e197fc7b-5321-49de-80c6-afd89e960dff urn:uuid eng UTF-8 nonGeographicDataset nonGeographicDataset 2026-01-19T20:01:25 creation ISO 19115 2016 National Gravity Compilation 2019 includes airborne (free air grid) e197fc7b-5321-49de-80c6-afd89e960dff Gravity data measures small changes in gravity due to changes in the density of rocks beneath the Earth's surface. The data collected are processed via standard methods to ensure the response recorded is that due only to the rocks in the ground. The results produce datasets that can be interpreted to reveal the geological structure of the sub-surface. The processed data is checked for quality by GA geophysicists to ensure that the final data released by GA are fit-for-purpose. This National Gravity Compilation 2019 includes airborne (free air grid) is a free air anomaly grid for the 2019 Australian National Gravity Grids B series. This gravity survey was acquired under the project No. 202008. This gravity anomaly grid is derived from ground observations stored in the Australian National Gravity Database (ANGD) as at September 2019, supplemented with offshore data sourced from v28.1 of the Global Gravity grid developed using data from the Scripps Institution of Oceanography, the National Oceanic and Atmospheric Administration (NOAA), and National Geospatial-Intelligence Agency (NGA) at Scripps Institution of Oceanography, University of California San Diego. Airborne gravity and gravity gradiometry data were also included to provide better resolution to areas where ground gravity data was not of a suitable quality. Out of the approximately 1.8 million gravity observations, nearly 1.4 million gravity stations in the ANGD together with Airborne Gravity surveys totaling 345,000 line km and 106,000 line km of Airborne Gravity Gradiometry were used to generate this grid. The grid shows free air gravity anomalies over Australia and its continental margins. The ground and airborne gravity data used in this grid has been acquired by the Commonwealth, State and Territory Governments, the mining and exploration industry, universities and research organisations from the 1940's to the present day. Station spacing varies from approximately 11 km down to less than 1 km, with major parts of the continent having station spacing between 2.5 and 7 km. Airborne surveys have a line spacing ranging from 0.5 km to 2.5 km. The grid has a cell size of 0.00417 degrees (approximately 435m). The data are given in units of um/s^2, also known as 'gravity units', or gu. {"type": "Polygon", "coordinates": [[[107.9979, -48.0021], [164.0021, -48.0021], [164.0021, -7.9979], [107.9979, -7.9979], [107.9979, -48.0021]]]} 107.9979 164.0021 -48.0021 -7.9979 Australia EARTH SCIENCES Earth sciences GADDS2.0 NCI None Published_External free air geophysical survey geophysics grav gravity grid ground digital data raster survey 202008 File available for download in various formats from the GADDS2 portal documentDigital The Geophysical Archive Data Delivery System (GADDS2) portal provides HTTP download of geophysics datasets in a number of formats. Point and line datasets are available in NetCDF and ASEG-GDF2. Grid datasets are available in NetCDF, GeoTIFF and ERS. HTML /g/data/iv65/Geoscience_Australia_Geophysics_Reference_Data_Collection/national_geophysical_compilations/Gravmap2019/Gravmap2019-grid-grv_fa-IncludesAirborne.nc file at NCI documentDigital Fully qualified pathname of NetCDF file on NCI filesystem for National Gravity Compilation 2019 includes airborne (free air grid). Users must be logged onto the NCI network to access this file system. application/x-netcdf /g/data/iv65/Geoscience_Australia_Geophysics_Reference_Data_Collection/national_geophysical_compilations/Gravmap2019/Gravmap2019-grid-grv_fa-IncludesAirborne.nc file download documentDigital File download for National Gravity Compilation 2019 includes airborne (free air grid) application/x-netcdf