Wiluna thorium grid geodetic

The radiometric, or gamma-ray spectrometric method, measures the natural variations in the gamma-rays detected near the Earth's surface as the result of the natural radioactive decay of potassium (K), uranium (U) and thorium (Th). The data collected 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 radiometric thorium grid has a cell size of 0.00083 degrees (approximately 88m) and shows thorium element concentration of the Wiluna, WA, 1991 in units of parts per million (or ppm). The data used to produce this grid was acquired in 1990 by the WA Government, and consisted of 47000 line-kilometres of data at 400m line spacing and 60m terrain clearance.辐射测量法（radiometric method，即伽马射线能谱法）可检测地球表面附近的伽马射线自然变化，该变化源自钾（K）、铀（U）与钍（Th）的自然放射性衰变。所采集的数据将通过标准化流程进行预处理，确保记录的响应信号仅来自地下岩石的辐射贡献。经处理得到的数据集可通过解译，揭示地下地质构造。预处理完成的数据将由GA地球物理学家开展质量核验，确保GA发布的最终数据满足使用需求。本次发布的辐射测量钍元素网格数据，单元格分辨率为0.00083度（约合88米），展示了1991年西澳大利亚州（Western Australia，WA）威卢纳（Wiluna）地区的钍元素浓度分布，浓度单位为百万分之一（ppm）。用于生成该网格的数据由西澳大利亚州政府于1990年采集，总测线长度达47000千米，测线间距为400米，飞行离地高度为60米。