ASTER Expedited L1A: Fast-Turnaround Satellite Imagery

NASA's ASTER Expedited Level 1A (AST_L1AE) dataset provides reconstructed, unprocessed instrument data from the Terra satellite's Visible and Near Infrared (VNIR), Shortwave Infrared (SWIR), and Thermal Infrared (TIR) telescopes. It is available for download within 48 hours of acquisition to support time-sensitive applications like emergency response and field calibration, but has lower registration quality and lacks the VNIR 3B band compared to the standard AST_L1A product. The dataset is only available for 30 days post-acquisition before being removed for reprocessing.

Use Cases

• Initial damage assessment for natural disasters based on expedited 48-hour data availability.
• Field calibration of ground instruments using unprocessed VNIR, SWIR, and TIR instrument data.
• Monitoring thermal anomalies from expedited Thermal Infrared (TIR) observations, noting the instrument was permanently turned off on January 16, 2026.

Strengths

• Expedited availability within 48 hours of acquisition for time-critical use.
• Cross-platform presence on Data.gov and NASA Earthdata signals importance and reliability.
• Provides data from three ASTER telescope systems: VNIR, SWIR, and TIR.

Limitations

• Registration quality is lower than the standard AST_L1A product and varies scene-to-scene.
• Lacks the VNIR 3B (aft-viewing) band and short-term calibration for the TIR sensor.
• Contains known data gaps, including a major acquisition halt from November 28, 2024, to January 18, 2025, for VNIR.
• SWIR data from April 2008 onward exhibits anomalous saturation and striping.

Provenance

Source

National Aeronautics and Space Administration (NASA)

Collection Method

Acquired telemetry streams from the ASTER instrument on the Terra spacecraft.

Time Range

Coverage spans from the instrument's operational period, with specific acquisition gaps noted. TIR acquisitions ended on January 16, 2026.

Freshness

Last updated on Data.gov: 2026-03-13.

Geography

Global