Antarctic Geodetic Symposium 2001, St Petersburg

GPS at Australian Tide Gauge Bench Marks (TGBM)

John ManningGary

JohnstonPaul Digney

Antarctic Geodetic Symposium 2001, St Petersburg

A network of Tide Gauges deployed at AustralianAntarctic Stations in 1992/1993. Including the establishment of TGBMs in close proximity

Continuous GPS Stations - Part of the AUSTRALIAN Regional GPS Network (ARGN),established at each permanent Australian Station in1993/1994.

Establishment in 1995 of the Southern Ocean Sea Level Centre to foster international cooperation into Southern Ocean sea level research

Background

Antarctic Geodetic Symposium 2001, St Petersburg

Activities 2000/2001 Summer

EDM-Heighting technique used to connect GPS to TGBM at both Mawson and Davis Stations

3 days GPS data observed at Davis, Mawson and Larsemann Hills TGBMs

Antarctic Geodetic Symposium 2001, St Petersburg

A comparison of GPS Heighting and Orthometric levelling between the ARGN mark and the TGBM.

Year

Baseline

2000/2001

HeightDifference(m)

Mawson Station

AUS064-AUS258( h GPS) 31.042

AUS064-AUS258( H derived) 31.052

AUS064-AUS258( H levelled) 31.035

Difference 0.017

Davis Station

AUS099-AUS186( h GPS) 23.151

AUS099-AUS186( H derived) 23.151

AUS099-AUS186( H levelled) 23.148

Difference 0.003

AUS099-NMVS4( h GPS) 25.682

AUS099-NMVS4( H derived) 25.692

AUS099-NMVS4( H levelled) 25.689

Difference 0.003

Antarctic Geodetic Symposium 2001, St Petersburg

MAWSON TGBM

Antarctic Geodetic Symposium 2001, St Petersburg

MAWSON Permanent GPS

Antarctic Geodetic Symposium 2001, St Petersburg

http://www.auslig.gov.au/geodesy/antarc/mawsontg.htm

Antarctic Geodetic Symposium 2001, St Petersburg

AUS064 & RMs

ISTS051 – RM4

AUS258

AUS300

AUS301

Two Way LevellingOne Way Levelling

Level Connections at Mawson

Antarctic Geodetic Symposium 2001, St Petersburg

Permanent GPS at Davis Station

Antarctic Geodetic Symposium 2001, St Petersburg

Antarctic Geodetic Symposium 2001, St Petersburg

EDM Height Traversing “Leap Frogging” Technique

Variant of the common technique of spirit levelling, where the differences in height between change points are determined using observations of zenith angles and slope distances.

Use of Leica TLC2000 Total Station and single fixed height survey rod and reflector

A total of 12 measurements taken to both backsight and foresight

Sight lengths kept below 50 metres

Misclose to comply with allowable maximum for SP1 Class LA - 4k

Antarctic Geodetic Symposium 2001, St Petersburg

AUS099

D3

D5

AUS303

AUS186

MET BM

NMVS 4

RM 1

SS Pin – Change Point

Bench Mark

Level Connections at Davis Station

Antarctic Geodetic Symposium 2001, St Petersburg

NMVS4Original TGBM at Davis

Antarctic Geodetic Symposium 2001, St Petersburg

http://www.auslig.gov.au/geodesy/antarc/davistg.htm

Antarctic Geodetic Symposium 2001, St Petersburg

Attempting to transfer MSL from the Tide Gauge at Davis to the TGBM

Antarctic Geodetic Symposium 2001, St Petersburg

Permanent GPS at Casey Station

Antarctic Geodetic Symposium 2001, St Petersburg

http://www.auslig.gov.au/geodesy/antarc/caseytg.htm

Antarctic Geodetic Symposium 2001, St Petersburg

TGBM Network Casey Station

Antarctic Geodetic Symposium 2001, St Petersburg

Australian TGBM (AUS334) Larsemann Hills

Antarctic Geodetic Symposium 2001, St Petersburg

Future Program

Continue monitoring the vertical connection between GPS and TGBM, by:

• levelling, by adopting at least 2nd order standards• Repeat GPS observations on TGBMs at each Station

Continue the development of fixed levelling routes to maintain consistency