Measurements of Surface River Doppler Velocities With Along-Track InSAR Using a Single Antenna

Abstract

Nowadays, a worldwide database containing the historical and reliable data concerning the water surface speed of rivers is not available and would be highly desirable. In order to meet this requirement, the present work is aimed at the design of an estimation procedure for water flow velocity by means of synthetic aperture radar (SAR) data. The main technical aspect of the proposed procedure is that an along-track geometry is synthesized using a single antenna and a single image. This is achieved by exploiting a multichromatic analysis in the Doppler domain. The application of this approach allows us to obtain along-track interferometry equivalent virtual baselines much lower than the equivalent baseline corresponding to the decorrelation time of raw data preserving data coherence. The performance analysis, conducted on live airborne full-polarimetric SAR data, highlights the effectiveness of the proposed approach in providing reliable river surface velocity estimates without the need of multiple passes on the observed scene.Index Terms-Along-track interferometry (ATI), doppler subapertures, multichromatic analysis (MCA), radar, river surface doppler velocity estimation, synthetic aperture radar (SAR).

Innovative Solutions Based on the EM-Algorithm for Covariance Structure Detection and Classification in Polarimetric SAR Images

“…m) × − log det(C 1 ) − Tr C −1 1 z k z † k = S q (1, m) (h−1) .The last equality concludes the proof.APPENDIX B DERIVATION OF(24) (UPDATE RULE FOR C 2 )As first step, let us notice thatU C 2 U † = A 0 0 d , (44)where A ∈ C 2×2 is positive definite and d > 0. It follows that problem(22) can be recast as m) [− log det(A) − log d−z † k,1 A −1 z k,1 − |z k,2 | 2 d −1(45)whereU z k = [z T k,1 z k,2 ] T with z k,1 ∈ C 2×1and z k,2 ∈ C. In order to maximize (45) with respect to d, it is not difficult to show that lim m)(log d + |z k,2 | 2 d −1 ) = −∞.…”

“…In the last 20 years, the benefits of information extraction from synthetic aperture radar (SAR) [1]- [3] and, in particular, polarimetric SAR images have been widely demonstrated in a range of applications including environmental monitoring [4]- [6], security [7], [8] and urban area monitoring [9], [10]. Thanks to the increasing number of use cases for this specific type of sensor, more and more current and future remote sensing missions use polarimetric SAR, despite their increased costs.…”

Measuring River Surface Velocity with Doppler Radar and Particle Image Velocimetry (PIV) Using Unmanned Aerial Systems (UASs)

“…Recently, Biondi at al. [39] have demonstrated the possibility to measure surface velocity with UAVSAR, an L-band SAR developed by NASA (characteristics are reported in [40]), showing that high velocity measurements correlated well with the river portions where high velocities are expected from river morphology.…”

Bathymetry Inversion using a Deep-Learning-Based Surrogate for Shallow Water Equations Solvers

“…This work adopts the deterministic approach to invert bathymetry from flow information, which is increasingly available using acoustic, radar, and image-based technologies at high resolution and low cost. For example, surface velocity can be obtained using Lagrangian drifters, large-scale particle image velocimetry (PIV), and synthetic -3-manuscript submitted to Water Resources Research aperture radar (SAR) (Bradley et al, 2002;Muste et al, 2008;Lewis & Rhoads, 2015;Steissberg et al, 2005;Biondi et al, 2020).…”