GSNSW Exploration NSW Area L Gilgandra 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 L Gilgandra 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 1999 by the NSW Government, and consisted of 31389 line-kilometres of data at 250m line spacing and 60m terrain clearance.

总磁场强度（Total Magnetic Intensity, TMI）数据可表征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），其类型取决于岩石的磁化率。该数据通过标准处理流程进行加工，以确保记录的磁场响应仅源于地下岩石。处理后得到的数据集可通过解译揭示地下地质构造。经处理的数据由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应用需求。本次GSNSW新南威尔士州L吉尔格拉勘探区磁测大地测量网格数据的网格单元尺寸为0.00048度（约50米），数据单位为纳特斯拉（nanoTesla, nT）。用于生成该网格的数据由新南威尔士州政府于1999年采集，总测线长度达31389线公里，测线间距为250米，地形离地高度为60米。