Ayr-St Lawrence, QLD, AIRDATA, 1996 (P796), 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 Ayr-St Lawrence, QLD, AIRDATA, 1996 survey were acquired in 1995 by the QLD Government, and consisted of 108435 line-kilometres of data at 400m line spacing and 80m 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）数据用于量化表征地壳中成岩矿物含量差异所引起的地球磁场强度变化。磁异常可分为正磁异常（磁场强度高于正常水平）与负磁异常（磁场强度低于正常水平），其类型取决于岩石的磁化率。本数据集通过标准流程完成预处理，以确保记录得到的响应仅来源于地下岩体。经处理后得到的数据集可通过解译揭示地下地质构造。预处理完成的数据将由GA地球物理学家开展质量核验，以确保GA发布的最终数据满足实际应用需求。本次测线数据集源自1996年开展的艾尔-圣劳伦斯（Ayr-St Lawrence）、昆士兰州（QLD）航空数据（AIRDATA）调查项目，该项目由昆士兰州政府于1995年实施，共获取108435线公里的测线数据，测线布设间距为400米，飞行离地高度为80米。为约束数据中的长波长分量，研究人员采用独立数据集——澳大利亚全域航空地球物理调查（Airborne Geophysical Survey, AWAGS）航空磁测数据——对本次调查数据的基准水平进行校正。本调查数据实质上已匹配至AWAGS基准。