTO e NEXT GI INT TCS User Manual New source from catalogue with local corrections to the pointing model New source from catalogue specified by name only New source moon coords from s1a_DMOON New source direct input of name right ascension declination and equinox New source using data in edit source block 3 5 Positional and Aperture offsets e APERTURE e BEAMSWITCH e ENTER e OFFSET e POSITION e SLOWOFF e STORE e TWEAK 3 6 Autoguiding AGSELECT and PROBI e AGLIMIT e AGSEL ECT e AGVIEW e AUTOGUIDE e PROBE ENTER is allowed in engineering mode the remainder are not Execute a preset numbered aperture offset Execute an aperture offset with direct input of x and y Input data for numbered aperture or positional offsets Execute a positional offset with direct input of Aa Ad or ny Execute a preset n
52. n alias aperture 0 offset from the rotator centre in x4 and y4 arcsec Topocentric azimuth and elevation of the target not the telescope e Telescope state The possible messages are O O O O ENG MODE the system is in engineering mode STOPPED the telescope drives are stopped MOVING the telescope is in motion but has not yet reached its required position TRACKING the telescope is within 1 arcsecond of its demanded position during a sidereal track TV GUIDE autoguiding on signals provided by the TV system not normally used for the INT A GUIDE autoguiding on signals provided by the CCD autoguider S W LIM flashing the demanded position is inaccessible This will occur when the telescope tracks into a software limit or on source change when the new object is below the horizon e Telescope position O Right ascension or hour angle and declination displayed only when the telescope is tracking This is in the coordinate system set by the DISPLAY command and indicated by the equinox field see below Equinox usual conventions Topocentric hour angle HA and declination DEC Position errors in hour angle and declination Note that the pointing error in HA on the sky is Ahcos6 so a relatively large Ah may be tolerated at high declination Note that the coordinate system may be changed using the DISPLAY command The available DISPLAY options are O 0 INPUT default the coordinate syste
53. n Heidenhain head 1 o Declination Heidenhain head 2 o Declination Baldwin e Rotators units are degrees minutes seconds o Cassegrain rotator o Prime focus rotator e Dome units are degrees minutes e Shutter e Lower windshield broken e Focus this is the encoder reading without corrections for temperature e Temperatures units are degrees Centigrade o Top end ring o Serrurier Truss used for focus correction o Centre section O Mirror cover 44 HA worm gear phase in the range 0 to 360 updated only in slow motion This is used to INT TCS 1 issue 3 1 INT TCS User Manual e Autoguider packet most recent 6 4 Limit page This page displays the state of the hardware limits and pre limits for the hour angle declination rotator and focus drives together with emergency stop power and engineering computer mode indicators The layout is shown in Figure 4 A a Emergency stop Hour angle Hour angle ve prelimit ve limit Declination ve prelimit Declination ve limit Focus ve limit Horizon limit Oil alarm ACTUATED Mode selected CLEAR CLEAR Hour angle Hour angle ve prelimit ve limit CLEAR CLEAR Declination ve prelimit Declination ve limit CLEAR Focus ve limit SET Mains alarm Power amplifier ENGINEER CLEAR CLEAR CLEAR CLEAR CLEAR CLEAR WORKING Mirror support alarm CLEAR HA SM clamp Dec SM clamp HA SM clamp Dec SM
54. n use is displayed in the DF field on the bottom line of the Information Display 4 14 DIFF_RATES Enter differential tracking rate in right ascension and declination Format Defaults Parameters Keywords Limits Examples Comments DIFF_RATES lt diff_rate_in_ra gt lt diff_rate_in_dec gt None Unspecified differential rates are assumed to be zero Right ascension and declination differential tracking rates in seconds second and arcseconds second respectively None 100 to 100 s s in RA and 100 to 100 arcsec s in declination DIFF_RATES 0 01 0 3 The differential non sidereal tracking rates are added to the edit source block They must be actioned using the NEXT command Note that differential rates are not included in a catalogue entry 4 15 DISPLAY Change the coordinate system of the information display Format Defaults Parameters Keywords DISPLAY lt coordinate_system gt None The default coordinate system on startup is INPUT None The allowed coordinate systems are INPUT a and in the system used to input the source position APPARENT a and in geocentric apparent coordinates 32000 a and in J2000 mean coordinates B1950 a and in B1950 mean coordinates HA_DEC Topocentric hour angle and declination e INT TCS 1 issue 3 1 INT TCS User Manual Examples DISPLAY J2000 Comments For technical reasons there are restrictions on the permitted combin
