Etheridge Airborne Gravity Gradiometry Survey, 2024

The Etheridge Airborne Gravity Gradiometer (AGG) survey of Northern Queensland was flown between April 8th to 1st June 2024. Contracted to Xcalibur Smart Mapping, Geoscience Australia undertook the project management, contract management and quality control on behalf of the Geological Survey of Queensland. The located data, gridded data and quality control reports are contained within this record.Survey area was centered on longitude 143° 31’ E and latitude 18° 27’ S to the east of Croydon. A total of 53 production flights were flown for a combined total of 32,482.0 line kilometres of data and acquired on 1000 m line spacing at 100 m nominal terrain clearance. Quality control was performed by airborne gravity consultant Dr Mark Dransfield on behalf of Geoscience Australia, with his report included here.The survey was designed to supplement the regional legacy ground gravity data and improve the definition of gravimetric anomalies in the region. In addition, the AGG survey will provide better understanding of the cover sequence thickness and characteristics of the underlying basement geology.The data will also be released by the Geological Survey of Queensland and can be found at: https://geoscience.data.qld.gov.au/data/gravity-gradiometry/gg104290.Survey Name: Etheridge airborne gravity gradiometery survey, 2024Datasets Acquired: Gravity gradiometry, gravity, digital terrain modelGeoscience Australia Project Number: P5025Acquisition Start Date: 08/04/2024Acquisition End Date: 01/06/2024Flight line spacing: 1000 mFlight line direction: East-West (090-270)Total distance flown: 32,482.0 line kmNominal terrain clearance: 100 mBlocks: 1Data Acquisition: Xcalibur Smart MappingProject Management: Geoscience AustraliaQuality Control: Mark Dransfield on behalf of Geoscience AustraliaDataset Ownership: Geological Survey of Queensland and Geoscience AustraliaIncluded in this release:1. Point-located DataASCII-column data in ASEG-GDF format with accompanying description and definition files.• Gravity gradiometry data including the various corrections• Gravity gradiometry data noise estimates• Vertical gravity estimate including various reduction and levelled corrections• Digital terrain model2. GridsGridded data in ERMapper (.ers) format (GDA2020/MGA zone 54):• Free-air vertical gravity gradiometry• Free-air corrected vertical gravity• Terrain and bouguer corrected vertical gravity gradiometry (densities for terrain correction: 2.3g/cm3 and 2.67 g/cm3)• Terrain and bouguer corrected vertical gravity (densities for terrain correction: 2.3g/cm3 and 2.67 g/cm3)• Conformed, terrain and bouguer corrected vertical gravity gradiometry (densities for terrain correction: 2.3g/cm3 and 2.67 g/cm3)• Conformed, terrain and bouguer vertical gravity (densities for terrain correction: 2.3g/cm3 and 2.67 g/cm3)• Digital terrain model3. Reports• Contractors Logistics Report• Quality Control Report (Mark Dransfield)

2024年4月8日至6月1日期间，昆士兰州北部埃斯里奇航空重力梯度仪（Airborne Gravity Gradiometer, AGG）测量飞行作业顺利开展。本次作业由Xcalibur Smart Mapping承接，澳大利亚地质科学局（Geoscience Australia）受昆士兰州地质调查局（Geological Survey of Queensland）委托，负责项目管理、合同管理与质量控制工作。本数据集记录包含点位定位数据、网格化数据与质量控制报告。

测量区域以克罗伊登（Croydon）东侧的东经143°31′、南纬18°27′为中心，共完成53架次生产飞行，累计获取32482.0线公里的测量数据，测线布设间距为1000米，标称离地飞行高度为100米。

本次测量的质量控制工作由航空重力领域顾问马克·德兰斯菲尔德（Mark Dransfield）博士代表澳大利亚地质科学局完成，其编制的质量控制报告已纳入本数据集。

本航空重力梯度测量项目旨在补充该区域既往的区域地面重力数据，提升区域重力异常的解译精度与清晰度。此外，本次测量成果还将助力深化对区域地表覆盖层厚度及基底地质特征的认知。

本数据集由昆士兰州地质调查局公开发布，获取链接为：https://geoscience.data.qld.gov.au/data/gravity-gradiometry/gg104290。

### 项目基础信息
项目名称：2024年埃斯里奇航空重力梯度测量
获取数据集类型：重力梯度数据、重力数据、数字地形模型（Digital Terrain Model）
澳大利亚地质科学局项目编号：P5025
采集开始日期：2024/04/08
采集结束日期：2024/06/01
测线间距：1000米
测线方向：东西向（090-270方位）
累计飞行线公里数：32482.0线公里
标称离地高度：100米
作业区块数：1
数据采集方：Xcalibur Smart Mapping
项目管理方：澳大利亚地质科学局
质量控制方：马克·德兰斯菲尔德博士（代表澳大利亚地质科学局）
数据集所有权：昆士兰州地质调查局与澳大利亚地质科学局

### 本次发布包含的内容
1. 点位定位数据
采用ASEG-GDF格式的ASCII列数据，附带配套说明与定义文件，具体包括：
• 包含各类校正项的重力梯度数据
• 重力梯度数据噪声评估结果
• 包含各类归算与平差校正项的垂直重力估算结果
• 数字地形模型
2. 网格化数据
采用ERMapper（.ers）格式的网格化数据（坐标系为GDA2020/MGA第54带），具体包括：
• 自由空气垂直重力梯度
• 经自由空气校正的垂直重力
• 经地形与布格校正的垂直重力梯度（地形校正密度分别为2.3g/cm³与2.67g/cm³）
• 经地形与布格校正的垂直重力（地形校正密度分别为2.3g/cm³与2.67g/cm³）
• 经标准化校正、地形与布格校正的垂直重力梯度（地形校正密度分别为2.3g/cm³与2.67g/cm³）
• 经标准化校正、地形与布格校正的垂直重力（地形校正密度分别为2.3g/cm³与2.67g/cm³）
• 数字地形模型
3. 报告文件
• 承包商后勤报告
• 质量控制报告（马克·德兰斯菲尔德博士编制）