PHASE NOISE INVESTIGATION OF MAXIMUM LIKELIHOOD ESTIMATION METHOD FOR AIRBORNE MULTIBASELINE SAR INTERFEROMETRY
Keywords: Synthetic aperture radar (SAR), Interferometry, Multibaseline, Maximum likelihood, Phase unwrapping, MEMPHIS, Millimeter wave radar, Ka-band
Abstract. The phase estimation of cross-track multibaseline synthetic aperture interferometric data is usually thought to be very efficiently achieved using the maximum likelihood (ML) method. The suitability of this method is investigated here as applied to airborne single pass multibaseline data. Experimental interferometric data acquired with a Ka-band sensor were processed using (a) a ML method that fuses the complex data from all receivers and (b) a coarse-to-fine method that only uses the intermediate baselines to unwrap the phase values from the longest baseline. The phase noise was analyzed for both methods: in most cases, a small improvement was found when the ML method was used.