12D LEAST SQUARES NETWORK ADJUSTMENT FROM LEICA 1200

Transcription

1 12D LEAST SQUARES NETWORK ADJUSTMENT FROM LEICA 1200 READINGS The following steps show the conversion of a Leica 1200 DBX file to a horizontal and level network adjustment file and the subsequent adjustments 1.1 Setting up Copy the format files ANG_Code_Office.FRT and ANG_ID_Office.FRT from the folder C:\Program Files\12d\12dmodel\8.00\Library or C:\Program Files\12d\12dmodel\9.00\Library to the 1200 data card. Transfer the format file from CF card to System RAM These files are used to convert the DBX files on the instrument to an SOA editable text file format (example below shows observations from STN1) ANG_Code_Office.FRT is the format file used when the Station number is put in as a code ANG_ID_Office.FRT is the format file used when the Station number is put in as a Point ID 1.2 Notes on Observations on Leica 1200 You can use the Sets of Angles program but it is not necessary. All you need to do is measure rounds of angles/distances making sure that the point id / code is correct. If you are chasing levels then if you occupy the same point again ensure the instrument height is identical or close, the macro might not be able differentiate between different setups. There is a chance the heights will be incorrect but the angles remain unaffected. Remember this is a least squares network, not a traverse; all points should have redundant measurements and be well 'braced'.

2 1.3 Creating the SOA text file Select Convert or 4 to go to Convert menu Select 1 to Export data Select 1 to Export ASCII

3 Select the Job to convert Select the relevant format file (in this case codes were used for Station numbers) Type in file name with extension.soa Select CONT or F1 Select NO or F4 to finish Copy the newly created file from the CF Card DATA folder to the 12d project working folder

4 1.4 Converting SOA file to ANG file format This option takes the SOA file format and converts it to a TP-Stakeout Angles file format (shown below) Select option Survey Adjustments Utilities Leica DBX to ANG Select the SOA file Type in ANG file name Type in the report file name Select Process and check the report file for errors The observations we are processing are single readings so no standard deviations are displayed

5 1.5 Creating PTA file of fixed stations A control file of the fixed station coordinates must be created prior to converting the ANG file to the LSF file. The PTA file can be created as a space separated file. Select option File I/O Data Output XYZ General Select the fixed station data source Type in the file name with extension.pta Change the delimiter to space Set the file order as shown here Select Write

6 1.6 Creating LSF file This option takes the ANG file format and converts it to a TP-Setout LSF format (shown below) Select option Survey Adjustments Utilities ANG to LSF Select the ANG file Select the PTA file Type in LSF file name Type in the report file name Select Process and check the report file for errors

7 1.7 Creating 12d Horizontal and Level Input files This option takes the LSF file format and converts it to a Horizontal network input file and a Level Network input file formats (shown below) Select option Survey Adjustments Utilities LSF to 12d Select the LSF file Type in the Horizontal network file name Tick check box to create Levels network file Type in the Level network file name Select Process

8 1.8 Performing Horizontal adjustment Read in the input file Open up the Least Squares Horizontal Network Adjustment panel using option Survey Adjustments Least squares network Read in the input file to populate the panels Select the file LSOBSH.in Click on <Read>

9 Distances Select the Distances tab Type in the required Standard deviation Type in the Parts per million values Angles Select the Angles tab Type in the required Standard deviation The values shown are the angles read in a clockwise direction. Note that the angles are not from the same reference object as observed in the field

10 Fixed points Select the Fixed tab These coordinates are populated from those values in the PTA file. The Z coord is in fact the weigtht is for a fixed point. As no heights are used in this adjustment the Z values are given a dummy height of the weight (1000) Select the Draw tab Draw options The Draw tab is used to plot the traverse to the screen as a diagram prior to any adjustments. Tick check box to Clear draw model beforehand, so that if we run it a few times we will not create multiple strings. Select the Output tab Output options The Output tab allows you to output a report file and to save the values typed into the panel so they can be read back in at a later date. Enter an Output file name, a Report file name and set the Number of decimal places to 3 (Who are we kidding?!)

