Surveying made easy
Contents
1. 4 Required 1 351 AM E AH Preparing to Measure 7 Height Difference between two Points The basic principle of levelling involves determining the height difference between two points To eliminate systematic errors related to atmospheric conditions or to residual line of sight error the instrument should be about equidistant from the two points The height difference is calculated from the difference between the two staff readings for the points A and B respectively Reading 2 521 R backsight q V foresight D AH R V 2 521 1 345 1 176 Slope in 100 x AH D Reading 1 345 8 Measuring with the Level Measuring Distances Optically with the Level The reticle has two stadia lines arranged symmetrically to the cross hairs Their spacing is such that the distance can be derived by multiplying the corresponding staff section by 100 Accuracy of the distance measurement 10 30 cm 4 12in Example Reading on upper stadia line B 1 205 Reading on lower stadia line A 0 996 Staff section l B A 0 209 Distance 100 x 20 9 m Measuring with the Level 9 Line Levelling If the points A and B are widely separated the height difference between them is determined by line level ling with target distances generally between 30 and 50m 95 160ft Pace out the distances between the instrument and the two staffs they2. E y 22 Setup to Measure Extrapolating a Straight Line 1 Position the instrument at point B 2 Target point A transit the telescope i e reverse it and mark point C 3 Turn the instrument 200 gon 180 and target point A again 4 Transit the telescope again and mark the point C Point C the mid point between C and C corresponds exactly to the extrapolation of the line AB A line of sight error is responsible for the discrepancy between C and C Where the line of sight is inclined the influence of the errors is a combination of target error tilting axis error and vertical axis error Polar Stake out of a Point The setting out elements angle and distance here relate to a known point A and to a known starting direction from A to B 1 Set up the instrument at point A and target point B 2 Set the horizontal circle to zero refer to the user manual 3 Rotate the instrument until appears in the display 4 Guide the reflector carrier person into and along the line of sight of the telescope continually measuring the horizontal distance until point P is reached Simple Surveying Tasks 23 Measuring Slopes Place the instrument on a point along the straight line the refer to user manual so that the slope can be read off slope of which is to be determined and position a reflector directly in pole at a second point along that line Target the center of the prism and measure the distance
3. Enter the instrument height i and the target height t prism The slope is shown on the display in The vertical angle reading in gon or degrees can be set to 24 Simple Surveying Tasks Plumbing Up or Down Plumbing down from a height point plumbing up from The mid point between the points B and C is the exact a ground point and inspecting a vertical line on a struc plumbing point ture can be carried out accurately in just one telescope face but only if the telescope describes a precisely verti The reason why these two points do not coincide can be cal plane when it is moved up and down To ascertain that a tilting axis error and or an inclined vertical axis this is so proceed as follows For work of this type make sure that the total station has 1 Target a high point A then tilt the telescope down been levelled up precisely so that the influence of vertical wards and mark the ground point B axis tilt on steep sights is minimized 2 Transit the telescope and repeat the procedure in the second face Mark point C Simple Surveying Tasks 25 Surveys polar method To create e g an as built plan the position and height of points are determined by measuring angles and dis tances To do this the instrument is set up on any promi nent point to create a local coordinate system Enter the coordinates as X 0 Y 0 instrument height i A second prominent point is selected for the purposes of orient
4. Leica Geosystems total stations include not only a conventional infrared distancer that measures to prisms but also an integrated laser distancer that requires no reflector You can switch between these two options The reflectorless distance measurement brings many advantages where points are accessible only with difficulty or not at all for example during the recording of build ing faces when positioning pipes and for measurements across gorges or fences The co axial visible red laser dot is also suitable for mark ing targets in connection with the recording of tunnel profiles or indoor work Automatic Target Aiming Many total stations from Leica Geosystems are equipped with an automatic target aiming system This makes tar geting faster and easier It is enough to point the telescope approximately at the reflector the touch of a button then automatically triggers the fine pointing the angle and dis tance measurements and records all of the values This technology also makes it possible to carry out fully auto matic measurements Automatic target aiming can also be switched to a mode in which moving targets can be fol lowed and measured after establishing the initial contact with the target the instrument locks on to it and tracks it Advantages High speed of measurement combined with a constant measuring accuracy independent of the observer The Total Station 15 Coordinates To describe the position of a po
