Officer Basin (Browne,Yowalga,Westwood,Lennis,Waigen), WA, 1976 (P431), 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 (Browne,Yowalga,Westwood,Lennis,Waigen), WA, 1976 survey were acquired in 1976 by the WA Government, and consisted of 33329 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）数据用于测量地壳内造岩矿物成分差异所引起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。该数据通过标准处理流程处理，以确保记录的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。经处理后的数据会由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要求。本次1976年勘查的测线数据集源自西澳大利亚州奥菲尔盆地（Browne、Yowalga、Westwood、Lennis、Waigen区域），由西澳大利亚州政府于1976年采集，总测线覆盖长度达33329测线公里，测线间距为3000米，地形飞行离地高度为150米。为约束数据中的长波长区域场成分，本次勘查采用独立数据集——全澳航空地球物理调查（Australia-wide Airborne Geophysical Survey, AWAGS）航空磁测数据——对测线数据的基准面进行校正。本勘查数据实质上已平差至AWAGS基准。