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AUSTRALIAN LOCAL TIE SURVEYS. PLAN OF PRESENTATION. Stromlo Network Design Monument Design Calibration Targets Instrumentation and Methodology Survey-to-Survey Consistency GPS Stability Survey Report Format MINICO and Calibration Stability See also the BIG ORANGE POSTER. - PowerPoint PPT Presentation
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AUSTRALIAN LOCAL TIE SURVEYS
27 May 2004
PLAN OF PRESENTATION
• Stromlo Network Design• Monument Design• Calibration Targets• Instrumentation and Methodology• Survey-to-Survey Consistency• GPS Stability• Survey Report Format• MINICO and Calibration Stability
See also the BIG ORANGE POSTER
27 May 2004
STROMLO LOCAL TIES
27 May 2004
SLR, DIMM, NEW MONUMENT & NORTH PIER
27 May 2004
FIDUCIAL MONUMENT & MASSIVE BASE
27 May 2004
FIDUCIAL & GLONASS CONE
27 May 2004
SURVEY PLATE ATOP FIDUCIAL
27 May 2004
NEW GPS MONUMENT & MASSIVE BASS
27 May 2004
TOP OF NEW MONUMENT
27 May 2004
GA MONUMENT DESIGN
GA Monument Diagram.PDF
27 May 2004
GA MONUMENT – TOP DETAIL
GA Monument Top Detail.PDF
27 May 2004
NORTH PIER WITH GPS & CAL TARGET
27 May 2004
SITES SURVEYED BY GA
EVERY TWO YEARS (where possible)
• Yarragadee (SLR/GPS/DORIS/GLONASS/Absolute-Gravity);
• Mount Stromlo (SLR/GPS/ DORIS/GLONASS);• Orroral (SLR now obsolete, was 27km from Tidbinbilla);• Hobart (VLBI/GPS/Absolute-Gravity);• Tidbinbilla. (VLBI/GPS);• Darwin (GPS/GLONASS);• Davis, Antarctica (GPS/GLONASS/Tide-Gauge).
ALSO: GPS to tide gauge connections throughout the South Pacific including stations at Samoa, Cook Islands, Fiji, Tuvalu, Tonga, Manus Island, PNG, Kiribati, Vanuatu, Nauru and Micronesia
27 May 2004
PLANNING AND STRATEGIES
• Be timed for optimum survey observations, i.e. timing the survey when weather conditions are neutral to minimise atmospheric effects;
• Allow for several days down time, particularly on Satellite Laser Ranging (SLR) or Very Long Baseline Interferometry (VLBI) systems;
• Be planned to avoid critical tracking campaigns;• Plan the placement of marks on the telescope/antenna to optimise
observations for the determination of axes (in the case of indirect reference point determination), i.e. optimise the target trajectories and the radius of the trajectories; and
• Place instrument stand-points to satisfy survey accuracy demands (as determined by network simulation if necessary).
• Forced centring is used to eliminate the introduction of setup errors wherever possible. A Leica Zenith Nadir precise optical plummet is used for all tripod setups, to ensure near zero plumbing errors. Additionally, wherever possible concrete pillars are used for instrument standpoints. This ensures setup stability during the often long observation periods when observations are taken to the antenna or telescope systems.
27 May 2004
EQUIPMENT & CALIBRATION
• Leica TCA 2003 Total Station• Angular Precision (lab. calibrated) 0.”6• Distance Precision (lab.calibrated) 0.5mm + 0.4ppm• Annually compared with standard baseline traceable to Aust’n
National Standards
• Leica precision prisms with tribrach and carriers incl. plate bubble• Annually calibrated over standard baseline, plus GPS• Zenith nadir plummet for centring tripods• Fixed height prism pole for Total Station levelling• Invar staff for instrument heighting, calibrated biennially.
27 May 2004
MONUMENTATION AND NETWORK DESIGN
• Ideally instrument standpoints are stable bedrock anchored pillars;
• Pillars should have reference marks to monitor local deformation; and
• Survey marks should have an unambiguous reference point.