5. most used applications It has two basic methods 1 Measuring to a Reference Line The horizontal and vertical position and the offset of a manually measured point can be calculated relative to the defined reference line 2 Staking to a Reference Line Allows for the position of a point to be defined relative to a reference line and then staked out Please refer to the user manual of your total station or GNSS system to see which tasks are supported 28 Application Programs Volume Calculation Another onboard application mostly used on construction sites is Volume Calculations This application allows surfac es to be measured and volumes and other information to be computed from these surfaces Measure points surface points and boundary points that define a surface or extend existing surfaces Volumes are directly computed You can also use stored points to calcu late volumes Please refer to the user manual of your total station or GNSS system to see which tasks are supported Area Calculation 1 Set up the total station in the terrain so that it is 3 Afterwards the area is calculated and displayed auto within view of the entire area to be surveyed It is not matically at the touch of a button necessary to position the horizontal circle 2 Determine the boundary points of the area sequentially For detailed instructions refer to the user manual of in the clockwise direction You m
6. the baseline 4 Set up the total station on point A target point B and set out the points A A and A in this alignment in accordance with the planned length of the side of the building 5 With point B sighted set the horizontal circle to zero turn the total station by 100 gon 90 and set out the second line AC with the points A A and A The easiest way to stake out profile boards is to use the Reference Line application This application allows you to complete all steps as described above more efficiently and conveniently In most cases only one instrument setup is required 32 Application Programs Surveying with GNSS GPS amp Glonass GNSS surveys use the signals transmitted by satellites hav ing trajectories such that any point on the Earth s surface can be determined around the clock and independent of weather conditions The positioning accuracy depends on the type of GNSS receiver and on the observation and processing techniques used Compared with the use of a total station GNSS surveying offers the advantage that the points to be measured do not have to be mutually visible Today provided that the sky is relatively unobstructed by trees buildings etc and therefore that adequate satellite signals can be received GNSS equipment can be applied to many survey tasks that were traditionally carried out using electronic total sta tions All Leica GNSS systems enable the most diverse range of su
7. Surveying Made Easy when it has to be Introduction Dear students teachers and everyone interested in surveying In recent years the development of modern and easy to use measuring instruments has contributed to the use of such instruments by more and more users in many fields The following booklet provides information on the basics of surveying measurement the most commonly used instruments and the most important everyday tasks employed by surveyors and other users Trainees students and professionals in the fields of surveying civil engineering architecture and many other fields can find answers to their questions a What are the characteristics of survey instruments What do need to take care of when measuring with a level or total station a What is the effect of instrument error and how to recognize determine and eliminate such errors How do I perform simple measurement tasks Many survey tasks the calculation of areas or volumes the collection checking and staking of points or the transfer of heights can be performed automatically using built in application programs In addition to total station and level measurement surveying with GNSS satellite systems will be briefly discussed 2 Introduction With nearly 200 years of experience in developing and manufacturing surveying instruments Leica Geosystems provides a comprehensive range of innovative products and solutions for surveying tasks To
8. a tion after this has been targeted the horizontal circle is set to zero refer to the user manual If a coordinate system already exists set up the instru ment on a known point within it and set the horizontal circle to a second known point refer to the user manual You can also use the resection method to setup and orient your instrument see page 22 26 Measuring with a Total Station Staking Out 1 Set up the instrument at a known point and set the horizontal circle refer to the section Instrument Set up in the user manual 2 Enter the coordinates of the point to be staked out The program automatically calculates direction and distance to the point the two parameters needed for staking out 3 Turn the total station until the horizontal circle reads zero 4 Position the reflector at this point point P N 5 Measure the distance the difference in the distance AD to the point P will be displayed automatically The coordinates of the points to be staked out can be transferred beforehand from the computer to the total station Under these circumstances only the point number then needs to be selected If two points are known you can also use the resection method to setup and orient your instrument Application Programs 27 Reference Line All Leica Geosystems total stations and GNSS systems are equipped with modern onboard applications Refer ence Line is one of the
