Engineering Geodesy II

Engineering Geodesy II Exercise: Design and preanalysis of networks Geodätische Messtechnik - Prof. Dr. H. Ingensand ETH Zürich 1

Goals of the Exercise Becoming acquainted with the pre-analysis tool of the LTOP software Getting experience in error propagation in elongated tunnel- and shafts networks Preparation for bidding at the Swissmetro invitation to tender Geodätische Messtechnik - Prof. Dr. H. Ingensand ETH Zürich 2

Software Options for Adjustment / Analysis LTOP swisstopo, official Swiss governmental adjustment software Trinet und Trinet+ (3D-Ausgleichung), by Moritz Wittensöldner & Sebastian Kracher, Fachhochschule Nordwestschweiz CAPLAN + NETZ2X: (Cremer Auswertung und Planerstellung) for adjustment of geodetic networks. Cremer Programmentwicklung GmbH NEPTAN (Technet GmbH) Berlin Matlab: N = A' * A; Q = Inv(N); dx = Q *(A' * L); Geodätische Messtechnik - Prof. Dr. H. Ingensand ETH Zürich 3

Documents Instructions : see handout pre-analysis using LTOP (German & English) Documentation of LTOP WIN: EG II Website or at the Swisstopo Website: http://www.swisstopo.admin.ch/internet/swisstopo/de/home/products/downloads/so ftware.parsys.14521.downloadlist.7018.downloadfile.tmp/ltopd.pdf LTOP WIN: Editor for the parameter file (.dat) LTOP can also used via the internet: (webservice) http://ilgeos.ethz.ch/geoportal/index.php?code=1 (access with gmtuser[1...10] and user_gmt[1...10]) documentation: http://ilgeos.ethz.ch/geoportal/dload/ltop_d.pdf Geodätische Messtechnik - Prof. Dr. H. Ingensand ETH Zürich 4

Introduction Exercise Maximal Line of Sight Maximal line of sight in a tunnel A B R min = 7000 m M minimal clearance to wall is 1 m due to refraction! Geodätische Messtechnik - Prof. Dr. H. Ingensand ETH Zürich 5

LTOP required data Requirements for a pre-analysis: approximation values for all network coordinates configuration of the network, observations (Messelemente, A-matrix) a priori assumptions of all observations not necessary: measured values (Messwerte) coordinate file (*.koo): approximate coordinates of all network nodes observation file (*.mes): network configuration; for a pre-analysis no observations are necessary parameter file (*.dat): key parameters for the adjustment, includes a priori accuracy assumptions Geodätische Messtechnik - Prof. Dr. H. Ingensand ETH Zürich 6

LTOP File Formats Coordinate File: *.KOO $$PK ** comment line A0000 683000.000 248000.000 400.000 A0320 683320.000 248000.000 400.000 A0640 683640.000 248000.000 400.000 A0960 683960.000 248000.000 400.000 A1280 684280.000 248000.000 400.000 A1600 684600.000 248000.000 400.000 A1920 684920.000 248000.000 400.000... format is explained in detail: http://www.swisstopo.admin.ch/swisstopo/geodesy/geo_software/samples/ltop/format_description/ltop_de.html#pk Geodätische Messtechnik - Prof. Dr. H. Ingensand ETH Zürich 7

LTOP File Formats Observation File: *.MES $$ME STA0000 APA0320 STA0320 RIA0000 RIA0640 DPA0000 DPA0640 STA0640 RIA0320 RIA0960 DPA0320 DPA0960 STA0960 RIA0640... format is explained in detail: http://www.swisstopo.admin.ch/swisstopo/geodesy/geo_software/samples/ltop/format_description/ltop_de.html#mess ST: station AP: azimuth to e.g. A0320, RI: direction [GON], DP: horizontal distance [m], DS: slope dist. Geodätische Messtechnik - Prof. Dr. H. Ingensand ETH Zürich 8