55. nse that the TCS gives an additional more accurate description of the problem e DRAMA does not allow a command to be issued if a previous attempt at the same action is still in progress The TCS local interface allows the first command to be overridden by the second This can sometimes lead to problems e g if the wrong object is selected e A few commands primarily those which produce screen output are not available from DRAMA These are noted explicitly below 4 1 ACKNOWLEDGE Turn off the engineering mode and or software limit alarms Format ACKNOWLEDGE lt alarm_type gt Defaults ACKNOWLEDGE ALL Parameters None Keywords LIMIT turn off an alarm caused by a main drive software limit ENGINEERING turn off an alarm caused by an unexpected switch into engineering mode ALL turn off any alarm Example ACKNOWLEDGE Comments An alarm continuous bleeping is triggered if the telescope or rotator encounters a software limit whilst tracking or when requested to slew to an object below the horizon or if a switch from computer to engineering mode occurs unexpectedly i e not as a result of an ENGINEERING or TCSEXIT command T 4 2 ADD Write the current contents of the edit source block as a new entry in the user catalogue Format ADD pen INT TCS 1 issue 3 1 INT TCS User Manual Defaults Parameters Keywords None None None 4 3 AGLIMIT
56. nstrument names are IDS Intermediate Dispersion Spectrograph and FOS 1 WEC Prime focus wide field camera Examples INSTRUMENT IDS Comments This command sets the origin of position angle used for a specific instrument and the scale and orientation for the TWEAK command q v Position angle on the sky is normally defined to be along the slit in a spectrograph and aligned with one of the detector axes for an imaging instrument The scale and orientation parameters are currently set to match the standard TCS xy coordinate system 4 33 LIMITOFFSET Set the value defining the limits of the forbidden zone for the Cass rotator Format LIMITOFFSET lt offset gt Defaults None The offset on startup is currently 2 Parameters The offset in degrees either side of 140 which defines the forbidden zone Keywords None Examples LIMIT 1 5 Comments The Cass rotator is not allowed to move to within offset degrees of the Cass rotator software limit which is currently 140 The command SHOW LIMITS will display the current value of offset See also the command ROTATOR 2 93 INT TCS 1 issue 3 1 INT TCS User Manual 4 34 LOG Log encoders tracking errors and associated data every cycle log autoguider data on receipt of packet Format Defaults Parameters Keywords Examples Comments LOG lt system gt lt state gt lt duration gt The duration parameter defaults to 15 minutes if omitted it will
57. omments The STOP ALL or STOP commands stop all mechanisms 4 63 STORE Store aperture and positional offsets T Format STORE lt offset_type gt lt offset_number gt Defaults None Parameters lt offset_number gt is the aperture number if the APERTURE keyword is specified see below It must be an integer in the range 0 to 20 APERTURE 0 is the reference position and is not reset on source change lt offset_number gt is the position number if the POSTTION keyword is specified see below It must be an integer in the range 0 to 20 POSITION 0 is the nominal offset and is reset on source change Keywords Valid offset types are POSITION sets up a 7 or Aq AO positional offset which can be applied using the POSITION command APERTURE sets up a beamswitch position which can be applied to the telescope using the APERTURE command Examples STORE APERTURE 3 Comments The command may be used to store positional or aperture offsets which have been found using the APOFF or OFFSET handset modes or input using the BEAMSWITCH OFFSET or SLOWOFF commands They may then be recalled for future use with the APERTURE or POSITION commands When STORE is executed the aperture or offset stored becomes the current one and the Information Display is updated Note that offsets stored after using the handset OFFSET mode OFFSET ARC or SLOWOFF are stored as amp 7 whereas those from OFFSET TIME are stored as A
58. on e UTLUTC Input UT1 UTC e WAVELENGTH Input wavelength used in refraction calculation ll INT TCS 1 issue 3 1 INT TCS User Manual 4 TCS USER INTERFACE COMMAND LIST The following section gives a brief description of the operation of each command together with examples and defaults It refers to the TCS local interface Notation e Examples of commands entered at the terminal are in typewriter font DEC 12 34 56 78 e Angle brackets denote parameter values or keywords lt angle gt e Square brackets denote optional parameter values or keywords x y all other parameters and keywords are obligatory In most cases TCS commands can be issued either at the local user interface terminal or using the DRAMA interface The command syntax when using DRAMA is identical to the local interface but the complete command must be issued Prompts for unspecified input are issued on the local interface not on the DRAMA interface and if the prompted for input is not given on the local interface the DRAMA command will hang until it times out The main differences between the local interface and the DRAMA interface are e DRAMA will always acknowledge completion of a command Response will be almost instantaneous except for commands which move the telescope mechanisms These complete when the mechanisms concerned are in position e There is no prompting on the DRAMA interface e Error messages differ usually in the se
