ASTER Expedited L1A: Near-Real-Time Satellite Imagery

ASTER Expedited Level 1A Reconstructed Unprocessed Instrument Data (AST_L1AE) provides reconstructed, unprocessed digital data from the ASTER instrument's Visible and Near Infrared (VNIR), Shortwave Infrared (SWIR), and Thermal Infrared (TIR) telescopes. This expedited product is available for download within 48 hours of acquisition to support time-sensitive applications like emergency response and field calibration, but it has lower registration quality and lacks the VNIR 3B band and TIR short-term calibration compared to the standard AST_L1A product. Data acquisition has experienced gaps, and TIR band collection was permanently ended on January 16, 2026.

Use Cases

• Initial damage assessment for natural disasters based on the 48-hour availability for emergency response.
• Field calibration and validation of ground instruments using the expedited, unprocessed instrument data.
• Land surface temperature analysis using Thermal Infrared (TIR) bands, noting the lack of short-term calibration in this product.
• Geological and vegetation studies using Visible and Near Infrared (VNIR) and Shortwave Infrared (SWIR) spectral data.

Strengths

• Expedited availability within 48 hours of satellite acquisition for time-sensitive use.
• Provides multispectral data across three telescope systems: VNIR, SWIR, and TIR.
• Data is reprocessed into a higher-quality standard product (AST_L1A) after 30 days.

Limitations

• Registration quality is lower than the standard product and varies per scene.
• Missing the VNIR 3B (aft-viewing) band and lacks short-term calibration for the TIR sensor.
• Contains known data anomalies: SWIR data from April 2008 onward exhibits saturation and striping.
• Data availability is transient; files are removed for reprocessing 30 days after acquisition.

Provenance

Source

National Aeronautics and Space Administration (NASA)

Collection Method

Acquired from the Advanced Spaceborne Thermal Emission and Reflection Radiometer (ASTER) instrument aboard the Terra satellite.

Time Range

Coverage spans from the ASTER mission start, with specific acquisition gaps from November 28, 2024, to January 16, 2025 (VNIR), and TIR acquisitions ending permanently on January 16, 2026.

Freshness

Metadata was last updated on 2026-03-13 according to datagov.

Geography

Global