Cobar P5009 EXT 2 dose rate grid

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. The terrestrial dose rate grid is derived as a linear combination of the filtered K, U and Th grids. A low pass filter is applied to this grid to generate the filtered terrestrial dose rate grid. This Cobar P5009 EXT 2 dose rate grid has a cell size of 0.00039074 degrees (approximately 40m) and shows the terrestrial dose rate of the Cobar Magnetic and Radiometric Survey, 2021. The data used to produce this grid was acquired in 2021 by the NSW Government, and consisted of 53617 line-kilometres of data at 200m line spacing and 60m terrain clearance.

放射测量法（radiometric method，或称伽马射线光谱法gamma-ray spectrometric method）测量地球表面附近探测到的伽马射线的自然变化，这些变化由钾（K）、铀（U）和钍（Th）的自然放射性衰变引起。收集的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。GA地球物理学家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。陆地剂量率网格是通过滤波后的K、U和Th网格的线性组合得到的。对该网格应用低通滤波器，生成滤波后的陆地剂量率网格。此Cobar P5009 EXT 2剂量率网格的单元格大小为0.00039074度（约40米），展示了2021年Cobar磁法与放射测量调查的陆地剂量率。生成该网格所用的数据由新南威尔士州政府（NSW Government）于2021年采集，包含53617线公里的数据，线间距为200米，地形净空高度为60米。