Murray Basin (Ana Branch, Pooncarie), NSW, 1981 (P465), magnetic line data, AWAGS levelled

Total magnetic intensity (TMI) data measures variations in the intensity of the Earth's magnetic field caused by the contrasting content of rock-forming minerals in the Earth crust. Magnetic anomalies can be either positive (field stronger than normal) or negative (field weaker) depending on the susceptibility of the rock. The data 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. These line dataset from the Murray Basin (Ana Branch, Pooncarie), NSW, 1981 survey were acquired in 1981 by the NSW Government, and consisted of 14574 line-kilometres of data at 3000m line spacing and 150m terrain clearance. To constrain long wavelengths in the data, an independent data set, the Australia-wide Airborne Geophysical Survey (AWAGS) airborne magnetic data, was used to control the base levels of the survey data. This survey data is essentially levelled to AWAGS.

总磁场强度（Total Magnetic Intensity, TMI）数据可用于量化地壳中成岩矿物组分差异引发的地球磁场强度变化。磁异常可分为正异常（磁场强度高于正常背景水平）与负异常（磁场强度低于正常背景水平）两类，其类型取决于岩石的磁化率特性。该数据集通过标准流程开展预处理，以确保记录的磁场响应仅源于地下岩石的影响。经处理得到的数据集可通过地质解译，用以揭示地下地质结构。预处理后的数据会由GA地球物理学家进行质量核验，以确保GA发布的最终数据符合实际应用需求。本次涉及的测线数据集源自1981年新南威尔士州（New South Wales, NSW）政府实施的默里盆地（安娜支流、庞卡里地区）航磁测量项目，该项目于1981年完成，共涵盖14574测线公里的数据，测线间距为3000米，航高（相对地形）为150米。为约束数据中的长波长分量，项目采用独立数据集——澳大利亚全域航空地球物理调查（Australia-wide Airborne Geophysical Survey, AWAGS）航空磁测数据——对本次航测数据的基准面进行校正。本次航测数据已基本匹配AWAGS基准面。