Exercise analyses of four different of tunnel driving surveying strategies. comparison of different surveying set-ups with their configuration and resulting error propagation comparison of the a priori confidence ellipses at km 8.640 (break through error) four alternative strategies, see exercise documentation files: 1.koo - 4.koo 1.mes - 4.mes 1.dat - 4.dat LTOP - results: Listing *.prn File containing information for plotting *.ipl Geodätische Messtechnik - Prof. Dr. H. Ingensand ETH Zürich 9

instrument station Listing File: *.PRN LTOP File Formats repetition of approximate coordinates influence of mean error to the transverse deviation LAGE - ABRISS MITTL. FEHLER A PRIORI VON REDUZIERTEN DISTANZEN, RICHTUNGEN UND AZIMUTEN ************* DISTANZ-GRUPPE ZENTR. A B C M.F. F. 1KM EDM 3 0.30 MM 1.00 MM 1.00 MM/KM 0.00 MM/KM2 2.02 MM RICHTUNGEN 1 0.30 MM 5.00 CC 5.00 CC AZIMUTE 1 0.30 MM 15.00 CC 15.00 CC NR PUNKT TYP NP OR/BEOB. GR KORR. VERB. M.F. ZI NABLA WI GI AZI. AUS DIST. AUS QUER. G/M CC/MM CC/MM CC/MM % CC/MM CC/MM KOORD.(G) KOORD.(M) MM target A0000 AZIMUTE ---------------------------- 1 A0320 N 100.0000* 1 15.0 0. 4113 100.0000 320.000 8. A0320 N 0.00000 15.8 ---------------------------- 2 A0000 300.0000* 1 5.0 0. UNEND. NICHT BESTI 300.0000 320.000 3. 3 A0640 N 100.0000* 1 5.0 0. UNEND. NICHT BESTI 100.0000 320.000 3. A0320 N DISTANZEN ---------------------------- 4 A0000 320.000 3 1.4 0. UNEND. NICHT BESTI 300.0000 320.000 5 A0640 N 320.000* 3 1.4 50. 10 100.0000 320.000 is a new point Distance measured also in other direction a priori mean error of observation confidence: how much control does this observation have? 100% = reference point standardized residuals w i < 3.5 nabla: how large could be an undetected error? Geodätische Messtechnik - Prof. Dr. H. Ingensand ETH Zürich 1

LTOP File Formats Listing File: *.PRN (continued) above tolerance AEUSSERE ZUVERLAESSIGKEIT UND MITTLERE FEHLERELLIPSEN A PRIORI ************************************************************** PUNKT TYP TK NA NB AZI(NA) NH NR.A NR.B NR.H DY DX DH MFA MFB MFAZ MFH MM MM G MM MM MM MM MM MM G MM A0320 22 2066.6** UNEND. 200.0 1 4 0.0 0.0 7.5 1.4 0.0 A0640 22 4133.1** UNEND. 200.0 1 4 0.0 0.0 15.5 1.7 0.0 A0960 22 6199.4** UNEND. 200.0 1 4 0.0 0.0 24.0 1.9 0.0 A1280 22 8265.6** UNEND. 200.0 1 4 0.0 0.0 33.0** 2.1 0.0 A1600 22 10331.6** UNEND. 200.0 1 4 0.0 0.0 42.5** 2.3 0.0 A1920 22 12397.5** UNEND. 200.0 1 4 0.0 0.0 52.5** 2.5 0.0 A2240 22 14463.2** UNEND. 200.0 1 4 0.0 0.0 62.9** 2.7 0.0 A2560 22 16528.8** UNEND. 200.0 1 4 0.0 0.0 73.7** 2.9 0.0 A2880 22 18594.3** UNEND. 200.0 1 4 0.0 0.0 85.0** 3.0 0.0 A3200 22 20659.6** UNEND. 200.0 1 4 0.0 0.0 96.6** 3.2 0.0 confidence rectangle, characterizes geometry, NA = big, NB = small side direction of confidence rectangle which observation number is responsible for the rectangle side change of coordinates between approximate and adjusted error ellipse a priori Geodätische Messtechnik - Prof. Dr. H. Ingensand ETH Zürich 1

Improvement of the network Meeting the requirements of the contracting body (client): standard deviation at breakthrough: < 6 cm improvement of the network configuration Improvement by lessening the a priori accuracies? If so, then justify your assumptions! try out different strategies to meet the requirements Geodätische Messtechnik - Prof. Dr. H. Ingensand ETH Zürich 1

Use a gyroscope? tachymetric accuracy for directions: 5 cc gyroscope accuracy: 15 cc At which length of the traverse (Polygonzug) is the use of a gyro justified from the accuracy point of view? 5 mgon n < 1.5 mgon n = number of polygon points With n < 9 every 2-3 km a gyroscope measurement would improve accuracy significantly Further aspects to consider: reliability, costs, time Geodätische Messtechnik - Prof. Dr. H. Ingensand ETH Zürich 1