Napperby/Hermannsburg1 2, 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）数据用于测量由地壳内造岩矿物成分差异所引起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，其分类取决于岩石的磁化率特性。该数据集已通过标准流程进行预处理，以确保所记录的响应仅源自地下岩石。经处理后得到的数据集可通过解译，用以揭示地下地质构造。经处理的数据已由GA地球物理学家开展质量核查，以确保GA发布的最终数据集符合使用要求。该批测线数据集源自1997年于北领地（NT）纳珀比/赫尔曼斯堡开展的航空磁测工作，由北领地政府于1997年完成采集，总测线长度达105377测线千米，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成分，研究人员采用了独立数据集——全澳航空地球物理调查（Australia-wide Airborne Geophysical Survey, AWAGS）航空磁测数据，以对本次调查数据的基准电平进行校正。本次调查数据已基本校准至AWAGS基准体系。