Abstract: The downward continuation of potential fields plays an important role not only in gravity and magnetic data interpretation, but also in geomagnetic navigation. The downward continuation problem is essentially the solution of the Fredholm integral equation of the first kind. This paper presents a correlation coefficient method for downward continuation of potential fields adapted from the principle of probability tomography. Model experiment and real data application arrives at following conclusions: 1) when the downward-continuation distance reaches 10 grid intervals, the RMS error is about 0.23% of the maximal theoretical potential value; 2) adding white noise of MSE amplitude 1% and 5% of the maximal potential value to the theoretical potential field, MSE propagation coefficients 1.18 and 0.54 are obtained; 3) the result of realdata downward continuation by 10 grid intervals proves that the method has high precision, strong antinoise ability and good stability.

Key words: downward continuation, correlation coefficient, precision, anti-noise ability, stability