We are developing an ultra wideband (UWB) radar sensor payload for the man-portable iRobot PackBot UGV. Our goal is to develop a sensor array that will allow the PackBot to navigate autonomously through foliage (such as tall grass) while avoiding obstacles and building a map of the terrain. We plan to use UWB radars in conjunction with other sensors such as LIDAR and vision. We propose an algor...

This study presents a two-dimensional variational approach to retrieving raindrop size distributions (DSDs) from polarimetric radar data in the presence of attenuation. A two-parameter DSD model, the constrained-gamma model, is used to represent rain DSDs. Three polarimetric radar measurements, reflectivity (ZH), differential reflectivity (ZDR) and specific differential phase (KDP), are optimal...

Polarization properties of radar waves that are scattered from atmospheric objects are of great interest in meteorological studies. However, polarimetric radar measurements are often not sufficiently accurate for retrieving physical properties of targets. To compensate for errors, radar polarimetric calibration is applied. Typical calibrations are performed based on measurements of point target...

A major limitation of improved radar-based rainfall estimation is accurate calibration of radar reflectivity. In this paper, the authors fully automate a polarimetric method that uses the consistency between radar reflectivity, differential reflectivity, and the path integral of specific differential phase to calibrate reflectivity. Complete instructions are provided such that this study can se...

This paper presents the relations among polarimetric backscattering coefficients from the viewpoint of symmetry groups. Symmetry of geophysical media encountered in remote sensing due to reflection, rotation, azimuthal, and centrical symmetry groups is considered for both reciprocal and nonreciprocal cases. On the basis of the invariance under symmetry transformations in the linear polarization...

Weather surveillance radars observe clear-air radar echoes (CAE); aerial biota and irregularities in atmospheric refractive index caused the echoes. Using weak returns of atmospheric CAE, the radars have been applied to wind findings in a short radar range in a fair weather, in particular S-band radars. Long wavelength radars perform good to observe air motion, because a detectable turbulent sc...

The recent deployment of multiparameter, polarimetric radars provides the impetus for development of microphysical retrievals. The primary objective of this paper is to describe a particle classification technique that makes use of polarimetric radar observations. The particle classification technique is computationally simple enough to be implemented for real-time research and operational fiel...

Automatic classifications of radar polarimetric measurements into hydrometeor types using fuzzy-logic or other similar algorithms are now routinely done using ground-based cm-wavelength polarimetric radars (e.g., Vivekanandan et al. 1999; Lim. et al. 2005). In most of these algorithms, the polarimetric thresholds for various hydrometeor types are based on computational studies. A comprehensive ...