Envisat ASAR Image Mode Level 0 Source Packets

Level 0 data product from the Envisat ASAR instrument's Image Mode, consisting of time-ordered Annotated Instrument Source Packets (AISPs). The European Space Agency (ESA) produced this product, which provides a continuation of the ERS-SAR_RAW product, with the last recorded update in April 2012. Echo samples within the AISPs are compressed to 4 bits per sample using Flexible Block Adaptive Quantisation (FBAQ).

Use Cases

• Process raw echo samples from AISPs into calibrated SAR imagery for land or ocean monitoring.
• Analyze the 4-bit FBAQ compression scheme's impact on image quality for different surface types.
• Study the time-ordered AISP sequence to understand instrument performance and data acquisition patterns.
• Develop algorithms to handle data from one of seven possible image swaths in this narrow swath mode.
• Use the product as a continuation dataset for long-term studies previously reliant on ERS-SAR_RAW data.

Strengths

• Provides systematic Level 0 data for all acquisitions within the ASAR Image Mode.
• Echo samples are compressed using a defined 4-bit FBAQ method, offering a consistent data format.

Limitations

• Data acquisition is partial, covering only specific orbit segments, not full global coverage.
• The dataset's last known update was in 2012, indicating it is a historical archive with no recent additions.
• Specific details on total data volume, row count, and geographic coverage are not provided.

Provenance

Source

European Space Agency (ESA) via NASA Earthdata.

Collection Method

Collected by the ASAR instrument on the Envisat satellite operating in Image Mode.

Freshness

Last updated on 2012-04-08; no update frequency specified.

Geography

Partial orbit segments; may be from one of seven possible image swaths.