Transcript

Chapter 12 Collection Procedures for the Leica DNA 10 Digital level

Digital Level Data Collection ........................................................................................... 12-2 Required Equipment and Material ................................................................................... 12-2 Instrument and Tripod Setup ........................................................................................... 12-2 Job Setup ....................................................................................................................... 12-3 Collimation Error Correction ............................................................................................ 12-8 Check and Adjust (Peg Test) Procedures ....................................................................... 12-9 Line Leveling ................................................................................................................. 12-17 Setup ..................................................................................................................... 12-17 Starting the Run ..................................................................................................... 12-22 Check Shots ........................................................................................................... 12-26 Allowable Misclosure.............................................................................................. 12-29 Warning Messages ................................................................................................ 12-32

Interesting New Topics in this Chapter Multiple check and adjust procedures (peg tests) for correcting collimation errors. How to set up a leveling job prior to beginning a run. How to calculate the allowable misclosure on a level line or loop. How to correct a measurement when warning messages are displayed.

Collection Procedures for the Leica DNA 10 Digital Level Digital Level Data Collection
The Leica DNA 10 level is the latest digital level utilized by WYDOT. These levels began replacing the older Leica NA2002 digital levels in 2004. This chapter deals exclusively with the DNA 10 level. The previous edition of chapter 12, which provides instructions for the NA2002 level, can still be accessed by clicking on the “Previous Chapter Editions” link. There are several advantages inherent with digital levels: Typically, readings can be taken faster with a digital level than with an optical level. Increased accuracy can be achieved by taking and averaging multiple readings. Human errors associated with reading and recording observations are eliminated. The observation data is stored on an internal memory card. After the level line or loop has been collected, the data can be transferred from the memory card and saved as a .GSI file on a desktop computer. This file along with a copy of the field notes can be submitted to the State Photogrammetry and Surveys Engineer. Refer to Chapter 13 in this manual for more information on transferring survey data. Once the Photogrammetry and Surveys (P&S) Section receives the level data, it will be processed using Leica’s Geo Office (LGO) software.

Required Equipment and Material
DNA 10 digital level Battery and battery charger Internal memory card Fixed legged tripod Bar coded level rod Field book Temporary turning point platform (Turtle) 1" x 1" wooden hubs or railroad spikes (used for the peg test)

Instrument and Tripod Setup
Place the digital level on the tripod. Tighten the central fixing screw to securely fasten the level to the tripod. Turn the tribrach foot screws to their middle positions. Set the tripod such that the tripod plate is as level as possible. Using the foot pegs on the tripod, firmly press the points into the ground. Center the circular bubble by adjusting the foot screws.

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Revised April, 2009

Chapter 12

Figure 12-1. Instrument and tripod setup.

Job Setup
Turn on the DNA 10 by pressing the On/Off key.

Figure 12-2. DNA 10 keyboard and display screen.

Revised April, 2009

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use the yellow navigation keys to scroll down to option 2.Collection Procedures for the Leica DNA 10 Digital Level Figure 12-3. LINE LEVELLING and press the red Enter key or just press the 2 digit key. Program and Enter key. 12-4 Revised April. To start a new job press the PROG key. Navigation keys. 2009 . At the PROGRAMS menu. Figure 12-4.

2009 12-5 . create a new job. Highlight option 1. PROGRAMS menu. Figure 12-6.Chapter 12 Figure 12-5. Job and press the Enter key or press the 1 digit key. LINE LEVELLING menu. Revised April. At the LINE LEVELLING menu.

After keying in the job name. Figure 12-7. Figure 12-8.Collection Procedures for the Leica DNA 10 Digital Level At the SELECT JOB menu. NEW JOB screen. type in the job name (up to 16 characters). then press Enter. Use the white SHIFT key to alternate between numerical digits and alphabetical letters which includes special characters. use the navigation keys to highlight NEW. then press Enter. The message Job Set! will be briefly displayed. 2009 . At the NEW JOB menu. press Enter and key in the operator’s name or initials. SELECT JOB screen. Press the Enter key and use the navigation keys to scroll down to highlight SET. 12-6 Revised April.

