Aral Sea profile Selection of area 24 February April May 1998

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1 250 km Aral Sea profile ? Selection of area Area of interest Kzyl-Orda Dried seabed 185 km Syrdarya river Aral Sea Salt residuals 185 km Cardara water supply reservoir Ajdarkul lake 24 February April May

2 7 June July August September October November

3 Image Processing False colour: Band 6 (thermal) on Red Band 4 (near-) on Green Band 2 (green) on Blue 17 May July 2001 Landsat The era of Landsat satellites started in 1973 with the launch of the first MSS satellite. Since then, the specifications of the Landsat satellites have improved and data from the ETM+ sensor on Landsat 7 provides 15 m panchromatic data and 30 m multispectral data. A huge archive of data is available, making Landsat an ideal and costeffective choice in change detection applications. 21 August September 2001 TM AND ETM+ SPECTRAL BANDWIDTHS FOR LANDSAT 7 ETM+ A single Landsat scene covers app. 185 x 185 km. The revisit time is also good, 16 days between acquisitions. Bandwidth (µm) Sensor Blue Band 1 Green Band 2 Red Band 3 Near Band 4 Mid. Band 5 Therm. Band 6 Mid Band 7 Panchr. Band 8 ETM QuickBird Featuring the highest spatial resolution of any commercial remote sensing satellite, QuickBird offers 60 cm resolution (panchromatic or pansharpened) and 2.4 m multispectral collected in a wide swath of 16.5 km which means that large areas can be acquired in one image. Prices start from as low as app. 500 US $ for a 5 x 5 km area. QuickBird Characteristics Launch Date Orbit Altitude Orbit Inclination Speed Equator Time Orbit Time Revisit Time Swath Width Metric Accuracy Digitization Resolution: Image Bands Crossing October 18, km 97.2 degrees, sun-synchronous 7.1 km/second 10:30 a.m. (descending node) 93.5 minutes days depending on latitude (30 off-nadir) 16.5 km x 16.5 km at nadir 23 meter horizontal (CE90%) 11 bits Pan: 0.61 m (nadir) to 0.72 m (25 off-nadir) MS: 2.44 m (nadir) to 2.88 m (25 off-nadir) Pan: nm Blue: nm Green: nm Red: nm Near IR: nm 3

4 Ikonos Ikonos was launched by SpaceImaging in 1999 and was the first commercial satellite in the world to offer very high resolution satellite data. Ikonos offers spatial resolutions of 1 m panchromatic or pansharpened and 4 m multispectral. Digital elevation models (DEM) can be produced by tilting the camera in the along-flight direction. Tehran, Iran - QuickBird Ikonos Characteristics Launch Date Orbit Altitude Orbit Inclination Speed September 24, km 98.1 degrees, sun-synchronous 7 km/second Equator Crossing 10:30 a.m. (descending node) Time Orbit Time 98 minutes Revisit Time days depending on latitude Swath Width 11 km x 11 km at nadir Metric Accuracy 12 meter horizontal (CE90%) Digitization 11 bits Resolution: Pan: 0.81 m (nadir) to 1.00 m (26 offnadir) MS: 3.2 m (nadir) to 4.00 m (26 off-nadir) Image Bands Pan: nm Blue: nm Green: nm Red: nm Near IR: nm Airport -Frankfurt Ikonos SPOT Characteristics SPOT 2 SPOT 4 SPOT 5 Launch Date 22 Jan Mar May 2005 SPOT Various SPOT sensors are currently in orbit with spatial resolutions from 20 m down to 2.5 metres. The SPOT archive dates back to 1986 when SPOT-1 was launched and this makes SPOT an ideal solution for time series analysis. Like QuickBird and Ikonos, the SPOT satellite can be programmed to acquire new images from any location on Earth. Orbit Altitude Orbit Inclination Speed Equator Crossing Time Orbit Time Revisit Time Swath Width Metric Accuracy Digitization 350 m 60 x 60 km at nadir 350 m 822 km 98.7 degrees 7.4 km/second 10:30 a.m minutes 2-3 days 8 bits 50 m Resolution: Pan: 10 m Pan: 10 m Pan: m Image Bands MS: 20 m Pan: nm Gr: nm Red: nm NIR: nm MS: 20 m Pan: nm Gr: nm Red: nm NIR: nm MS: m Pan: nm Gr: nm Red: nm NIR: nm SW: µm SW: µm 4

5 17 May 2001 Saudi Arabia SPOT 4 July August 2001 Spatial Resolution 22 September

6 Image of Eiffel Tower Paris QuickBird satellite: 0.6m resolution Ikonos satellite: 1m True colour Image of Libya Airport Spot satellite: 2.5m resolution Image of Oman for Geological purposes Landsat satellite: 15m resolution Image of Yemen for Geological purposes Aster satellite: 15m resolution False colour composite: Red: SWIR band; Green: NIR band; Blue: Red band. In this display scheme, vegetation appears in shades of green. Bare soils and clearcut areas appear purplish or magenta. The patch of bright red area on the left is the location of active fires. A smoke plume originating from the active fire site appears faint bluish in colour. 6

7 False colour composite: Red: NIR band; Green: Red band; Blue: Green band. Vegetation appears in shades of red. The smoke plume appears bright bluish white. 2 bit image 4 bit image 8 bit image 16 bit image Thermal image of coast displaying temperatures 7