National Gravity Compilation 2019: Airborne DGIR Tilt Grid for Australia

Approximately 1.8 million gravity observations, including nearly 1.4 million ground stations and 451,000 line km of airborne surveys, were used to generate this grid. The data, compiled by Geoscience Australia and sourced from government, industry, and research organizations from the 1940s onward, reveals sub-surface geological structure. The final 2019 grid has a cell size of 0.00417 degrees (approximately 435m) and applies a tilt filter to de-trended global isostatic residual anomalies.

Use Cases

• Edge detection of geological units based on the applied tilt filter.
• Regional crustal density modeling based on de-trended global isostatic residual (DGIR) anomalies.
• Integrating ground and airborne gravity data to improve resolution in areas with sparse ground coverage.

Strengths

• Integrates a large volume of data, including nearly 1.4 million ground stations and 451,000 line km of airborne surveys.
• Data quality is checked by GA geophysicists to ensure it is fit-for-purpose.
• Combines multiple data sources (ground, airborne, offshore) collected from the 1940s to 2019 for comprehensive spatial coverage.

Limitations

• Column-level documentation is absent; field semantics must be inferred after download.
• The dataset's specific update cycle is not described, though it was last updated in the catalog in April 2026.

Provenance

Source

Geoscience Australia (GA), Australian National Gravity Database (ANGD), and global sources including Scripps Institution of Oceanography, NOAA, and NGA.

Collection Method

Processed from ground observations, airborne gravity and gradiometry surveys, and offshore global grids using standard geophysical methods and a Fast Fourier Transform (FFT) tilt filter.

Time Range

Data acquired from the 1940s to September 2019.

Freshness

Last updated 2026-04-16 10:19:34.499779; freshness should be verified

Geography

Australia and its continental margins.