National Gravity Compilation 2019 CSCBA 1VD image

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 1VD image is an image derived from the complete spherical cap Bouguer anomaly grid for the 2019 Australian National Gravity Grids A series. These gravity data were acquired under the project No. 202008. The grid used to create this image has a cell size of 0.00417 degrees (approximately 435m). 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, and marine data were used to generate this grid. The ground gravity data used in the national gravity grids 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. Terrain corrections to gravity were calculated using both offshore bathymetry and onshore topography data. The image shows the first vertical derivative of the complete Bouguer anomalies over Australia and its continental margins. A first vertical derivative was calculated by applying a fast Fourier transform (FFT) process to the complete spherical cap Bouguer anomaly grid of the 2019 Australian National Gravity Grids A series.

重力数据用于测量地球表层下方岩石密度变化所引发的微小重力变动。所采集的数据将通过标准化方法进行处理，以确保记录得到的响应仅由地下岩石引起。经处理后可生成数据集，通过解译该数据集能够揭示地下地质构造。经处理的数据需由澳大利亚地质调查局（Geoscience Australia，简称GA）的地球物理学家开展质量核验，以确保GA发布的最终数据符合使用要求。

本2019年国家重力汇编（National Gravity Compilation 2019）CSCBA 1VD影像，是基于2019年澳大利亚国家重力网格A系列的完整球冠布格异常（complete spherical cap Bouguer anomaly）网格生成的影像。此类重力数据采集自项目编号202008。用于生成该影像的网格单元尺寸为0.00417度（约435米）。该重力异常网格源自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，并补充了全球重力网格v28.1版本提供的近海数据；该全球重力网格的开发采用了加州大学圣地亚哥分校斯克里普斯海洋研究所（Scripps Institution of Oceanography, University of California San Diego）、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）提供的数据。在约180万条重力观测数据中，ANGD内近140万个重力测点与海洋数据被用于生成该网格。用于构建国家重力网格的地面重力数据，采集时段可追溯至20世纪40年代直至今日，采集主体包括英联邦、各州及领地政府、矿业与勘探行业、高校及科研机构。测点间距约为11千米至不足1千米，澳大利亚大陆的大部分区域测点间距介于2.5千米至7千米之间。重力地形校正的计算同时采用了近海水深数据与陆域地形数据。该影像展示了澳大利亚及其大陆边缘区域完整布格异常的一阶垂直导数（first vertical derivative）。一阶垂直导数的计算通过对2019年澳大利亚国家重力网格A系列的完整球冠布格异常网格应用快速傅里叶变换（Fast Fourier Transform, FFT）流程完成。

搜集汇总

背景与挑战

背景概述

该数据集是2019年国家重力编译项目的一部分，专注于通过重力数据测量地球表面下岩石密度变化，以揭示地下地质结构。数据由Geoscience Australia处理和质量检查，确保适用于地质研究目的，并以开放访问和许可证形式提供。