A method includes determining a rotational position of a rotating projectile as a function of an orientation of a sensor on the rotating projectile. The method also includes actuating a steering mechanism on the rotating projectile at the determined rotational position. The method also includes altering the trajectory of the rotating projectile.

A system for finding up in a projectile flight relative to earth. The system having a transmitter which transmits polarized reference signals to a guidance sub-system on the projectile. The guidance sub-system includes a magnetometer and polarized and non-polarized receivers. Measurements from the magnetometer are used to determine a general up direction. The polarized and non-polarized receivers are arranged such that, during rotation of the projectile, reference signals received by the polarized receiver modulate whereas reference signals received by the non-polarized receivers are unaffected. A ratio of the strengths of the signals received by the polarized and non-polarized receivers determines alignment of a vertical axis. From the general up direction and alignment of the vertical axis, a precise up direction of the projectile in flight relative to the earth can be determined.

A device for detecting and/or tracking a projectile has a receiving antenna, for receiving at least an electromagnetic signal emitted by at least one radar, at least one amplifier configured to amplify the electromagnetic signal received by the receiving antenna, and at least one emitting antenna. The emitting antenna is configured to return, at an output of the device, an amplified electromagnetic signal for calculating data indicative of the trajectory of the projectile based at least on the amplified electromagnetic signal. A system for detecting a projectile has a transmitting device mounted on the projectile, a radar configured to sense an electromagnetic signal produced and sent by the transmitting device. The signals emitted from the projectile are limited to the electromagnetic signal sent by the transmitting device, and a processing unit, configured to calculate data indicative of the trajectory of the projectile, based on the sensing of the electromagnetic signal.

A method includes determining a rotational position of a rotating projectile as a function of an orientation of a sensor on the rotating projectile. The method also includes actuating a steering mechanism on the rotating projectile at the determined rotational position. The method also includes altering the trajectory of the rotating projectile.

A system for finding up in a projectile flight relative to earth. The system having a transmitter which transmits polarized reference signals to a guidance sub-system on the projectile. The guidance sub-system includes a magnetometer and polarized and non-polarized receivers. Measurements from the magnetometer are used to determine a general up direction. The polarized and non-polarized receivers are arranged such that, during rotation of the projectile, reference signals received by the polarized receiver modulate whereas reference signals received by the non-polarized receivers are unaffected. A ratio of the strengths of the signals received by the polarized and non-polarized receivers determines alignment of a vertical axis. From the general up direction and alignment of the vertical axis, a precise up direction of the projectile in flight relative to the earth can be determined.

A device for detecting and/or tracking a projectile has a receiving antenna, for receiving at least an electromagnetic signal emitted by at least one radar, at least one amplifier configured to amplify the electromagnetic signal received by the receiving antenna, and at least one emitting antenna. The emitting antenna is configured to return, at an output of the device, an amplified electromagnetic signal for calculating data indicative of the trajectory of the projectile based at least on the amplified electromagnetic signal. A system for detecting a projectile has a transmitting device mounted on the projectile, a radar configured to sense an electromagnetic signal produced and sent by the transmitting device. The signals emitted from the projectile are limited to the electromagnetic signal sent by the transmitting device, and a processing unit, configured to calculate data indicative of the trajectory of the projectile, based on the sensing of the electromagnetic signal.

An inverted F antenna for use in a projectile includes a ground plane and a radiating element oriented orthogonal to the ground plane and centered on the ground plane. The radiating element includes a ground stub trace having a relatively thick width, a meandering trace with a vertical orientation and a relatively high ground clearance and a feed trace having a tapered head.

The system and method for a digital light processing (DLP) guidance system having a digital light processing (DLP) mirror array at the laser source. A receiver tracks location of the air-borne object using a retro reflector on a pulse-to-pulse basis. The DLP mirror array tracks the air-borne object with a non-scanning beam and immediately provides a correction update to the controller using a pulse repetition interval (PRI) varying code. The system can be packaged in a small format, at a lower cost, and with a higher reliability.

The system and method for a digital light processing (DLP) guidance system having a digital light processing (DLP) mirror array at the laser source. A receiver tracks location of the air-borne object using a retro reflector on a pulse-to-pulse basis. The DLP mirror array tracks the air-borne object with a non-scanning beam and immediately provides a correction update to the controller using a pulse repetition interval (PRI) varying code. The system can be packaged in a small format, at a lower cost, and with a higher reliability.