ICESat-2 ATL03 Ancillary Masks: Static Surface Classification

ATLAS/ICESat-2 ATL03 Ancillary Masks provide four static geospatial masks to filter laser altimeter data for specific Earth surfaces. These masks—for land ice, sea ice, land, and ocean—direct downstream algorithms like ATL06 and ATL07 to process only data relevant to their scientific communities. The masks are defined in the ATL03 Algorithm Theoretical Basis Document, enabling efficient, targeted analysis of ICESat-2's global observations.

Use Cases

• Filtering ICESat-2 photon data for land ice elevation change analysis using the land ice mask.
• Isolating sea ice freeboard measurements by applying the sea ice mask to ATL07 processing.
• Directing vegetation and terrain height algorithms (ATL08) to land-only regions.
• Processing ocean surface waveform data (ATL12) exclusively over masked ocean areas.

Strengths

• Cross-platform presence on NASA Earthdata and Data.gov signals importance and official provenance.
• Masks are defined in a documented Algorithm Theoretical Basis Document (ATBD), providing a technical foundation.
• Static design reduces computational volume for downstream, surface-specific data products.

Limitations

• Critical metadata like row count, file size, and specific column names are unavailable across all sources.
• The 'last updated' date (2026-03-13) appears inconsistent, as it is a future date relative to the current time.
• Data format is listed as BIN and ISO, which may require specialized tools for access and interpretation.

Provenance

Source

NSIDCV0 (National Snow and Ice Data Center?)

Collection Method

Derived as ancillary data from the ATL03 product of the ICESat-2 mission.

Time Range

Static (not time-varying)

Freshness

2026-03-13 14:20:21.379047

Geography

Global, corresponding to ICESat-2's orbital coverage.