Simulatneous dual polarization radar system

• US 6,803,875 B1
• Filed: 03/21/2003
• Issued: 10/12/2004
• Est. Priority Date: 09/20/2002
• Status: Expired due to Term

• Current Assignee: Enterprise Electronics
• Original Assignee: DRS Weather Systems, Inc. (The Weather Company)
• Inventors: Alford, James Larry, Helvin, James Rogers
• Primary Examiner(s): Gregory, Bernarr E.
• Assistant Examiner(s): ANDREA, BRIAN K
• Application Number:
  US10/393,732
• Time in Patent Office: 571 Days
• Field of Search: 342/26, 342/188, 342/460, 702/2, 702/3, 702/4
• US Class Current: 342/26.00R
• CPC Class Codes: G01S 13/951 ground based
• CPC Class Codes: G01S 7/025 involving the transmission of linearly polarised waves
• CPC Class Codes: G01S 7/03 Details of HF subsystems specially adapted therefor, e.g. common to transmitter and receiver
• CPC Class Codes: Y02A 90/10 Information and communication technologies [ICT] supporting adaptation to climate change, e.g. for weather forecasting or climate simulation

Abstract

A simultaneous dual polarization radar system is disclosed that utilizes a RF power divider to replace high speed dual polarization switches utilized in current dual polarized 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.

Claims

1. A weather radar system, comprising:

a. an energy pulse train generator for producing radio emissions adapted for weather radar use;

b. an antenna in electrical communication with said pulse train generator for transmitting said radio emissions into space in a controlled manner and for collecting reflected signals from objects of interest;

c. an orthomode feed horn adjacent to said antenna for channeling reflectivity signals of disparate phase relative to one another into separate receiving channels;

d. a receiver subsystem for processing reflectivity signals collected by said antenna, wherein said receiver subsystem is co-located with said antenna;

e. at least one channel circulator electrically positioned between said antenna and said energy pulse train generator for isolating said radio emissions from said receiver subsystem; and

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f. a coaxial switch in electrical communication with said receiver subsystem and said at least one circulator for selectively connecting said receiver subsystem with said separate receiving channels in response to preprogrammed logic.

2. A radar system as recited in claim 1, further comprising a single channel rotary coupler electrically connecting said energy pulse train generator to said antenna.

3. A radar system as recited in claim 2, further including a wave guide signal port electrically located between said energy pulse train generator and said at least one circulator for extracting a reference signal from said radio emissions for use by said receiver subsystem.

4. A radar system as recited in claim 3, wherein said orthomode feed horn is positioned on said antenna and produces dual emission components substantially out of phase with each other by 90 degrees.

5. A radar system as recited in claim 4, further comprising an azimuth rotary coupling to allow rotation of said antenna, an elevation rotary coupling positioned proximal to said azimuth rotary coupling to allow declination and elevation of said antenna, and wherein said receiver subsystem is positioned above said elevation and azimuth couplings for processing reflectivity signals collected by said antenna.

6. A radar system as recited in claim 5, wherein said antenna is parabolic in shape.

7. A radar system as recited in claim 6, wherein said radar signal processor is in electrical communication with a remote terminal for remote viewing of processed radar data.

8. A radar system as recited in claim 7, wherein said energy pulse train generator comprises a Klystron signal generator and wherein said radar system further comprises a reference signal tap in electrical communication with one of said circulators to provide a reference signal to said klystron signal generator.

9. A radar system as recited in claim 1, further comprising a radar signal processor in electrical communication with said receiver subsystem for processing reflected signal returns received by said receiver subsystem, wherein said orthomode feed horn is positioned on said antenna and produces dual emission components substantially out of phase with each other by 90 degrees.

10. A weather radar system, comprising:

a. means for generating radio emissions adapted for weather radar use;

b. an antenna in electrical communication with said radio emissions generating means for transmitting said radio emissions into space in a controlled manner and for collecting reflected signals from objects of interest;

c. means positioned on said antenna for channeling reflectivity signals of disparate phase relative to one another into separate receiving channels;

d. means in electrical communication with said channeling reflectivity signals means for receiving reflectivity signals collected by said antenna, wherein said receiving means is co-located with said antenna;

e. means in electrical communication with said antenna and said receiving means for isolating said generated radio emissions from said receiving means; and

,

f. means electrically positioned between said receiving means and said channeling reflectivity signals means for selectively connecting said receiving means with said separate receiving channels in response to preprogrammed logic.

11. A radar system as recited in claim 10, further comprising a single channel rotary coupler electrically connecting said radio emissions generating means to said isolation means.

12. A radar system as recited in claim 11, further including a wave guide signal port electrically located between said radio emissions generating means and said isolation means and further in electrical communication with said receiver means for extracting a reference signal from said radio emissions for use by said receiver means.

13. A radar system as recited in claim 12, further including means to permit rotation of said antenna and means to allow raising and lowering of the elevation angle of said antenna, and wherein said receiving means is located above said rotational and elevation means.

14. A method for utilizing dual polarized radar emission reflection in a radar system to enhance weather reflectivity data, the steps comprising:

a. generating radio emissions suitable for radar system usage;

b. passing said radio emissions to a radar antenna;

c. directing said radio emissions into space from said antenna in a controlled manner;

d. using said antenna to collect polarized emission reflections from objects of interest through an adjacent orthomode feed horn;

e. said feed horn channeling and orthogonally parsing said reflections signals into duel receiving channels;

f. using a coaxial switch to intermittently connect each receiving channel to a radar receiver subsection in response to pre-programmed instructions; and

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g. processing said reflections in said receiver subsystem to produce radar acquisition data.

15. A method as recited in claim 14, wherein said radar system includes at least one rotary coupler to assist in said directing step and wherein said processing step occurs in a receiver subsystem located above said at least one rotary coupler.

16. A method as recited in claim 15, further comprising the step of conducting said radio emissions from said radio emission generator to said antenna through a single channel rotary coupler.

17. A method as recited in claim 16, wherein said coaxial connection step occurs without passing said collected polarized emission reflections through a rotary coupling.

18. A weather radar system, comprising:

a. means for generating radio emissions adapted for weather radar use;

b. an antenna in electrical communication with said radio emissions generating means for transmitting said radio emissions into space and for collecting reflected signals from objects of interest;

c. means positioned on said antenna for channeling reflectivity signals of disparate phase relative to one another into separate receiving channels, wherein only one of said channels is connected to said radio emissions generating means for transmission of said radio emissions;

d. means in electrical communication with said channeling reflectivity signals means for receiving reflectivity signals collected by said antenna; and

,

e. means electrically interspersed between said radio emissions generating means, said antenna, and said receiving means for isolating said generated radio emissions from said receiving means while allowing reflectivity signals to flow to said receiving means from said channeling reflectivity signals means.

19. A weather radar system as recited in claim 18, wherein said receiving means is co-located with said antenna.

20. A radar system as recited in claim 19, further including means to permit rotation of said antenna and means to allow raising and lowering of the elevation angle of said antenna, and wherein said receiving means is located above said rotational and elevation means.