GSNSW Exploration NSW Area A3 Bancannia Trough magnetic grid geodetic

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.This GSNSW Exploration NSW Area A3 Bancannia Trough magnetic grid geodetic has a cell size of 0.00048 degrees (approximately 50m). The units are in nanoTesla (or nT). The data used to produce this grid was acquired in 1995 by the NSW Government, and consisted of 21000 line-kilometres of data at 400m line spacing and 80m terrain clearance.

总磁强度（Total Magnetic Intensity, TMI）数据用于表征由地壳中成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（磁场强度高于正常基准）与负异常（磁场强度低于正常基准），其分类取决于岩石的磁化率。该数据通过标准化处理流程开展预处理，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地质解译揭示地下地质结构。经处理的数据会由GA地球物理学家进行质量核验，以保障GA发布的最终数据符合使用要求。本次的GSNSW新南威尔士州勘探区A3班卡尼亚海槽磁测大地网格数据，其格网单元尺寸为0.00048度（约50米），数据单位为纳特斯拉（nanoTesla，简称nT）。用于生成该网格的数据由新南威尔士州政府于1995年采集，总测线长度达21000线公里，测线间距为400米，地形离地高度为80米。