Wyloo (BHP), WA, 1973 (P585), 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 Wyloo (BHP), WA, 1973 survey were acquired in 1973 by the WA Government, and consisted of 15307 line-kilometres of data at a line spacing between 500m and 500m, and 130m 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含量差异所引发的地球磁场强度变化。磁异常可分为正异常（磁场强度高于正常背景场）与负异常（磁场强度低于正常背景场），其类型取决于岩石的磁化率。该数据通过标准化流程处理，以确保所记录的响应仅源自地下岩石。经处理得到的数据集可通过解译揭示地下地质结构。处理后的数据需由GA地球物理学家开展质量核验，以确保GA发布的最终数据符合使用需求。本次航线数据集源自1973年西澳大利亚州（Western Australia，WA）怀卢（Wyloo，必和必拓（BHP））的航空物探调查，由西澳大利亚州政府于1973年采集，总数据量为15307线公里，线间距为500米，飞行离地高度为130米。为约束数据中的长波长分量，本次调查采用独立数据集全澳航空物探调查（Australia-wide Airborne Geophysical Survey，AWAGS）航空磁测数据，对本次调查数据的基准面进行校准。本次调查数据实质上已校准至AWAGS基准。