9. e Boards Surveying with GNSS GPS amp Glonass GNSS Reference Stations 18 18 20 21 21 22 23 23 23 24 25 26 26 27 28 28 29 30 31 32 33 34 Contents 3 A level is essentially a telescope that rotates around a ver Leica Geosystems levels are also equipped with a horizon tical axis It is used to create a horizontal line of sight so tal circle that is very useful for setting out right angles that height differences can be determined and stakeouts e g during the recording of transverse profiles In addi can be performed tion these levels can be used to determine distances opti cally with an accuracy of 0 1 to 0 3m 4 12in 4 The Level Setting up the Level 1 Extend the legs of the tripod as far as required and tighten the screws firmly 2 Set up the tripod so that the tripod plate is as hori zontal as possible and the legs of the tripod are firm in the ground Levelling up the Instrument After setting up the instrument level it up approximately with the bull s eye bubble Turn two of the footscrews together in opposite direc tions The index finger of your right hand indicates the direction in which the bubble should move Now use the third footscrew to center the bubble 3 Now and only now place the instrument on the tripod and secure it with the central fixing screw To check rotate the instrument by 180 The bubble should remain within the setting circle If i
10. ems provides more reference booklets online at http www leica geosystems com booklets Leica Geosystems Construction Tools Leica Builder Leica SmartPole and SmartStation Introduction to GPS Guide to Reference Stations More Booklets 35 Whether building a house or a bridge a map or an aircraft you need reliable measurements So when it has to be right professionals trust Leica Geosystems to help them collect analyze and present spatial information With close to 200 years of pioneering solutions to measure the world Leica Geosystems is best known for its broad array of products that capture data accurately model quickly analyze easily and visualize and present spatial information Those who use Leica Geosystems products every day trust them for their dependability the value they deliver and the superior customer support Precision value and service from Leica Geosystems When it has to be right Illustrations descriptions and technical data are not binding and may be changed Printed in Switzerland Copyright Leica Geosystems AG Heerbrugg Switzerland 2013 722510en 1 13 RVA Leica Geosystems AG 2 when it has to be right eca Heerbrugg Switzerland www leica geosystems com Geosys tems
11. get points Taking measurements in both telescope faces eliminates line of sight errors and tilting axis errors The line of sight error and for highly precise total stations also the tilt ing axis error which is generally very small can also be determined and stored These errors are then taken into consideration automatically whenever an angle is mea sured and then it is possible to take measurements prac tically free of error even using just one telescope face The determination of these errors and their storage are described in detail in the appropriate user manual Verti cal axis tilt does not rate as being an instrument error it arises because the instrument has not been adequately levelled up and measuring in both telescope faces cannot eliminate it Its influence on the measurement of the hori zontal and vertical angles is automatically corrected by means of the internal compensator d Height index error i the angle between the zenith direction and the zero reading of the vertical circle i e the vertical circle reading when using a horizontal line of sight is not 100 gon 90 but 100 gon i Height index error i V index By measuring in both faces and then averaging the index error is eliminated it can also be determined and stored Note Instrument errors change with temperature as a result of vibration and after long periods of transport If you want to measure in just one face then immedia
12. ial errors in the instrument and by inadequate levelling up refer to section Instrument Errors Z zenith angle to P Z zenith angle to P a Horizontal angle between the two directions lead ing to the points P and P i e the angle between two vertical planes formed by dropping perpendiculars from P and P respectively Zenith j Pi amp lt a gt D Horizontal and Vertical Angles 17 Instrument Errors of a Total Station Ideally the total station should meet the following require ments a Line of sight ZZ perpendicular to tilting axis KK b Tilting axis KK perpendicular to vertical axis VV c Vertical axis VV strictly vertical d Vertical circle reading precisely zero at the zenith o Se G4 o Ss 2e Z ori j w J2 18 Instrument Errors If these conditions are not met the following terms are used to describe the particular errors a Line of sight error or collimation error c deviation from the right angle between the line of sight and the tilting axis Line of sight error c Hz collimation b Tilting axis error a deviation from the right angle between the tilting axis and the vertical axis Tilting axis error a c Vertical axis tilt angle between plumb line and vertical axis Vertical axis tilt The effects of these three errors on the measurement of horizontal angles increase with the height difference between the tar
