Nonuniform sampling and robust stacking of transient electromagnetic signal

Abstract

A nonuniform sampling technique has been used to correct the sampling errors caused by an unstable timebase and interleaving. However, the nonuniform sampling method is intentionally used in this paper for a logarithmically changing signal to save storage space and reduce spike-like noise and Gaussian noise with a robust statistical method and variable rate stacking. The variable sampling rate, subsampling and robust stacking techniques are described. The advantages of the methods provided here are saving storage space, improving signal-to-noise ratio (SNR), reducing stacking time and minimizing spike-like and Gaussian noise effectively. The method provided is applied to the transient electromagnetic (TEM) measurement system design and the system SNR is improved significantly.