Small Reflectors for Ground Motion Monitoring With InSAR

In recent years, synthetic aperture radar interferometry has become a recognized geodetic tool for observing ground motion. For monitoring areas with low density of coherent targets, artificial corner reflectors (CRs) are usually introduced. The required size of a reflector depends on radar wavelength and resolution and on the required deformation accuracy. CRs have been traditionally used to provide a high signal-to-clutter ratio (SCR). However, large dimensions can make the reflector bulky, difficult to install and maintain. Furthermore, if a large number of reflectors are needed for long infrastructure, such as vegetation-covered dikes, the total price of the reflectors can become unaffordable. On the other hand, small reflectors have the advantage of easy installation and low cost. In this paper, we design and study the use of small reflectors with low SCR for ground motion monitoring. In addition, we propose a new closed-form expression to estimate the interferometric phase precision of resolution cells containing a (strong or weak) point target and a clutter. Through experiments, we demonstrate that the small reflectors can also deliver displacement estimates with an accuracy of a few millimeters. To achieve this, we apply a filtering method for reducing clutter noise.

[1]  J. Goodman Some fundamental properties of speckle , 1976 .

[2]  Yuxiao Qin,et al.  The Design and Experiments on Corner Reflectors for Urban Ground Deformation Monitoring in Hong Kong , 2013 .

[3]  Fabio Rocca,et al.  Submillimeter Accuracy of InSAR Time Series: Experimental Validation , 2007, IEEE Transactions on Geoscience and Remote Sensing.

[4]  Peter Hoogeboom,et al.  Deployment and design of bi-directional corner reflectors for op-timal ground motion monitoring using InSAR , 2014 .

[5]  Betlem Rosich,et al.  Geometric Calibration and Validation of ASAR Imagery , 1993 .

[6]  B. Frieden,et al.  Laser speckle and related phenomena , 1984, IEEE Journal of Quantum Electronics.

[7]  Giuseppe Molesini,et al.  Experimental statistics of fully developed speckle fields by phase-shifting interferometry , 1990 .

[8]  K. Sarabandi,et al.  Optimum corner reflectors for calibration of imaging radars , 1996 .

[9]  Peter Hoogeboom,et al.  The Dutch ROVE Program , 1982, IEEE Transactions on Geoscience and Remote Sensing.

[10]  F. Ulaby,et al.  Handbook of radar scattering statistics for terrain , 1989 .

[11]  J. Goodman Statistical Properties of Laser Speckle Patterns , 1963 .

[12]  R. Hanssen Radar Interferometry: Data Interpretation and Error Analysis , 2001 .

[13]  Fuk K. Li,et al.  Synthetic aperture radar interferometry , 2000, Proceedings of the IEEE.

[14]  Anthony Freeman Polarization effects and multipolarization SAR , 1992 .

[15]  Ramon F. Hanssen,et al.  High-precision positioning of radar scatterers , 2016, Journal of Geodesy.

[16]  Fabio Rocca,et al.  Modeling Interferogram Stacks , 2007, IEEE Transactions on Geoscience and Remote Sensing.

[17]  R. Bamler,et al.  Phase statistics of interferograms with applications to synthetic aperture radar. , 1994, Applied optics.

[18]  M. Skolnik,et al.  Introduction to Radar Systems , 2021, Advances in Adaptive Radar Detection and Range Estimation.

[19]  W. Root,et al.  An introduction to the theory of random signals and noise , 1958 .

[20]  Corina da Costa Freitas,et al.  A model for extremely heterogeneous clutter , 1997, IEEE Trans. Geosci. Remote. Sens..