GA factsheet on Interferometric Synthetic Aperture Radar (InSAR)

This data was compiled by ACRES Remote Sensing Science and Strategy Group. It is intended that this data be applied to the evaluation of satellite imagery geolocation and coarse resolution Digital Elevation Model evaluation. dGPS_track.txt contains yxz differential Global Positioning System tracking data. This data was collected as part of ACRES Landsat Pass Control Project, Phases 1 to 3 from 2001 to 2003. The data was filtered to remove periodic "spiking" of anomalous height values in the data Points which with a height difference of more than 5 metres between adjacent points where considered "spikes" and removed. The data present in dGPS_track.txt is considered "clean" although some "spikes" and data anomalies may still be present.

Poster abstract submission for the AGU2013 Meeting

The Allen Osborne Associates Dorne Margolin type T chokering antenna has been used extensively in the International Global Navigation Satellite System Service (IGS) tracking network for over 20 years. This antenna type, using the IGS naming convention, ''AOAD/M\_T'', was predominately installed at the original IGS sites in the late 80's, early 90's, to track signals from the Global Positioning System satellite constellation, and is still in use at operational sites today. The antenna is also used as the standard reference for relative to absolute antenna calibration conversions, which hold an important role in the history of IGS antenna calibration values. It is suspected that there may be a previously unknown subgroup of antennas that maintain a different set of phase center values which, if true, will change antenna calibration values in the IGS ANTEX file and possibly bias the International Terrestrial Reference Frame as is it currently defined.

AUSGeoid98 data files contain a 2 minute grid of AUSGeoid98 data covering the Australian region, which you can use to interpolate geoid-ellipsoid separations for the positions required.You can use your own interpolation software, or you can use Geoscience Australia's Windows Interpolation software (Winter). The data files are text files in a standard format that cover the same area as standard topographic map areas. Files covering both 1:250,000 (approximately 100 x 150 km) and 1:1,000,000 (approximately 400 x 600 km) map areas are available. There is a 4 minute overlap on all sides of each area. Data format: AUSGeoid98 data files have a header record at the start of each file, to distinguish them from the superseded AUSGeoid93 data files. AUSGeoid98 data files show the geoid-ellipsoid separation to 3 decimal places, while the superseded AUSGeoid93 data files showed only 2 decimal places. AUSGeoid98 deflections of the vertical were computed from the geoid-ellipsoid separation surface, while the AUSGeoid93 deflections of the vertical were computed from OSU91A.

AUSGeoid98 data files contain a 2 minute grid of AUSGeoid98 data covering the Australian region, which you can use to interpolate geoid-ellipsoid separations for the positions required.You can use your own interpolation software, or you can use Geoscience Australia's Windows Interpolation software (Winter). The data files are text files in a standard format that cover the same area as standard topographic map areas. Files covering both 1:250,000 (approximately 100 x 150 km) and 1:1,000,000 (approximately 400 x 600 km) map areas are available. There is a 4 minute overlap on all sides of each area. Data format: AUSGeoid98 data files have a header record at the start of each file, to distinguish them from the superseded AUSGeoid93 data files. AUSGeoid98 data files show the geoid-ellipsoid separation to 3 decimal places, while the superseded AUSGeoid93 data files showed only 2 decimal places. AUSGeoid98 deflections of the vertical were computed from the geoid-ellipsoid separation surface, while the AUSGeoid93 deflections of the vertical were computed from OSU91A.

The National Geodetic Data Base (NGDB) is an archive of positions and related information for geodetic survey marks in Australia and its offshore territories. The information includes the horizontal position (latitude and longitude and/or UTM grid coordinates) and height, accuracy and source of the position and mark name(s) and description. The database includes historical information (e.g. pre-1966 "Clarke" and astronomic coordinates as well as superseded AGD66 and AGD84) and current GDA94 information. Additional or more recent information (particularly for GDA94) may be obtained from the relevant State and Territory authorities. (for more detail on GDA94 see <a href="http://www.icsm.gov.au/gda/">www.icsm.gov.au/gda/</a>). The NGDB includes heights determined by a variety of means and hence with a variety of accuracies (e.g. optical levelling, trigonometric and barometric heighting). A separate database contains the Australian Height Datum (AHD) heights for benchmarks in the Basic optical levelling network in Australia (the Australian National Levelling Network, ANLN).

Data collected from the Australian Regional Global Navigation Satellite System (GNSS) network, AuScope network and other GNSS observatories located around the world over the last 15 years.

The Australian Regional GPS Network (ARGN) consists of 15 permanent geodetic quality GPS receivers, on geologically stable marks, in Australia and its Territories, with the stations within Australia known as the Australian Fiducial Network (AFN). The AFN provides the fundamental framework for spatial data in Australia, through the GDA94 (see <a href="http://www.icsm.gov.au/gda/">www.icsm.gov.au/gda/</a> for more information on GDA94). The Antarctic sites also provide the fundamental framework for the Australian Antarctic Geodetic Network. The data from these sites is used by Geoscience Australia's Space Geodesy Analysis Centre to compute precise positions and to monitor the Earth's Pole position, the Earth's gravity field, and tectonic motion. The data is automatically contributed to the International GPS Service (IGS) and is available on Geoscience Australia's website for other use (<a href="http://www.ga.gov.au/bin/data_server/">www.ga.gov.au/bin/data_server/</a>) The GPS data is recorded at the ARGN sites at 30 second epochs and is available in Receiver Independent Exchange (Rinex) format. This data is available from Geoscience Australia's WWW within a few hours of the end of the GMT day of observation. Performance statistics and other related information is available.

This report outlines the level survey completed during the visit to Nauru, between 1 - 8 February 2009. This is the third EDM Height Traversing levelling survey of the deep bench mark array in Nauru. This is a repeat survey. On nine previous occasions, from 1993 to 2003, the Nauru level survey was performed by the National Tidal Centre (NTC) using the Precise Differential Levelling technique. This project is sponsored by the Australian Agency for International Development (AusAID), managed by the Bureau of Meteorology (BOM) and supported by the National Geospatial Reference Systems Project (NGRS), Geospatial Earth Monitoring Division, GEOSCIENCE AUSTRALIA.