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