ASTER Operation Scenario and Status Y. Yamaguchi (Nagoya Univ., Japan) M. Fujita, T. Tachikawa, M. Kato, H. Tsu （ ERSDAC, Japan), M.J. Abrams, L. Maldonado (JPL, U.S.A.) IGARSS 2011, July 28, 2011 Vancouver, Canada

1. 1.ASTER Characteristics 2. 2.SWIR Cryocooler Problem 3. 3.Operation Scenario and Status (1) Global Mapping (GM) (2) TIR Nighttime Global Mapping (TGM) (3) Gap Filler (4) Underserved Area STAR Contents

Advanced Spaceborne Thermal Emission and Reflection Radiometer on NASA’s Terra (EOS AM-1) spacecraft ASTER instrument was provided by METI, Japan. Launched in December, 1999 MODIS ASTER (TIR) ASTER (SWIR) ASTER (VNIR) MISR MOPITT CERES Instruments on Terra ASTER Characteristics (1)

ASTER Characteristics (2) High Spatial Resolution 15m for VNIR bands 30m for SWIR bands 90m for TIR bands Wide Spectral Coverage 3 bands in VNIR (0.52 – 0.86 μm) 6 bands in SWIR (1.6 – 2.43 μm) 5 bands in TIR (8.125 – μm) Along-Track Stereo Capability B/H 0.6 DEM Elevation accuracy: 15m (3σ) DEM Geolocation accuracy: 50m (3σ)  ASTER Global DEM (GDEM) Nadir Backward

Multiband Observation of Mt.Etna 6km ASTER VNIR RGB : 3,2,1 ASTER SWIR RGB : 9,5,4 ASTER TIR Band 13 Snow (high albedo) Fumarole Lava (high temp.) Snow (low temp.) Lava (low albedo) Snow (low albedo) Imaged on May 7, 2000

SWIR Cooler Problem

SWIR Temperature ( ) K 317K The SWIR detector temperature had been kept at 77 K by the cryocooler. The detector temperature started rising in 2004 due to the cryocooler malfunction, and exceeded 90 K in May Partial saturation in SWIR image data occurred in 2007, and no usable SWIR data has been acquired since May 2009.

Totally saturated SWIR image (band 4 and 5) acquired at 94 K Partially saturated SWIR image (band 9) acquired at 86.9 K SWIR Image Saturation

Observation Mode Subsystem Data Rate (Mbps) VNIRSWIRTIR Daytime Full Mode89.2 VNIR Mode TIR Mode Nighttime S + T Mode ASTER Observation Modes OperationalUnavailable

Operation Scenario and Status

Total ASTER Scenes : 2,014,401 As of June 1, 2011 ■Observed □Never Observed

ASTER Daytime VNIR Scenes

ASTER TIR Nighttime Scenes

Data Acquisition Requests Data Acquisition Request (DAR) Local Observations by Individual Users Science Team Acquisition Request (STAR) Regional Monitoring (vegetation, volcanoes, glaciers, cities) Global Mapping (GM) TIR Nighttime Global Mapping (TGM) Gap Filler Underserved Area STAR

Operation Scenario and Status (1) Global Mapping (GM) Daytime Full Mode Observation High Sun Angle Optimum Gain for Local Land Surface No More Than 20 % Cloud Cover Minimum Snow and Ice Cover

Global Mapping (GM-3) □GM3H : Area 67,688,813 km 2 □GM3M : Area 64,472,470 km 2 □GM3L : Area 47,787,553 km 2 Life Time: 2006/03/ /04/01 Observation Condition Cloud < 20 %, Day, Full Mode, Sun Angle: 40-90°

Global Mapping LifetimeTarget Areas Observation Parameters GM-1 Dec to Mar All land + coastal areas (High, medium, low priority areas) Depend on the priority, surface type, season, latitude, etc. GM-2 Aug to Mar Selected areas (GM-1 high priority areas only) Similar to GM-1, but relaxed the sun elevation condition GM-3 Mar to Oct All land + coastal areas (High, medium, low priority areas, GM-1 high priority areas extended) Same as GM-2 GM-4 Oct to Apr Same as GM-3Same as GM-2

GM Daily Observation Scenes As of Nov. 24 th, ,253 10,730 54,868 13,067 93,063 GM to GM to GM to ,830 76,230 GM to

Operation Scenario and Status (2) TIR Nighttime Global Mapping (TGM)

TIR Nighttime Global Mapping (TGM) □AOI of TGM1, Life Time: 2004/12/01 – 2006/08/31 □AOI of TGM2-1, Life Time: 2006/04/01 – 2010/04/01 □AOI of TGM2-2, Life Time: 2007/04/01 – 2010/03/31 □AOI of TGM2-3, Life Time: 2008/01/10 – 2009/04/01 □AOI of TGM2-4, Life Time: 2008/04/11 – 2009/04/01 Observation Condition AvoidCloud : NO, Night, TIR only Mode

■ TGM % ■ TGM % Achievement ■ < 20 % ■ 50 to 80 % ■ < 20 % ■ 50 to 80 % ■ 20 to 50 % ■ > 80 % ■ 20 to 50 % ■ > 80 % TIR Nighttime Global Mapping (TGM-3, 4)

Operation Scenario and Status (3) Gap Filler For the areas where cloud-free ASTER imagery has never been acquired. We identify the target areas and submit STAR every half a year.

Observed Scenes of Gap Filler Observation Condition Avoid Cloud : 10 %, Day, Full Mode, Sun Angle:20-90 ° ■ 8 scenes with Cloud Coverage < 10 % ■ 140 observed Scenes ■ AOI of Under-served Area STAR Life Time: 2011/05/01 – 2011/12/01 As of June 1 st,2011

Operation Scenario and Status (4) Underserved Area STAR For the areas where 3 times or less cloud-free ASTER imagery has been acquired. The target areas were identified in the GDEM processing.

Underserved Area STAR Observation Condition Cloud < 20 %, Day, Full Mode, Sun Angle : 40-90°or 20-90° □ Underserved Area : 21,609,180 km 2 UA2008 : UA2008 : Life Time:2008/12/ /03/11 UA2010 : UA2010 : Life Time:2010/03/ /01/01

Achievement of Underserved Area STAR 2010 Achievement ■ < 20 % ■ 50 to 80 % ■ < 20 % ■ 50 to 80 % ■ 20 to 50 % ■ > 80 % ■ 20 to 50 % ■ > 80 % Observation Condition Cloud < 20 %, Day, Full Mode, Sun Angle : 40-90°or 20-90° 75.6% as of June 1 st,2011

Acquired Scenes of Different Data Acquisition Categories

Concluding Remarks The ASTER instrument has been acquiring data since January 2000, and has obtained more than 2 million scenes. ASTER operation scenario is carefully designed to maximize data acquisition. The ASTER SWIR subsystem is not functioning now due to the SWIR cryocooler malfunction.

To get ASTER Data ersdac.or.jp/ ASTER Homepage Thank you for your attention.