59. on o LIMIT I Alarms o Oilalarm Normal state CLEAR alarm state SET o Mains alarm Normal state CLEAR alarm state SET o Power amplifier Normal state WORKING alarm state FAULTY o Mirror support alarm Normal state CLEAR HA clamp status This refers to the state of the clamp which is engaged when the telescope is being driven in slow motion There are two status bits o The first is set when the clamp is fully engaged ON otherwise it reads NOT ON o The second is set when the clamp is fully disengaged OFF otherwise it reads NOT OFF Dec clamp status as for HA 6 5 Dome status and manual overrides page This page contains the engineering override indicators for individual mechanisms and the status bits concerning dome and shutters The layout is shown in Figure 5 Dome manual override ENABLED Focus manual override DISABLED HA manual override DISABLED Dec manual override DISABLED Cass TT manual override DISABLED Dome control LOCAL Dome power OFF Shutter control LOCAL Shutter pover OFF Shutter overtravel CLEAR Windshield control LOCAL Windshield power OFF Windshield overtravel CLEAR Primary mirror cover Primary mirror cover NOT OPEN Declination tie l Figure 5 The status screen Engineering overrides These cause computer control for individual mechanisms to be disabled and are controlled by latching buttons on the engineering desk Overrides are on when the buttons are latched down The yellow lamps w
60. ote terminals This command is not allowed from DRAMA Format TRANSFER lt state gt lt remote_host gt Defaults None Parameters lt remote_host gt is the IP name or address of the remote host Keywords The lt state gt keyword may take the following values ON Creates a USER window on a remote terminal and enables it as the user interface To return control to the original terminal window either enter CTRL Z on the original terminal or type TRANSFER OFF at the remote terminal OFF Disables the remote terminal entirely returns command input to the control room terminal and clears the remote display Examples TRANSFER ON TRANSFER ON 1px28 4 68 TWEAK Apply a given x4 v4 pa aperture offset to align a field on an instrument Format TWEAK lt x_offset gt lt y_offset gt lt rotation gt Defaults lt rotation gt defaults to 0 Parameters lt x_offset gt lt y_offset gt are displacements in x4 and yy in arcsec lt rotation gt is the rotation of the field in degrees Keywords None Examples TWEAK 0 5 0 6 0 1 Comments This command is used to position a field precisely on an instrument It can be used whether or not the telescope is being autoguided and is useful for long slit spectroscopy especially when two objects are to be placed on the slit simultaneously It is not advisable to use displacements of more than 1 arcsec or rotations of more than 0 1 when autoguiding since the guide star m
61. pe is driven to the first star and the handset mode is selected When the telescope is tracking the star should be moved on to the reference position using the handset keys Once you are satisfied press F6 This logs the position and drives to the next star If you do not wish to log the star then press I while still in handset mode the star will be skipped and the telescope will drive to the next star Repeat these operations until all 7 positions have been logged You will then be asked whether all of the stars were centred correctly If you do not answer Y to this question then the procedure will be aborted The derived and previous values will be displayed together with their r m s errors and you will be asked whether the solution is reasonable The errors should be in the range 0 5 to 1 0 arcsec for ID 1 0 to 2 0 arcsec for CH and 1 0 to 3 0 arcsec for IH If the errors are much larger than these values then the solution should be rejected Unless there has been a major change of configuration the coefficients should not alter by more than a few arcseconds from night to night Gross differences may indicate a problem CTRL Z may be used to abort the procedure at any time but all of the measurements will be lost G Pi G Py LAST 4 11 CLONE Create delete a copy of the DISPLAY screen Format Defaults Parameters Keywords Examples Comments 4 12 DEC CLONE lt state gt lt device gt Non
62. r reading and analyses it with a modified TPOINT procedure to calculate and install the 2 encoder zeropoints IH and ID This is the equivalent of the SNAFU command on the Perkin Elmer TCS COLLIMATION logs the current encoder reading and analyses it with a modified TPOINT procedure to calculate and install the 2 collimation coefficients CH and ID ANALYSE analyses the pointing log file generated by a series of POINT commands then calculates and installs the coefficients IH ID and CH It is designed to be used when the procedure is run by the system computer rather than the TCS and allows other TCS is fe INT TCS 1 issue 3 1 INT TCS User Manual Examples Comments commands to be input during the procedure This means that the autoguider can be used to centre the star as AUTOGUIDE commands will be accepted The ANALYSE keyword can take an optional keyword ZERO or COLL In this case the log file generated by a single POINT CALIBRATE command is analysed then the coefficients IH ID or CH ID respectively are calculated and installed CALIBRAT CALIBRAT The CALIBRATE NEW command initiates an automatic sequence which does a restricted pointing measurement on 7 stars from the pointing grid in order to update the values for the encoder zero points in hour angle and declination and the collimation error in hour angle Stars are selected to be close to the meridian and covering the full range of declinations The telesco
