MOPSIC – An Extended Version of MOPSI
Contents
1. 5 2 Example MOPSIC reduction script2. 4 8 Bad channels CHAPTER 4 From MOPSI to MOPSIC 4 8 Bad channels There is a default list of bad channels see Sect 3 1 The user can also delete channels manually as usual with the command del rc lt number gt or use his own bad channel file after inspecting the data set lts syntax is as described in Sect 3 1 and can be accessed via del rc lt file gt Examples del rc 2 12 del rc bad drc 4 9 Calibration Calibration of the data can be achieved either with the default set of calibration values see Sect 3 2 or using your own calibration This can be done as in MOPSI just by multiplying the data with the calibration factor in mJy count or providing a calibration file similar to the default calibration The syntax is the same as in Sect 3 2 The calibration is done with calibrate lt file gt Example calibrate factors cal calibrate 4 10 Opacities We suggest to use the standard opacity correction as described in Sect 3 3 Apart from that the correction for atmospheric extinction has not changed from the procedure in MOPSI using an own opacity file usually called tau TAUS Example tau tau 2000 correct ext Chapter 5 SIMBA data reduction 5 1 Baseline fitting We found that one should not apply any baseline fitting per subscan e g base 1 0 to the data before reducing the skynoise with CSF or SNF Instead it is suggested only to use the correction on the whole data set e g base t 4 However if possible the
3. replace in 1 out 1 4 2 Buffers Only one standard buffer is available at the start of the programme It is the backup buffer As usual data can be stored with the command store However to recover the content of the backup buffer one has to use the command take old is not available anymore One can define new buffers in order to store data For this it must have the suitable dimensions for the data set to fit in This can be achieved with the command define see help pages define and help define The syntax is define lt type gt lt name gt lt size gt A typical example is define double buffer like data This creates a new data buffer of variable type double called buffer with the same dimension as the current data The data in the working memory can now be put there with store buffer It can be retrieved again with take buffer After its usage the buffer must be erased with del var buffer Example def double memi like data store meml take meml del var meml 4 3 FOR Loops Both the variable for the last entry in a file list and the running index have changed Instead of last one has to write nobsin Hence the loop definition is written as for i 1 to nobsin When indicating a file to be read from the previously loaded file list the running index has to be put in quotes like read 17 The typical header of a loop should read something like CHAPTER 4 From MOPSIto MOPSIC 4 4 Skynoise filtering for i
4. fitting should only be conducted on an area excluded with a previously defined polygon to avoid the influence of any real positive emission A fit per subscan can be used after the skynoise reduction sequence Example pol base pol base r out sys eq base t 4 base t 4 store weight rms2 out sys eq csf base 1 3 store weight rms2 out sys eq 5 2 Example MOPSIC reduction script init gfit init histo init spike sys rm btd init in list init out 1 in lis fits sort in list select ecar for i 1 to nobsin read i del dc del rc default del rc default 10 5 2 Example MOPSIC reduction script init spike pol ecar_1 base r out sys eq base t 5 Iset mask gt 5 rms I lt 5 rms linterpol blank Imask lbase t 5 set mask deconv mask correct ge tau default 20000 correct ext calibrate def calibrate mask spike spike_buffer base t 5 Istore weight rms2 az lt 1e9 gt 1e9 store weight rms2 out sys eq csf iter 60 gt 5 rms not_in_data lt 5 rms not_in_data disable gt disable lt rang 1 900 best 6 cn av Icn med Idisable source source model gdf sb run base 1 2 Istore weight rms2 az lt 1e9 gt 1e9 store weight rms2 out sys eq wr btd next init spike replace in 1 out 1 read 1 convert command extent 1200 1200 CHAPTER 5 SIMBA data reduction 11 CHAPTER 5 SIMBA data reduction pix 4 4 run all exit file out ecar gdf write close out 12
5. to merge this software with the com mand interpreter of GILDAS into the successor now called MOPSIC This simplified its use but made the change of part of its syntax unavoidable Furthermore the skynoise reduction has been improved considerably being now more sensitive to faint extended emission that previously had escaped de tection In the following will explain the changes necessary to convert old MOPSI procedures into MOPSIC style Additionally will mention important changes to the philosophy of the data reduction assume the reader is already familiar with the usage of MOPSI A comprehensive summary can be found in the old SEST SIMBA user manual Chapter 2 General changes 2 1 GILDAS commands MOPSIC can access the command set of the GILDAS software by indicating the package where the command resides see example in Sect 2 2 2 2 Abbreviations All commands need at least the first three letters in order be recognised by the command interpreter Sometimes even this is not enough to avoid confusion with other commands MOPSIC will announce this with an error message MOPSIC gt ext E INTER Ambiguous command could be GREG2 EXTREMA MOPSIC EXTINCT MOPSIC EXTRACT MOPSIC EXTREMA IMAGE EXTENT 2 3 Scrolling It is now possible to scroll the command history up and down using the cursor keys Instead the command reexecute has disappeared 2 4 File names The extension for scripts to be recognised by MOPSIC is changed t
