31 March 2003
ACRES Manager Ian Shepherd recently presented ACRES Computer Operations staff with their new certificates of competence in Quality Assurance.
This presentation is the final step in an exhaustive re-certification program designed to ensure that all QA Operators have the desired competency levels and are up to date with the latest issues in quality assurance of remote sensing data products.
Bill Levett of ACRES Applications established procedures and identified the testing criteria. Bill also conducted the competency testing over a two month period. Regular retesting will ensure that remote sensing products are of consistently high quality.
10 February 2003
The positional accuracy of ACRES orthocorrected products is being progressively improved through the use of geocoded image chips, more correctly described as Supplemental Control Points (SCP's). SCPs are now available for the generation of Landsat ortho products in Eastern Australia and Western Australia. It is planned to have complete SCP coverage of Australia later this year.
The Department of Environment and Heritage (DEH) South Australia, has conducted an independent accuracy assessment on ACRES Landsat 7 orthocorrected imagery. Approximately 114 check points, with an accuracy of 7 metres (1σ), have been used to assess the geometric accuracy of ACRES orthocorrected products.
The RMS errors of these check points was ±13 metres. "The small RMS error shows that this orthocorrected imagery is extremely accurate. It is much superior to the old ACRES orthocorrected product which used GCP's sourced from paper maps (normally at 1:100 000 scale)", said David Gibson from DEH.
10 February 2003
Geoscience Australia acquired a number of satellite images that clearly show the effects of the fires that swept through the south-western suburbs of Canberra on 18 January.
The two Landsat ETM+ images below, were acquired on 7 November 2002 and 26 January 2003 at approximately 11:00 am (AEST). They show the contrast between large areas of healthy vegetation in November and the burn scars caused by the fires in January.
These images show land cover across the Canberra region in pseudo-natural colour (Landsat ETM+ bands 2, 4, 7 are displayed as Blue, Green, Red). The bushfire smoke can be identified as pale blue in colour. Healthy vegetation shows as green and burnt areas show as dark red-brown.
The geographical extent of the images covers Lake George, at the top of the image, to the Victorian border in the lower left corner.
The two Landsat ETM+ images below, were acquired on 10 January 2003 and 17 January 2003. They show the development of 'minor' fires in the 10 January image to extensive fire-fronts in the 17 January image. Encouraged by high temperatures and winds, these fires were to combine and sweep through Canberra on 18 January.
Satellite imagery is a very useful tool in managing fires and their effects. In the lead-up to the fire season, images are used to assess fuel loads and plan access points and fire breaks. Images are also very useful in mapping the extent of fire scars and assessing damage.
10 February 2003
Shanti Reddy, Director of Operations at ACRES, is currently visiting the USA investigating recent developments for MODIS data and imagery. He will be spending a week at the University of Arizona looking at work being done there on Vegetation Indices, then visiting Boston University to study BRDF (Bi-differential Reflectance Distribution Function) techniques using MODIS data.
The information gained will be reported to each of the various research teams working with MODIS data in Australia, and will be used in the development of future MODIS products by ACRES and other users of MODIS.
MODIS (Moderate Resolution Imaging Spectroradiometer) is the key instrument aboard the satellites Terra (EOS AM-1) and Aqua (EOS PM-1) and covers almost the entire surface of the Earth every day. MODIS imagery such as this plays a vital role in the development of validated, global, interactive Earth system models able to predict global change.
30 January 2003
There has been a lot of activity at the Alice Springs site during January, in preparation for ACRES role in supporting the Landsat 7 mission for USGS (United States Geological Survey).
The 9-metre antenna's ability to receive S-band signals has been reactivated, and a rigorous testing process has been undertaken.
Leading the process has been Mr Grant Mah, Senior Applications Engineer with USGS at Sioux Falls. After the testing process, ACRES at Alice Springs will be receiving S-band housekeeping data from every overpass of Landsat 7( generally four contacts per 24 hour period) and forwarding this data to the Mission Operations Centre (MOC) for Landsat 7, at Goddard Space Flight Centre. This process will provide MOC with maximum information about the health and operational status of the spacecraft.
Further testing will then be required on the antenna's capacity to acquire dual downlink of X-band data from the onboard recorders. As a result, ACRES will be acquiring raw X-band data for the USGS data archive, as well as data of Australia for our own archive. The data acquired for USGS will not be available in the ACRES digital catalogue.
30 January 2003
The agreement between SPOT Image and Geoscience Australia for reception and distribution of SPOT imagery in Australia expired on 31 December 2002.
Raytheon Australia has announced an agreement with SPOT Image for the exclusive distribution and acquisition of Spot 2, 4 and 5 data over the Australian region.
Consequently, as of 1 January 2003 Geoscience Australia, through ACRES, ceased SPOT data acquisitions and can no longer sell or distribute SPOT data.
SPOT archive data acquired up to 31 December 2002 is available for viewing in the ACRES Digital Catalogue. This service will be available until 31 December 2003. Available archive data can be purchased through Raytheon Australia.
20 September 2002
You can now view and download Australia from space free of charge thanks to a picture mosaic of 369 Landsat satellite images available on our website.
Viewing the mosaic online allows you to zoom and pan around your own area of interest. In addition, you can also download the same image to use as a picture or import it into a GIS system as a georeferenced backdrop.
The spatial resolution of the mosaic is 300 metres, meaning it is more suitable for broadscale studies. The image is also available in smaller jpeg files (less detail) that are quicker to download. Note that ACRES standard Landsat products are provided with much greater spatial and spectral detail.