Orroroo, Parachilna, SA, 1965 (P314), 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 Orroroo, Parachilna, SA, 1965 survey were acquired in 1965 by the SA Government, and consisted of 23067 line-kilometres of data at 1600m 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源于地下岩石。经处理得到的数据集可通过解译揭示地下地质结构。预处理后的数据已由GA地球物理学家完成质量核查，以确保GA发布的最终数据符合使用要求。本次1965年测量的测线数据集采集自南澳大利亚州奥罗鲁（Orroroo）、帕拉奇尔纳（Parachilna）区域，由南澳大利亚州政府于1965年完成采集，数据总长度达23067测线千米，测线间距为1600米，飞行离地高度为150米。为约束数据中的长波长分量，研究人员采用独立数据集——全澳航空地球物理调查（Airborne Geophysical Survey, AWAGS）航空磁测数据——对本次测量数据的基准水平进行校正。本次测量数据已基本匹配AWAGS的数据基准。