Napperby/Hermannsburg cpmpany data, NT, 1997 (P1002), 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 Napperby/Hermannsburg, NT, 1997 survey were acquired in 1997 by the NT Government, and consisted of 105377 line-kilometres of data at 400m line spacing 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）数据用于量化地壳中成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（磁场强度高于背景水平）与负异常（磁场强度低于背景水平），具体取决于岩石的磁化率。该数据集通过标准处理流程开展预处理，以确保所记录的磁场响应仅由地下岩石引起。经处理得到的数据集可通过地质解译揭示地下地质构造。经处理的数据将由GA地球物理学家开展质量核查，确保GA对外发布的最终数据集满足使用需求。本次1997年北领地（NT）纳珀比/赫曼斯堡测线调查数据集由北领地政府于1997年采集，总测线长度达105377测线公里，测线间距为400米，飞行离地高度为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——对本次测线数据的基准水平进行校正。本次测线数据已基本匹配AWAGS数据集的基准。