2009 12-7 .Chapter 12 At the LINE LEVELLING menu. then press the Enter key. New job created. Revised April. Figure 12-9. use the navigation keys to scroll down and highlight END.

12-8 Revised April. With the DNA 10. a peg test should be performed in the following situations: Prior to starting a new job At the beginning of each week. A CHECK & ADJUST (Peg Test) is performed to determine the collimation error and should be conducted at the job site and on a regular basis.30 deg F Any time the level has been dropped or significantly jarred Follow the instructions on pages 9 through 16 to perform a CHECK & ADJUST (Peg Test) procedure. optical and electronic collimation errors can occur.Collection Procedures for the Leica DNA 10 Digital Level Collimation Error Correction The collimation error is the vertical angle between the actual line-of-sight and the ideal horizontal line. 2009 . At a minimum. Optical collimation errors are eliminated by adjusting the reticle (cross-hairs) with the ocular (eye-piece). Figure 12-10. Collimation error ( ). even when working on the same job for more than one week When there is an ambient temperature change of +/. Staff readings are automatically corrected for the electronic collimation error and stored in the instrument.

Peg test method. PROGRAMS menu. 2009 12-9 . Select option 2. Figure 12-12. Meth.Chapter 12 Check and Adjust (Peg Test) Procedures At the PROGRAMS menu. Figure 12-11. In the CHECK & ADJUST menu. Revised April. the job that was previously created should be active. select option 4. CHECK & ADJUST.

Figure 12-13. Setting the peg test method. The message Method Set! will be briefly displayed. Selecting a peg test method. and press Enter again to set the method. The Stf1 and Stf2 lines should be left blank.Collection Procedures for the Leica DNA 10 Digital Level Use the left or right navigation keys to select a peg test method. 12-10 Revised April. 2009 . A x Bx or A x x B. Figure 12-14. Press Enter to highlight SET.

The distance between A and B is 30 meters.Chapter 12 Place 1" x 1" wooden hubs or railroad spikes at stations A and B. A x x B method. When performing a peg test. Revised April. The distance between A and B is 60 meters. choose a site with level terrain. 2009 12-11 . choose a site with level terrain. When performing a peg test. Figure 12-16. Place 1" x 1" wooden hubs or railroad spikes at stations A and B. A x Bx method. Figure 12-15.

START and press the Enter key to begin the peg test. select option 3.Collection Procedures for the Leica DNA 10 Digital Level At the CHECK & ADJUST menu. At the CHECK & ADJUST screen. Figure 12-18. 2009 . First instrument setup (station 1). Start the peg test. press the Enter key to continue. Figure 12-17. 12-12 Revised April.

Chapter 12 With the DNA 10 set in position 1. Revised April. 2009 12-13 . If necessary. Figure 12-19. adjust the focusing knob to focus clearly on the rod. and press the red measure button on the right side of the instrument. Measure button. aim the instrument at the level rod located at station A. The DNA 10 will then take and average three readings for each measurement.

record the rod reading and distance for A1 in the field book. 2009 . Figure 12-20. The rod person will now move to station B. 12-14 Revised April.Collection Procedures for the Leica DNA 10 Digital Level After the measurement has been taken. Accept the measurement and continue by pressing Enter. At the CHECK & ADJUST screen. record the rod reading and distance for B1 in the field book. Aim the DNA 10 at station B. press the Enter key to continue. Accept the measurement and continue by pressing Enter. and press the measure button. Second instrument setup (station 2). Peg test measurements at station 1. After the measurement has been taken. focus the instrument (if needed). Figure 12-21.

and press the measure button. Accept the measurement and continue by pressing Enter. Revised April.Chapter 12 The rod person will stay at station B and the instrument person will move to position 2. The rod person will now move back to station A. record the rod reading and distance for B2 in the field book. After the measurement has been taken. Figure 12-22. Focus the instrument on the rod. Accept the measurement and continue by pressing Enter. When the setup is complete. and press the measure button. Aim the DNA 10 at station A. focus the instrument (if needed). 2009 12-15 . After the measurement has been taken. record the rod reading and the distance for A2 in the field book. Peg test measurements at station 2. aim the DNA 10 at station B.

