Officer Basin (Birksgate, Lindsay, Everard), SA, 1982 (P477), 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 Officer Basin (Birksgate, Lindsay, Everard), SA, 1982 survey were acquired in 1982 by the SA Government, and consisted of 10311 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.

总磁强度（Total Magnetic Intensity, TMI）数据用于测量由地壳中成岩矿物成分差异所引发的地球磁场强度变化。磁异常可分为正异常（磁场强度高于正常水平）与负异常（磁场强度低于正常水平），具体取决于岩石的磁化率。该数据通过标准处理流程开展预处理，以确保记录的磁场响应仅来自地下岩石。经处理后得到的数据集可通过地质解译揭示地下地质构造。GA地球物理学家会对预处理后的数据进行质量核验，以确保GA发布的最终数据满足使用需求。本次1982年科考的测线数据集采自南澳大利亚州（South Australia, SA）的Officer盆地（Birksgate、Lindsay、Everard区块），由南澳大利亚州政府于1982年采集，涵盖总长度10311线千米的数据，测线间距为3000米，飞行离地高度为150米。为约束数据中的长波长分量，研究人员引入独立数据集——全澳航空地球物理调查（Australia-wide Airborne Geophysical Survey, AWAGS）航空磁测数据——对本次科考数据的基准水平进行校正。本次科考数据已基本校准至AWAGS基准体系。