Dubbo 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 85m) and shows thorium element concentration of the Dubbo Detail NSW 1991 in units of parts per million (or ppm). The data used to produce this grid was acquired in 1991 by the NSW Government, and consisted of 63636 line-kilometres of data at a line spacing between 200m and 400m, and 100m terrain clearance.

放射性测量法（Radiometric Method，亦称伽马能谱法（Gamma-ray Spectrometric Method））通过探测地球表面附近的伽马射线自然变化，量化由钾（K）、铀（U）及钍（Th）天然放射性衰变所产生的辐射响应。所采集的数据将通过标准化流程进行处理，以确保记录的响应仅源于地下岩石的辐射。经处理得到的数据集可通过解译，用以揭示地下地质构造特征。经处理的数据将由GA地球物理学家开展质量核验，确保GA发布的最终数据符合使用要求。本放射性钍元素网格的单元尺寸为0.00083度（约合85米），展示了1991年新南威尔士州（NSW）达博（Dubbo）详细测区的钍元素浓度，单位为百万分之一（ppm）。用于生成该网格的数据由新南威尔士州政府于1991年采集，总测线长度达63636线公里，测线间距介于200米至400米之间，地形离地高度为100米。