another peg test will need to be performed. Press Enter to set the new collimation value in the instrument. If the difference is greater than 15"+/-. 2009 . the instrument may need to be calibrated by a Leica vendor. The message New Collimation Set! will be briefly displayed. At this point the instrument should be at the PROGRAMS menu. When the difference is within the 15" tolerance. Collimation results. Figure 12-23. The difference between the old and new collimation errors should not be greater than 15" +/-. note all of the collimation information in the field book. If the 2nd peg test is still greater than 15" +/-. 12-16 Revised April.Collection Procedures for the Leica DNA 10 Digital Level The collimation results will be computed and displayed as seen in figure 12-23.

scroll down and highlight option 2.Chapter 12 Line Leveling Line leveling is a series of backsight and foresight readings that can be accomplished with an instrument person and a rod person. The line will end at another point with a known elevation. The job should still be set. Create a new line. select option 2. Revised April. To create a new line. 2009 12-17 . A level line is started at a point with a known elevation and runs through a series of points with unknown elevations. and returns to the original starting point. runs through a series of points with unknown elevations. Figure 12-24. LINE LEVELLING and press Enter. Line and press Enter. Setup At the PROGRAMS menu. A level loop begins at a point with a known or assumed elevation.

The instrument will then correctly sort these point names in numerical order when the point list includes point numbers higher than ten. If assuming an elevation. The Pt ID line only allows eight characters. Set a new line. Examples of point names are LABS 01. 2009 . etc. LACC 03. The H0 line will now be highlighted. Once the line name has been keyed in. press Enter. After the Pt ID line has been keyed in. or B 67. This is the point that the level run is starting from and can be a benchmark. 12-18 Revised April. LACC 83A. Point names with numbers less than ten should be entered into the instrument with a leading zero.Collection Procedures for the Leica DNA 10 Digital Level A line name of up to 16 characters can be entered. WYDOT 03. LACC 01. Enter a point name in the Pt ID line. Point names with eight or more characters will have to be abbreviated or spaces may have to be omitted (e. This elevation should be entered in meters.e. project control monument. Figure 12-25. LACC 02. The Meth line should always read BF (a backsight shot followed by a foresight shot). The H0 line is the elevation of the starting point. i. The message Line Set! will be briefly displayed. A67Reset). LNAS125A.g. or flight line target. Scroll down until SET is highlighted and press the Enter key. use 1000 m. press the Enter key.

Use the navigation keys to set the Precise line to Off and the other lines to On. select option 3.Chapter 12 From the LINE LEVELLING menu. Figure 12-26. 2009 12-19 . Set tolerances. and press the Enter key. Figure 12-27. Tolerance settings. Scroll down and highlight LIMITS and press the Enter key. Revised April. Set.

At the LINE LEVELLING menu. Scroll down and highlight SET and press the Enter key. The message Tolerances Set! will be briefly displayed. refer to the WYDOT Survey Manual. 2009 . Tolerance values. the START/ CONT line will be highlighted. Section IX. Survey Standards. Start the level run. For more information on digital level standards. 12-20 Revised April. change the tolerances to the values shown in Figure 12-28. Figure 12-29.Collection Procedures for the Leica DNA 10 Digital Level At the Enter TOLERANCES screen. Figure 12-28. Select SET one more time at the SET TOLERANCES screen and press Enter to accept the changes. press the Enter key to start the level run.

Revised April. Verify that the settings are the same as shown in Figure 12-30. Change the necessary settings and press the Enter key when SET is highlighted. a CHECK LIST menu will be displayed. If these values need to be edited.Chapter 12 Before the new line is started. CHECK LIST settings. Figure 12-30. 2009 12-21 . press the MODE key.

