Helen Springs - Monmoona, NT, 1993 (P611), 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 Helen Springs/Beetaloo, NT, 1993 survey were acquired in 1993 by the NT Government, and consisted of 117753 line-kilometres of data at a line spacing between 300m and 300m, and 100m 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（磁场强度高于正常水平）与负异常（磁场强度低于正常水平），其类型取决于岩石的磁化率。本数据集通过标准处理流程进行处理，以确保记录的响应仅源于地下岩石。经处理得到的数据集可用于解译，以揭示地下地质结构。处理后的数据已由GA地球物理学家开展质量核查，以确保GA发布的最终数据符合使用要求。
本次测线数据集源自北领地（NT）海伦斯普林斯/比塔卢地区1993年开展的调查，由北领地政府于1993年采集完成，总数据量达117753线公里，线间距介于300米至300米之间，地形离地高度为100米。
为约束数据中的长波长成分，研究人员采用了全澳航空地球物理调查（Australia-wide Airborne Geophysical Survey, AWAGS）的航空磁测数据作为独立数据集，对本次调查数据的基准面进行控制。本调查数据实质上已校准至AWAGS基准。