Infrared small target distance estimation method with no need of atmospheric extinction coefficient

Abstract

The invention provides an infrared small target distance estimation method with no need of an atmospheric extinction coefficient, belongs to the technical field of photoelectric detection, and mainly solves the problem of poor accuracy and practicability existing in the conventional small target distance estimation. The method comprises the following implementation steps of: measuring irradiance E [n] of a target by using an infrared sensor; acquiring an azimuth alpha n and a pitch angle beta n of the target by using photoelectric theodolite; acquiring space coordinates (xn-1, yn-1, zn-1) of a detector by using a positioning system; determining direction cosine 1n of the target according to the azimuth alpha n and the pitch angle beta n; calculating target distance ratio rho by using target irradiances E[n-1] and E[n] at (n-1) and n adjacent sampling moments; and estimating the distance of the target. By adopting the method, the distance is estimated without the atmospheric extinctioncoefficient or priori knowledge and other restrictive conditions of the target; and the method is suitable for distance estimation of the infrared small target by a single-band infrared sensor.

Description

technical field [0001] The invention belongs to the technical field of photoelectric detection, and relates to the distance estimation of a target whose imaging area is less than 20 pixels, that is, a small infrared target, and can be used for passive infrared distance detection of a small target. Background technique [0002] With the rapid development of electro-optical countermeasure technology and its widespread use in modern warfare, both sides in combat have higher and higher requirements for the concealment of weapon systems. Airborne or missile-borne passive infrared detection system, because it does not radiate energy to the outside world, greatly enhances the stealth ability and defense penetration ability, and has become one of the current research hotspots. However, for small infrared targets with an imaging area of ​​less than 20 pixels, the distance information is difficult to obtain, which reduces the performance of the electro-optical countermeasure system an...

AI Technical Summary

Problems solved by technology

Although this method has good simulation results, its implementation needs to assume that the outward energy radiation output of the target remains constant during the movement process, and this assumption is unreasonable in practical applications

Therefore, this method is difficult to be practical

[0006] To sum up, the shortcomings of the existing methods are firstly the need for prior knowledge, such as the atmospheric extinction coefficient in Document 1 and the target velocity in Document 2; secondly, the need to conditionally limit the target, such as the assumption in Document 3 that the target radiation exits degree is always constant, so the existing methods are subject to many restrictions in practical applications, and the estimation accuracy and practicability are poor.

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