13. int two coordinates are required Polar coordinates need a line and an angle Car tesian coordinates need two lines within an orthogonal coordinate system Polar coordinates Cartesian coordinates Direction x of reference Oo Abscissa x Ordinate 16 Polar and Cartesian Coordinates The total station measures polar coordinates these are recalculated as cartesian coordinates within the given orthogonal system either within the instrument itself or subsequently in the office Recalculation given D X required x y y Dxsinae y P x Dxcosa given x y required D a D Vy x sina y D or cos a x D Measuring Angles An angle represents the difference between two directions The horizontal angle a between the two directions lead ing to the points P and P is independent of the height difference between those points provided the telescope always moves in a Strictly vertical plane when tilted what ever its horizontal orientation This stipulation is met only under ideal conditions The vertical angle also termed the zenith angle is the difference between a prescribed direction namely the direction of the zenith and the direction to the point under consideration The vertical angle is therefore correct only if the zero reading of the vertical circle lies exactly in the zenith direc tion This stipulation is also only met under ideal condi tions Deviations from the ideal case are caused by ax
14. need to be about the same 1 Set up the instrument at S 2 Set up the staff precisely vertically at point A read off and record the height backsight R 3 Set up the staff at the change point 1 ground plate or prominent and stable ground point read off and Station Point No Backsight R Foresight V Height Remarks record the height foresight V A 420 300 4 Set up the instrument at S the staff remains at the S A 2 806 turning point 1 1 1 328 421 778 height A R V 5 Carefully rotate the staff at the turning point 1 so that S 1 0 919 it faces the instrument 2 3 376 419 321 6 Read off the backsight and continue S 2 3 415 B 1 623 421 113 The height difference between A and B is equal to Sum 7 140 6 327 the sum of the backsight and the foresight 6 327 0 813 height B height A AH 0 813 height difference AB 10 Measuring with the Level Staking out Point Heights At an excavation point B is to be staked out at a height AH 1 00m below street level Point A 1 Set up the level so that the sighting distances to A and B are about the same 2 Set up the staff at A and read off the backsight R 1 305 Set up the staff at B and read off the foresight V 2 520 The difference h from the required height at B is calculated as h V R AH 2 520 1 305 1 00 0 215 m 3 Drive in a post at B and mark the required height 0 215 m above ground level In another frequently used method the req
15. oints on the transverse profile from the instrument height this gives the heights of the points involved The distances from the station point to the various points in the transverse profiles are determined either with the surveyor s tape or optically using the level When repre senting a longitudinal profile graphically the heights of the station points are expressed at a much bigger scale e g 10x greater than that of the stationing in the longitudinal direction which is related to a reference height see illus tration below Transverse profile stn175 Reference height 420 m The Digital Level Leica Geosystems was the pioneer of digital levels with the world s first level to digitally process images to deter mine heights and distances the bar code on a staff is read completely automatically and electronically see illus tration The staff reading and the distance are displayed digitally and can be recorded the heights of the staff stations are calculated continuously and so there can be no errors related to reading recording and calculating Leica Geosystems also offers software packages to post process the recorded data The Rotating Laser If for example on a large construction site a large num ber of points at different heights need to be staked out or monitored it often makes sense to use a rotating laser With this type of instrument a rotating laser beam sweeps out a horizontal plane which serves a
16. own point enter the coordinates or 4 Switch on the laser plummet or for older instruments horizontal direction angle look through the optical plummet and turn the foot 10 Now your instrument is setup and oriented You can screws so that the laser dot or the optical plummet is now stake out coordinates or measure more points in centered on the ground point illustration bottom middle this coordinate system 5 Center the bull s eye bubble by adjusting the lengths of the tripod legs illustration bottom right Setup to Measure 21 Resection calculate station coordinates and orientation Resection is used to calculate the position and height forced to use a known point that is in an unsatisfactory of the instrument station along with the orientation of location the horizontal circle from measurements to at least two points the coordinates of which are known The options for measuring and the measuring procedure are described in detail in the user manuals The coordinates of the known points can be entered man ually or they can be stored in the instrument beforehand Note When performing survey tasks that involve determining Resection has the great advantage that for large projects heights or staking them out always remember to take involving surveying or staking out you can choose the the height of the instrument and that of the reflector into most favourable station for the instrument You are not account Hz 0
