04 October 2006
Since April 2005 ACRES has distributed mosaiced Landsat MSS, TM and ETM+ data covering Australia. This data, originally provided by ACRES, was further processed and mosaiced by the Australian Greenhouse Office (AGO) who used the data in their National Carbon Accounting System for monitoring land clearing and revegetation. The data is publicly available through ACRES and our Landsat distributors, and not through the AGO.
After recent processing of ACRES data by the AGO, we are now able to release the 2005 epoch of processed Landsat 5 data covering the whole continent. As with the previous 13 epochs which range from 1972 to 2004, the 2005 data is available in 1:1M scale tiles or as an individual continental image of the Australian landmass.
This data is available from Geoscience Australia, ACRES and Landsat distributors. More information on this product suite can be found at the AGO Landsat product suite page.
13 September 2006
Geoscience Australia (GA) became the first receiving station outside Japan to successfully acquire and process data from the Japanese Advanced Land Observing Satellite (ALOS). The AVNIR-2 data, captured over Canberra, was acquired on the 27th of April, 2006 by Geoscience Australia's Alice Springs Data Acquisition Facility after extensive preparations by the Australian Centre for Remote Sensing (ACRES).
ALOS will supply the Australian Government and the community with high quality, low cost Earth observation data for purposes including topographic mapping and environmental and disaster monitoring.
The ALOS satellite carries 3 imaging sensors:
Under an arrangement with the Japan Aerospace Exploration Agency (JAXA), GA is one of only four worldwide nodes to down-link, process and distribute ALOS satellite data products. Other worldwide nodes are JAXA in Japan, National Oceanic and Atmospheric Administration (NOAA) in the USA and the European Space Agency (ESA).
Geoscience Australia is licensed to distribute ALOS data for non-commercial purposes within Australia, New Zealand, Papua New Guinea and many Pacific islands. Images will be available to users in late October 2006.
04 September 2006
Geoscience Australia are working with the Great Barrier Reef Marine Park Authority (GBRMPA) to monitor sediment plumes in the Great Barrier Reef World Heritage Area on a daily basis. The plumes are produced by dredging at the Hay Point coal terminal in North Queensland as the Ports Corporation of Queensland (PCQ) increases the depth of the shipping channel. The dredging will move approximately 9 million cubic metres of sediment between May and October 2006. The sediment produced by the dredging poses risks to fringing coral reef communities in the area, and can also affect recreational and commercial fishing. Areas to be dredged and the dredge disposal site are both known to be soft sediment environments that support low-to-medium density seagrass meadows and benthic invertebrate communities.
Using Landsat 5, Landsat 7 and MODIS, ACRES has developed a new, automated process to map, measure and monitor the spatial distribution of the sediment plume and to estimate levels of total suspended sediments (TSS) produced by the dredging. In addition, a detailed water quality monitoring program has been established by PCQ through four remotely-operated water quality loggers and a vessel-based monitoring program measuring TSS, sediment deposition and light. Correlations between the satellite image data and these in-situ field measurements allow the TSS to be estimated spatially.
Figure 1 shows a sequence of MODIS images in which the sediment plume can be clearly seen near the dredging area and the dump site and estimates of elevated TSS derived from the images. Figure 2 shows the same analysis at larger spatial scale from Landsat 5 imagery acquired at 4th of August. Thumb-nail images are emailed to the GBRMPA and PCQ daily.
It is already clear from the pilot project that daily monitoring with remote sensing can bring a wealth of new information and a unique new perspective to activities such as Hay Point. The production and spread of the sediment plume is better understood, including movement of the plume on the tides and the effects of strong winds, which were not factored into the pre-project modelling. The sediment plumes appear to be larger than predicted by 2-dimensional hydrodynamic modelling prior to the dredging.
The project is a good example of how ACRES remote sensing capabilities can be used to best effect for Australia. The image processing is also informed by science from the CRC for Spatial Information, in which Geoscience Australia is a partner. A workshop with key stakeholders is planned for October to review the project.