Youanmi 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 Youanmi magnetic grid geodetic has a cell size of 0.00063 degrees (approximately 65m). The units are in nanoTesla (or nT). The data used to produce this grid was acquired in 1999 by the WA Government, and consisted of 17233 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），具体取决于岩石的磁化率。该数据集通过标准流程进行预处理，以确保记录的响应仅源自地下岩石。经处理后得到的数据集可通过解译揭示地下地质结构。预处理后的数据由GA地球物理学家开展质量校验，以确保GA发布的最终数据符合使用要求。本尤阿米（Youanmi）磁格大地测量数据集的网格单元尺寸为0.00063度（约65米），数据单位为纳特斯拉（nanoTesla, nT）。该磁格的数据由西澳大利亚州政府于1999年采集，总测线长度达17233线公里，测线间距为400米，地形离地高度为80米。