Always enter the point designation in the Pt ID line instead of the Rem line. The instrument person will start pacing towards the next point in the run. The rod person will then place the turning plate (turtle) the same distance past the instrument. the rod person will place the level rod on the starting point.3 m above the bottom of the rod. Figure 12-31. This “leap frog” procedure continues until the level run is complete. and press the measure button. Once the DNA 10 is set up for the first measurement. Focus on the level rod. The point name is the benchmark. 2009 . the instrument person must also consider the requirements of sighting below the top of the level rod and a minimum of 0.Collection Procedures for the Leica DNA 10 Digital Level Starting the Run Figure 12-31 is the first screen of the level run. After the foresight measurement is taken. Once the measurement is taken. 12-22 Revised April. project control point. This is particularly important when working in hilly terrain. LINE LEV screen. the rod person will stay in the same position without picking up the turtle. The instrument should be placed as far from the starting point as possible to minimize the number of turns without exceeding the 70 m maximum distance. However. or flight line target at the start of the run. To begin the run. The H line is the elevation entered in Figure 12-25. the DNA 10 will store the backsight reading and is now ready for the foresight reading The instrument person will remain in the same location as the rod person paces the distance to the instrument. aim the instrument toward the level rod on the starting point. The instrument person will move past the rod person to setup the instrument and take the next backsight shot.

SHIFT and USER/FNC keys. press the SHIFT key. Measurements can be taken in this mode without storing the data. A running total of the distance balance is computed by subtracting the foresight distance(s) from the backsight distance(s). To set the test measurement mode. Any problems encountered during the level run should be noted in the field book. then the USER key to access the FUNCTIONS menu. or flight line target. These line of sight errors are caused by internal instrument mis-adjustments and imperfectly leveled instrument setups. control point. This distance balance should not exceed 5 m and should be kept as close to zero as possible for each backsight/foresight combination and for the cumulative backsight/foresight distances. Figure 12-32. A useful function of the DNA 10 is the test measurement mode.Chapter 12 Balancing the backsight and foresight distances is referred to as the distance balance. After the foresight measurement is taken. the run will need to be restarted. Keeping the sight distances balanced reduces earth curvature and atmospheric refraction errors. Additionally. If the turning point is disturbed before the backsight measurement has been taken. then the instrument person can move to the next setup. the TBal line will show a distance balance value. it minimizes errors due to the instrument’s line of sight differing from a true horizontal line. A new level line will need to be created when starting over at the last benchmark. see Figure 12-34. the run will also need to be restarted. Important: If the instrument is disturbed before the foresight shot has been taken and the backsight is not available. Revised April. The distance balance is calculated by the DNA 10 for each backsight/foresight combination. Test measurements are always single measurements regardless of the current measuring mode. If the distance balance is less than the set tolerance value. 2009 12-23 . The distance balance should be corrected by the rod person on the foresight measurement only. This mode is intended to optimize target distances.

select option 1. Test Measurement. The display screen will go back to the LINE LEV screen to resume the level run. The dH T value is the difference in elevation from the start of the run to the last foresight location. press Enter while QUIT is highlighted. Backsight measurement. TEST MEASUREMENT screen. 2009 . This screen shows several key values of the current run. the display will show the rod reading and the distance to the rod. Figure 12-34. The H value is the elevation at the last foresight location. Any number of test measurements can be made and the results viewed.Collection Procedures for the Leica DNA 10 Digital Level At the FUNCTIONS menu. 12-24 Revised April. Once the measurement has been taken. Figure 12-34 is the LINE LEV screen for a backsight measurement. The TBal value is the difference in the cumulative backsight and foresight distances. When the optimum distance is achieved. Figure 12-33.

or flight line target. Revised April. DTot is the distance of the current run. This screen also shows several key values of the current run. 2009 12-25 . project control point. Foresight measurement. Figure 12-35. Figure 12-36 is the LINE LEV screen before the foresight is taken when approaching a benchmark. the designation should be entered in the Pt ID line. The LDst value is the distance of the last backsight measurement. Press the SHIFT key to select numerical digits or alphabetical letters and special characters.Chapter 12 Figure 12-35 is the LINE LEV screen for a foresight measurement. The TBal value is the sum of the LDst and the TBal value from the backsight screen (Figure 12-34). Figure 12-36. As mentioned earlier. The TBal value is the distance required for the foresight measurement to balance the cumulative backsight and foresight distances. Entering a point ID.

