A Polarization Diversity Radar Data Processor
Title | A Polarization Diversity Radar Data Processor PDF eBook |
Author | James I. Metcalf |
Publisher | |
Pages | 27 |
Release | 1983 |
Genre | Electromagnetic waves |
ISBN |
A Polarization Diversity Radar Data Processor
Title | A Polarization Diversity Radar Data Processor PDF eBook |
Author | James I. Metcalf |
Publisher | |
Pages | 32 |
Release | 1983 |
Genre | Electromagnetic waves |
ISBN |
A real time data processor has been designed for use with the AFGL 10-cm Doppler weather radar which is to be operated with alternating transmission of horizontally and vertically polarized signals. In this mode of operation the reception of backscattered signals of polarizations identical to those of the transmitted signals allows the computation of the differential reflectivity between the two polarizations in addition to the absolute reflectivity and the Doppler mean velocity and variance. The switching of transmitted polarization introduces difficulties in the estimation of the autocovariance of the received signals, from which the Doppler velocity parameters are derived. The processor design and the allowed modes of radar operation circumvent these difficulties. This report describes the processing algorithms theoretically and presents details of the implementation of these algorithms in hardware. (Author).
A Polarization Diversity Meteorological Radar System
Title | A Polarization Diversity Meteorological Radar System PDF eBook |
Author | James I. Metcalf |
Publisher | |
Pages | 36 |
Release | 1987 |
Genre | Doppler radar |
ISBN |
The AFGL 10-cm Doppler weather radar was modified to enable the measurement of the differential reflectivity between horizontal and vertical polarizations in addition to the absolute reflectivity and the Doppler mean velocity and spectrum variance. Polarization switching is achieved by means of a diplexer, which separates at the antenna the transmitted signals of two frequencies, 2710 and 2760 MHz, and permits nearly simultaneous transmission of signals of orthogonal polarizations. Signals of these frequencies can be transmitted either with horizontal and vertical polarization, respectively, or with left and right circular, polarization, respectively. We describe the design and performance of the diplexer and the performance of the real-time data processor, present examples of meteorological measurements, and discuss future developments of the radar system. Keywords: Polarization diversity weather radar, Dual polarization radar, and Polarization switching.
Precipitation and Lightning Measurements by Polarization Diversity Radar
Title | Precipitation and Lightning Measurements by Polarization Diversity Radar PDF eBook |
Author | James I. Metcalf |
Publisher | |
Pages | 30 |
Release | 1988 |
Genre | Electromagnetic waves |
ISBN |
Observations of severe convective storms in June 1987 by an 11-cm polarization diversity Doppler radar are described. Specific features include heavy rain, large hail, melting ice particles, lightning, and signal propagation effects. Of particular interest are the first measurements of the polarization differential reflectivity of lightning channels, which reveal the predominant orientations of the channels. Successive radar pulses were transmitted with alternating horizontal and vertical polarization by means of a high-power microwave switch to permit derivation of the differential reflectivity with a small standard error of estimate.
Design Study for a Coherent Polarization-Diversity Radar
Title | Design Study for a Coherent Polarization-Diversity Radar PDF eBook |
Author | James I. Metcalf |
Publisher | |
Pages | 95 |
Release | 1980 |
Genre | |
ISBN |
Design concepts for a coherent polarization-diversity radar are presented. The desired capability is the measurement of microphysical parameters of hydrometeors, including thermodynamic phase, shape, size, orientation, and number density. The postulated use of a polarization-diversity radar is based on the relationships of these parameters to the anisotropy of the scattering and propagation media. The measurement objectives lead to the specification of primary and secondary coverage regions. Target detection within the primary region (less than 40 km range) and propagation effects lead to the specification of S-band and Ka-band as optimum frequency bands for observations of precipitation and clouds, respectively. Radar system parameters are specified, and schematic diagrams of system hardware are presented. Antenna design concepts and practical considerations are discussed. We discuss concepts of data processing and a possible computer-oriented implementation of radar control and data processing. (Author).
A Polarization Diversity Meteorological Radar System
Title | A Polarization Diversity Meteorological Radar System PDF eBook |
Author | James I. Metcalf |
Publisher | |
Pages | 0 |
Release | 1987 |
Genre | Doppler radar |
ISBN |
The AFGL 10-cm Doppler weather radar was modified to enable the measurement of the differential reflectivity between horizontal and vertical polarizations in addition to the absolute reflectivity and the Doppler mean velocity and spectrum variance. Polarization switching is achieved by means of a diplexer, which separates at the antenna the transmitted signals of two frequencies, 2710 and 2760 MHz, and permits nearly simultaneous transmission of signals of orthogonal polarizations. Signals of these frequencies can be transmitted either with horizontal and vertical polarization, respectively, or with left and right circular, polarization, respectively. We describe the design and performance of the diplexer and the performance of the real-time data processor, present examples of meteorological measurements, and discuss future developments of the radar system. Keywords: Polarization diversity weather radar, Dual polarization radar, and Polarization switching.
Instrumentation Papers
Title | Instrumentation Papers PDF eBook |
Author | |
Publisher | |
Pages | 324 |
Release | 1982 |
Genre | Aeronautical instruments |
ISBN |