Abstract

The advent of interferometric SAR for geophysical studies has resulted in the need for accurate methods of two-dimensional phase unwrapping. Main approaches for phase unwrapping begin with the measured gradient of the phase field, which is subsequently integrated to recover the unwrapped phases. They also incorporate residue identification and cuts hence limiting the possible integration paths. In this paper, first principal components of different quality maps are used to guide the processes of phase unwrapping. Principal component analysis seeks directions in feature space that best represents the data in least squares sense. It is a way of expressing data to highlight their similarities and differences.Four types of quality maps are introduced, including Pearson coefficients, pseudo-correlation, phase derivate variance, and maximum phase gradient. The proposed scheme depends on quality maps to guide the placement of branch cut. It depends on the assumption that the residues are confined to a low quality regions and a quality map guides the integration path.The proposed model using different quality maps is verified. It was found that the branch-cut algorithm is quite accurate but does not produce estimates in regions of highly phase noise. A new synthesis model, combining the cuts and the first principal component transformation offers greater spatial coverage with less distortion in many instances.

Keywords: Phase Unwrapping, Radar Images, Interferometry, Quality maps, Principle Component

(P1150810001, 3.61 MB)

	Ashraf K. Helmy is Researcher in Data Reception, Analysis and Receiving Station Affairs Division, National Authority for Remote Sensing and Space Sciences. He has got his Ph.D. in information technology from Cairo University, 2005. His area of interest includes Satellite image processing, System analysis, design and implementation of GIS models.
	G.S.El-Taweel is a lecturer in faculty of computers and   Informatics, Suez Canal University. She got her Ph. D. In Information Technology from Cairo University, 2005. She Area of interest including Digital Image Processing, Signal Processing, and Computer Vision.

@ARTICLE{P1150810001,

AUTHOR = {Ashraf. K. Helmy and G.S.El-taweel},

TITLE = {Enhanced Model for Generating 3-D Images from RADAR Interferometric Satellite Images},

JOURNAL ={ICGST International Journal on Graphics, Vision and Image Processing, GVIP},

YEAR = {2008},

VOLUME = {08},

ISSUE ={I},

PAGES={41--46}

}

(P1150810001, 3.61 MB)