Detecting changes in persistent scatterers

In PSI (Persistent Scatterer Interferometry) the PSs are implicitly assumed to have a stable phase throughout a stack of images so that all images can be used for estimation. However, PSs can fade due to changes in acquisition geometry where the elevation or azimuth response of the PS for different baselines or zero Doppler frequencies is imprinted on the return. Physical changes caused by construction or seasonal changes due to snow cover can also cause the sudden appearance or disappearance of a PS. Here, several parametric change point estimators are assessed for their suitability in detecting such events both through simulation and their application to an ERS stack over Hamburg.