MRTAS NE Tasmania 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（或称伽马能谱测量法）通过探测地球表面附近的伽马射线，测量由钾、铀和钍的自然放射性衰变所引起的该射线的自然变化。这些数据通过联邦、州及北领地政府与私营部门开展的航空地球物理勘查获取。