ASTER Registered Radiance at the Sensor - Orthorectified V003

The Terra Advanced Spaceborne Thermal Emission and Reflection Radiometer (ASTER) Orthorectified Registered Radiance at the Sensor (AST14OTH) products contain imagery transformed from a perspective projection to an orthogonal one. An orthorectified image possesses the geometric characteristics of a map with near-vertical views for every location. These products are terrain corrected, provide radiometrically calibrated radiance, and are mapped to the Universal Transverse Mercator (UTM) coordinate system. The inputs include the following: an ASTER Level 1A Reconstructed Unprocessed Instrument dataset; georeferencing information from the ASTER instrument's and Terra platform's ephemeris and attitude data; and an ASTER-derived digital elevation model (DEM). The output product includes fifteen orthorectified ASTER Level 1B calibrated radiance images, one per band, as listed below. The ASTER Orthorectified Registered Radiance at the Sensor data product is only available through [NASA's Earthdata Search](https://search.earthdata.nasa.gov/search?q=C1299783684-LPDAAC_ECS). The ASTER Order Instructions provide step-by-step directions for ordering this product. Known Issues * 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 for more details. * Data acquisition gaps: On November 28, 2024, one of Terra's power-transmitting shunt units failed. As a result, there was insufficient power to maintain functionality of the ASTER instrument. ASTER resumed acquisitions for the VNIR bands on January 18, 2025, and for the TIR bands on April 15, 2025. Users should note the data gap in ASTER acquisitions from November 28, 2024, through January 16, 2025, for VNIR observations, and a gap from November 28, 2024, through April 15, 2025, for TIR acquisitions. Improvements/Changes from Previous Version * As of January 2021, the LP DAAC has implemented version 3.0 of the Sensor Information Laboratory Corporation ASTER DEM/Ortho (SILCAST) software, which is used to generate the Level 2 on-demand ASTER Orthorectified and Digital Elevation Model (DEM) products (AST14). The updated software provides digital elevation extraction and orthorectification from ASTER L1A input data without needing to enter ground control points or depending on external global DEMs at 30-arc-second resolution (GTOPO30). It utilizes the ephemeris and attitude data derived from both the ASTER instrument and the Terra spacecraft platform. The outputs are geoid height-corrected and waterbodies are automatically detected in this version. Users will notice differences between AST14DEM, AST14DMO, and AST14OTH products ordered before January 2021 (generated with SILCAST V1) and those generated with the updated version of the production software (version 3.0). Differences may include slight elevation changes over different surface types, including waterbodies. Differences have also been observed over cloudy portions of ASTER scenes. Additional information on SILCAST version 3.0 can be found on the [SILCAST website](http://www.silc.co.jp/en/products.html). * In addition to the recent SILCAST upgrade from Version 1.0 to 3.0, on March 18, 2021, the LP DAAC updated the Interactive Data Language (IDL) software used in the processing system from 8.7.0 to 8.8.0. As a result, users may notice minor and isolated differences in the output files produced for this product in bands 1 – 3(B/N) when comparing output files produced before and after the updates. * Starting June 23, 2021, radiometric calibration coefficient Version 5 (RCC V5) will be applied to newly observed ASTER data and archived ASTER data products. Details regarding RCC V5 are described in the following journal article. * Tsuchida, S., Yamamoto, H., Kouyama, T., Obata, K., Sakuma, F., Tachikawa, T., Kamei, A., Arai, K., Czapla-Myers, J.S., Biggar, S.F., and Thome, K.J., 2020, Radiometric Degradation Curves for the ASTER VNIR Processing Using Vicarious and Lunar Calibrations: Remote Sensing, v. 12, no. 3, at https://doi.org/10.3390/rs12030427.

Tags: earth-science-infrared-wavelengths-spectral-engineering-infrared-radiance, earth-science-infrared-wavelengths-spectral-engineering-thermal-infrared, earth-science-land-use-land-cover-land-surface, earth-science-visible-wavelengths-spectral-engineering-visible-radiance
Organization: National Aeronautics and Space Administration