GSWA Charnley Thorium 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, uranium and thorium. The data are collected on airborne geophysical surveys conducted by Commonwealth, State & NT Governments and the private sector.

放射性测量法（radiometric method，又称伽马射线能谱法（gamma-ray spectrometric method））能够测量地球表面附近探测到的伽马射线的自然变化，此类变化源于钾、铀和钍的自然放射性衰变。此类数据采集自由联邦、各州及北领地政府与私营部门开展的航空地球物理勘测项目。