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13/05/2016

FranceWebAsso,FranceWebSharing,MyNewsCenterNavigator..Know why, Know who, Know where, Know what..AM-1, NASA, Japan Make ASTER Earth Data Available At No Cost, ASTER’s database currently consists of more than 2.95 million individual scenes,

 nasa,sru-electronics,francewebasso,francewebsharing,japan,mynewscenternavigator,earth observing system (eos) satellite,aster’s database currently consists of more than 2.95 million inFranceWebAsso   ProjectWebCitizens

nasa,sru-electronics,francewebasso,francewebsharing,japan,mynewscenternavigator,earth observing system (eos) satellite,aster’s database currently consists of more than 2.95 million inGet connected !

nasa,sru-electronics,francewebasso,francewebsharing,japan,mynewscenternavigator,earth observing system (eos) satellite,aster’s database currently consists of more than 2.95 million innasa,sru-electronics,francewebasso,francewebsharing,japan,mynewscenternavigator,earth observing system (eos) satellite,aster’s database currently consists of more than 2.95 million inASTER AM-1

An ASTER image of the Greek island of Santorini.

The first Earth Observing System (EOS) satellite called Terra (previously AM-1) was launched on December 18, 1999. Terra flys in a sun-synchronous polar orbit, crossing the equator in the morning at 10:30.

The Advanced Spaceborne Thermal Emission and Reflection Radiometer (ASTER) is one of the five state-of-the-art instrument sensor systems on-board Terra with a unique combination of wide spectral coverage and high spatial resolution in the visible near-infrared through shortwave infrared to the thermal infrared regions. ASTER is a partnership between NASA, Japan's Ministry of Economy, Trade and Industry (METI), the National Institude of Advanced Industrial Science and Technology (AIST) in Japan, and Japan Space Systems (J-spacesystems).

ASTER data contributes to a wide array of global change-related application areas including vegetation and ecosystem dynamics, hazard monitoring, geology and soils, hydrology, and land cover change.

What makes ASTER unique?

  • The Visible Near Infra-Red (VNIR) telescope's backward viewing band for high-resolution along-track stereoscopic observation
  • Multispectral thermal infrared data of high spatial resolution (8 to 12 µ window region, globally)
  • Highest spatial resolution surface spectral reflectance, temperature, and emissivity data within the Terra instrument suite
  • Capability to schedule on-demand data acquisition requests

ASTER Sensor Systems: Baseline Performance Requirements

Subsystem: VNIR

Band No.

Spectral Range
(µm)

Radiometric Resolution

Absolute Accuracy
(σ)

Spatial Resolution

Signal Quantization Levels

1
2
3N
3B
0.52–0.60
0.63–0.69
0.78–0.86
0.78–0.86
NEΔρ 0.5%
NEΔρ 0.5%
NEΔρ 0.5%
NEΔρ 0.5%
≤±4%
≤±4%
≤±4%
≤±4%
15 m
15 m
15 m
15 m
8 bits
8 bits
8 bits
8 bits

Subsystem: SWIR

Band No.

Spectral Range
(µm)

Radiometric Resolution

Absolute Accuracy
(σ)

Spatial Resolution

Signal Quantization Levels

4
5
6
7
8
9
1.600–1.700
2.145–2.185
2.185–2.225
2.235–2.285
2.295–2.365
2.360–2.430
NEΔρ≤ 0.5%
NEΔρ≤ 1.3%
NEΔρ≤ 1.3%
NEΔρ≤ 1.3%
NEΔρ≤ 1.0%
NEΔρ≤ 1.3%
≤±4%
≤±4%
≤±4%
≤±4%
≤±4%
≤±4%
30 m
30 m
30 m
30 m
30 m
30 m
8 bits
8 bits
8 bits
8 bits
8 bits
8 bits

Subsystem: TIR

Band No.

Spectral Range
(µm)

Radiometric Resolution

Absolute Accuracy
(σ)

Spatial Resolution

Signal Quantization Levels

10
11
12
13
14
8.125–8.475
8.475–8.825
8.925–9.275
10.25–10.95
10.95–11.65
NEΔΤ≤ 0.3%
NEΔΤ≤ 0.3%
NEΔΤ≤ 0.3%
NEΔΤ≤ 0.3%
NEΔΤ≤ 0.3%
--
≤3K (200–240K)
≤2K (240–270K)
≤1K (270–340)
≤2K (340–370)
90 m
90 m
90 m
90 m
90 m
12 bits
12 bits
12 bits
12 bits
12 bits

 

ASTER System Baseline Performance Requirements

Swath Width

60 Kms

Total Cross-Track Coverage

±116 to ±318 Kms

Stereo Base-to-Height Ratio

0.6 (along-track)

Modulation Transfer Frequency

0.25 (cross-track
0.20 (along-track)

Band-to-Band Registration

0.2 pixels (intra-telescope)
0.3 pixels (inter-telescope)

Duty Cycle

8% (VNIR & SWIR)
16% (TIR)

Peak Data Rate

89.2 Mbps

Mass

406 Kgs

Peak Power

726 W

 

ASTER Metadata

The ASTER Level-1 data are swath-based HDF-EOS products. The Level-1B data set provides scaled or calibrated radiance values, and is the input for most of the higher-level products. The data are contained in separate Vgroups for each of the three sensor systems. Refer to the following link, which describes the structure of an ASTER Level-1B HDF-EOS file:

The ASTER Level-1 data have two sources of metadata: the embedded HDF metadata, and the external ECS metadata. There are similarities and differences between them. For georeferencing purposes, we generally recommend using the values delineated in the embedded HDF metadata. Other product-specific and core metadata can be referred from either source.

The HDF metadata file is the information that is embedded within the header of the Level-1 HDF file. The embedded HDF metadata are written in ODL (Object Description Language), an ASCII-based Òparameter = valueÓ format, and contains a number of attributes relating to the Level-1 data set. The HDF metadata file broadly contains eight attribute groups with a number of specific attributes in each of them. These groups are listed below:

  • Attribute 1: HDFEOS Version
  • Attribute 2: StructMetadata.0
  • Attribute 3: ProductMetadata.0
  • Attribute 4: ProductMetadata.1
  • Attribute 5: ProductMetadata.v
  • Attribute 6: ProductMetadata.s
  • Attribute 7: ProductMetadata.t
  • Attribute 8: CoreMetadata.0

Refer to the ASTER User Handbook for details on the individual attributes contained in each of the above attribute groups.

The ECS (generated by the EOSDIS Core System) metadata file is the external .met file, which is delivered to the user along with the Level-1 data set. It contains a number of attributes relating to the Level-1 data set. The .met file provides a subset of the HDF metadata. It contains three broad groups of information:

  • INVENTORYMETADATA
  • COLLECTIONMETADATA
  • ARCHIVEMETADATA

The ASTER higher level products are also packaged similarly with embedded HDF metadata, and external ECS metadata. As an additional source of some valuable metadata, a set of attributes and their values are appended (product summary) at the end of the embedded metadata for all the higher-level products except the ASTER DEM.

 
 
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