Control system for controlling a projectile

1. A control system for controlling a projectile, the control system comprising:

a plurality of transmitters, wherein each transmitter of the plurality of transmitters is arranged to transmit an electromagnetic wave from a corresponding transmission position, and at least one of the plurality of transmitters is arranged to communicate its own transmission position to the projectile either in the corresponding transmitted electromagnetic wave or by transmitting another electromagnetic wave;

a receiver associated with the projectile, the receiver being arranged to receive a plurality of electromagnetic waves transmitted from the plurality of transmitters, the plurality of electromagnetic waves including the corresponding electromagnetic wave or another electromagnetic wave transmitted by the at least one of the plurality of transmitters; and

a controller associated with the projectile, the controller being arranged to

extract the transmission position of the at least one of the plurality of transmitters from the received corresponding electromagnetic wave or the received another electromagnetic wave,

determine at least one of a position, a velocity, and/or an acceleration of the projectile based on transmission positions of the plurality of transmitters and Doppler measurements derived from the received plurality of electromagnetic waves, and

generate a control signal for performing an action with the projectile depending on the determined at least one of position, velocity, and/or acceleration of the projectile.

2. The control system of claim 1 , wherein at least one of the plurality of transmitters is arranged to be mobile.

3. The control system of claim 1 , further comprising a locator arranged to:

detect at least one of the plurality of transmitters;

determine at least one transmission position of the detected at least one of the plurality of transmitters;

encode data for identifying each of the detected at least one transmitter and its determined transmission position on an electromagnetic wave; and

transmit that electromagnetic wave to the projectile, wherein the projectile is arranged to:

receive, from the locator, the electromagnetic wave; and

retrieve the determined at least one transmission position from the data by decoding data encoded in the received electromagnetic wave.

4. A weapon comprising: the control system of claim 1 , the ranged weapon arranged to fire the projectile toward a target, and provide target position information to the projectile.

5. The ranged weapon of claim 4 , wherein the projectile is a steerable projectile, and the action comprises adjusting a trajectory of the projectile using the target position information and the determined at least one of position, velocity, and/or acceleration of the projectile.

6. The ranged weapon of claim 5 , wherein the plurality of transmitters are arranged to be positioned so that the transmission positions are dispersed around the trajectory of the projectile.

7. The ranged weapon of claim 4 , wherein at least one transmission position is pre-arranged before the projectile is fired from the ranged weapon so that the pre-arranged at least one transmission position is determinable from data stored in a memory provided in the projectile.

8. The ranged weapon of claim 4 , wherein the action comprises activating a fuze of the projectile using the target position information and the determined at least one of position, velocity, and/or acceleration of the projectile.

9. The control system of claim 1 , further comprising a Global Navigation Satellite System (GNSS) receiver associated with the projectile and/or an Inertial Measurement Unit (IMU) associated with the projectile, wherein the GNSS receiver and/or the IMU is arranged to determine a position and/or velocity estimate of the projectile, and the controller of the projectile is arranged to determine the at least one of position, velocity, and/or acceleration of the projectile from: the transmission positions; the Doppler measurements derived from the received plurality of electromagnetic waves; and a position estimate determined using the GNSS receiver and/or the IMU, or a position estimate determined using pseudo-range measurements from the GNSS receiver.

10. A projectile comprising:

a receiver arranged to receive a plurality of electromagnetic waves transmitted from a plurality of corresponding transmitters, the plurality of electromagnetic waves including a corresponding electromagnetic wave or another electromagnetic wave transmitted by at least one of the plurality of transmitters that includes a transmission position of the at least one of the plurality of transmitters; and

a controller arranged to

extract the transmission position of the at least one of the plurality of transmitters from the received corresponding electromagnetic wave or the received another electromagnetic wave,

determine at least one of a position, a velocity, and/or an acceleration of the projectile based on respective transmission positions of the plurality of transmitters and Doppler measurements derived from the received plurality of electromagnetic waves, and

generate a control signal for performing an action with the projectile depending on the determined at least one of position, velocity, and/or acceleration of the projectile.