11 Control model Select the Control Model tab The Control Model tab allows you to enter a new model, or select an existing model for the adjusted control points. If you select an existing model, and there is a point in the model with the same point id as a point being calculated, then rather than a new point being created, the coordinates of the existing point can be updated after the reduction is complete Type in the model name, give it a colour and set the Style to DS STN Click on <Calc Init> Calculate Initial results A report file of just the initial data will be created and the model of OBS will give an indication what the network looks like Turn on model OBS Check the diagram for obvious errors prior to adjustment

12 View the report file The report file can be checked for errors prior to running the adjustment

13 Calculate network adjustment Click on <Process> Click <Replace> to overwrite the preliminary input file created previously Click <Replace> to overwrite the preliminary report file created previously In the graphics error ellipses are created around each of the new station positions indicating the accuracy of the solution Turning on the names will show the residuals

14 View the report file

15 Errors can be located by analysing the differences in distances and angles

16 Update control model Return to the Control Model tab and click on <Update> The station model can be turned on

17 1.9 Least Squares Level Adjustment We will now perform a least squares adjustment on the levels for the previously created stations The input file created previously will be read in to populate the panels Level Adjustment Open up the Least Squares Level Network Adjustment panel using option Survey Adjustments Level network Read in the input file to populate the panels Select the file LSOBSV.in then select Read The Use weight allows you to weight each observation by either Distance or Standard deviation or to have no weighting at all. Leave it at none Click on <Process> Type in output (input) and report file names for both the required files Type in 3 for the number of decimal places Observations Select the Observation tab The values shown are the observed vertical distances between each point. The distance is shown in the Weight column and can be used as a weight if specified at the top of the panel Any vertical differences shown between fixed points will be given a large variance in the report file so these lines should be deleted prior to processing Right click at the start of the line to delete then select Delete Delete the lines where observations are done between the fixed points STN1, STN2 and STN4 (3 lines)

18 Benchmarks Select the Benchmark tab The values shown are the heights of all of the fixed stations. Select the Control Model tab Control model The Control Model tab allows you to select the control model whose heights are to be updated Choose the station model Click on <Process> View the report file Calculate level adjustment

19 Errors can be located by analysing the differences in heights Update control model Return to the Control Model tab and click on <Update> Toggle on the Z values for the stations

20 1.10 Appendices..ANG file format. The angle file is a file of angles and distances, the data line looks as such: <Backsight Name> <Backsight Target Height> <Instrument Name> <Instrument Height> <Foresight Name> <Foresight Target Height> <Horizontal Bearing Backsight> <Vertical Angle Backsight> <Slope Distance Backsight> <Horizontal Bearing Foresight> <Vertical Angle Foresight> <Slope Distance Foresight> e.g. E STN E If a backsight or foresight is not used the name should be entered as 0. e.g. no foresight: E STN LSF file format. The first section of the file contains the station coordinates and weight along with the station height and weight. A station weighted 1000 is fixed, one weighted 1 is easily adjusted. Once you have entered the stations the next line must be. Eg. <Name> <East> <North> <Weight> <Height> <Weight>.. <Name> <East> <North> <Weight> <Height> <Weight> Example S S S

21 Next comes the angular data, if you are using distances only just enter as the next line after the after the stations. Angles are enter in degrees, minutes and seconds and are measured clockwise. <Name> <Name> <Name> <1st bearing> <2nd bearing> You are set on station B, you point 45 to station A and 120 to station C, the line is entered as such - A B C if you set zero on A or calculated the angle from repeated measurements then the line would be entered as - A B C Finish angle data with an also. Example S8 S1 S S5 S2 S For distances enter the two stations and the horizontal distance between them in metres. The order of the stations is not important Example S1 S S1 S S1 S S1 S S1 S Height differences are entered as the difference in height from the first stations to the second. Example S3 S S5 S If you aren't using distances then just enter after the angular data. Brief examples below.

22 Full file: No measured angles: No measured distances: S S S S S S S S S8 S1 S S5 S2 S S1 S S1 S S1 S S1 S S1 S S1 S S1 S S2 S S2 S S2 S S2 S S2 S S2 S S4 S S4 S S5 S S5 S S3 S S3 S S5 S S S S S S S S S S S S S S S S S S1 S S1 S S1 S S1 S S1 S S1 S S1 S S2 S S S S2 S S2 S S2 S S2 S S4 S S4 S S5 S S5 S S3 S S3 S S5 S S S S S S S S S S S S S S S S S S8 S1 S S5 S2 S S3 S S5 S

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