In this paper, we examine the role of polarimetry in synthetic aperture radar (SAR) interferometry. We first propose a general formulation for vector wave interferometry that includes conventional scalar interferometry as a special case. Then, we show how polarimetric basis transformations can be introduced into SAR interferometry and applied to form interferograms between all possible linear combinations of polarization states. This allows us to reveal the strong polarization dependency of the interferometric coherence. We then solve the coherence optimization problem involving maximization of interferometric coherence and formulate a new coherent decomposition for polarimetric SAR interferometry that allows the separation of the effective phase centers of different scattering mechanisms. A simplified stochastic scattering model for an elevated forest canopy is introduced to demonstrate the effectiveness of the proposed algorithms. In this way, we demonstrate the importance of wave polarization for the physical interpretation of SAR interferograms. We investigate the potential of polarimetric SAR interferometry using results from the evaluation of fully polarimetric interferometric shuttle imaging radar (SIR)-C/X-SAR data collected during October 8-9, 1994, over the SE Baikal Lake Selenga delta region of Buriatia, Southeast Siberia, Russia.

Polarimetric SAR interferometry

https://www.geo.uzh.ch/microsite/rsl-documents/research/publications/peer-reviewed-articles/2011_Mulder_TheUseOfRemSens-3206019584/2011_Mulder_TheUseOfRemSens.pdf

The use of remote sensing in soil and terrain mapping — A review

Texture features for image classification and retrieval.

A fast, powerful and stable filter based on combined wavelet and Fourier analysis for the elimination of horizontal or vertical stripes in images is presented and compared with other types of destriping filters. Strict separation between artifacts and original features allowing both, suppression of the unwanted structures and high degree of preservation of the original image information is endeavoured. The results are validated by visual assessments, as well as by quantitative estimation of the image energy loss. The capabilities and the performance of the filter are tested on a number of case studies related to applications in tomographic imaging. The case studies include (i) suppression of waterfall artifacts in electron microscopy images based on focussed ion beam nanotomography, (ii) removal of different types of ring artifacts in synchrotron based X-ray microtomography and (iii) suppression of horizontal stripe artifacts from phase projections in grating interferometry.

/pdf/stripe-and-ring-artifact-removal-with-combined-wavelet-552aur2eiq.pdf

Stripe and ring artifact removal with combined wavelet--Fourier filtering.

(1981). Practical Nonparametric Statistics (2nd ed.) Technometrics: Vol. 23, No. 4, pp. 415-416.

Practical Nonparametric Statistics (2nd ed.)

Rice monitoring and production estimation using multitemporal RADARSAT

Sharp and repetitive stripes exist in many bands of Chinese Moderate Imaging Spectroradiometer (CMODIS) images because of gain and offset variations between neighboring forward and reverse scans of 22 detectors, which can distractingly and obstructively affect the interpretation and application of CMODIS data. In this letter, we suggest a method for destriping based on a finite-impulse response (FIR) filter in frequency domain and present the results obtained with the method on the experimental CMODIS images of heterogeneous targets. We also compare the method with some traditional destriping methods (e.g. lowpass filtering, moment matching) and display the result of comparison using one of the images. The destriping effectiveness is evaluated by means of appropriate indexes of quality in this letter.

Destriping CMODIS data by power filtering

Research advances of SAR remote sensing for agriculture applications: A review

Oblique sharp and repetitive stripes in remote sensing imagery can distractingly and obstructively affect the interpretation and application of remote sensing data. A new methodology for removing oblique stripes, based on discrete wavelet transform (DWT), is proposed. DWT has been used to transform a multispectral image into a frequency domain to find the frequency components caused by stripes. The new technique has been tested taking CMODIS imagery as an example and evaluated by a number of indices. The results show that the proposed method can remove oblique stripes effectively and keep most image information.

Oblique striping removal in remote sensing imagery based on wavelet transform

This paper presents the experimental results regarding changes in the dielectric properties of artificially moistened and salinized soils and on soil samples taken from a salt lake. The complex dielectric constants of soil samples were measured using a microwave network analyzer. We evaluated the real and imaginary parts of dielectric constants of artificially moistened and salinized soil samples prepared in the laboratory as a function of microwave frequency, salinity, and water content. The soil moisture strongly affected the real part of dielectric constant /spl epsiv/'. The frequency and the salinity of soils have little influence on the real part of dielectric constant /spl epsiv/'. The imaginary part of the dielectric constant /spl epsiv/'' is strongly affected by both the salinity and moisture of soil samples, especially at low frequencies. When f<2 GHz, the imaginary part /spl epsiv/'' decreases with each increment of frequency; in contrast, at higher frequencies, /spl epsiv/'' tends toward a constant. The results show that in the frequency range of 1-6 GHz, the imaginary part /spl epsiv/'' has greater sensitivity to soil salinity. Therefore, C and L band are more suitable for soil salinity detection, but L band is better than C band. The dielectric constant measurements for soil samples collected in Jilantai Salt Lake are in agreement with the results of the artificially moistened and salinized laboratory soil samples. These dielectric measurements were subsequently compared with the /spl sigma//sup 0/ backscattering coefficients extracted from a RADARSAT image (C-HH) that was acquired at same time with the soil sampling at the Jilantai Salt Lake area. We discovered that the correlation coefficient between /spl sigma//sup 0/ extracted from the RADARSAT image and /spl epsiv/" measured in the soil sample is 0.70, whereas the correlation coefficient of /spl sigma//sup 0/ and /spl epsiv/' is 0.27. The correlation coefficient between /spl sigma//sup 0/ and the soil sample salinity is 0.69. This suggests that soil salinity has a significant contribution to the backscattering coefficient /spl sigma//sup 0/ recorded in a synthetic aperture radar (SAR) image. Consequently, a SAR image can be a useful tool for monitoring soil salinity.

Yun Shao

Papers

Rice monitoring and production estimation using multitemporal RADARSAT

Destriping CMODIS data by power filtering

Research advances of SAR remote sensing for agriculture applications: A review

Oblique striping removal in remote sensing imagery based on wavelet transform

Effect of dielectric properties of moist salinized soils on backscattering coefficients extracted from RADARSAT image