29 March 2007
The Landsat 7 ETM+ instrument has been experiencing expected "wear and tear" of some moving parts since the satellite's launch in 1999. Various software adjustments have been made over the last few years to account for these gradual changes. The situation has now reached the stage that the USGS will transition to the imager's alternate 'Bumper' mode. Note that this will not affect the continued excellent radiometric quality of data from the ETM+ sensor.
USGS are planning to implement that change on April 1, 2007.
ACRES has commissioned an upgrade to our processing system to enable processing of the bumper mode data. The upgrade is expected to be implemented by the end of May. This will result in a short period of time where we are unable to process the bumper mode data we receive from Landsat 7 into image products. This will only affect data collected between operational implementation of L7 bumper mode by USGS and rollout of the ACRES processing system enhancement (April 1 to end-May 2007).
The transition to bumper mode does not impact on our ability to receive data from Landsat 7 for archive purposes.
29 March 2007
As predicted last year, ALOS PRISM and AVNIR-2 products will soon possess improved geo-location accuracy. Until now, the geo-location accuracies of PRISM and AVNIR-2 were around 30 metres and a few hundred metres respectively. Recent refinements in modelling the spacecraft and position have resulted in significant improvements in these accuracies. The exact specification will be released soon by the satellite operator (JAXA) and implemented in ACRES processing system by the end of April. We will keep you informed of developments.
29 March 2007
Since the release of ACRES ALOS products in late December 2006, the archive of ALOS data covering Australia and other Oceania areas has been steadily growing. Up until the end of March ACRES had over 1700 swaths of ALOS data over the Oceania region available for viewing and ordering from our online Digital catalogue. This now gives customers a much wider choice of images to help satisfy their needs.
ALOS data in the ACRES archive is down-linked by both Japanese and ACRES ground stations, thereby providing a comprehensive source of ALOS Oceania imagery.
29 March 2007
Customers ordering Landsat 5 systematic corrected imagery (ie Path Image and Map Image) should be aware that deterioration in bumper mode operation has resulted in some increased degradation in the geo-location accuracy of these products. This deterioration appears to become worse for acquisitions after August/ September 2006.
At this stage we are keeping our geo-location accuracy specifications unchanged but should the problem worsen, we may be forced to increase the acceptable geo-location error of our LS5 path image and map image products.
29 March 2007
USGS have processed a complete coverage of Landsat data covering Antarctica as part of their contribution to the International Polar Year. Although the mosaics aren't complete yet, the individual Landsat scenes are available for download.
15 February 2007
We are seeking input from government organisations within the Oceania region who are interested in participating in a group purchase of ALOS products for non-commercial purposes covering common areas. The main attraction for participants will be the significant reduction in cost for ALOS data.
Procedures are currently being developed to permit online ordering for a group of agencies requiring common data. This is likely to involve a lead agency responsible for order placement - in some cases this may be Geoscience Australia. Permission will need to be granted by the licensed party to have data ordered by the lead agency on their behalf.
Licensing requirements from our ALOS data provider, JAXA, mean that it is not possible to offer multi-user/shared or Whole of Government licences for our standard products. Therefore each individual requires a separate end-user licence for each product. We can, however, pass on cost savings if two or more agencies require the same data simultaneously. The more collaborators, the cheaper the data becomes.
Feedback on broad user requirements is essential in developing and implementing our procedures. To provide feedback or suggestions or to register your interest in participating in ALOS Data Group Purchases, please contact us on (02) 6249 9779 or earth.observation@ga.gov.au
15 February 2007
A new visualisation tool on the ACRES web page will allow visitors to get a real-time, bird's eye view of the planet from our suite of Earth observing satellites.
The front page of the tool displays a list of all satellites from which ACRES acquires data. After selecting a satellite, a 'third party' web tool called Earth Viewer displays a representation of Earth below the current position of that particular satellite.
15 February 2007
ACRES is now offering a new product package of Landsat 7 SLC-Off scenes for experienced customers who wish to use the individual scenes to create their own composite product.
Since May 2003, all Landsat 7 scenes have small regular gaps in the data due to the Scan Line Corrector (SLC) on the satellite being turned off after a malfunction. These products are known as SLC-Off products, and lead to the subsequent release of SLC Composite products. The SLC composite product combines several scenes of similar date in an attempt to fill the data gaps.
Until 1 January 2007, the ACRES Landsat 7 SLC composite product was a single scene made by ACRES from the combination of 2 to 6 ortho-corrected scenes selected by the customer. Even though such a product was very labour intensive for ACRES to produce, it was offered at a substantial discount to normal Landsat scenes to help encourage use of Landsat 7 SLC-Off scenes.
In addition to this current product, ACRES is now also offering a "Customer Composite Package" where customers may order all the individual scenes that would normally comprise a composite product and receive them separately. The compositing is then done by the customer in their own preferred manner.
This package of scenes is available at the same price as the single composite product. Please see the Landsat 7 ETM+ Price List for more information and links to more detailed descriptions.
15 February 2007
Until 1 January, the ACRES SLC-Off product had some minor interpolation and extrapolation applied to the image pixels along the edge of the data gaps within a scene. Graphical description.
This interpolation/extrapolation was not applied to SLC-Off products that were used for an ACRES composite product.
As of 1 January 2007, this interpolation and extrapolation is no longer applied to any SLC-Off products, resulting in a product slightly less pleasing to the eye, but more spectrally accurate.
15 January 2007
As bushfires burn across Victoria, Geoscience Australia is acquiring satellite imagery to aid Emergency Managers. Geoscience Australia's Sentinel bushfire monitoring system uses data acquired by MODIS to monitor fire events. The images below show the growth of the fire front towards the east between the 9th of December and 10th of January in the north-east of the State.
MODIS on Terra - 11:18am AESDT 10/12/2006
MODIS on Terra - 11:18am AESDT 10/01/2007
ACRES also acquires Landsat data which has been used by fire authorities to map the extent of burnt areas and aid the government response to the bushfire crisis. The two images below dramatically illustrate the impact before (at left) and during (at right) the bushfires which have ravaged eastern Victoria since early December.
Thematic Mapper on Landsat 5 - 16/11/2006 and 23/11/2006
Thematic Mapper on Landsat 5 - 25/12/2006 and 3/01/2007
In response to the bushfire crisis in Victoria, Geoscience Australia (GA) mapping experts have been sent to assist fire-fighters, by predicting where fires are heading, and to provide likely damage assessments. For more information on Geoscience Australia's mapping response follow this link.
4 January 2007
In late December 2006, ACRES Geoscience Australia commenced online distribution of images from the Japanese Advanced Land Observing Satellite (ALOS).
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.
Under an arrangement with the Japan Aerospace Exploration Agency (JAXA), ACRES Geoscience Australia is one of only four worldwide Data Nodes able to down-link, process and distribute images from the ALOS satellite.
Other Nodes are JAXA in Japan, the National Oceanic and Atmospheric Administration (NOAA) in the USA and the European Space Agency (ESA).
ACRES Geoscience Australia is licensed to distribute ALOS data for non-commercial purposes within Australia, New Zealand, Papua New Guinea and Pacific Island Nations. Other commercial entities will distribute data for commercial purposes.
To find out more about ALOS, including how to order ALOS imagery for non-commercial purposes from ACRES Geoscience Australia, please go to our 'ALOS overview - How to order' page.