Following up to TerraSAR-X captures detailed radar image of Grafton Floods. Apogee and Infoterra have tasked the TerraSAR-X satellite to acquire a ScanSAR image over the Northern New South Wales coast on the 28th May, to complement the StripMap image acquired on the 24th May. The additional ScanSAR image enhances the information that was available from the single StripMap image. Allowing Apogee to extract more information about the extent of the flooding and how the floods have receded between the two acquisition dates.
This composite below combines the TerraSAR-X StripMap acquired on the 24th of May with the TerraSAR-X ScanSAR image acquired on the 28th of May. The flooding can clearly be seen, where the Red areas show flood level on the 24th of May and the Dark areas show where there is still standing water. Below the composite the seperate StripMap and ScanSAR images show that in this area the water has receded almost completely.
Below the composite TerraSAR-X image shows the flooding extent in Grafton Northern NSW. Red areas in the composite show where there was flooding on the 24th of May, while Dark areas show where there is still flooding. The composite clearly shows that while flooding in the Grafton area has receded, there is still a significant amount of flooding around Grafton. This information is valuable for both managing recovery response during flooding emergency and planning for the emergency response for similar future disasters.
Apogee collected a StripMAP mode image over the flooding centred on Grafton NSW on Sunday the 24th of May 2:30 Local Time, This image clearly shows the extent of flooding. Apogee has processed this data to reveal details of the flood boundaries at 3m resolution. These maps will be valuable to Emergency Services and Insurance Companies. This level of detail can be used to check and refine existing flood models.
This image shows the TerraSAR-X Stripmap image as collected, with the dark black area indicating areas of inundation. Water surfaces appear as black on a radar image because the water acts like a mirror reflecting the incident energy away from the sensor. Underneath this image, the same image is shown again with the water mapped in Blue. The dataset and Floodmaping in vector format is available from Apogee.
Apogee and Infoterra have tasked TerraSAR-X to acquire a second image over the collapsed Wilkins ice bridge on the 15th April to show ice movements and current as well as the formation of new ice suggesting that the ice debris may not be escaping into the open ocean this year.
This composite below combines the TerraSAR images taken 2 days apart, where the Red ’shadow’ shows the earlier position and the Cyan colour is the later position. The arrows show the result of the drift analysis between the two dates as the direction of currents.
The second image acquired on the 15th April 2009 is shown by itself below and reveals interesting details about the ice structures and reforming new ice.
The image subsets below show a close up of broken ice components. Some of them appear black, probably due to high water content and a smooth surface acting like a mirror. Others show texture suggesting an undulating surface which may have been caused by the effect of strong winds over time.
Information about ice moisture and texture can be extracted from high resolution data. This ice classification map shows different types of ice. The pink large blocks are the existing ice from the shelf and the other colours represent newly formed ice, which was not present 2 days ago. If the cooling continues, and given the circular nature of the current, the ice may not escape this season.
An ice bridge connecting the Charcot Island and the Antarctic Peninsula has collapsed early April 2009 due to global warming and will allow icebergs to drift into the Southern Ocean.
Apogee tasked TerraSAR-X to acquire the first high resolution radar imagery over the Ice bridge supporting Wilkins Ice Shelf.
The image below is a ScanSAR image acquired on 13th April 2009 over Wilkins ice Shelf. The red rectangle outlining the collapsed ice bridge (seen in greater detail below) as well as two high resolution subsets.
TerraSAR-X ScanSAR over Wilkins Ice Shelf, 13 April 2009.
The ENVISAT image below shows the ice bridge between the Charcot Island and the Antarctic Peninsula in the early stages of the collapse.
The image below shows the same subset with TerraSAR-X. The ice bridge has collapsed and broken ice will drift into the Southern Ocean.
Subset 1 (see the overview above) shows in great details the western part of the broken ice bridge.
Subset 2 shows in great details the eastern part of the broken ice bridge.
On Monday March 30th 2009 Australian Bureau of Meteorology release a predition of minor to moderate flodding in the Orara, Bellinger and Nambucca River areas. By Wednesday April 1st the region was declared a natural disaster.
