Duchess, QLD, 1975 (P423), 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 Duchess, QLD, 1975 (P423), radiometric line data, AWAGS levelled were acquired in 1975 by the QLD Government, and consisted of 13936 line-kilometres of data at 1500m line spacing and 150m 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.

放射测量法（radiometric method），亦称伽马射线能谱法（gamma-ray spectrometric method），可检测地球表面附近探测到的伽马射线自然变化，该变化源自钾（K）、铀（U）与钍（Th）的天然放射性衰变。所采集的数据将经由标准流程进行处理，以确保记录的响应信号仅来自地下岩石。经解译该数据集可揭示地下地质构造。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既定使用要求。本次数据集为1975年由昆士兰州（QLD）政府采集的昆士兰州达奇斯（Duchess）地区放射测量航线数据（编号P423），该数据经AWAGS平差处理，总测线长度达13936公里，测线间距为1500米，飞行离地高度为150米。为抑制数据中的长波长区域漂移，本次调查采用独立数据集——澳大利亚全域航空地球物理调查（Australia-wide Airborne Geophysical Survey，AWAGS）航空磁测数据——对本次调查数据的基准值进行校准。本次调查数据本质上已按照AWAGS标准完成平差校正。