LOCAL NOISE PREDICTION FILTERING FOR CENTRAL INDUCTION TRANSIENT ELECTROMAGNETIC SOUNDING

This paper describes an alternative method of reducing the noise level, which will be termed local noise prediction filtering (LNPF). It can be used with the in-loop configuration, for which the receiver (either an induction coil or magnetometer) is located at the center of the transmitter loop. The technique relies on the fact that over a horizontally layered earth the TEM response is contained exclusively in the vertical component, and fields recorded contemporaneously in the horizontal component will be necessarily noise. 35 Refs.