Method to resolve ambiguities in a phase measurement

Details Method to resolve ambiguities in a phase measurement Method to resolve ambiguities in a phase measurement

1997-03-13

1998-06-30

Sotomayor, John B.

Communications: directive radio wave systems and devices (e.g.,

Synthetic aperture radar

342156, 342162, 342191, 342195, 342203, G01S 1390

Patent

active

057740895

ABSTRACT:
In a method to resolve ambiguities in a phase measurement for application in radar interferometry, a frequency estimation method is used, starting from conjugate complex products of pairs of adjacent pixels in an interferogram. The resolution of these products is subsequently reduced through successive addition or averaging, after which the differential phase of adjacent resolution levels is determined in each resolution level. The sum of the phase differences yields the estimated value for the phase gradient which is then used in a known method, such as the least-squares method, to reconstruct the absolute phase, thus resolving the phase ambiguities. The method according to the invention serves to resolve phase ambiguities in radar interferograms without producing the known distortions produced by the existing methods. The method is also robust at low coherence values as they occur in repeat-pass interferometry where the existing methods fail. The method allows for a simple adaptation to the common local variations in interferogram quality.

REFERENCES:
patent: 4843597 (1989-06-01), Gjessing et al.
patent: 4975704 (1990-12-01), Gabriel et al.
patent: 5332999 (1994-07-01), Prati et al.
patent: 5424743 (1995-06-01), Ghiglia et al.
patent: 5463397 (1995-10-01), Frankot
patent: 5488374 (1996-01-01), Frankot et al.
patent: 5552787 (1996-09-01), Schuler et al.
patent: 5659318 (1997-08-01), Madsen et al.
patent: 5677693 (1997-10-01), Frankot et al.
patent: 5706012 (1998-01-01), Kay
Goldstein et al., "Satellite Radar Interferometry: Two-Dimensional Phase Unwrapping", Radio Science, vol. 23, No. 4, pp. 713-720, Jul.-Aug. 1988.
Hunt, "Matrix Formulation of the Reconstruction of Phase Values from Phase Differences", Journal of the Optical Society of America, vol. 69, No. 3, pp. 393-399, Mar. 1979.
Takajo et al., "Least-Squares Phase Estimation from the Difference", Journal of the Optical Society of America, vol. 5, No. 3, pp. 416-425, Mar. 1988.
Ghiglia et al., "Direct Phase Estimation from Phase Difference Using Fast Elliptic Partial Differential Equatin Solvers", Optics Letters, vol. 14, No. 20, pp. 1107-1109, Oct. 15, 1989.
Ghiglia et al., "Robust Two-Dimensional Weighted and Unweighted Phase Unwrapping that Uses Fast Transforms and Iterative Methods", Journal of the Optical Society of America, vol. 11, No. 1, pp. 107-117, Jan. 1994.
Pritt et al., "Least-Squares Two Dimensional Phase Unwrapping Using FFT's", IEEE Transactions on Geoscience and Remote Sensing, vol. 32, No. 3, pp. 706-708, May 1994.
Buckland et al., "Unwrapping Noisy Phase Maps by Use of a Minimum-Cost-Matching Algorithm", Applied Optics, vol. 34, No. 23, pp. 5100-5108, Aug. 10, 1995.
Quiroga et al., "Stable-Marriages Algorithm for Preprocessing Phase Maps With Discontinuity Sources", Applied Optics, vol. 34, No. 23, pp. 5029-5038, Aug. 10, 1995.
Fornaro et al., "Two Dimensional Phase Unwrapping Based on the Laplace and Eikonal Equations", 1995 International Geoscience and Remote Sensing Symposium, vol. III, pp 1828-1830, 1995.
Prati et al., "SAR Interferometry: A 2-D Phase Unwrapping Technique Based on Phase and Absolute Value Information", Proc. of Intern. Geoscience and Remote Sensing Symposium, pp. 2043-2046, 1990.

Affiliated with

Also associated with

Rating

Method to resolve ambiguities in a phase measurement does not yet have a rating. At this time, there are no reviews or comments for this patent.

If you have personal experience with Method to resolve ambiguities in a phase measurement, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Method to resolve ambiguities in a phase measurement will most certainly appreciate the feedback.

Rate now

Comments { 0 }

Profile ID: LFUS-PAI-O-1864487