Relation: Asters

Theme: Satellite images from TERRA ASTER instrument covering the central plain of Phrae Province in the north of Thailand.

Source:

http://edcimswww.cr.usgs.gov/

Date of the data: A scene from the 7^th of March 2003

Quality of data: Excellent

Data exhaustiveness: complete

Datum and ellipsoid of the mosaic: Indian 1975, Everest

Projection of the mosaic: UTM; Central Meridian 99, Zone 47

Description of the processes performed on the image:

The image was previously processed to derive a colour composite image in Abode Photoshop. The original format of the image is hdf0 and was converted to Tiff using MultiSpecWin32.

Original resolution: 15 metres per pixel

Resolution of the mosaic: 15 metres per pixel

Person in charge of the rectification and integration: Bernard Lortic, Florent Demoraes, IRD

Person in charge of the metadata: Florent Demoraes, IRD

Integration Date: 2005

Description of the attributes

Band 1: 0.52 - 0.60 µm (Green)

Band 2: 0.63 - 0.69 µm (Red)

Band 3: 0.76 - 0.86 µm (Near Infra Red)

2003_03_07_C1 stands for the band 1 of the scene taken on the 7^th of March 2003 (Integer)

2003_03_07_C2 stands for the band 2 of the scene taken on the 7^th of March 2003 (Integer)

2003_03_07_C3 stands for the band 3 of the scene taken on the 7^th of March 2003 (Integer)

2003_03_07_CC stands for the false colour composite derived from the combination of the three bands of the scene taken on the 7^th of March 2003 (RGB colours)

Knowing more about ASTER images:

The ASTER instrument consists of three separate instrument subsystems. Each subsystem operates in a different spectral region, has its own telescope(s), and was built by a different Japanese company. ASTER's three subsystems are: the Visible and Near Infrared (VNIR), the Shortwave Infrared (SWIR), and the Thermal Infrared (TIR). To find out more about each module click on the item of interest.

In the present relation were integrated only the bands corresponding to the Visible and Near Infrared portion of the electromagnetic spectrum, as described below.

The VNIR subsystem operates in three spectral bands at visible and near-IR wavelengths, with a resolution of 15 m. It consists of two telescopes--one nadir-looking with a three-spectral-band detector, and the other backward-looking with a single-band detector. The backward-looking telescope provides a second view of the target area in Band 3 for stereo observations. Thermal control of the CCD detectors is provided by a platform-provided cold plate. Cross-track pointing to 24 degrees on either side of the track is accomplished by rotating the entire telescope assembly. Band separation is through a combination of dichroic elements and interference filters that allow all three bands to view the same ground area simultaneously. The data rate is 62 Mbps when all four bands are operating. Two on-board halogen lamps are used for calibration of the nadir-looking detectors. This calibration source is always in the optical path (http://asterweb.jpl.nasa.gov/instrument.asp ).