GSNSW Exploration NSW Area Y Murray Riverina 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 Y Murray Riverina magnetic first vd grid geodetic is a first vertical derivative of the Total Magnetic Intensity grid for the Murray - Riverina, NSW, 2003 (Area Y).This grid has a cell size of 0.00098 degrees (approximately 100m). The grid has units of nanoTesla per km (or nT/km). The data used to produce the TMI grid was acquired in 2003 by the NSW Government, and consisted of 160619 line-kilometres of data at 400m line spacing and 60m 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）数据用于量化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（磁场强度高于正常基准值）与负异常（磁场强度低于正常基准值），具体取决于岩石的磁化率。
该数据集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。经处理得到的数据集可通过解译揭示地下地质构造。预处理后的数据会由GA地球物理学家进行质量核验，确保GA发布的最终数据符合使用需求。
本次提供的GSNSW勘探新南威尔士州Y区域墨累-里弗赖纳磁一阶垂直导数大地测量网格，为2003年新南威尔士州墨累-里弗赖纳（Y区域）总磁场强度网格的一阶垂直导数产品。该网格的单元尺寸为0.00098度（约合100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2003年采集，共计160619线千米的测量数据，测线间距为400米，飞行离地高度为60米。研究人员通过快速傅里叶变换（Fast Fourier Transform, FFT）流程对原始总磁场强度网格进行处理，以计算得到该一阶垂直导数网格。