National Gravity Compilation 2019 (CSCBA)

Gravity data measure 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 (CSCBA) is a complete spherical cap Bouguer anomaly grid for the 2019 Australian National Gravity Grids A 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. Out of the approximately 1.8 million gravity observations, nearly 1.4 million gravity stations in the ANGD were used to generate this grid. 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.

重力数据用于测量地球表层下方岩石密度变化引发的微小重力变化。所采集的数据将通过标准流程进行处理，以确保记录的响应仅源自地下岩石。经处理得到的数据集可通过解译揭示地下地质构造。经GA地球物理学家对处理后的数据开展质量核查，以确保GA发布的最终数据符合使用要求。
本次2019年国家重力编目（CSCBA）是针对2019年澳大利亚国家重力网格A系列的完整球冠布格异常（spherical cap Bouguer anomaly）网格。本次重力勘测依托项目编号202008完成采集。该重力异常网格源自截至2019年9月存储于澳大利亚国家重力数据库（Australian National Gravity Database, ANGD）的地面观测数据，并补充了源自全球重力网格v28.1的近海数据。全球重力网格v28.1由加利福尼亚大学圣迭戈分校斯克里普斯海洋研究所（Scripps Institution of Oceanography）主导开发，所用数据来自斯克里普斯海洋研究所、美国国家海洋和大气管理局（National Oceanic and Atmospheric Administration, NOAA）以及美国国家地理空间情报局（National Geospatial-Intelligence Agency, NGA）。在总计约180万条重力观测数据中，本次网格生成使用了ANGD内近140万个重力测点。该网格的单元尺寸为0.00417度（约合435米）。数据以μm/s²为单位，该单位也被称为“重力单位”，简称gu。