Check Shots While on the way back to close the loop. The purpose of the check shot is to verify that a level “bust” has not occurred somewhere along the run. continue the line toward the next point or complete the loop by returning to the starting point. 12-26 Revised April. use several of the control points or flight line targets that were previously collected as a check. Since the check shot will not affect the distance balance. continue with the run by taking the foresight. are also known as side shots. Figure 12-37. To perform a side shot press the INT button. When the instrument is ready for the foresight reading. the rod person will set the rod on the check point. INT key.Collection Procedures for the Leica DNA 10 Digital Level Once the foresight shot on a benchmark or control point has been stored. 2009 . make sure the low and high staff readings are within set tolerances. The instrument person will move to a new location to take a backsight while the rod person stays at the benchmark or control point. the distance to the side shot does not matter as long as it is less than the maximum set distance. When taking a side shot. These check shots or intermediate shots. After the check shot has been taken.

Chapter 12 At the INTERMEDIATE screen. Intermediate (side shot) measurement. Figure 12-38 INTERMEDIATE screen. the rod reading. Figure 12-39. 2009 12-27 . The instrument will return to the line leveling screen. press the Enter key. Once the values have been noted. Revised April. The point elevation on the screen should be recorded in the field book along with a brief explanation of the shot. The rod person can then move to the next foresight shot. enter the point ID in the NEXT line then press the Enter button. After the shot has been taken. and the check point elevation will be given. and QUIT is highlighted. distance from the instrument to the rod.

record the elevation of the ending point in the field book. Figure 12-40.Collection Procedures for the Leica DNA 10 Digital Level Continue taking backsight and foresight shots until the end of the level line or the starting point of the level loop is reached. When the foresight measurement has been taken. type in the point name. the instrument person will pace the distance from the rod person to the ending benchmark or control point. 12-28 Revised April. To end the level loop. Minor adjustments may have to be made to keep the cumulative distance balance under the set tolerance. 2009 . scroll down to highlight END and press the Enter key. On the last instrument setup. Ending the level run. The instrument person should then split this distance for the final setup. After the final backsight has been taken.

DATA key. DATA MANAGER menu. Revised April. Figure 12-42. select option 1. press the DATA key. At the DATA MANAGER menu.Chapter 12 Allowable Misclosure Based on the total distance of the loop. To view the total distance of the completed line. the allowable misclosure can be calculated to determine if the level loop misclosure is acceptable. Figure 12-41. 2009 12-29 . VIEW / EDIT DATA.

2009 . VIEW / EDIT DATA menu. highlight VIEW and press Enter to load the line data.Collection Procedures for the Leica DNA 10 Digital Level At the VIEW / EDIT DATA menu. 12-30 Revised April. MEASUREMENTS. select option 1. When these have been selected. Use the navigation keys to select the current job and level line. Figure 12-44. Figure 12-43. VIEW MEASUREMENT screen.

Chapter 12 In the upper right corner of the screen is a page number. Figure 12-45. First page of the level line. Figure 12-46. The DTot value is the total distance for the entire line. Press the left navigation key to scroll to the last page. There are several parameters listed on this page. This number is the first page of the level line. Last page of the level line. This is the distance value used to compute the allowable misclosure. 2009 12-31 . Revised April.

