RU2363017C2 - Fiber-optic device to counteract laser range finders - Google Patents

Abstract

FIELD: weapons and ammunition.

SUBSTANCE: invention relates to protection of arms and combat equipment against artillery reconnaissance and can be used to counteract laser range finders of enemy. Proposed device comprises optical input, fiber-optic holdback circuit designed to hold back reflected laser beams with the help of fiber-optic multiple fiber. It includes also optical output device. Note here that proposed device comprises additionally fiber-optic splitters communicating input and output devices with the said holdback circuit. Multiple fiber features various-diametre fibers. Note here that difference in fiber lengths makes, at least, the range-finder resolution in range.

EFFECT: generation of several false signals to misinform enemy.

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Description

The invention relates to the field of protection of weapons and military equipment from artillery reconnaissance and can be used to counter enemy laser rangefinders.

Currently, the existing optical devices for counteracting laser rangefinders with the aim of misinformation about the true value of the range consist of a triple prism line. These devices are installed at a certain distance from the protected object. When measuring with a laser range finder to such an object, several reflected signals are obtained. Known devices provide disinformation of laser rangefinders about the true value of the distance to objects in a static mode of operation. In the dynamic mode of operation of the protected object, the use of such devices is impossible. It is desirable to have a device that would be located on the protected object and provide the possibility of generating false reflected signals.

A known fiber-optic device for counteracting laser rangefinders (GB 2221364 A, dated 3l.01.l990), which is a prototype and which, with the aim of misinformation with its own probing signal about the true position of the object in both static and dynamic modes of operation, is installed on the object . The device contains an optical receiving device, a fiber delay line that delays reflected laser radiation using a fiber optic bundle, an optical output device, and the disinformation signal is generated in the direction of the laser rangefinder due to the parallel optical axis of the receiving and output devices.

This allows delaying the reflected signal, while a false signal that has passed the delay line will carry misinformation about the true value of the distance to the protected object. The installation of a fiber-optic device on the protected object makes it possible to counter laser range finders both in the static mode of operation and in the dynamic one. Two reflected signals from one object arrive from the protected object to the photodetector of the laser rangefinder, one is misinforming. The disinformation signal in its spectral and spatial parameters is an analogue of the reflected probe pulse. Modern laser rangefinders to increase noise immunity have devices for selecting reflected signals, therefore, they can most likely distinguish a false signal from two signals. It is desirable to have a device that provides the formation of several false signals, which provides the possibility of more reliable misinformation about the true position of the object.

This goal is achieved by the fact that in addition to the optical system, optical fiber splitters are installed that optically connect the receiving and output devices to the fiber delay line, where the optical bundle is replaced by a multi-strand of various lengths, while the length difference of the cores is not less than the range resolution of the range finder.

The invention is illustrated in the drawing, which shows a diagram of the proposed fiber optic device.

Fiber optic device consists of an optical receiver of laser radiation 1, a fiber splitter 2, a fiber delay line 3 with a multi-strand optical bundle 4; optical output device 5, forming a false misinformation signal with a time delay. The optical axis of the output forming and receiving devices are parallel. Fiber-optic device is placed in the housing 6, is installed on the protected object using the mount 7.

Fiber optic device for countering laser rangefinders works as follows.

The probe pulse 8 of the laser rangefinder is reflected from the protected object, at the same time it enters the optical receiving device 1, which provides the input of laser radiation into the fiber splitter 2 of the delay line. The fiber splitter is optically coupled to a multi-strand optical bundle 3. The length of the optical cores is different. The difference in the lengths of the cores is selected from the calculation of not less than the resolution of the laser rangefinder in range. After passing the fiber delay line 3, the optical output device 5 generates several signals 9 with a time delay in the direction of the laser rangefinder. Thus, from the protected object to the photodetector of the laser rangefinder, more than two reflected signals from one object are received, one of which is true, the rest are misinforming.

According to the laws of the theory of shooting, the probability of hitting a target is close to zero if the error in measuring the range is 200 meters or more. The current level of fiber optics manufacturing technology allows the manufacture of multicore optical bundles in cross section up to 1 mm, which allows you to create a small-sized device.

Claims (1)

A fiber optic device for counteracting laser rangefinders, comprising an optical receiving device, a fiber delay line delaying reflected laser radiation using a fiber optic bundle, an optical output device, and the generation of a disinformation signal in the direction of the laser rangefinder occurs due to the parallel optical axis of the receiving and output devices, characterized in that in addition to the optical system are installed optical fiber splitters, which are optically connect the receiving and output devices with a fiber delay line, where the optical fiber is multi-strand with conductors of various lengths, while the difference in the lengths of the wires is not less than the range finder resolution.