DUAL POLARIZATION RADAR APPARATUS AND INTERFERENCE JUDGMENT METHOD

• US 20110063161A1
• Filed: 06/29/2010
• Published: 03/17/2011
• Est. Priority Date: 09/14/2009
• Status: Active Grant

• Current Assignee: Kabushiki Kaisha Toshiba (Toshiba Corporation)
• Original Assignee: Kabushiki Kaisha Toshiba (Toshiba Corporation)
• Inventors: ISHIZAWA, Hiroshi, MIZUTANI, Fumihiko, WADA, Masakazu
• Granted Patent: US 8,207,889 B2
• Time in Patent Office: Days
• US Class Current: 342/159
• CPC Class Codes: G01S 13/95 for meteorological use
• CPC Class Codes: G01S 7/023 Interference mitigation, e.g. reducing or avoiding non-intentional interference with other HF-transmitters, base station transmitters for mobile communication or other radar systems, e.g. using electro-magnetic interference [EMI] reduction techniques auxiliary means for detecting or identifying radar signals or the like G01S7/021; means for anti-jamming G01S7/36
• CPC Class Codes: G01S 7/0231 Avoidance by polarisation multiplex
• 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: G01S 7/2886 using I/Q processing
• CPC Class Codes: G01S 7/40 Means for monitoring or calibrating
• 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

According to one embodiment, a dual polarization radar apparatus includes a received power calculation unit configured to calculate a horizontal polarization received power and a vertical polarization received power, the horizontal polarization received power indicating a power value of a horizontal polarization received signal reflected from an observation target, the vertical polarization received power indicating a power value of a vertical polarization received signal reflected from the observation target, a power ratio calculation unit configured to calculate a power ratio between the horizontal polarization received power and the vertical polarization received power, and an interference judgment unit configured to judge that an interference signal is mixed to the horizontal polarization received signal or the vertical polarization received signal when the power ratio is greater than a predetermined threshold value.

Claims

1. A dual polarization radar apparatus, comprising:

a received power calculation unit configured to calculate a horizontal polarization received power and a vertical polarization received power, the horizontal polarization received power indicating a power value of a horizontal polarization received signal reflected from an observation target, the vertical polarization received power indicating a power value of a vertical polarization received signal reflected from the observation target;

a power ratio calculation unit configured to calculate a power ratio between the horizontal polarization received power and the vertical polarization received power; and

an interference judgment unit configured to judge that an interference signal is mixed to the horizontal polarization received signal or the vertical polarization received signal when the power ratio is greater than a predetermined threshold value.

2. The apparatus according to claim 1, wherein

the power ratio calculation unit calculates a power ratio of the horizontal polarization received power to the vertical polarization received power;

and

the interference judgment unit judges that an interference signal is mixed to the horizontal polarization received signal when the power ratio is greater than a predetermined threshold value.

3. The apparatus according to claim 2, further comprising:

an interference wave removal unit configured to remove the horizontal polarization received power from the received data when the interference judgment unit has judged that an interference signal is mixed into the horizontal polarization received signal.

4. The apparatus according to claim 3, wherein the interference wave removal unit replaces the value of the horizontal polarization received power with the value of the vertical polarization received power.

5. The apparatus according to claim 3, wherein the interference wave removal unit replaces the value of the horizontal polarization received power with a mean value of horizontal polarization received powers of hits before and after the received signal.

6. The apparatus according to claim 1, wherein

the power ratio calculation unit calculates a power ratio of the vertical polarization received power to the horizontal polarization received power;

and

the interference judgment unit judges that an interference signal is mixed into the vertical polarization received signal when the power ratio is greater than a predetermined threshold value.

7. The apparatus according to claim 6, further comprising:

an interference wave removal unit configured to remove the vertical polarization received power from received data when the interference judgment unit has judged that an interference signal is mixed into the vertical polarization received signal.

8. The apparatus according to claim 7, wherein the interference wave removal unit replaces the value of the vertical polarization received power with the value of the horizontal polarization received power.

9. The apparatus according to claim 7, wherein the interference wave removal unit replaces the value of the vertical polarization received power with a mean value of the vertical polarization received power of hits before and after the received signal.

10. An interference judgment method used in a dual polarization radar apparatus, comprising:

calculating a horizontal polarization received power and a vertical polarization received power, the horizontal polarization received power indicating a power value of a horizontal polarization received signal reflected from an observation target, the vertical polarization received power indicating a power value of a vertical polarization received signal reflected from the observation target;

calculating a power ratio between the horizontal polarization received power and the vertical polarization received power; and

judging that an interference signal is mixed to the horizontal polarization received signal or the vertical polarization received signal when the power ratio is greater than a predetermined threshold value.

11. The method according to claim 10, wherein

in calculating, the power ratio is a power ratio of the horizontal polarization received power to the vertical polarization received power;

and

in judging, it is judged that an interference signal is mixed to the horizontal polarization received signal when the power ratio is greater than a predetermined threshold value.

12. The method according to claim 11, further comprising:

removing the horizontal polarization received power from the received data when it has judged that an interference signal is mixed into the horizontal polarization received signal.

13. The method according to claim 12, wherein in removing, the value of the horizontal polarization received power is replaced with the value of the vertical polarization received power.

14. The method according to claim 12, wherein in removing, the value of the horizontal polarization received power is replaced with a mean value of horizontal polarization received powers of hits before and after the received signal.

15. The method according to claim 10, wherein

in calculating, the power ratio is a power ratio of the vertical polarization received power to the horizontal polarization received power;

and

in judging, it is judged that an interference signal is mixed into the vertical polarization received signal when the power ratio is greater than a predetermined threshold value.

16. The method according to claim 15, further comprising:

removing the vertical polarization received power from received data when it has judged that an interference signal is mixed into the vertical polarization received signal.

17. The method according to claim 16, wherein in removing, the value of the vertical polarization received power is replaced with the value of the horizontal polarization received power.

18. The method according to claim 16, wherein in removing, the value of the vertical polarization received power is replaced with a mean value of vertical polarization received powers of hits before and after the received signal.