GPS guided munition

• US 5,943,009 A
• Filed: 07/11/1997
• Issued: 08/24/1999
• Est. Priority Date: 02/27/1997
• Status: Expired due to Term

• Current Assignee: Northrop Grumman Systems Corporation (Northrop Grumman Corporation)
• Original Assignee: Northrop Grumman Corporation
• Inventors: Abbott, Anthony Steven
• Primary Examiner(s): Issing, Gregory C.
• Application Number:
  US08/890,384
• Time in Patent Office: 774 Days
• Field of Search: 342/357, 244/3.14, 244/3.19, 244/3.24, 701/214
• US Class Current: 342/357.44
• CPC Class Codes: B64C 13/20 using radiated signals
• CPC Class Codes: B64C 5/02 Tailplanes
• CPC Class Codes: F41G 7/007 Preparatory measures taken before the launching of the guided missiles
• CPC Class Codes: F41G 7/346 using global navigation satellite systems, e.g. GPS, GALILEO, GLONASS
• CPC Class Codes: F41G 7/36 using inertial references
• CPC Class Codes: F42B 10/64 of fins
• CPC Class Codes: G01S 19/071 DGPS corrections
• CPC Class Codes: G01S 19/18 Military applications
• CPC Class Codes: G01S 19/41 Differential correction, e.g. DGPS [differential GPS]

Abstract

A tail fin assembly for a munition having a housing configured for attachment to the munition, at least one flight control surface, an actuator for effecting movement of the flight control surface(s), so as to facilitate guiding of the munition, and a guidance system for controlling the actuator mechanism. The guidance system has a global positioning system (GPS) receiver for effecting control of the actuator mechanism.

Claims

1. A weapon system for an aircraft launchable munition comprising:

a) a bomb control unit having;

i) a housing;

ii) a control unit C/A-code global positioning system (GPS) receiver disposed within the housing, the control unit C/A-code GPS receiver being operative to receive GPS satellite signals and generate a control unit C/A-code GPS location signal therefrom;

iii) a control unit P-code GPS receiver disposed within the housing, the control unit P-code GPS receiver being operative to receive GPS satellite signals and generate a control unit P-code GPS location signal therefrom;

iv) a bomb control processor disposed within the housing and in electrical communication with the control unit C/A code GPS receiver and the control unit P-code GPS receiver, the processor being operative to generate a GPS error signal responsive to the difference between the control unit C/A code GPS location signal and the control unit P-code GPS location signal; and

v) a transmitter disposed within the housing and in electrical communication with the processor, the transmitter being operative to transmit the GPS error signal only before launch of the munition; and

b) an air launchable munition attachable to the aircraft, the munition having;

i) an internal guidance system disposed within the munition and having a munition C/A code GPS receiver operative to receive GPS satellite signals and generate a munition C/A code GPS location signal therefrom, the guidance system being configured to receive the GPS error signal only before launch of the munition and generate an actuator control signal responsive to the GPS error signal and the munition C/A code GPS location signal only after release of the munition;

ii) at least one translatable flight control surface disposed along an outer surface of the munition; and

iii) an actuator mechanism disposed within the munition and mechanically coupled to the flight control surface and in electrical communication with the guidance system, the actuator mechanism being operative to control the flight control surface in response to the actuator control signal.

2. The weapon system of claim 1 wherein the bomb control unit transmitter is a RF transmitter to transmit the GPS error signal before launch of the munition and the munition comprises a RF receiver to receive the GPS error signal.

3. The weapon system of claim 1 wherein the bomb control processor is configured to generate the GPS error signal having ephemeris and pseudo-range corrections that represent the difference between the control unit C/A code GPS location signal and the control unit P-code GPS location signal.

4. The weapon system of claim 1 wherein the bomb control unit further comprises an internal power supply disposed within the housing and operative to power the bomb control unit independent from the aircraft.

5. The weapon system of claim 1 wherein the housing is configured for attachment to a leg of a crew member of the aircraft.

