TEISA - Area A1, SA, 1999 (P850), 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 TEISA - Area A (A1-A7), SA, 1999 survey were acquired in 1999 by the SA Government, and consisted of 60817 line-kilometres of data at 400m line spacing 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.

总磁强度（Total Magnetic Intensity, TMI）数据用于测量地壳中成岩矿物成分差异引发的地球磁场强度变化。磁异常可依据岩石磁化率的差异，表现为正异常（磁场强度高于正常值）或负异常（磁场强度低于正常值）。该数据集通过标准流程处理，以确保记录的响应仅来源于地下岩石。经处理后得到的数据集可通过解译揭示地下地质构造。经处理的数据将由GA地球物理学家开展质量核验，确保GA发布的最终数据符合使用要求。本次测线数据集由南澳州政府于1999年采集，源自南澳（SA）TEISA A区（A1-A7）的1999年勘测项目，总测线长度达60817线公里，测线间距为400米，飞行离地高度为80米。为压制数据中的长波长信号，项目采用独立数据集——全澳航空地球物理调查（Australia-wide Airborne Geophysical Survey, AWAGS）航空磁测数据——对本次勘测数据的基准水平进行校正。本次勘测数据已基本匹配AWAGS基准。