A new futering technique for correcting time variations in magnetic data

The earth's magnetic field fluctuates with time. The short-duration and small-amplitude fluctuations, known as Time Variations, distort the anomalies due to the geology during magnetic surveys. The standard method for removing time variations from the magnetic data is based on the assumption that the time variations measured at the base station and those encountered at the field stations are exactly the same, and accordingly the time variations are removed from the field data simply by subtracting the base station reading from the corresponding field station reading. This assumption is practically true for very local land-based surveys, in which the base and field stations are close to one another.