GSNSW Exploration NSW Area A3 Bancannia Trough magnetic first vd 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 first vd grid geodetic is a first vertical derivative of the Total Magnetic Intensity grid for the NSW DMR, Discovery 2000, 1994-95, AREA A3, Bancannia Trough.This grid has a cell size of 0.00063 degrees (approximately 65m). The grid has units of nanoTesla per km (or nT/km). The data used to produce the TMI 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. A Fast Fourier Transform (FFT) process was applied to the original grid to calculate the first vertical derivative grid.

总磁场强度（Total Magnetic Intensity, TMI）数据可测量由地壳内造岩矿物成分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，具体取决于岩石的磁化率。该数据通过标准化流程处理，以确保记录的响应仅源自地下岩石。处理后生成的数据集可通过解译揭示地下地质构造。经处理的数据将由GA地球物理学家开展质量检查，以确保GA发布的最终数据符合使用需求。本数据集为GSNSW勘探项目新南威尔士州A3区班卡尼亚海槽的地磁一阶垂直导数大地测量网格，对应新南威尔士州矿产资源局（New South Wales Department of Mineral Resources, NSW DMR）1994-1995年及2000年勘探项目（Discovery 2000）中A3区班卡尼亚海槽的总磁场强度网格的一阶垂直导数。该网格的单元尺寸为0.00063度（约65米），单位为纳特斯拉每千米（nT/km）。用于生成该总磁场强度网格的数据由新南威尔士州政府于1995年采集，共包含21000线千米的测量数据，测线间距为400米，地形离地高度为80米。研究人员对原始网格应用快速傅里叶变换（Fast Fourier Transform, FFT）流程，以计算得到该一阶垂直导数网格。