Abstract: An apparatus and method for the pre and post processing of radar signals to allow for improved measuring of circular depolarization ratio data in a weather radar. The system uses a phase shifter, which is periodically calibrated to ensure proper polarity, to alter the transmission phase of one channel of a radar transmission output. Reflectivity signals are then processed in accordance with rules dependent upon the transmission phase shift to reliably extract circular depolarization ratio (“CDR”) data from the reflectivity signals. CDR data is used to enhance hydrometer recognition in a weather radar system.

Abstract: An apparatus and method for the pre and post processing of radar signals to allow for improved measuring of circular depolarization ratio data in a weather radar. The system uses a phase shifter, which is periodically calibrated to ensure proper polarity, to alter the transmission phase of one channel of a radar transmission output. Reflectivity signals are then processed in accordance with rules dependent upon the transmission phase shift to reliably extract circular depolarization ratio (“CDR”) data from the reflectivity signals. CDR data is used to enhance hydrometer recognition in a weather radar system.

Abstract: A transportable weather radar having radar electronics functionally located above the elevational joint and a frame superstructure rotationally connected to the elevational joint onto which is mounted a parabolic radar antenna adapted for Doppler weather radar use. The radar has a rotational drive assembly mounted below and supporting the elevational joint and a harmonic drive unit positioned inside the elevational joint so that the antennae may be rotated without significant backlash during rotational changes. A hollow center in the rotational joint allows for the passing of electronics cable through the middle of the joint and down through rotating assemblies and to electronics in or adjacent to the radar pedestal.

Abstract: A transportable weather radar, including radar electronics functionally located above the elevational joint, a frame superstructure rotationally connected to an elevational assembly supporting the elevational joint, a rotational drive assembly mounted below and supporting the elevational assembly, and at least one harmonic drive for positioning the radar antenna. The radar includes a fiber optic rotary joint positioned above a slip ring assembly which is positioned within a lower portion of the elevational assembly so that as the elevational assembly rotates a fiber optic cable connected to the lower end of the fiber optic rotary joint is stationary relative to the rotating elevational assembly. The slip ring assembly permits electrical signals to traverse through traditional metal cables from the pedestal to the frame superstructure where electronics are held.

Abstract: A transportable weather radar having radar electronics functionally located above the elevational joint and a frame superstructure rotationally connected to the elevational joint onto which is mounted a parabolic radar antenna adapted for Doppler weather radar use. The radar has a rotational drive assembly mounted below and supporting the elevational joint and a harmonic drive unit positioned inside the elevational joint so that the antennae may be rotated without significant backlash during rotational changes. A hollow center in the rotational joint allows for the passing of electronics cable through the middle of the joint and down through rotating assemblies and to electronics in or adjacent to the radar pedestal.

Abstract: A transportable weather radar, including radar electronics functionally located above the elevational joint, a frame superstructure rotationally connected to an elevational assembly supporting the elevational joint, a rotational drive assembly mounted below and supporting the elevational assembly, and at least one harmonic drive for positioning the radar antenna. The radar includes a fiber optic rotary joint positioned above a slip ring assembly which is positioned within a lower portion of the elevational assembly so that as the elevational assembly rotates a fiber optic cable connected to the lower end of the fiber optic rotary joint is stationary relative to the rotating elevational assembly. The slip ring assembly permits electrical signals to traverse through traditional metal cables from the pedestal to the frame superstructure where electronics are held.

Abstract: A transportable weather radar having radar electronics functionally located above the elevational joint and a frame superstructure rotationally connected to the elevational joint onto which is mounted a parabolic radar antenna adapted for Doppler weather radar use. The radar has a rotational drive assembly mounted below and supporting the elevational joint and a harmonic drive unit positioned inside the elevational joint so that the antennae may be rotated without significant backlash during rotational changes. A hollow center in the rotational joint allows for the passing of electronics cable through the middle of the joint and down through rotating assemblies and to electronics in or adjacent to the radar pedestal.

Abstract: A transportable weather radar having radar electronics functionally located above the elevational joint and a frame superstructure rotationally connected to the elevational joint onto which is mounted a parabolic radar antenna adapted for Doppler weather radar use. The radar has a rotational drive assembly mounted below and supporting the elevational joint and a harmonic drive unit positioned inside the elevational joint so that the antennae may be rotated without significant backlash during rotational changes. A hollow center in the rotational joint allows for the passing of electronics cable through the middle of the joint and down through rotating assemblies and to electronics in or adjacent to the radar pedestal.

