B. S. Schmeing 23-September-2009 Automated measurement of local ties and antenna parameters Benno Schmeing University of Bonn, IGG Benno Schmeing University.

B. S. Schmeing 23-September-2009 Automated measurement of local ties and antenna parameters Benno Schmeing University of Bonn, IGG Benno Schmeing University of Bonn, IGG automated measurement of local ties and antenna parameters Proof-of-concept demonstration automated measurement of local ties and antenna parameters Proof-of-concept demonstration

B. S. Schmeing 23-September-2009 Automated measurement of local ties and antenna parameters Contents Introduction –Motivation –Objectives GGAO local site Chosen Approach –Design of the monitoring system –Measurement procedure –Mathematical model –Analysis Results –Calibration –Simulation –Measurement results

B. S. Schmeing 23-September-2009 Automated measurement of local ties and antenna parameters Motivation for VLBI 2010 + GGOS 2020 reduce working hours needed for determination of local ties shorten monitoring interval  here: proof-of-concept for VLBI antenna at GGAO

B. S. Schmeing 23-September-2009 Automated measurement of local ties and antenna parameters Motivation

B. S. Schmeing 23-September-2009 Automated measurement of local ties and antenna parameters Objectives Monitoring of VLBI antenna‘s –Reference point –Axis offset –Orientation of azimuth and elevation axes Requirements: –Accuracy < 1mm –Automatic operations –Ability to include additional sensors, e.g. GPS, SLR

B. S. Schmeing 23-September-2009 Automated measurement of local ties and antenna parameters GGAO 4 different geodetic sensors: –GPS –VLBI –SLR –DORIS Geodetic network consisting of several piers and ground markers We will concentrate on the VLBI antenna:

B. S. Schmeing 23-September-2009 Automated measurement of local ties and antenna parameters

B. S. Schmeing 23-September-2009 Automated measurement of local ties and antenna parameters Design of the monitoring system? How to identify antenna dish movement?  360° prism marks one discrete point of the dish  total station determines prism’s movement How to embed antenna parameters into (local) reference frame, e.g. to get local ties?  coordinates of piers and ground markers define local reference frame  Additionally possible: GPS sensors set up on the points How to control antenna movement?  connection to Field System computer  Field System puts movement commands into practice

B. S. Schmeing 23-September-2009 Automated measurement of local ties and antenna parameters Design of the monitoring system? How to control station?  using implemented interface (Lemo-RS232 interface with GSI commands) How to achieve needed accuracy?  calibration of 360° prism’s orientation-dependent errors  correct atmospheric influence on total station measurements  eliminate instrument errors using the right measurement procedure

B. S. Schmeing 23-September-2009 Automated measurement of local ties and antenna parameters 360° prism mounted on antenna Design of the monitoring system

B. S. Schmeing 23-September-2009 Automated measurement of local ties and antenna parameters Design of the monitoring system Total station(s) on piers around the antenna

B. S. Schmeing 23-September-2009 Automated measurement of local ties and antenna parameters Design of the monitoring system TCA specifications: (from: http://leica.loyola.com/products/total-stations/images/tps2000_lg.jpg; 09/14/2009)

B. S. Schmeing 23-September-2009 Automated measurement of local ties and antenna parameters Design of the monitoring system TCA specifications: –angle measurement accuracy: 0.15 mgon (due atmosphere influence etc reachable accuracy is somewhat lower) –distance measurement accuracy: 1 mm + 1ppm –measurement distance (ATR): 5 … 500 m –measurement time:~ 3 sec

B. S. Schmeing 23-September-2009 Automated measurement of local ties and antenna parameters Design of the monitoring system Laptop as control unit for total station and antenna

B. S. Schmeing 23-September-2009 Automated measurement of local ties and antenna parameters Design of the monitoring system measures to antenna controls antenna movement, measures weather directions + distances  antenna control commands  antenna positions,  weather information  marker positions, control commands

B. S. Schmeing 23-September-2009 Automated measurement of local ties and antenna parameters Design of the monitoring system Measurements controlled by Laptop (with Matlab)  Field System controls antenna movement and returns antenna position  Field System provides atmospheric conditions  Total station measures marker position Data structure  Based on ASCII files  Files for … … network point coordinates and accuracy … calibration results … measurement schedules … measurement results

B. S. Schmeing 23-September-2009 Automated measurement of local ties and antenna parameters Design of the monitoring system Example: antenna measurement plan

B. S. Schmeing 23-September-2009 Automated measurement of local ties and antenna parameters Design of the monitoring system Example: network measurement plan

