DETRENDING OF NONSTATIONARY NOISE DATA BY SPLINE TECHNIQUES

An off-line method of detrending non-stationary noise data is given. I t uses a least-squares spline approximation of the noise data with equ ally spaced breakpoints. Subtraction of the spline approximation from the noise signal at each data point gives a residual noise signal. The method acts as a high-pass filter with very sharp frequency cut-off. The cut-off frequency is determined by the breakpoint distance. The st eepness of the cut-off is controlled by the spline order. (C) 1998 Els evier Science Ltd. All rights reserved.