An approach for improving building height estimation from interferometric SAR data

Synthetic Aperture Radar interferometry (InSAR) is an established technique for retrieving digital elevation models. Last generation of metric resolution SAR systems promoted interest in investigations about InSAR potential for urban observation. It has been shown that accurate InSAR retrieval of the vertical dimension of buildings could be partially impaired by layover. Within a single baseline framework, firstly this paper aims at a further insight into the consequence of layover effect on InSAR observation of buildings, by working a suitable model. Secondly, following the model indications, a processing strategy is proposed to improve height estimation, exploiting the backscattering from highly reflecting structures which are frequently present on the roofs of buildings, at least in some geographic areas like Italy. A preliminary validation of the procedure is carried out using Italian Space Agency (ASI) COSMO-SkyMed Spotlight data acquired on the Tor Vergata University Campus test site in Rome.