Nonlinear transformation analysis of the misregistered trade-off heterocorrelation filter: part 2, using the phase-only filter

Abstract

We continue our study of the misregistered trade-off heterocorrelation filter (HCF), introduced in Part 1. Instead of using the matched filter, we use only the phases of the Fourier transforms of the functions constituting the filter, with our basic filter being the phase-only filter. We show that by adjusting the value of the trade-off factor it is possible to make the correlation pattern and intensities of the heterocorrelation peaks equal to those of the autocorrelation peaks; in effect, making the HCF a homogeneous filter. This means that it can equally recognize totally different objects that one designs it to recognize. These results (1) turn out to be independent of the amount of misregistration (i.e., shift) between the centers of the impulse responses of the functions making up the filter and (2) can also support the claim that a HCF is a totally new approach to generating synthetic discriminant filter functions. We also produce plots showing how the intensities, peak-to-noise ratios, and peak-to-secondary ratios of both autocorrelation and heterocorrelation peaks behave as a function of trade-off factor.