Yilgarn Block (Hyden), WA, 1976 (P439), 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 Yilgarn Block (Hyden), WA, 1976 survey were acquired in 1976 by the WA Government, and consisted of 12173 line-kilometres of data at 1500m 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.

总磁场强度（Total Magnetic Intensity, TMI）数据可量化表征地壳内造岩矿物组分差异引发的地球磁场强度变化。磁异常可分为正异常（磁场强度高于正常背景）与负异常（磁场强度低于正常背景），具体取决于岩石的磁化率。该数据集通过标准化流程处理，确保记录的响应仅源于地下岩石。经处理后得到的数据集可通过解译揭示地下地质构造。经处理的数据已由GA地球物理学家开展质量校验，确保GA发布的最终数据符合使用要求。本次1976年西澳大利亚州伊尔冈地块（哈登）航磁测量获取的测线数据集，由西澳大利亚州政府于1976年采集，总测线长度达12173千米，测线间距为1500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（Australia-wide Airborne Geophysical Survey, AWAGS）航空磁测数据——对本次航磁数据的基准水平进行校正。本次航磁数据已基本校准至AWAGS基准体系。