Newcastle Waters, Beetaloo, NT, 1987 (P528), 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 Newcastle Waters, Beetaloo, NT, 1987 survey were acquired in 1987 by the NT Government, and consisted of 31050 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），其分类结果取决于岩石的磁化率。该数据通过标准化处理流程进行加工，以确保记录的磁场响应仅源自地下岩石。经处理后得到的数据集可通过解译揭示地下地质结构。经处理的数据由GA地球物理学家开展质量核查，以确保GA发布的最终数据满足使用需求。本次1987年采集的测线数据集源自北领地（Northern Territory，NT）比塔罗（Beetaloo）的纽卡斯尔水域（Newcastle Waters）勘探项目，由NT政府于1987年完成数据采集，总测线长度达31050线公里，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——对本次测线数据的基准面进行校正。本次测线数据实质上已基于AWAGS数据完成平差校正。