US 6,057,915 A · Projectile tracking system

Abstract

A projectile tracking system for acquiring and precisely tracking a projectile in flight in order to reveal the source from which the projectile was fired. The source is revealed by the back projection of a 3-dimensional track file. The system is particularly suited for tracking a bullet fired by a sniper and identifying the location of the sniper. Projectiles of interest typically become hot due to aerodynamic heating. A telescope focuses infrared light from a relatively large field of view on to an infrared focal plane array. In a detection mode, the system searches for the infrared signature of the projectile. The telescope's field of view is steered in the azimuth by a step and stare mirror which is driven by an azimuth drive motor mounted on the frame. When a projectile is detected, the system switches to a tracking mode and the mirror is steered by the azimuth drive motor and a pivot motor to track the projectile. A laser radar system provides a laser beam which is optically coaligned with the telescope axis. Mirror angular position information, laser radar pulse travel time, and the missile spot position on detector array are used by a computer to calculate projectile trajectory information and to determine the origin of the projectile using known ballistic trajectory methods. Although only a small portion of the total trajectory may be captured, the very accurate position information permits extrapolation to determine the launch point of the projectile.

Claims8

Dependent claims

A system for tracking a projectile, comprising:

a steerable optical system including:
an azimuth drive motor having a rotational element defining an axis of rotation;
a step and stare mirror mounted to the rotational element of the azimuth drive motor along the axis of rotation, and pivotable to define an elevation angle;
an elevation cam mounted coaxially about the axis of rotation;
an elevation drive motor coupled to the elevation cam to rotate the elevation cam about the axis of rotation;
a cam follower extending from the step and stare mirror and in contact with the elevation cam wherein rotation of the elevation cam results in a corresponding change in elevation angle;
an optoelectronic system, coupled to the steerable optical system, for detecting a projectile through the steerable optical system, steering the steerable optical system to track the detected projectile, and generating range and position for the detected projectile;
and
an analysis system, coupled to the steerable optical system and the optoelectronic system, for determining the trajectory of the detected projectile based upon range and position data generated by the optoelectronic system.

6 more elements

Dependencies are inferred from the claim text.

Projectile tracking system

Life of this patent

Projectile tracking system

Life of this patent

Abstract

Claims8