GPS at Australian Tide Gauge Bench Marks (TGBM)

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GPS at Australian Tide Gauge Bench Marks (TGBM)
John Manning Gary Johnston Paul Digney
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Background
A network of Tide Gauges deployed at
Australian Antarctic 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 in 1993/1994. Establishment in 1995 of
the Southern Ocean Sea Level Centre to foster
international cooperation into Southern Ocean
sea level research
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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

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A comparison of GPS Heighting and Orthometric
levelling between the ARGN mark and the TGBM.
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MAWSON TGBM
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MAWSON Permanent GPS
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http//www.auslig.gov.au/geodesy/antarc/mawsontg.h
tm
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Level Connections at Mawson
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Permanent GPS at Davis Station
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(No Transcript)
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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 - 4?k
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Level Connections at Davis Station
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NMVS4 Original TGBM at Davis
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http//www.auslig.gov.au/geodesy/antarc/davistg.ht
m
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Attempting to transfer MSL from the Tide Gauge
at Davis to the TGBM
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Permanent GPS at Casey Station
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http//www.auslig.gov.au/geodesy/antarc/caseytg.ht
m
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TGBM Network Casey Station
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Australian TGBM (AUS334) Larsemann Hills
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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