Encoded transmitted signals in a simultaneous dual polarization weather system

• US 7,439,899 B2
• Filed: 03/22/2006
• Issued: 10/21/2008
• Est. Priority Date: 03/22/2006
• Status: Active Grant

• Current Assignee: Enterprise Electronics
• Original Assignee: Enterprise Electronics
• Inventors: Alford, James Larry, Helvin, James Rogers, Stagliano, James J. Jr., Nelson, Dean A.
• Primary Examiner(s): Sotomayor; John B
• Application Number:
  US11/386,312
• Publication Number:
  US 20070222660A1
• Time in Patent Office: 944 Days
• Field of Search: 342/21, 342/26.R, 342/26.A, 342/26.B, 342/26.C, 342/26.D, 342/188, 342/194
• US Class Current: 342/26.00R
• CPC Class Codes: G01S 13/95 for meteorological use
• CPC Class Codes: G01S 7/025 involving the transmission of linearly polarised waves
• CPC Class Codes: G01S 7/285 Receivers
• 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 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.

Claims

1. A radar system, comprising:

a. a waveform generator configured to generate a first signal and a second signal, said first signal having a different shape from said second signal;

b. amplifiers configured to amplify said first and second signals;

c. an antenna configured to simultaneously propagate said amplified first signal in a first plane and said amplified second signal in a second plane angularly rotated from said first plane;

d. a receiver configured to receive a first reflected signal having the shape of said first signal and a second reflected signal having a shape of said second amplified signal;

e. a stable local oscillator configured to generate a stable oscillating signal at a frequency equal to the difference between said propagated frequency and said intermediate frequency; and

f. wherein said waveform generator generates said first and second signals at an intermediate frequency less than the frequency of said propagated first and second signals.

2. The radar system of claim 1, further comprising a mixer configured to mix said first and second signals with said stable oscillating signal.

3. The radar system of claim 2, wherein said first and second signals are mixed with said stable oscillating signal prior to the amplification of said first and second signals.

4. The radar system of claim 3, further comprising a pair of mixers configured to mix said stable oscillating signal with said first and second reflected signals.

5. A radar system comprising:

a. an oscillator configured to generate a low power signal;

b. an amplifier configured to amplify said low power signal to a high power signal;

c. a power divider configured to split said high power signal into a first amplified signal and a second amplified signal;

d. a high powered coding device configured to inject a code into said first signal;

e. an antenna configured to simultaneously propagate said amplified first signal in a first plane and said amplified second signal in a second plane angularly rotated from said first plane; and

,

f. a receiver configured to receive a first reflected signal having the shape of said first signal and a second reflected signal having a shape of said second amplified signal.

6. The radar system of claim 5, wherein said first plane is orthogonal to said second plane.

7. The radar system of claim 5, wherein said first amplified signal is identical to said second amplified signal.

8. The radar system of claim 5, further comprising a second high powered coding device configured to code said second amplified signal wherein said oscillator generates said first and second signals at an intermediate frequency less than the frequency of said propagated first and second signals.

9. The radar system of claim 8, wherein said high power devices are configured to generate a first and second code at a frequency equal to the difference between said propagated frequency and said intermediate frequency.

10. The radar system of claim 9, wherein said first code is orthogonal to said second code.

11. The radar system of claim 10, further comprising a pair of mixers configured to mix said low power signal with said first and second reflected signals.

12. The radar system of claim 11, wherein said first and second codes are sent to said receiver.

13. The radar system of claim 5, wherein said receiver is further configured to receive said code from said high powered coding device.

14. The radar system of claim 13, wherein said receiver isolates said first and second reflected signals by comparing said first and second received signals to said code.

15. The radar system of claim 5, wherein said antenna is further configured to receive said first and second reflected signals.

16. The radar system of claim 5 wherein said antenna receives said first and second reflected signals received in said first and second plane.

17. The radar system of claim 16 wherein said first plane is orthogonal to said second plane.

18. The radar system of claim 16 wherein:

a. said antenna is further configured to receive a first planar signal including a portion of said first reflected signal and a portion of said second reflected signal;

b. said antenna is further configured to receive a second planar signal including a portion of said first reflected signal and a portion of said second reflected signal; and

c. said receiver is further configured to calculate an angular rotation of said first and second reflected signal from said first and second plane.