B. S. Schmeing 23-September-2009 Automated measurement of local ties and antenna parameters Measurement procedure 1)set up total station –leveling –determine approximate orientation + position 2)target prisms on other network points –‘network measurement plans’ –provides data for exact determination of orientation (and position) 3)target prism on VLBI antenna at different azimuth and elevation positions –‘antenna measurement plans’ –measuring the marker positions at different antenna azimuth and elevation positions

B. S. Schmeing 23-September-2009 Automated measurement of local ties and antenna parameters set up total station: –levelling –determine orientation and position Measurement procedure

B. S. Schmeing 23-September-2009 Automated measurement of local ties and antenna parameters Measurement procedure Set up total station: –levelling –determine orientation and position

B. S. Schmeing 23-September-2009 Automated measurement of local ties and antenna parameters Measurement procedure Network measurements: –measure directions and distances to other network points –observationsobservations

B. S. Schmeing 23-September-2009 Automated measurement of local ties and antenna parameters Antenna measurements: –measure directions and distances to antenna in different positions –observations Measurement procedure

B. S. Schmeing 23-September-2009 Automated measurement of local ties and antenna parameters Measurement procedure Antenna measurements: –measure directions and distances to antenna in different positions –observations

B. S. Schmeing 23-September-2009 Automated measurement of local ties and antenna parameters Measurement procedure Antenna measurements: –measure directions and distances to antenna in different positions –observationsobservations

B. S. Schmeing 23-September-2009 Automated measurement of local ties and antenna parameters Traditional approach circle fitting: –separate antenna rotations around azimuth and elevation axis –estimation of circles described by antenna movement –reference point is projection from elevation axis onto azimuth axis

B. S. Schmeing 23-September-2009 Automated measurement of local ties and antenna parameters Traditional approach circle fitting: (Johnston: The 2003 Yarragadee (Moblas 5) Local Tie Survey, GEOSCIENCE AUSTRALIA, RECORD 2004/19 )

B. S. Schmeing 23-September-2009 Automated measurement of local ties and antenna parameters Mathematical model new approach [Loesler2008a, Loesler2008b]: –set of rotations and translations –describing transformation from antenna-fixed into local coordinate system –transformation parameters describe antenna characteristics

B. S. Schmeing 23-September-2009 Automated measurement of local ties and antenna parameters Mathematical model

B. S. Schmeing 23-September-2009 Automated measurement of local ties and antenna parameters Mathematical model a,b … marker coordinates in telescope system E,O E … rotation around elevation axis (+orientation) ecc … axis offset (eccentricity) A,O A … rotation around Azimuth axis (+orientation) P R … antenna’s reference point  … correction for non-orthogonality of axes  … correction for inclination

B. S. Schmeing 23-September-2009 Automated measurement of local ties and antenna parameters Marker position (in telescope system):

B. S. Schmeing 23-September-2009 Automated measurement of local ties and antenna parameters Elevation rotation:

B. S. Schmeing 23-September-2009 Automated measurement of local ties and antenna parameters Axis offset (eccentricity):

B. S. Schmeing 23-September-2009 Automated measurement of local ties and antenna parameters Azimuth rotation:

B. S. Schmeing 23-September-2009 Automated measurement of local ties and antenna parameters Translation into local system:

B. S. Schmeing 23-September-2009 Automated measurement of local ties and antenna parameters Mathematical model Observations: –Marker positions: x, y, z (by total station) –Antenna positions: A, E (by Field System) Parameters: –“antenna”: P R, ecc, , , , O A –“marker”: a, b, O E

B. S. Schmeing 23-September-2009 Automated measurement of local ties and antenna parameters Mathematical model Observations: –Marker positions: x, y, z(by total station) –Antenna positions: A, E(by Field System) Parameters: –“antenna”: P R, ecc, , , , O A –“marker”: a, b, O E

B. S. Schmeing 23-September-2009 Automated measurement of local ties and antenna parameters Analysis data record for local network observations: –position and target ID –horizontal + vertical direction and distance to target –instrument settings (distance corrections, serial no.) –time tag –information about atmospheric conditions data record for observations of VLBI antenna: –local network observables plus –antenna position (azimuth + elevation)

B. S. Schmeing 23-September-2009 Automated measurement of local ties and antenna parameters coordinate estimation using weak datum Analysis network measurement antenna measurement antenna parameter estimation: loesler algorithm antenna parameters Hz,V, Sd + weather data Hz,V, Sd coordinates of the marker on the VLBI antenna in the local system azimuth + elevation of antenna previous measurements point coordinates + covariance matrix