Abstract: A system and method for adaptation of a radar receiver in response to frequency drift in a transmission source is disclosed that utilizes a stable local oscillator established at a single, non-fluctuating frequency and compensates for transmission frequency fluctuation in the signal processor module. The disclosed system and method use mathematical processing techniques to compensate for variations in transmitter frequency during baseband processing of radar reflectivity signals. The system estimates the frequency of the transmitter to a high degree of accuracy and mathematically converts the reflectivity signal energy to a baseband intermediate frequency which is adjusted to compensate for fluctuations in transmitter frequency. A digital down converter circuit and numerically controlled oscillator circuit are also utilized to convert reflectivity signal energy to baseband and compensate for transmitter frequency drift.

Abstract: A simultaneous dual polarization radar system is disclosed repositioning critical processing components below the elevation rotary coupler to avoid radar emission pulse train corruption due to waveguide phase error introductions and to fully capitalize on the simultaneous transmission of polarized signals. A fiber optic rotational coupler is introduced to allow an improved alternate data path for data transmission from the receivers to the signal processors and to allow for transmitting reflected signal returns from the receiver subsystem located above the elevation rotary coupler to the radar system processor located below the elevation rotary coupler.

Abstract: The invention consists, generally, of a method for automatically reducing power to an electron emitting cathode by sensing an operating condition of the electron emitting cathode, calculating a condition number based upon the operating condition, comparing the condition number to a threshold value, and reducing the power to the electron emitting cathode when the condition number is greater than the threshold. The apparatus and method may be implemented upon a system having a high voltage power source, an RF tube, a control processor, and a signal processor.

Abstract: A device and method for measuring phase and power shifts in a simultaneous dual polarization radar system comprises an access port, a quadrature mixer, and a power detector. The access port is configured to couple to the simultaneous dual polarization radar system near the antenna of the simultaneous dual polarization radar system. The quadrature mixer is configured to mix a first signal from a first polarization and a second signal from a second polarization. The first signal and the second signal are sampled through the access port. The first power detector is configured to measure the power level of the first signal.

Abstract: A system for simultaneously propagating dual polarized signals in a polarimetric radar system includes a system for shifting the phase of one of the two signals. The simultaneous dual polarization weather radar transmits signals in both the horizontal and vertical orientations at the same time. Upon reception, the signals in each channel are isolated and a number of standard and polarimetric parameters characterizing atmospheric conditions are determined. The accuracy upon which these parameters can be determined depends partially upon the interference between these two channels. The system and method isolates the vertical and horizontal channels by using the phase information from the signals to minimize the interference.

Abstract: A system for simultaneously propagating dual polarized signals in a polarimetric radar system includes a system for coding at least one of the two signals. The simultaneous dual polarization weather radar transmits signals in both the horizontal and vertical orientations at the same time. Upon reception, the signals in each channel are decoded and a number of standard and polarimetric parameters characterizing atmospheric conditions are determined. The accuracy upon which these parameters can be determined depends partially upon the interference between these two channels. The system and method isolates the vertical and horizontal channels to minimize the interference.

Abstract: A system for synthesizing data received from a weather radar system includes a digital signal processor, a data synthesizer, a convolution filter, and data storage. The digital signal processor digitizes reflectivity data from a radar antenna. The data synthesizer generates an M×N matrix for a digitized reflectivity data point and populates each element in the M×N matrix with the value of the digitized reflectivity data point. The convolution filter calculates a filtered value for each element in the M×N matrix. The data storage stores the M×N matrix for display.

Abstract: A system for synthesizing data received from a weather radar system includes a digital signal processor, a data synthesizer, a convolution filter, and data storage. The digital signal processor digitizes reflectivity data from a radar antenna. The data synthesizer generates an M×N matrix for a digitized reflectivity data point and populates each element in the M×N matrix with the value of the digitized reflectivity data point. The convolution filter calculates a filtered value for each element in the M×N matrix. The data storage stores the M×N matrix for display.

Abstract: A method of reducing power to an electron emitting cathode comprises the steps of sensing a weather condition; calculating a condition number based upon the weather condition; comparing the condition number to a threshold; and reducing the power to the electron emitting cathode when the condition number is greater than the threshold. The apparatus and method may be implemented upon a system having a high voltage power source, an RF tube, a control processor, and a signal processor.

Abstract: A simultaneous dual polarization radar system is disclosed that utilizes a RF power divider to replace the high speed dual polarization switches utilized in current dual polarization radar systems. The disclosed systems allow for transmission and reception in both horizontal and vertical signal modes simultaneously while repositioning critical receiver components above the elevation rotary coupler in a radar pedestal. A bypass switch is also utilized to allow for mode switching of a radar system and a dual polarization reception design is shown to allow for the economical capturing of linear depolarization ratios of selected atmospheric areas. These new designs eliminate the current problems experienced in current dual polarization radar system of long dwell times and velocity range reductions, and the elimination of the relatively expensive and unreliable polarization switch.