Apogee tasked TerraSAR-X to acquire high resolution radar imagery over flood affected areas. Radar is the only remote-sensing technique capable of imaging an area through clouds or at night. The data was acquired at 6:15am on April 3rd. The flood water analysis was conducted with a StripMap scene at 3m resolution and clearly shows the inundated areas.
The image below is part of one of the StripMap images over the north coast of NSW with the white rectangle outlining the subset shown in greater detail.
StripMap over NSW coast on the 3rd April.
The image below shows a Google Map of the subset (see overview above).
The image below shows the same subset with TerraSAR-X. Calm water bodies appear as black in SAR data, which makes flooded areas visually easy to identify. These have been mapped in blue as an inundation layer.
The article for the Byron Shire News shows photos of this specific flooded area.
A significant amount of oil leaked from a cargo ship, the Pacific Adventurer on the 10th of March 2009 as a result of Cyclone Hamish. The heavy fuel oil has been washing up on the south eastern Queensland coast and inlets.
Apogee had tasked TerraSAR-X to obtain images over the disaster area. On the 12th of March 2009 at 5:15 local time, a ScanSAR image was acquired which clearly shows the extent of the oil spill still off-shore at that time. Radar satellite are the only alternative to monitor the area due to heavy cloud cover caused by the Cyclone Hamish and are well known to delineate the presence of oil on the ocean due to the suppression of capillary waves resulting in a smoother surface where oil is present and a different appearance within the image.
The MODIS image acquired on the 12th March shows the heavy cloud cover. The extent of the TerraSAR-X ScanSAR is outlined in red.
The dark linear features in the waters off the Sunshine Coast show the extent of the oil spill still remaining off-shore after some of it had already been washed up on the beaches of Moreton Island.
An estimation of the area of the oil spill can be extracted from this ScanSAR data and used to derive a reliable estimate of the total tonnage of oil spilled in this accident. From an initial estimate of 20 tonnes, the company owning the vessel corrected this estimate to 42 tonnes and now the government suspects that it may have been as much as 250 tonnes of oil. This TerraSAR-X image is the only extensive record of the oil spill and may prove invaluable in determining the quantity of oil released from the damaged vessel.
While we wait in anticipation of the World Wind Java SVN to be released, the release of a nightly build is great news. Keeping us up to date with changes in the World Wind Java core code, we can now follow the development more closely. Thanks should go to Bull for putting up a video show casing some of the features of the latest World Wind Java release. Although the development still has some way to go before a World Wind Java SDK 1.0 is released it was great to see some of features of the SDK 0.6 release featured in a short video.
Apogee and Intermap have partnered to bring you the very best in imagery and digital terrain models in 2009 over Australia.
This fly-through has been made using very high resolution digital aerial imagery at 10cm resolution draped over an IFSAR digital terrain model with an exceptional accuracy of 50cm over the Murray Mouth and the Coorong in South Australia.
To display the following video in full screen High Definition (up to 1280×720), click the link below and righ click on the video and select full screen.
Imagery over fires is being donated by Apogee and our associates to assist the firefighters in Victoria
Apogee tasked ImageSat International EROS-B high-resolution satellite to capture the affected area between the 14th and the 19th of February.
EROS satellites are high performance, light, highly manoeuvrable high-resolution observation satellites. The satellite’s light weight and rigidity allows a quick and stable re-pointing of it’s line of sight allowing fast manoeuvring between targets.
The images below have been acquired with EROS-B, the second of the EROS constellation. The camera system produces an image resolution of 70cm at nadir which allows accurate feature detection.
Overview of EROS-B acquisition over the burnt area.
Sub-metre resolution satellites make it possible to produce accurate assessments of the damage and assist the reconstruction effort.
South of the Bunyip State Park with EROS-B
The Town of Waterford Park spared by the blaze
A property destroyed by the fire which has spread along the highway
Fire scars after the powerful blaze jumped out of the forest.
