In:
Journal of Geophysical Research: Oceans, American Geophysical Union (AGU), Vol. 99, No. C12 ( 1994-12-15), p. 24505-24516
Abstract:
As a check on the total system accuracy of the TOPEX/POSEIDON satellite, a southern hemisphere verification study was undertaken in Bass Strait (41°S) immediately adjacent to the Southern Ocean. An acoustic tide gauge and two pressure gauges were installed on the southern side of Bass Strait near where descending pass 88 crosses the Tasmanian coast. The tide gauge benchmark height was estimated relative to the laser tracking station at Orroral Valley and the very long baseline interferometry station near Hobart using Global Positioning System surveying techniques. In the TOPEX/POSEIDON geophysical data records, flags on the altimeter data began to be set 15–20 km from land and little useful altimeter data were available within about 13 km of the coast. The acoustic tide gauge heights were corrected for changes in tidal phase and amplitude between the coast and the offshore subsatellite point using results from a numerical model. The altimeter correction for atmospheric water vapor calculated from the TOPEX microwave radiometer data and the insitu precipitable water data agreed to 2 cm RMS, with no significant bias. The RMS variability between the insitu sea level estimates and the TOPEX/POSEIDON estimates was less than 3.5 cm. As part of this variability is caused by inaccuracies in the estimates of the sea level variations between the coast and the subsatellite point, the result indicates that the precision of the TOPEX/POSEIDON sea level height measurement system, including the time dependent orbit errors, the ionospheric corrections and the wet and dry tropospheric path delays, is less than 3.5 cm over Bass Strait, considerably below the original system specifications of 13 cm. Our estimate of the altimeter bias (including geographically correlated orbit error) is −25±10 cm, consistent with the results at the NASA (Harvest Platform) and Centre National d'Etudes Spatiales (Lampedusa) calibration sites. However, accurate estimation of this total altimeter bias is confounded by the lack of altimeter data close to land and in particular, limitations in the available local geoid data. The altimeter bias shows no significant drift at this site.
Type of Medium:
Online Resource
ISSN:
0148-0227
Language:
English
Publisher:
American Geophysical Union (AGU)
Publication Date:
1994
detail.hit.zdb_id:
2033040-6
detail.hit.zdb_id:
3094104-0
detail.hit.zdb_id:
2130824-X
detail.hit.zdb_id:
2016813-5
detail.hit.zdb_id:
2016810-X
detail.hit.zdb_id:
2403298-0
detail.hit.zdb_id:
2016800-7
detail.hit.zdb_id:
161666-3
detail.hit.zdb_id:
161667-5
detail.hit.zdb_id:
2969341-X
detail.hit.zdb_id:
161665-1
detail.hit.zdb_id:
3094268-8
detail.hit.zdb_id:
710256-2
detail.hit.zdb_id:
2016804-4
detail.hit.zdb_id:
3094181-7
detail.hit.zdb_id:
3094219-6
detail.hit.zdb_id:
3094167-2
detail.hit.zdb_id:
2220777-6
detail.hit.zdb_id:
3094197-0
SSG:
16,13
Permalink
