AST_07XT - SWIR bands

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s6039553
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AST_07XT - SWIR bands

by s6039553 » Thu Feb 18, 2021 3:46 am America/New_York

i have been ordering ASTER datasets AST_07XT (ASTER L2 Surface Reflectance VNIR and Crosstalk Corrected SWIR V003). However, after receiving the order via my email, SWIR bands and make the downloading. Within the downloaded zip file only contains VNIR bands, SWIR bands are NOT available.

Is it my ordering mistake or just the available dataset is like that ?

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LP DAAC - jwilson
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Re: AST_07XT - SWIR bands

by LP DAAC - jwilson » Thu Feb 18, 2021 3:21 pm America/New_York

ASTER is a non-continuous on-demand sensor. Acquisitions must be requested by authorized users so this means ASTER data is not collected continuously and will have sporadic coverage. It is possible that not all bands were collected for each scene. You will need to check the metadata to view the bands collected.

Users are advised that ASTER SWIR data acquired from April 2008 to the present exhibit anomalous saturation of values and anomalous striping. This effect is also present for some prior acquisition periods. Please refer to the ASTER SWIR User Advisory Document for more details. https://lpdaac.usgs.gov/documents/217/A ... _18_08.pdf

Please let us know if you have any further questions.
Janice

s6039553
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Joined: Thu Feb 18, 2021 3:43 am America/New_York

Re: AST_07XT - SWIR bands

by s6039553 » Fri Feb 19, 2021 1:31 am America/New_York

Thank you for your quick response.

So how do I know whether full stack bands are available ? Which year and date was ASTER providing full band coverage of the world ?

LP DAAC - jwilson
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Re: AST_07XT - SWIR bands

by LP DAAC - jwilson » Tue Feb 23, 2021 10:51 am America/New_York

ASTER acquisitions are submitted by approved users who have authorization to request bands to be turned on during acquisition. Each granule will have a metadata file that will have the bands collected.

The Terra satellite was launched on December 18, 1999.

ASTER SWIR detectors are no longer functioning due to anomalously high SWIR detector temperatures. ASTER SWIR data acquired since April 2008 are not useable, and show saturation of values and severe striping. All attempts to bring the SWIR bands back to life have failed, and no further action is envisioned. VNIR and TIR data continue to show excellent quality, meeting all mission requirements and specifications.

LP DAAC offers nearly 1.5 million global ASTER Level 1A scenes and related on-demand products. The vast majority of these scenes were acquired prior to the SWIR detector temperature increase, and SWIR bands present may be used in investigations: https://lpdaac.usgs.gov/news/aster-user ... y-14-2009/

ASTER Overview: https://lpdaac.usgs.gov/data/get-starte ... -overview/

Please let us know if you have any further questions or contact LPDAAC@usgs.gov
Kind regards,
Janice

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