Other

The University of Oklahoma

The United States of America As Represented by the Department of Commerce

Dusan S Zrnic

Robert Dean Palmer

Guifu Zhang

Richard J Doviak

Sebastian Torres

Mangalore Sachidananda

A method of collecting data using a polarimetric phased array antenna is described. The method includes directing electromagnetic signals to selected panels of an array of panels so as to transmit a dual H and V polarized electromagnetic beam (1) having the same beam width in all azimuth directions and (2) maintaining cross-polarization isolation via orthogonal dual-polarizations in all beam pointing directions. The panels include antennas having a horizontally (H) polarized array element and a vertically (V) polarized array element arranged to form two orthogonally polarized horizontal and vertical radiating fields which together form the dual H and V polarized electromagnetic beam. The array of panels is arranged so as to form a substantially cylindrical configuration on a support system. Reflection signals sensed by the selected panels formed by scattering of said dual H and V polarized electromagnetic beam are received and have a reflection frequency spectrum.

Cylindrical polarimetric phased array radar

A method for estimation of Doppler spectrum, its moments, and polarimetric variables on pulsed weather radars which uses over sampled echo components at a rate several times larger than the reciprocal of transmitted pulse length. The variables are estimated by suitably combining weighted averages of the over sampled signals in range with usual processing of samples at a fixed range location. The invention may be Used on pulsed weather radar, lidars, sonars and accoustic flow meters.

Efficient estimation of spectral moments and the polarimetric variables on weather radars, sonars, sodars, acoustic flow meters, lidars, and similar active remote sensing instruments

A method for resolving range ambiguities and separating overlaid signals in a Doppler weather radar is proposed. For uniform PRT transmission, it consists of a special deterministic code for phases of the transmitted pulsed, and associated decoding and processing of return signals. In the decoding process when the signal from one range interval is made coherent, the signal from the other range interval has a multiple split spectrum. The multiple spectra have the same shape but are offset from each other. Processing steps to separate the overlaid signals and a procedure to estimate the spectral moments are given. One crucial aspect in this procedure is the magnitude domain deconvolution. The magnitude domain deconvolution is also applied to a staggered PRT transmission scheme whereby it enables the estimation of spectral parameters with much lower standard error than the known methods. Moreover, the magnitude domain deconvolution combined with special spectral processing solves the outstanding problem of ground clutter filtering in the staggered PRT sample sequence.

Signal processing and systematic phase coding for mitigation of range

A polarimetric Doppler weather radar system which allows measurement of linear orthogonal polarimetric variables without a switch by using simultaneous transmission of horizontally and vertically polarized waves. This is accomplished by splitting the transmitted power into two waveguides and combining them with an orthomode coupler at the antenna feed. Thus, in general the transmitted polarization is elliptical but with equal amount of power in horizontal and vertical polarization. On reception, the power is divided, at the orthomode coupler, into linear horizontal and vertical components. These components are processed and combined to yield Doppler and polarimetric information about storm structure.

Growing community of inventors

Norman, OK, United States of America

Dusan S Zrnic