63. rd information relevant to an observation or to provide evidence of problems In the case of a problem with the telescope please take a snapshot of each display screen and include the snapshot filenames as output by the TCS in any defect report GI 4 60 SOURCE Enter new source data into the edit source block 32 INT TCS 1 issue 3 1 INT TCS User Manual Format SOURCE lt source_name gt right_ascension gt lt declination gt lt equinox gt Defaults Name right ascension declination equinox None All other source values User defaults Parameters lt source_name gt The name of the new source It must be a string of up to 20 characters extra characters are lost To include spaces the whole string should be enclosed within double quotes lt right_ascension gt Specifies the right ascension of the new source in three fields separated by spaces Format lt ra_hours gt lt ra_minutes gt lt ra_seconds gt The right ascension is rejected if any of the components lie outside the following ranges lt ra_hours gt 0 to 23 inclusive lt ra_minutes gt 0 to 59 inclusive lt ra_seconds gt 0 0 to 59 99 inclusive lt declination gt Specifies the declination of the new source in three fields separated by spaces The lt dec_degrees gt field may be signed If not signed the default is Format lt dec_degrees gt lt dec_minutes gt lt dec_seconds gt The declination is rejected if any of the components lie outs
64. s in X_Y and RA DEC are identical RA_ DEC mode is most useful for wandering around finding charts and establishing orientations on the instrument It can also be used for offsetting from a reference source although this can be done more flexibly with other methods such as the BLIND_OFFSET command 5 2 2 X_Y mode Changes the demand position in directions fixed in the focal plane units are arcseconds This is the most commonly used of all the modes It moves the telescope in a sensible way corresponding to the customary sense of x y coordinates on the acquisition TV screen or detector independent of rotator orientation and with equal steps in x and y and is the normal method for final alignment of an object on to an instrument aperture such as a spectrograph slit unless the guiding loop is already locked see APOFF below 5 2 3 OFFSET mode This is used in conjunction with the STORE POSITION command to set up positional offsets which may be recalled with the POSTTION command To define an offset move an object to the start position using one of X_Y or RA_ DEC Then switch to OFFSET mode move the object to the end position exit from the handset and store the offset with STORE POSITION lt position_number gt where lt position_number gt is in the range 0 to 20 POSITION lt position_number gt recalls the offset which is defined in the tangent plane POSITION 0 is the nominal offset and is reset on source change 5 2 4 APOFF mod
65. set_type gt defaults to ABS lt xi gt lt eta gt are in arcseconds parallel to right ascension and declination in the tangent plane Positive offsets imply that the right ascension and declination of the telescope both increase The magnitude of the offset is independent of position lt rate gt is in arcseconds second in the range 0 1 to 200 lt offset_type gt is one of ABS the origin of the offset is the nominal offset position as defined by POSITION 0 ADD the origin of the offset is the current offset i e cumulative SLOWOFF 6 6 2 SLOWOFF 1 5 1 8 0 1 ADD The nominal offset POSITION 0 can be set by the ENTER or STORE commands On source change e g GOTO NEXT the current and nominal offsets are reset to zero The telescope moves from its current position to the offset position at the rate specified Note that the telescope position before the offset is not necessarily at the offset origin if the lt offset_type gt is ABS The SLOWOFF command cannot be used if an OFFSET TIME offset is in use for the current target as tangent plane and incremental offsets should not be mixed 4 59 SNAPSHOT Dump a copy of the information display screen to a file Format Parameters Defaults Examples Comments SNAPSHOT lt filename gt lt filename gt is the name of the snapshot file Directory SNAP_LOG on the telescope computer Extension SNAP SNAPSHOT ARCHIV This command may be used to reco
