SA Exploration Initiative, Area E3, 1994 (P721), 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 SA Exploration Initiative, Area E3, 1994 survey were acquired in 1994 by the SA Government, and consisted of 23209 line-kilometres of data at a line spacing between 200m and 200m, and 80m 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）数据可测量由地壳内造岩矿物成分差异引发的地球磁场强度变化。磁异常可分为正异常（磁场强度高于正常值）与负异常（磁场强度低于正常值），具体取决于岩石的磁化率。该数据集通过标准化方法开展处理，以确保所记录的响应仅源自地下岩石。经处理后得到的数据集可通过解译揭示地下地质结构。经处理的数据已由GA地球物理学家进行质量核查，以确保GA发布的最终数据符合使用要求。这套测线数据集源自南澳勘探倡议（SA Exploration Initiative）E3区1994年调查项目，由南澳政府于1994年采集，总测线长度达23209千米，测线间距为200米至200米，飞行离地高度为80米。为约束数据中的长波长成分，本次调查采用独立数据集——全澳航空地球物理调查（Australia-wide Airborne Geophysical Survey, AWAGS）航空磁测数据——作为基准以校正本次调查数据的基线水平，本测区数据已基本校准至AWAGS基准。