6. 1 to nobsin read i 4 4 Skynoise filtering The section in reduction scripts defining the skynoise reduction was previously called with snf Sky Noise Filtering This command is still valid but it should be replaced by the synonymous command csf Correlated Skynoise Filtering and is indicated as such with the prompt Most commands should now be explicitly written in full words to avoid possible ambiguities The command no for switching off actions during the skynoise reduction has been replaced with the command disable because of discrepancies with the GILDAS command set Possible example csf iter 60 l gt 5 rms not_in_data lt 5 rms not_in_data disable gt disable lt range 1 900 best 6 cn av cn med disable source l source model gdf Isb run 4 5 Combine and Convert The subroutines of combine and convert do no longer use the command no either lt has also been replaced with disable Furthermore most commands have to be written in full words too The command quit was replaced with exit Example combine extent 600 600 disable weight exit 4 6 Integration The integrate command is no longer provided in its interactive form All integration parameters must now be listed along with the command in one line Example integrate factor 1 b lev 0 1e10 4 7 Corrections The command correct used in the gain elevation and opacity correction see Sect 4 10 must be written in a full word Example correct ge
7. MOPSIC An Extended Version of MOPSI Version 1 0 Markus Nielbock June 14 2004 Contents 1 Introduction 2 General changes 2 1 GILDAS commands 2 2 ADDreviatlONS cial A WAS cda 2 37 SCrollInG aA tyes mu sm ed de at oh ee ae SR eee aS 2 4 ENE names 2 a 24 2 SR ke i ROO EEE Bee SE BS 2 5 Helpfacility vaa RAE Rae RR wah E RARA PARADA 3 Default settings 3 1 Bad hannels rca De dore A a eS BE EER 3 2 Galibratlon ME es meme doe eas a aa aa a E EO Z 3 3 Opacity correction ee e 445444444444 du R N KK KR eee es O O1 O1 O1 4 From MOPSI to MOPSIC All FISAS 4 aus Dac oO Be EE PERRO d au Lab dus tt oh 4 20 BUON EE nn e abs sd 4 3 FOR LO0PS 40 48 ate LE e AS AS dado de DE A hk qu ee gts 44 Skynoise filtering 4 5 Combine and Gonvert 4 d 2 e DR aa ant de eee Me de de ee ue 4 6 Integration as orita ss Bb bare DA RUE oad REG A ere AN Correctionss lt a value rd m re ad BS eee Re re 48 BadichannelS 4 64 ti A de dt pe ke BS 4 9 Calibration lt L Re RA ee ee ER Bie lee ee a A En Re 4 10 OpacitieS s stk ce roe bg Gale AA ded AAA SLR a OO OO OO NN HN I 5 SIMBA data reduction 10 5 1 Baseline fitting lt ST atk LE a LR NR ee R 10 5 2 Example MOPSIC reduction script 10 Chapter 1 Introduction After the success of MOPSI its developer Robert Zylka started
8. he file containing all calibration values is called SEST_SIMBA CAL Every line consists of the Julian date until the calibration is valid followed by the calibration factor in mJy count A typical section of the file is 2452079 5516 86 2452079 5581 86 2452079 5646 86 2452083 4547 86 CHAPTER 3 Default settings 3 3 Opacity correction We created an almost complete database of opacity values determined from skydip observations It can be used to automatically correct for the atmospheric extinction The referring file is called SEST_SIMBA TAUS Every line lists the scan number of the skynoise measurement the UT date of the observation its Julian date and the zenith opacity value Here is a section from this file 0945 0973 1003 1029 1043 1047 16 06 01 16 06 01 16 06 01 17 06 01 17 06 01 17 06 01 2452076 2452076 2452077 2452077 2452077 2452077 lt can be used with tau def 20000 correct ext 69792 63609 84722 76544 40278 38276 53681 49888 60069 55423 65972 60537 096 103 119 112 141 116 3 3 Opacity correction Chapter 4 From MOPSI to MOPSIC 4 1 File lists File lists have to be read in with the command in list lt list gt The list command can only be used to display the current file list Consequently it must be initialised with init in list The command replace to replace the output list with the input list must be written in a full word init in list in list fits LIST list
9. o mopsic All the other file extensions are the same as in MOPSI 2 5 Help facility The GILDAS help is initiated with help while the MOPSIC help function is accessed with Chapter 3 Default settings After reducing and combining data from many observers during the SIMBA sessions from 2001 until 2003 we are able to provide a database containing calibrations and opacities for almost the whole lifetime of SIMBA There is also a set of bad channels that should be deleted for various observing periods They reside in the standard directory where MOPSI and MOPSIC have been installed and can all be accessed via options of the different commands as described in the following sections 3 1 Bad channels The file containing the bad channels of SIMBA is called SEST_SIMBA DRC Every line consists of the keyword JD the Julian date until the entry is valid followed by the numbers of channels to be deleted A typical section of such a file is JD 2452425 00 38 39 40 JD 2452499 06 2 12 JD 2452500 00 2 14 JD 2452500 03 2 12 14 JD 2452500 08 2 12 14 32 The command to erase the bad channels using this file s del rc default found out that sometimes it might be necessary to repeat this command in order to function 3 2 Calibration We compiled calibration factors in a consistent manner using Uranus calibration maps for the whole period of SIMBA If the user wishes to access them it can be done with calibrate default calibrate T
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