Boorabbin, WA,1959 (P197), 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 Boorabbin, Norseman, WA,1959 survey were acquired in 1959 by the WA Government, and consisted of 22100 line-kilometres of data at 1600m line spacing and 400m 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）数据用于量化地壳中成岩矿物组分差异所引发的地球磁场强度波动。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）两类，具体取决于岩石的磁化率。该数据集通过标准化流程进行处理，以确保所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构造。经处理的数据需由GA地球物理学家开展质量核查，以确保GA发布的最终数据符合使用需求。1959年布罗本（Boorabbin）、诺斯曼（Norseman）及西澳大利亚州（Western Australia, WA）测线数据集，由西澳大利亚州政府于1959年采集完成，总测线里程达22100测线公里，测线间距为1600米，飞行离地高度为400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（Australia-wide Airborne Geophysical Survey, AWAGS）航空磁测数据——对本次测线数据的基准水平进行校正。本测线数据实质上已与AWAGS数据集完成平差对齐。