17. rvey tasks with user guided onboard applications to be carried out with centimeter accuracy in real time kine matic RTK or post processed on a tripod on a pole on ships vehicles agrilcultural and construction machinery Surveying with GNSS 33 GNSS Reference Stations Also known as a Continuously Operating Reference Station CORS this is typically a multi frequency GNSS receiver located at known coordinates supplied with permanent power and connected to several communication devices A CORS normally logs GNSS data for use in post proces sing tasks or supplies real time GNSS correction data to DGPS and or RTK applications In many cases it performs both tasks satisfying the demands of many different applications including surveying engineering construction geodetic control GIS monitoring tectonic studies 34 GNSS Reference Stations and hydrography With additional CORS larger areas even countries can be covered with a CORS network infrastructure CORS are controlled remotely by a specialized software program such as Leica GNSS Spider which connects to the CORS via a range of telecommunication media serial radio or phone modem even the Internet Once config ured a CORS network receiver will run continuously sup plying the full range of GNSS data DGPS RTK and network RTK services to a virtually unlimited number of users Are you interested in learning more about this topics Leica Geosyst
18. s the refer ence plane for staking out or monitoring heights A laser receiver is slid up down a levelling staff until it detects the laser beam the height can then be read directly off the staff There is no need for an observer at the instrument station A digital level is recommended for use where a lot of lev elling needs to be carried out under these circumstances time savings can amount to 50 Digital Level and Rotating Laser 13 Total stations are used wherever the positions and heights of points or merely their positions need to be determined A total station consists of a theodolite with a built in distance meter enabling it to simultaneously mea sure angles and distances Today s electronic total stations all have an opto electronic distance meter EDM and elec tronic angle scanning The coded scales of the horizontal and vertical circles are scanned electronically and then the angles and distances are displayed digitally The horizon tal distance the height difference and the coordinates are calculated automatically and all measurements and addi tional information is recorded Leica Geosystems total stations are supplied with a soft ware package that enables most survey tasks to be carried out easily quickly and efficiently The most important of these programs are presented later in this document 14 The Total Station Reflectorless Distance Measurement Most of the
19. t does not then readjustment is required refer to the user manual For a level the compensator automatically takes care of the final levelling up The compensator consists of a thread suspended mirror that directs the horizontal light beam to the center of the crosshair even if there is residual tilt in the telescope If you lightly tap a leg of the tripod then provided the bull s eye bubble is centered you will see how the line of sight swings around the staff reading and always steadies at the same point This is how to test whether or not the compensator can swing freely Preparing to Measure 5 Preparing the Instrument for Parallax free Measurements A cross hair parallax is an error that affects optical and staff or the aiming of the prism is incorrect and conse electro optical instruments such as levels and total sta quently leads to wrong results tions Everytime before you start measuring check the parallax The error occurs when the plane of the cross hair reticle and eliminate as follows if required does not coincide with the image plane of the focused aim the telescope at a high contrast or bright object i e the level staff or the prism background e g a piece of paper focus the cross hairs by turning the eyepiece drive This can be easily recognized by moving your head slightly now focus on the staff or the prism up down or left right in front of the eyepiece The reticle appears to move and does not s
20. tay in line with the optical The image plane of both the cross hairs and the object axis If this error is not corrected the readings of the level aimed at now coincide 6 Preparing to Measure Inspecting the Line of Sight two peg test In new levels the compensator has been adjusted at room temperature so that the line of sight is horizontal even if the instrument is tilted slightly This situation changes if the temperature fluctuates by more than ten or fifteen degrees after a long journey or if the instrument is sub jected to excessive vibration It is then advisable to inspect the line of sight particularly if more than one target dis tance is being used 1 In flat terrain set up two staffs not more than 30m 95 ft apart 2 Set up the instrument so that it is equidistant from the two staffs it is enough to pace out the distance 1 549 3 Read off both staffs and calculate the height difference illustration below Staff reading A 1 549 Staff reading B 1 404 AH A B 0 145 Set up the instrument about one meter 3 ft in front of staff A and take the staff reading illustration below Staff reading A 1 496 Calculate the required reading B Staff reading A 1 496 AH 0 145 Required reading B 1 351 6 Take the staff reading B If it differs from the required reading by more than 3mm 1 10in adjust the line of sight refer to instruction manual Actual 1 496