6. A tail fin assembly mountable to an air launchable munition and for use with a bomb control unit operative to transmit a RF GPS error signal generated from a control unit C/A code GPS receiver and a control unit P-code GPS receiver, the tail fin assembly comprising:

a) at least one translatable flight control surface projecting outwardly from the tail fin assembly;

b) a guidance system disposed within the tail fin assembly having;

i) a munition C/A code GPS receiver configured to receive a GPS satellite signal and generate a munition C/A code GPS location signal therefrom;

ii) a tail fin receiver configured to receive the RF GPS error signal from the bomb control unit before launch of the munition; and

iii) a guidance and control processor in electrical communication with the munition C/A code GPS receiver and the tail fin receiver, the guidance and control processor being operative to generate a guidance control signal responsive to the munition C/A code GPS location signal and the GPS error signal; and

c) an actuator mechanism in electrical communication with the guidance system and mechanically coupled to the flight control surface, the actuator mechanism being configured to control the flight control surface solely in response to the guidance control signal.

7. The tail fin assembly of claim 6 wherein the flight control surface comprises at least three fins.

8. The tail fin assembly of claim 6 wherein the GPS error signal comprises ephemeris and pseudo-range corrections that represent the difference between the control unit C/A code GPS signal and the control unit P-code GPS location signal.

9. The tail fin assembly of claim 6 wherein the tail fin receiver is configured to receive RF signals from the bomb control unit only before launch of the munition.

10. A bomb control unit for an air launchable GPS guided munition, comprising:

a) a housing;

b) a control unit P-code GPS receiver disposed within the housing, the control unit P-code GPS receiver being operative to receive GPS satellite signals and generate a control unit P-code GPS location signal therefrom;

c) a control unit C/A code GPS receiver disposed within the housing, the control unit C/A code GPS receiver being operative to receive GPS satellite signals and generate a control unit C/A code GPS location signal therefrom;

d) a bomb control processor disposed within the housing and in electrical communication with the control unit P-code GPS receiver and the control unit C/A code GPS receiver, the processor being configured to generate a GPS error signal responsive to the difference between the control unit P-code GPS location signal and the control unit C/A code GPS location signal; and

e) a transmitter disposed within the housing and in electrical communication with the bomb control processor, the transmitter being configured to transmit the GPS error signal to the munition before launch.

11. The bomb control unit of claim 10 wherein the bomb control unit further comprises an internal power supply disposed within the housing and being operative to solely power the bomb control unit independent from the aircraft.

12. The bomb control unit of claim 10 wherein the housing is configured for attachment to a leg of a crew member.

13. The bomb control unit of claim 10 wherein the bomb control unit is configured to determine a continuously computed release point (CCRP) to facilitate launching of the munition at a desired target.

14. The bomb control unit of claim 10 wherein the bomb control unit transmitter is a RF transmitter to transmit the GPS error signal before launch of the munition.

15. The bomb control unit of claim 14 wherein the bomb control processor is configured to generate the GPS error signal having ephemeris and pseudo-range corrections that represent the difference between the control unit C/A code GPS signal and the control unit P-code GPS location signal.

16. A method for delivery of a munition from an aircraft to a target, the method comprising the steps of:

a) determining a first location of the munition before launch with a bomb control unit C/A code GPS receiver;

b) determining a second location of the munition before launch with a bomb control unit P-code GPS receiver wherein the second location is closer to an actual location of the munition than the first location;

c) generating a GPS error signal before launch with a bomb control unit processor from the first location and the second location;

d) communicating the GPS error signal to the munition;

e) releasing the munition from the aircraft;

f) determining an in-flight munition location from a munition C/A code GPS receiver disposed within the munition and the GPS error signal wherein an accuracy of the in-flight munition location is improved by the GPS error signal; and

g) guiding the munition to the target from the in-flight location.

17. The method of claim 16 wherein step (c) further comprises calculating a continuously computed release point (CCRP) with the bomb control unit to facilitate release of the muntion.

18. The method of claim 17 further comprising preprogramming the bomb control unit with information representative of the targets location before determining a first location.

19. The method of claim 16 wherein step (c) comprises generating a GPS error signal having ephemeris and pseudo-range correction data that represent the difference between the first location and the second location.