Journals Information
Universal Journal of Geoscience(CEASE PUBLICATION) Vol. 2(2), pp. 35 - 42
DOI: 10.13189/ujg.2014.020201
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Solving Rank-deficient Linear Systems for the Estimation of the Atmospheric Phase Delay Parameter
Vassilia Karathanassi *, Arlinda Saqellari-Likoka
Laboratory of Remote Sensing, School of Rural and Surveying Engineering, National Technical University of Athens, 9 Heroon Polytechniou Street, 15780, Zographos, Greece
ABSTRACT
For each pixel, the values of the unwrapped phase produced by interferometric pairs can be parameterized and phase components, such as height, atmospheric path delay difference for the dates of every interferometric set image acquisition, and unwrapping error can be estimated through the solution of a rank deficient system of equations. There are several state of the art methods for solving rank deficient systems of equations, such as the Lower-Upper method, QR factorization and Singular Value Decomposition (SVD). In a previous work, the improved SVD method, which enables the accurate estimation of phase components, has been proposed. In this study, one alternative method for the estimation of the differential interferometry parameters, the improved QR, is proposed. The method relies on the reorganization of the system of equations by using external meteorological data which correspond to the acquisition dates that are less present in the interferometric SAR data set. All the aforementioned methods were tested and compared. The improved SVD and improved QR methods yield the most satisfactory results for all the phase components. The former estimates the heights by achieving almost GPS accuracy, whereas the latter is more robust, producing results of almost the same accuracy for all the estimated atmospheric path delays. However, the requirement of known values for at least two phase components makes the improved QR method less operational.
KEYWORDS
Interferometry, Atmospheric Path Delay, Dinsar, Rank Deficient Linear System
Cite This Paper in IEEE or APA Citation Styles
(a). IEEE Format:
[1] Vassilia Karathanassi , Arlinda Saqellari-Likoka , "Solving Rank-deficient Linear Systems for the Estimation of the Atmospheric Phase Delay Parameter," Universal Journal of Geoscience(CEASE PUBLICATION), Vol. 2, No. 2, pp. 35 - 42, 2014. DOI: 10.13189/ujg.2014.020201.
(b). APA Format:
Vassilia Karathanassi , Arlinda Saqellari-Likoka (2014). Solving Rank-deficient Linear Systems for the Estimation of the Atmospheric Phase Delay Parameter. Universal Journal of Geoscience(CEASE PUBLICATION), 2(2), 35 - 42. DOI: 10.13189/ujg.2014.020201.