NT P1268 Dunmarra 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 NT P1268 Dunmarra Doserate Grid Geodetic has a cell size of 0.00083 degrees (approximately 91m) and shows the terrestrial dose rate of the Dunmarra, NT, 2014. The data used to produce this grid was acquired in 2014 by the NT Government, and consisted of 104017 line-kilometres of data at 400m line spacing and 80m terrain clearance.

辐射测量法（radiometric method，又称伽马射线能谱法（gamma-ray spectrometric method））可通过探测地球表面附近的伽马射线自然变化，表征钾（K）、铀（U）及钍（Th）的天然放射性衰变所产生的伽马射线信号。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放射性衰变。最终生成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（Geoscience Australia）的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应用要求。地表剂量率网格（terrestrial dose rate grid）是经滤波后的钾、铀、钍网格的线性组合得到的。在此网格上应用低通滤波器（low pass filter），即可生成滤波后的地表剂量率网格。本数据集为北领地（Northern Territory，NT）P1268邓马拉剂量率大地测量网格，其像元尺寸为0.00083度（约91米），展示了2014年北领地邓马拉地区的地表剂量率分布。用于生成该网格的数据由北领地政府于2014年采集，包含104017线公里的测线数据，测线间距为400米，地形离地高度为80米。