Drysdale, Londonderry, WA, 1994 (P627), radiometric line data, AWAGS levelled

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 Drysdale, Londonderry, WA, 1994 (P627), radiometric line data, AWAGS levelled were acquired in 1994 by the WA Government, and consisted of 67630 line-kilometres of data at 400m line spacing and 80m terrain clearance. To constrain long wavelengths in the data, an independent data set, the Australia-wide Airborne Geophysical Survey (AWAGS) airborne magnetic data, was used to control the base levels of the survey data. This survey data is essentially levelled to AWAGS.

放射性测量法（radiometric method，亦称伽马能谱法（gamma-ray spectrometric method））可检测地球表面附近的伽马射线自然变化——该变化源于钾（K）、铀（U）以及钍（Th）的天然放射性衰变。所采集的数据将通过标准流程处理，以确保记录到的响应仅来自地下岩石。处理后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检查，以确保GA发布的最终数据符合使用要求。1994年由西澳大利亚州（Western Australia，简称WA）政府采集的编号为P627的干斯戴尔（Drysdale）、伦敦德里（Londonderry）地区航空放射性测线数据（经AWAGS平差处理），总测线长度达67630线公里，线间距为400米，飞行离地高度为80米。为约束数据中的长波长分量，研究人员采用独立数据集——全澳航空地球物理调查（Australia-wide Airborne Geophysical Survey，简称AWAGS）航空磁测数据——对本次测线数据的基准值进行校正。本次测线数据实质上已基于AWAGS数据完成平差校正。