0108 m (10.509 m and the ending elevation of CRHA 22 after closing the loop is 995. the instrument will disregard the last measurement taken. Warning Messages When a warning message is displayed. control point. This accepts the error and enables the operator to correct it. no warning messages will be displayed.119 m. However.008 m x /1.e. Refer to Figure 12-28 for these values.0 mm). it is usually due to one of the preset tolerances being exceeded. see Figure 12-48 If the REMEAS option is selected. then press the Enter key.0108 m or 10. then the level loop closed within the acceptable tolerance. Press the SHIFT key and then the Back navigation key to retake the measurement.511 m. when these measurements are taken. If the level loop did not close within the acceptable tolerance.119 m / 1000 m/km = 1. the preset tolerance values should not be exceeded. the total distance needs to be converted to kilometers.3532 = . or photo target.831119 = . Note: When performing a check shot. Use the navigation keys to scroll down and highlight IGNORE.008 m x /(total distance in kilometers) Example: The starting elevation of control point CRHA 22 is 995. If the last measurement was a backsight and the turning point is no longer available (i.8 mm) and the difference between the two elevations is . Always select the IGNORE option when a measurement needs to be retaken.831119 km allowable misclosure (meters) = . 12-32 Revised April.Collection Procedures for the Leica DNA 10 Digital Level Use the following equation to calculate the allowable misclosure for the loop or line: allowable misclosure (meters) = .002 m ( 2. 1831. then the entire loop would need to be rerun until the misclosure is within the allowable misclosure. First. 2009 . the turtle has been moved) the run will need to be restarted at the last benchmark.8 mm Since the allowable misclosure for this level loop is 0. The total distance of the level loop is 1831.008 m x 1.

below limit! is a warning message indicating the rod reading is below the tolerance set for a low staff reading. Figure 12-48. SHIFT and Back keys. 2009 12-33 . highlight IGNORE and press Enter.Chapter 12 Meas. Press the SHIFT key then press the Back navigation key. Figure 12-47. Revised April. Rod reading warning message. When this message is displayed.

The instrument may be moved to correct an error whenever the LINE LEV screen displays the BACK command for a backsight shot. Make the appropriate adjustment to the instrument for a backsight or the turning point for a foresight and take the measurement again. refer to Figure 12-35.Collection Procedures for the Leica DNA 10 Digital Level The DNA 10 will display a Remeasure Back? or Remeasure Fore? message with the point name. Remeasure Back? message. Press Enter while YES is highlighted. refer to Figure 12-34. Figure 12-50. Remeasure Fore? message. 2009 . 12-34 Revised April. Figure 12-49. The turning plate (turtle) may be moved to correct an error whenever the LINE LEV screen displays the FORE command for a foresight shot.

Press the SHIFT key then press the Back navigation key. 2009 12-35 . If the value is negative then the cumulative foresight distances are greater than the cumulative backsight distances. too big! is a warning message that the cumulative backsight/foresight distance balance is larger than the tolerance set for the total distance balance. During the level run. Distance balance warning message. This may be exceeded with a positive or negative value. To correct the error. highlight IGNORE and press Enter. If the value is positive then the cumulative backsight distances are greater than the cumulative foresight distances. the maximum TBal distance is set to 5 m. If the value is negative then the cumulative foresight distances are greater than the cumulative backsights.Chapter 12 Distance Bal. Revised April. If the value is positive then the cumulative backsight distances are greater than the cumulative foresight distances. Figure 12-51.

Collection Procedures for the Leica DNA 10 Digital Level Any adjustments to the distance balance should be made when the instrument is ready for a foresight. 12-36 Revised April. To correct this error. Figure 12-53. the rod person should move towards the instrument. thereby increasing the foresight distance. When this message is displayed. 2009 . Meas. Figure 12-52. move the instrument closer to the rod for a backsight shot or move the rod closer to the instrument for a foresight shot. Dist too big! is a warning message that the measured distance is larger than the tolerance set for the maximum allowable distance. the level process may continue. the rod person should move away from the instrument. If the TBal is a positive value. If the TBal is a negative value. Total distance value. Press the SHIFT key then press the Back navigation key. Measurement distance warning message. As long as the backsight and foresight distances remain balanced within the 5 m tolerance. highlight IGNORE and press Enter. thereby reducing the foresight distance.

Precision mode warning message. 2009 12-37 . When these messages are displayed. The Precise tolerance mode should be switched to Off before continuing with the run. select IGNORE then press the Enter key. Figure 12-54. Precision mode warning message. The shot does not need to be re-taken. Figure 12-55.Chapter 12 The warning messages in Figures 12-52 and 12-53 occur only if the Precise tolerance mode is set to On. Revised April.