Projectile tracking system

Abstract

A system and method for determining the track of a projectile use a thermal signature of the projectile. Sequential infrared image frames are acquired from a sensor at a given position. A set of frames containing spots with characteristics consistent with a projectile in flight are identified. A possible projectile track solution for said spots is identified. A thermal signature value for each pixel of each spot of the possible solution is determined. The determined thermal signature is then compared to an actual thermal signature for a substantially similar projectile track to ascertain whether the determined thermal signature substantially matches the actual thermal signature, which indicates that the possible projectile track solution is the correct solution.

Description

BACKGROUND OF THE INVENTION [0001] 1. Field of the Invention [0002] The present invention relates to infrared imaging methods and systems. More particularly, this invention relates to determining the track of a projectile using a thermal signature fingerprint of the projectile. [0003] 2. Description of Prior Art [0004] Existing counter-sniper systems predominantly use a passive sensor, which measures naturally available energy emitted by the target, rather than an active sensor, which actively emits radiation and uses the back reflection to detect objects. The passive sensors can be further categorized as acoustic and thermal infrared as well as hybrid sensors which fuse multiple sensing mechanisms. Acoustic sensors are usually microphone arrays that triangulate their recorded signals (e.g. sound wave produced by the targeted object) to rectify the source location. The benefits of using acoustic sensors are that they provide omni-directional detection and are inexpensive to build. H...

AI Technical Summary

Benefits of technology

[0022] Advantageously, the steps of the invention are efficiently and effectively performed on the processing component. Therefore, another aspect of the invention is a computer readable medium having computer executable instructions for performing a method for determining the track of a projectile using a thermal signature of the projectile, as described above.

Problems solved by technology

However, this technology is not completely appropriate for detecting subsonic projectiles or for detecting supersonic projectiles that arrive at the target prior to the arrival of the acoustical energy generated by the firing of these projectiles.

Moreover, muzzle blasts are often interfered with by background noise (e.g. sea current, urban noises) and / or signals that have similar propagation speeds.

Even though IR imaging provides images that might represent the bullet discharge (muzzle flash) as well as the projectile in flight, the existing counter-sniper targeting systems that use this technology fail in many cases to locate a sniper.

However, the series of spots 20a, 20b, 20c, 20d alone is not adequate to represent a unique bullet track solution since multiple bullet track solutions will produce successive images having substantially similar spots.

Thus, without additional information, such as time of fire (or the amount of time that the bullet was in flight prior to the infrared detector 10 detecting the first spot 20a), it is not possible to determine which bullet track solution is the correct or most accurate solution.

Because of the blended nature of the measured infrared radiation, simple frame differencing will not produce an accurate measure of the infrared radiation emitted by the bullet 14, and, therefore, cannot be used to accurately determine changes in the intensity of infrared radiation emitted from the bullet.

Thus, the issue of determining the path of a bullet by measuring changes in the intensity of infrared radiation emitted from the bullet is left unresolved.

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