ASTER Advanced Spaceborne Emission and Reflection Radiometer ASTER

ASTER Advanced Spaceborne Emission and Reflection Radiometer

ASTER Instrument Ø Has 3 sensors and detects 14 bands of spectrum. Ø Launched December 1999 Ø Ground resolution is 15 m ~ 90 m. VNIR Visible/Near Infrared Radiometer # of Bands: 3 Nadir + 1 Aft. Looking Spatial Resolution: 15 m SWIR Short Wave Infrared Radiometer # of Bands: 6 Nadir Spatial Resolution: 30 m TIR Thermal Infrared Radiometer # of Bands: 5 Nadir Spatial Resolution: 90 m

ASTER Data Acquisition

GDEM: The ASTER Global Topography Data Set

Methodology 1. Stereo-correlate entire ~ 1. 5 million scene ASTER Archive; 2. Cloud mask to remove cloudy pixels 3. Stack all DEMS & remove residual bad values and outliers; 4. Partition data into 1º x 1º tiles --- ASTER scene (60 km x 60 km) Tile (1 arc degree square) SRTM 3 coverage Automated processing Generation of a seamless tile of DEM using all ASTER data ever acquired over the tile ASTER coverage (~1. 5 million scenes in summer 2008) Deeper red indicates more data accumulated. GEOSS Contribution to ASTER GDEM Global coverage A seamless Tile of Both US and Japan committed to contribute to GEOSS at Capetown Summit

ASTER Global Digital Elevation Model (GDEM) v 23, 000 1 x 1 degree tiles v 30 m postings v Released June 2009 v Available thru LPDAAC & GDS v Free to ALL users v Version 2 to be released Spring 2011

Various Disasters

Eyjafjallajökull Iceland Volcano Eruption Time-lapse photo of eruption cloud and lightning

Eyjafjallajökull Iceland Volcano Eruption April 1 perspective view showing early phase of lava flow and lahar emplacement

Eyjafjallajökull Iceland Volcano Eruption April 19 MODIS image of ash plume. ASTER image

Eyjafjallajökull Iceland Volcano Eruption April 19 image of ash plume. Red is thermal infrared signature of active vent and earlier flows.

Eyjafjallajökull Iceland Volcano Eruption April 19 image of ash plume. Thermal infrared channels highlight ash vs SO 2 in plume.

Baja California April 4 Earthquake, M=7. 2

Baja California April 4 Earthquake, M=7. 2 Sub-pixel co-registration of before and after ASTER images allows determination of displacements between images. The results indicate ~4 m of right -lateral offset, and ~1 m vertical offset. This is in agreement with several field observations. Courtesy Dr. Sebastien Leprince, Caltech