B. S. Schmeing 23-September-2009 Automated measurement of local ties and antenna parameters Analysis antenna measurement

B. S. Schmeing 23-September-2009 Automated measurement of local ties and antenna parameters Analysis Separate antenna parameter estimation antenna measurement Hz, V, Sd + weather data Antenna parameters in different reference frames azimuth + elevation of antenna Separate coordinate estimation Comparison of reference frame- independent parameters marker coordinates in current instrument reference frame

B. S. Schmeing 23-September-2009 Automated measurement of local ties and antenna parameters TCA 2003: –additive constant Field System: –measurement accuracy prisms for network points: –additive constant 360° prism used as marker –additive constant –orientation-dependent change of reference point Calibration

B. S. Schmeing 23-September-2009 Automated measurement of local ties and antenna parameters TCA: –additive constant Field System: –measurement accuracy (azimuth and elevation positions) prisms for network points: –additive constants 360° prism used as marker –additive constant –orientation-dependent change of reference point Calibration

B. S. Schmeing 23-September-2009 Automated measurement of local ties and antenna parameters TCA: –additive constant Field System: –measurement accuracy prisms for network points: –additive constant 360° prism used as marker –additive constant –orientation-dependent change of reference point Calibration

B. S. Schmeing 23-September-2009 Automated measurement of local ties and antenna parameters Calibration

B. S. Schmeing 23-September-2009 Automated measurement of local ties and antenna parameters Simulation Network simulation –d–done using PANDA (commercial geodetic analysis software by Geotec GmbH) –i–input: approximate network coordinates instrument’s accuracy (0.45 mgon and 1mm+1ppm) planned measurement schedule (equivalent to carried out network measurement) –r–result: projected accuracy

B. S. Schmeing 23-September-2009 Automated measurement of local ties and antenna parameters Formal errors from PANDA network simulation: Centering accuracy: –forced centering on piers:~ 0.1 mm –forced centering above ground markers: ~ 1.0 mm (x,y) ~ … cm (z) Simulation Point IDPoint name # measurements from to formal errors [mm]  x  y  z 1Pier A420.220.230.14 2unnamed030.280.240.15 3RM 1530.240.210.14 4Pier C430.23 0.14 5JPL West420.200.240.12 6Pier B040.250.360.25

B. S. Schmeing 23-September-2009 Automated measurement of local ties and antenna parameters Accuracy of coordinates + instrument setup: Simulation Point IDPoint name # measurements from to formal errors [mm]  x  y  z 1Pier A420.220.230.14 2unnamed030.280.240.15 3RM 1531.00 - 4Pier C430.23 0.14 5JPL West421.00 - 6Pier B040.250.360.25

B. S. Schmeing 23-September-2009 Automated measurement of local ties and antenna parameters Simulation Antenna simulation –d–done using Matlab –i–input: network coordinates + accuracy (from network simulation) measurement accuracy measurement schedules to simulate –r–result: true errors and formal errors from antenna parameter estimation for chosen settings

B. S. Schmeing 23-September-2009 Automated measurement of local ties and antenna parameters Simulation Visualization of a single antenna measurement schedule

B. S. Schmeing 23-September-2009 Automated measurement of local ties and antenna parameters Simulation Antenna measurement simulation settings: –  angles : 0.45 mgon –  distances : 1.0 mm –  FieldSystem : 5.0 mdeg –  marker : 0.5 mm 2 simulations: –using just one instrument position (here: point 4) –using 4 instrument positions (points 1,3,4,5)

B. S. Schmeing 23-September-2009 Automated measurement of local ties and antenna parameters Simulation results (point 4): parameterTrue errorFormal errorratio ref point (x)0.1489mm0.1836mm0.81 ref point (y)0.0797mm0.1044mm0.76 ref point (z)0.1387mm0.1682mm0.82 axis offset0.1295mm0.1629mm0.80 alfa0.0655mrad0.0833mrad0.79 beta0.0339mrad0.0444mrad0.76 gamma0.1775mrad0.2283mrad0.78 azi orientation0.1440mrad0.1938mrad0.74 a0.1084mm0.1455mm0.75 b0.4638mm0.6035mm0.77 ele orientation0.0485mrad0.0591mrad0.82

B. S. Schmeing 23-September-2009 Automated measurement of local ties and antenna parameters Simulation results (points 1,3,4,5): parameterTrue errorFormal errorratio ref point (x)0.0402mm0.0533mm0.73 ref point (y)0.0409mm0.0525mm0.79 ref point (z)0.0625mm0.0797mm0.78 axis offset0.0649mm0.0764mm0.85 alfa0.0205mrad0.0248mrad0.83 beta0.0189mrad0.0232mrad0.81 gamma0.0910mrad0.1120mrad0.81 azi orientation0.0789mrad0.0936mrad0.84 a0.0585mm0.0683mm0.86 b0.2533mm0.2970mm0.85 ele orientation0.0209mrad0.0272mrad0.77