21. tely before the measurements you must determine the instrument errors and store them Instrument Errors 19 Checking the EDM of a Total Station Permanently mark three or four baselines within the range Measure these baselines with each EDM at least four typical for the user e g between 20 200m 60 600ft times per year Provided there are no systematic errors in excess of the expected measuring uncertainty the EDM is Using a new Electronic Distance Meter EDM or one in order that has been calibrated on a standard baseline measure these distances three times The mean values corrected for atmospheric influences refer to the user manual can be regarded as being the required values 20 Inspecting the EDM Setup over a Known Point enter station coordinates and orientation 1 Place the tripod approximately over the ground point 6 After accurately levelling up the instrument release 2 Inspect the tripod from various sides and correct its the central fixing screw so that you can displace it on position so that the tripod plate is roughly horizontal the tripod plate until the laser dot is centered precisely and above the ground point illustration bottom left over the ground point 3 Push the tripod legs firmly into the ground and use the 7 Tighten the central fixing screw again central fixing screw to secure the instrument on the tri 8 Enter station coordinates refer to user manual pod 9 Aim to another kn
22. uired staff reading is calculated in advance V R AH 1 305 1 000 2 305 The levelling staff is then moved upwards or downwards until the required value can be read off with the level R 1 305 Measuring with the Level 11 Longitudinal and Transverse Profiles Longitudinal and transverse profiles form the foundation for detailed planning and stakeout e g of roads for calculation of cut amp fill and for the best possible accom modation of the routes to the topography First of all the longitudinal axis roadline is staked out and stationed i e points are established and marked at regular intervals A longitudinal profile is then created along the roadline the heights of the station points determined by line level ling At the station points and at prominent topographic features transverse profiles at right angles to the road line are then recorded The ground heights for the points in the transverse profile are determined with the aid of the known instrument height First position the staff at a known station point the instrument height comprises Longitudinal profile terrain 424 00 planned height Roadline planned a Reference 25m A height 420 m N Station stn m N fe N uw N Q oO uw oO uw oO 12 Measuring with the Level the sum of the staff reading and the station point height Now subtract the staff readings at the p
23. ust always measure a your total station or GNSS system distance Application Programs 29 Remote Heights 1 Set up a reflector vertically beneath the point the 3 Target the high point height of which is to be determined The total station 4 The height difference H between the ground point and itself can be situated anywhere the high point is now calculated and displayed at the 2 Enter the reflector height target to it and measure touch of a button the distance 30 Application Programs Tie Distances The program determines the distance and height Points stored on the internal memory can also be used to difference between two points calculate the tie distance and height difference refer to manual 1 Set up the total station at any location 2 Measure the distance to each of the two points A and B 3 The distance D and the height difference H are displayed at the touch of a button Application Programs 31 Staking out Profile Boards In the following example profile boards are to be erected parallel to the proposed walls of a large building and at distances of a and b respectively from the boundaries 1 Establish a baseline AB parallel to the left hand bound ary and at a freely selectable distance c 2 Mark point A at the defined distance d from the upper boundary it will be the first location for the total sta tion 3 Using a ranging pole mark point B at the end of
24. view the entire product portfolio offered by Leica Geosystems please visit www leica geosystems com wish you every success with your training study and work and hope that you find this booklet useful With best regards AS Johannes Schwarz President Division Geomatics Leica Geosystems AG Contents The Level Preparing to Measure Setting up the Level Levelling up the Instrument Preparing the Instrument for Parallax free Measurements Inspecting the Line of Sight two peg test Measuring with the Level Height Difference between two Points Measuring Distances Optically with the Level Line Levelling Staking out Point Heights Longitudinal and Transverse Profiles Digital level and Rotating Laser The Digital Level The Rotating Laser The Total Station Overview Reflectorless Distance Measurement Automatic Target Aiming Coordinates Measuring Angles 10 11 12 13 13 13 14 15 15 15 16 17 Instrument Errors Instrument Errors of a Total Station Checking the EDM of a Total Station Setup to Measure Setup over a Known Point enter station coordinates and orientation Resection calculate station coordinates and orientation Simple Surveying Tasks Extrapolating a Straight Line Polar Stake out of a Point Measuring Slopes Plumbing Up or Down Application Programs Surveys polar method Staking Out Reference Line Volume Valculation Area Calculation Remote Heights Tie Distances Staking out Profil
Download Pdf Manuals
Related Search