GSWA Boorabbin Lake Johnston Doserate 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. 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 GSWA Boorabbin Lake Johnston Doserate Grid Geodetic has a cell size of 0.0005 degrees (approximately 51m) and shows the terrestrial dose rate of the Boorabbin-Lake Johnston merge, 1987-2005. The data used to produce this grid was acquired in 1987 by the WA Government, and consisted of 121097 line-kilometres of data at a line spacing between 200m and 400m, and 60m terrain clearance.

放射性测量法（radiometric method）或称伽马射线能谱法（gamma-ray spectrometric method）可通过探测地表附近的伽马射线，量化由钾（K）、铀（U）及钍（Th）天然放射性衰变产生的伽马射线自然变化。所采集的数据将通过标准化流程处理，以确保记录的响应仅源于地下岩石的放射性作用。经处理得到的数据集可通过解译，揭示地下地质构造。经处理的数据将由GA地球物理学家开展质量核查，以确保GA发布的最终数据符合使用要求。地面剂量率网格通过滤波后的钾、铀、钍网格的线性组合生成，并对该网格施加低通滤波器，得到滤波后的地面剂量率网格。本数据集为西澳地质调查局（GSWA）布尔宾-约翰逊湖剂量率大地测量网格，其网格单元尺寸为0.0005度（约51米），展示了1987-2005年布尔宾与约翰逊湖合并区域的地面剂量率分布。本网格的数据由西澳州政府于1987年采集，总测线长度达121097线公里，测线间距介于200米至400米之间，地形离地高度为60米。