Orbost, Vic, 1994 VIMP Survey (GSV2665) (P654), 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 Orbost, Vic, 1994 VIMP Survey (GSV2665) survey were acquired in 1994 by the VIC Government, and consisted of 20638 line-kilometres of data at 200m line spacing and 90m 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）数据用于量化地壳中成岩矿物含量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。该数据采用标准方法进行处理，以确保记录的磁场响应仅源自地下岩石。经处理得到的数据集可通过解译揭示地下地质结构。GA的地球物理学家会对处理后的数据开展质量核查，确保GA发布的最终数据满足使用需求。本次测线数据集源自1994年VIMP勘测项目（GSV2665），该项目位于维多利亚州奥博斯特，由维多利亚州政府于1994年完成，总测线长度达20638测线公里，测线间距为200米，飞行地形净空高度为90米。为约束数据中的长波长分量，项目采用了独立数据集——全澳航空地球物理勘测（Australia-wide Airborne Geophysical Survey，AWAGS）航空磁测数据，对本次勘测数据的基准值进行校准。本次勘测数据实质上已基于AWAGS数据完成平差校正。