Birrindudu - Wallamunga, NT, 1997 (P1001), 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 Tanami/Birrindudu, NT, 1997 survey were acquired in 1997 by the NT Government, and consisted of 81828 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.

总磁强度（Total Magnetic Intensity，TMI）数据用于表征地壳内造岩矿物成分差异所引发的地球磁场强度变化。磁异常可分为正异常（磁场强度高于正常值）与负异常（磁场强度低于正常值）两类，具体取决于岩石的磁化率。该数据集通过标准化处理流程进行预处理，以确保记录的磁场响应仅来源于地下岩石的影响。经处理后得到的数据集可通过地质解译，揭示地下的地质构造特征。经处理后的数据集由GA的地球物理学家开展质量核查，以确保GA发布的最终数据集符合使用需求。本次测线数据集源自1997年澳大利亚北领地（Northern Territory，NT）塔纳米/比林杜杜（Tanami/Birrindudu）地区的航磁测量项目，由北领地政府于1997年完成数据采集，总测线长度达81828线千米，测线间距介于200米至200米之间，离地高度为60米。为抑制数据中的长波长信号，项目引入了独立数据集——全澳航空地球物理调查（Airborne Geophysical Survey，AWAGS）航磁数据，用于校准本次测量数据的基准水平。本次测量数据实质上已基于AWAGS数据集完成了基准校正。