Birrindudu, WA, 1991 (wa241mr_b) (P871), 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 Balgo-West Tanami-Billiluna-Birrindudu merge, 1991-2002 survey were acquired in 1991 by the WA Government, and consisted of 176812 line-kilometres of data at a line spacing between 200m and 200m, and 60m 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）数据用于表征由地壳内成岩矿物成分差异所引发的地球磁场强度变化。依据岩石磁化率的差异，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）两类。该数据集已通过标准处理流程进行校正，确保仅记录地下岩石所产生的磁场响应。经处理后的数据集可通过解译揭示地下地质结构。GA地球物理学家已对处理后的数据开展质量核查，确保GA发布的最终数据符合使用要求。本次测线数据集源自1991-2002年实施的巴尔戈-西塔纳米-比利卢纳-比林杜杜联合航测，其原始数据于1991年由西澳大利亚州政府采集，总测线长度达176812测线千米，测线间距为200米，地形离地高度为60米。为约束数据中的长波长分量，研究人员采用全澳航空地球物理勘测（Australia-wide Airborne Geophysical Survey, AWAGS）的航空磁测数据作为基准，对本次航测数据的基准面进行校正，最终本次勘测数据已校准至AWAGS基准。