ARP DORIS
GPS
27 May 2004
INVARIANT POINT DETERMINATION
27 May 2004
RMS of IVP RESIDIALS:PRIMARY (Az or X) AXIS
Observatory (date) System Type RMS in-plane residual (mm)
RMS out-of-plane residual (mm)
Mount Stromlo (1999) AZ/EL 1.1 (AZ) 0.7 (AZ)
Mount Stromlo (2001) AZ/EL 0.5 (AZ) 0.7 (AZ)
Yarragadee (1998) AZ/EL 0.6 (AZ) 0.4 (AZ)
Yarragadee (2001) AZ/EL 0.5 (AZ) 0.4 (AZ)
Tidbinbilla (1995) AZ/EL 0.8 (AZ) 8.9 (AZ)
Hobart (1995) X/Y 0.2 (X) 4.0 (X)
Hobart (2002) X/Y 0.3 (X) 7.9 (X)
27 May 2004
RMS OF IVP RESIDUALSSECONDARY (EL or Y) AXIS
Observatory (date) System Type RMS in-plane residual (mm)
RMS out-of-plane residual (mm)
Mount Stromlo (1999) AZ/EL 1.1 (AZ) 0.7 (AZ)
Mount Stromlo (2001) AZ/EL 0.5 (AZ) 0.7 (AZ)
Yarragadee (1998) AZ/EL 0.6 (AZ) 0.4 (AZ)
Yarragadee (2001) AZ/EL 0.5 (AZ) 0.4 (AZ)
Tidbinbilla (1995) AZ/EL 0.8 (AZ) 8.9 (AZ)
Hobart (1995) X/Y 0.2 (X) 4.0 (X)
Hobart (2002) X/Y 0.3 (X) 7.9 (X)
27 May 2004
RMS MINIMUM DISTANCE BETWEEN AXES
Observatory (date) NorthRMS IVP to axis (mm)
East RMS IVP to axis (mm)
Up RMS IVP to axis (mm)
Mount Stromlo (1999) 0.1 0.3 2.1
Mount Stromlo (2001) 0.9 1.0 0.9
Yaragadee (1998) 0.4 0.3 0.4
Yaragadee (2001) 0.4 0.2 0.9
Tidbinbilla (1995) 2.3 4.1 0.9
Hobart (1995) 0.7 1.6 0.8
Hobart (2002) 0.4 1.6 0.4
27 May 2004
REPEATABILITY, SURVEY-TO-SURVEY
Observatory IVP East IVP to reference mark (mm)
North IVP to reference mark (mm)
Up IVP to reference mark mm)
Mt Stromlo (1999-2001) SLR -0.3 -0.4 0.4
Yarragadee (1998-2001) (from IGS GPS YAR1)
SLR 0.0
(-0.8)
1.9
(1.5)
-1.3
(-4.2)
Hobart (1995-2002) VLBI -1.2 -0.3 -0.4
27 May 2004
3 YEARS OF GPS DIFFERENCES, NORTH PIER TO FIDUCIAL MONUMENT
Y grid spacing is 1 mm
27 May 2004
THE AUSTRALIAN SURVEY REPORT FORMAT• Survey database• To ensure the long term archiving and storage of the survey results all
report information is stored in the National Geodetic DataBase (NGDB), which is a Windows relational database of geodetic positions and associated information. All survey are stored with the following information:
• Earth-centred Cartesian coordinates• Latitude, Longitude & ellipsoidal height automatically computed• Reference frame & epoch• Referenced to source of positions (SINEX file) • Exact mark descriptions • Images & diagrams• The NGDB allows the automatic generation of technical reports that are fully
user definable. Survey marks at each observatory are linked to facilitate easy report extraction.
• Report distribution• All Geoscience Australia survey reports are deposited on the Geoscience
Australia web site located at www.ga.gov.au. SINEX format results files are deposited on the Geoscience Australia ftp server, located at ftp.ga.gov.au/sgac/sinex/ties.
27 May 2004
STROMLO ~ weekly 4-GROUND
TARGET ‘MINICO’ STABILITY, Jan-Jun 2005
SYSTEM DELAY FROM MINICO
RMS 4.3 ps (0.6 mm)
-51305
-51300
-51295
-51290
-51285
-51280
0 30 60 90 120 150 180 210
Day of 2005
Syste
m D
ela
y (
ps)
MINICO 2005Means: East -0.1mm, North 0.0mm
-0.6
-0.4
-0.2
0.0
0.2
0.4
0.6
-1.5 -1.0 -0.5 0.0 0.5 1.0 1.5
EAST (mm)
NO
RT
H (
mm
)
RANGE ERROR TO CAL TARGETSMean -0.4 mm, RMS 0.8 mm
-4
-2
0
2
4
120 140 160 180 200 220
Day of 2005
RA
NG
E E
RR
OR
(m
m)
27 May 2004
CALIBRATION VALUES, May – July 2005From NICT Daily Reports
CAL VALUES, SELECTED STATIONS
-10
10
30
50
70
90
110
130
110 130 150 170 190 210Day of 2005
SD
(m
m)
Ad
j.O
rig
ins
STRM
YARR
RYAD
HERS
GRAZ
ZIMW
MONP
MLRO
WETZ
Symbol Station Points RMS (mm)
STRM Stromlo, Australia 268 0.7 YARR Yarragadee, Australia 353 1.9 RYAD Riyadh, Saudi Arabia (SALRO) 191 3.5 HERS Herstmonceus, England 116 3.0 GRAZ Graz, Austria 129 2.4 ZIMW Zimmerwald, Switzerland 204 6.7 MONP Monument Peak, CA, USA 203 3.3 MLRO Matera, Italy 212 6.4 WETZ Wettzell, Germany 209 7.1