B. S. Schmeing 23-September-2009 Automated measurement of local ties and antenna parameters Measurement results irregularities in results reason not found yet: –many outliers at measurement? –systematical errors? –software problems?  just preliminary results: comparison of reference-frame independent antenna parameters: –axis offset/eccentricity –correction angles –marker position: a, b, elevation orientation

B. S. Schmeing 23-September-2009 Automated measurement of local ties and antenna parameters Measurement results measurements from 4 points: –point 1 (Pier A) –point 3 (RM1) –point 4 (Pier C) –point 5 (JPL West) separate analysis of every instrument position settings: –angle measurement accuracy:0.45 mgon –distance measurement accuracy:1.00 mm –Field System accuracy:5.00 mdeg

B. S. Schmeing 23-September-2009 Automated measurement of local ties and antenna parameters geometry of the measured marker positions: Measurement results

B. S. Schmeing 23-September-2009 Automated measurement of local ties and antenna parameters Measurement results parameterEstimated values [m] & formal errors [mm] point 1point 3point 4point 5 position (x)5020.91060.125020.91120.255020.91430.245020.92120.20 position (y)453.60170.39453.60290.17453.60250.12453.59460.15 position (z)17.86740.2616.56000.2017.87040.1916.59770.19 axis offset1.9 * 10 -3 0.232.0 * 10 -3 0.181.5 * 10 -3 0.181.2 * 10 -3 0.18 …………… … selected estimated parameters [m] … according formal errors [mm]

B. S. Schmeing 23-September-2009 Automated measurement of local ties and antenna parameters Measurement results parameterdeviations from mean & formal errorsunit point 1point 3Point 4point 5 axis offset0.220.250.360.20-0.140.21-0.430.20mm alfa0.120.070.120.08-0.230.10-0.010.09m° beta-0.410.120.330.07-0.200.060.280.08m° gamma0.180.56-0.180.45-0.070.380.070.36m° a-0.210.20-0.730.160.300.170.640.17mm b-0.551.410.281.150.270.98-0.010.94mm ele orientation0.350.080.490.06-0.210.07-0.630.07m°

B. S. Schmeing 23-September-2009 Automated measurement of local ties and antenna parameters residuals: Measurement results

B. S. Schmeing 23-September-2009 Automated measurement of local ties and antenna parameters normalized residuals: Measurement results

B. S. Schmeing 23-September-2009 Automated measurement of local ties and antenna parameters Conclusions automated measurement procedure works easy operations / does not need expert surveyors projected accuracy meets goals some data anomalies need further investigation

B. S. Schmeing 23-September-2009 Automated measurement of local ties and antenna parameters Future Work investigate data anomalies use several total stations simultaneously –increased data collection rate –increased accuracy replace 360° prism with target sphere –eliminates one possible source of error –no limitations on observing angle apply the approach to SLR

B. S. Schmeing 23-September-2009 Automated measurement of local ties and antenna parameters Bibliography Loesler2008a Loesler, M. and M. Hennes (May 2008): An innovative mathematical solution for a time-efficient IVS reference point determination In MEASURING THE CHANGES – 13 th FIG Symposium on Deformation Measurement and Analysis, 4 th IAG Symposium on Geodesy for Geotechnical and Structural Engineering Geodetic Institute of Karlsruhe (TH), Germany Loesler2008b Loesler, M. (2008): Reference point determination with a new mathematical model at the 20 m VLBI telescope in Wettzell Journal of Applied Geodesy, pages 233-238

B. S. Schmeing 23-September-2009 Automated measurement of local ties and antenna parameters Acknowledgements Honeywell Technical Solutions Inc. –supply of robotic total station TCA 2003 NGS –calibration facility at Corbin Jim Long, Jay Redmond, Mark Evangelista and Irv Diegel (Honeywell) –site and equipment support

B. S. Schmeing 23-September-2009 Automated measurement of local ties and antenna parameters The End Thank you for your attention.

B. S. Schmeing 23-September-2009 Automated measurement of local ties and antenna parameters Benno Schmeing University of Bonn, IGG Benno Schmeing University.

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B. S. Schmeing 23-September-2009 Automated measurement of local ties and antenna parameters Benno Schmeing University of Bonn, IGG Benno Schmeing University.

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