66. steps These auto repeat when held down so a continuous motion may be generated by selecting a small increment and holding down the appropriate key The handset display a variant of that shown in Figure 1 is drawn at the top of the user interface screen HANDSET 0 1 0 3 30 0 100 0 0 0 arcsec Total 0 00 ALT_AZ F8 RA_DEC F9 RZGRN O FFSET A POFF F OCUS R OTATOR USER gt HANDSET Figure 1 An example of the handset display showing the default on startup It shows the available increment values the accumulated increments and the modes Currently selected values are in reverse video Only the keys listed in the following table remain active Key Action lt or select next smaller increment gt or select next larger increment 2 or request input of increment value F8 select ALT AZ mode F9 select RA DEC mode F10 select X Y mode Ooro select OFFSET mode Aora select APOFF mode Forf select FOCUS mode Rorr select ROTATOR mode lt 38 INT TCS 1 issue 3 1 INT TCS User Manual P requests the input of an increment value Enter the value in the appropriate units and then press RETURN Just press RETURN to escape from increment selection if you press the key by accident The F6 key is used to return to the USER gt prompt The default on first selecting the handset is the X_Y mode with an increment of 1 0 arcseconds Thereafter the accumulated in
67. t from HELP Abbreviate any topic name but note that ambiguous abbreviations result in all matches being displayed 4 30 HUMIDITY Enter the value of the relative humidity used in the calculation of refraction Format HUMIDITY lt relative_humidity gt Defaults None The value assumed on startup is 0 5 Parameters The fractional humidity Limits 0 to 1 0 ID INT TCS 1 issue 3 1 INT TCS User Manual Keywords None Examples HUMID 0 5 4 31 INCLUDE Read in a text format source catalogue Format INCLUDE directory lt catalogue_name gt Defaults Extension CAT Directory default user catalogue directories Parameters The name of the input catalogue Keywords None Examples IN USER_CAT SPECPHOT CAT or IN SPECPHOT to input a file called SPECPHOT CAT in the default directory INCLUDE int cat test cat to input a file prepared on the ICS and placed in int cat This format is necessary if there is a catalogue file of the same name in the default directory on the TCS computer Comments The default directory on the TCS computer is searched first followed by int cat the default directory on the ICS The directories are defined in the TCS version file by a logical name search list 4 32 INSTRUMENT Tell the TCS which instrument is in use Format INSTRUMENT lt instrument_name gt Defaults None The parameters for the WFC are set on startup Parameters None Keywords Valid i
68. t was set up SHOW POSITION displays the current list of offsets their types and values 4 47 PRESSURE Enter the value of the barometric pressure used in the calculation of refraction Format PRESSURE lt pressure gt Defaults None The pressure assumed on startup is 779 millibar Parameters The barometric pressure in millibars Limits 750 to 800 mbar Keywords None Examples PRESSURE 779 5 Comments The refraction correction is proportional to the pressure An error of 5 millibar is just about noticeable it corresponds to a pointing deviation of 1 arcsecond at a zenith distance of 75 4 48 PROBE Enter current position of the Cassegrain autoguider probe Format PROBE lt x gt lt y gt Defaults None Parameters The coordinates in um Cassegrain Limits 405000 lt x lt 595000 and 405000 lt y lt 595000 Cassegrain Keywords None Examples PROBE 500000 500000 Comments This command is needed for the AGVIEW command to work it is only applicable to movable autoguiders 4 49 PROPER_MOTION Enter proper motions into the edit source block Format PROPER_MOTION lt pm_in_ra gt lt pm_in_dec gt Defaults Unspecified proper motions are assumed to be 0 Parameters The proper motion in right ascension and declination in units of seconds year and arcseconds year respectively Limits 20 to 20 s year in RA 100 to 100 arcsec year in declination Keywords
69. umbered positional 7 or Aa Ao offset Execute a positional offset at a given rate with direct input of 7 and rate Store aperture or positional offsets set up using the handset Apply a given x4 ya pa aperture offset E are allowed in engineering mode AGVIEW and AUTOGUIDE are not Set the limit determining whether the guidestar is in position Identify the autoguider currently in use Aperture offset to move image to autoguider field Lock or unlock the autoguider loop Input coordinates of guide probe 3 7 Calibration procedures The keywords for this command which require the telescope to be moved are not allowed in engineering mode e CALIBRATE 7 Determine encoder zero points and collimation errors 3 8 Mechanism control None allowed in engineering mode e DOME e DFOCUS e FOCUS e PARK e ROTAT e STOP OR Move the dome to a given azimuth and stop it Change the focus by a specified amount Move the focus to a specified position Move the telescope to a defined position Move the rotator to a given sky PA Stop a mechanism or combination of mechanisms 3 9 Mechanism configuration ENCODER LI MITOFFS ETand ZEROSET are allowed in engineering mode TRACK is not e ENCOD T R e ENGIN T ERING Set the combination of encoders used for pointing Select engineering mode 10 INT TCS 1 issue 3 1 INT TCS User

INT - Isaac Newton Group of Telescopes

Contents

Download Pdf Manuals

Related Search

Related Contents