11. The projectile of claim 10 , wherein a locator is arranged to detect at least one of the plurality of transmitters, determine at least one transmission position of the detected at least one of the plurality of transmitters, encode data for identifying each of the detected at least one transmitters and its determined transmission position on an electromagnetic wave, and transmit that electromagnetic wave to the projectile, wherein:

the receiver is arranged to receive, from the locator, the electromagnetic wave; and

the controller is arranged to retrieve the determined at least one transmission position from the data by decoding data encoded in the received electromagnetic wave.

12. The projectile of claim 10 , wherein the projectile is a steerable projectile, and the action comprises adjusting a trajectory of the projectile using target position information and the determined at least one of position, velocity, and/or acceleration of the projectile, the target position information received by the projectile from a ranged weapon from which the projectile is fired toward a target.

13. The projectile of claim 12 , further comprising a memory, wherein at least one transmission position is pre-arranged before the projectile is fired from the ranged weapon so that the pre-arranged at least one transmission position is determinable from data stored in the memory.

14. The projectile of claim 10 , wherein the action comprises activating a fuze of the projectile using the target position information and the determined at least one of position, velocity, and/or acceleration of the projectile.

15. The projectile of claim 10 , further comprising a Global Navigation Satellite System (GNSS) receiver and/or an Inertial Measurement Unit (IMU), wherein the GNSS receiver and/or the IMU is arranged to determine a position or velocity estimate of the projectile, and the controller is arranged to determine the at least one of position, velocity, and/or acceleration of the projectile from: the transmission positions; the Doppler measurements derived from the received plurality of electromagnetic waves; and a position estimate determined using the GNSS receiver and/or the IMU, or a position estimate determined using pseudo-range measurements from the GNSS receiver.

16. A method of controlling a projectile, the method comprising:

at each transmitter of a plurality of transmitters, transmitting an electromagnetic wave from a corresponding transmission position, wherein at least one of the plurality of transmitters transmits its own transmission position to the projectile either in the corresponding transmitted electromagnetic wave or by transmitting another electromagnetic wave; and

at the projectile,

receiving a plurality of electromagnetic waves transmitted from the plurality of transmitters, the plurality of waves including the corresponding electromagnetic wave or another electromagnetic wave transmitted by the at least one of the plurality of transmitters,

extracting the transmission position of the at least one of the plurality of transmitters from the received corresponding electromagnetic wave or the received another electromagnetic wave,

determining at least one of a position, a velocity, and/or an acceleration of the projectile based on respective transmission positions of the plurality of transmitters and Doppler measurements derived from the received plurality of electromagnetic waves, and

generating a control signal for performing an action with the projectile depending on the determined at least one of position, velocity, and/or acceleration of the projectile.

17. The method of claim 16 further comprising:

at a locator,

detecting at least one of the plurality of transmitters,

determining at least one transmission position of the detected at least one of the plurality of transmitters,

encoding data for identifying each of the detected at least one transmitters and its determined transmission position on an electromagnetic wave, and

transmitting that electromagnetic wave to the projectile; and

at the projectile,

receiving the electromagnetic wave from the locator, and

retrieving the determined at least one transmission position from the data by decoding data encoded in the received electromagnetic wave.

18. The method of claim 16 , further comprising:

adjusting, at the projectile, a trajectory of the projectile using target position information and the determined at least one of position, velocity, and/or acceleration of the projectile, the target position information received from a ranged weapon from which the projectile is fired toward a target.

19. The method of claim 18 further comprising activating a fuze of the projectile using the target position information and the determined at least one of position, velocity, and/or acceleration of the projectile.

20. The method of claim 16 , wherein the projectile comprises a Global Navigation Satellite System (GNSS) receiver and/or an Inertial Measurement Unit (IMU), and the method further comprises:

at the GNSS receiver and/or the IMU, determining a position or velocity estimate of the projectile; and

at the projectile, determining the at least one of position, velocity, and/or acceleration of the projectile from: the transmission positions; the Doppler measurements derived from the received plurality of electromagnetic waves; and a position estimate determined using the GNSS receiver and/or the IMU, or a position estimate determined using pseudo-range measurements from the GNSS receiver.