Enhanced downward continuation of potential field data via smoothing filters

Abstract Downward continuation of potential field is a useful tool in the processing and interpretation of magnetic and gravity data, but its direct calculation in space or spectral domain is unstable even in the presence of a small level of the noise and consequently restricts its practical application. This paper introduces a new method that combines upward continuation, vertical gradient via smoothing filters (Tikhonov regularization or Gaussian filters) and an iterative method into a single scheme to improve the stability and accuracy of the downward continuation. The optimal interval of iteration numbers for our developed approach is estimated by analysing the correlation coefficient curve between consecutive iterations. Applications to synthetic and real magnetic data show that this method can yield a more stable downward continuation of potential field data.