MRTAS D'Aguilar Range tmi vd1 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 MRTAS D'Aguilar Range tmi vd1 grid geodetic is a first vertical derivative of the Total Magnetic Intensity grid for the D'Aguilar Range, Tas, 2001 (WTRMP Area E).This grid has a cell size of 0.00042 degrees (approximately 40m). The grid has units of nanoTesla per km (or nT/km). The data used to produce the TMI grid was acquired in 2001 by the TAS Government, and consisted of 1175 line-kilometres of data at 200m 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.

总磁强度（Total Magnetic Intensity, TMI）数据用于测量地壳中造岩矿物含量差异引起的地球磁场强度变化。磁异常可分为正异常（磁场强于正常值）或负异常（磁场弱于正常值），具体取决于岩石的磁化率。数据通过标准方法处理，以确保记录的响应仅来源于地下岩石。处理结果生成的数据集可通过解释揭示地下地质结构。澳大利亚地质调查局（GA）地球物理学家会对处理后的数据进行质量检查，确保GA发布的最终数据符合预期用途。

此MRTAS达吉拉山脉TMI vd1大地测量网格是2001年塔斯马尼亚州达吉拉山脉总磁强度网格（WTRMP E区）的一阶垂直导数。该网格的像元大小为0.00042度（约40米），单位为纳特斯拉每公里（nT/km）。生成TMI网格所用的数据由塔斯马尼亚州政府（TAS Government）于2001年采集，包含1175公里测线数据，测线间距200米，地形净空高度80米。通过快速傅里叶变换（Fast Fourier Transform, FFT）处理原始网格，计算得到一阶垂直导数网格。