FILTPHASE

This chapter describes the processing of step FILTPHASE. This step can be optionally used to filter the (latest) complex interferogram, in order to reduce noise, e.g., for visualization or aiding the phase unwrapping. It is probably best run after step SUBTRREFPHA. A lot of warnings can be generated if an image containing a lot of zeros is processed. These warnings can be ignored.

The method goldstein is described in [9]. Basically the fringes become sharper after filtering because the peak in the spectrum (caused by the fringes) is given a higher relative weight. Method spatialconv simply is a spatial convolution with a certain kernel function, e.g., a 3 point moving average. Method spectral is a multiplication of the spectrum with the kernel specified in an input file (e.g. a spectral low pass filter (LPF)).