US-12618977-B2 - Optical detection system and method for detecting a hostile optical component

US12618977B2US 12618977 B2US12618977 B2US 12618977B2US-12618977-B2

Abstract

An optical detection system for detecting a hostile optical component without exposing the surrounding to unnecessary hazards is disclosed. The system comprises a laser unit configured to provide an adjustable laser beam along an optical path to scan for the optic component or to act as jammer by providing a target spoofing; a single aperture for the optical path; a detector configured to detect through the single aperture retroreflections of the laser beam at the optical component; and a camera for detecting through the single aperture potential candidates for the hostile optical component.

Inventors

Oliver RUDOW
Lutz Hoering

Assignees

HENSOLDT SENSORS GMBH
HENSOLDT OPTRONICS GMBH

Dates

Publication Date: 20260505
Application Date: 20220901
Priority Date: 20210903

Claims (14)

1 . An optical detection system for detecting a hostile optical component without exposing the surrounding to unnecessary hazards, the system comprising: a laser unit configured to provide an adjustable laser beam along an optical path to scan for the optic component or to act as jammer by providing a target spoofing; a single aperture for the optical path; a detector configured to detect through the single aperture retroreflections of the laser beam at the hostile optical component; a camera for detecting through the single aperture potential candidates for the hostile optical component; and a control unit, the control unit being configured to: (i) determine a distance between the optical detection system and the optical component; (ii) utilize the laser unit for a laser-based countermeasure, and (iii) adjust the divergence of the laser beam, based on the determined distance, to minimize a laser hazard area for the laser beam.
2 . The optical detection system according to claim 1 , wherein the laser unit is configured to adjust a divergence of the laser beam to adapt an energy impact on an object in the optical path.
3 . The optical detection system according to claim 1 , wherein the laser unit is configured to select wavelengths of the laser beam to: reduce a scattering in atmosphere, by acting as a mid-infrared Band 1 laser, and/or act as soft-kill countermeasure, especially by acting as Band 4a/4b laser.
4 . The optical detection system according to claim 1 , wherein the detector is configured to detect other laser sources, in particular to detect laser guided missiles.
5 . The optical detection system according to claim 1 , wherein the camera includes a multispectral camera suitable for a target identification and to enable the target tracking.
6 . The optical detection system according to claim 1 , further comprising: a transparent dome head mounted to cover the single aperture; and a mirror mounted in the dome head and configured to enable a coverage area for the optical path in at least one of following angular regions: in azimuth: ±60°, ±90°, 360° surround view in elevation: ±10°, ±15°, up to 15°, up to 45°, up to 90°, up to 120°.
7 . The optical detection system according to claim 1 , further comprising one or more partial transparent mirrors configured to split the optical path into three sub-paths between the single aperture and the laser unit, the detector, and the camera.
8 . The optical detection system according to claim 1 , wherein the control unit is further configured for at least one of the following: tilting and rotating the mirror mounted in the dome head to scan a desired coverage area; processing of images captured by the camera; processing detection signals of the detector; implementing an artificial intelligence algorithm or other kinds of image processing methods utilizing images as recorded by the SAS by verifying potential hostile components in the recorded images as true hostile components due to detected retro reflections.
9 . The optical detection system according to claim 8 , wherein the control unit is further configured to perform an object detection in the images captured by the camera and, based thereon, to adjust the divergence of the laser beam.
10 . The optical detection system according to claim 8 , wherein the system is configured to at least one of the following components: a situational awareness system, SAS, a warner unit, a battle management system, additional sensors and/or effectors, wherein the control unit is further configured to make available data from the detector unit or from the camera or derived data therefrom to the at least one component; and/or wherein the control unit is further configured to receive context data about the scenery from the at least one component to provide a search for the optical component or other objects based on the received context data.
11 . The optical detection system according to claim 8 , wherein the control unit is further configured to enable at least one of the following functions: situational awareness functionalities, laser-based communication by controlling the laser unit, providing a ranging application to determine a distance to the optical component, to control the laser unit in a time multiplexed manner so that the transmit laser signals are transmitted in different time slots than the received signals.
12 . The optical detection system according to claim 11 , wherein the control unit is further configured to adjust the divergence of the laser beam emitted by the laser unit based on a threat classification, wherein the threat classification depends at least on the distance of the optical component.
13 . An apparatus suitable to be mounted on a periscope of a military vehicle, in particular a tank, comprising: an optical detection system for detecting a hostile optical component without exposing the surrounding to unnecessary hazards, the system comprising: a laser unit configured to provide an adjustable laser beam along an optical path to scan for the optic component or to act as jammer by providing a target spoofing; a single aperture for the optical path; a detector configured to detect through the single aperture retroreflections of the laser beam at the hostile optical component; a camera for detecting through the single aperture potential candidates for the hostile optical component, and a control unit, the control unit being configured to: (i) determine a distance between the optical detection system and the optical component; (ii) utilize the laser unit for a laser-based countermeasure, and (iii) adjust the divergence of the laser beam, based on the determined distance, to minimize a laser hazard area for the laser beam.
14 . A method for detecting a hostile optical component without exposing the surrounding to unnecessary hazards by utilizing a system with a laser unit, a single aperture for an optical path, a detector, and a camera, the method comprising: transmitting an adjustable laser beam along the optical path through the single aperture to scan for the optic component or to act as jammer by providing a target spoofing; detecting, by a detector unit through the single aperture, retroreflections of the laser beam at the optical component; and detecting, by a camera through the single aperture, potential candidates for the hostile optical component;- determining, by a control unit, a distance between the optical detection system and the optical component; utilizing, by the control unit, the laser unit for a laser-based countermeasure; and adjusting, by the control unit, the divergence of the laser beam of the laser unit, based on the determined distance, to minimize a laser hazard area for the laser beam.

Description

TECHNICAL FIELD The present invention relates to an optical detection system and a method for detecting a hostile optical component and, in particular, to a non-detectable optic detection system providing limited hazard area. BACKGROUND Optic detection systems are laser-based systems designed to detect hostile optic components or systems by means of the detection of a retro-reflection signal coming back from hostile optical systems such as periscopes, weapon stations, riflescopes or equivalent systems. For this, the optic detection systems may scan a narrow continuous wave, CW, or pulsed modulated laser beam of a certain beam width over a certain space angle in a short time in order to find the hostile optical systems in a range of some kilometer distances. The design of these optic detections systems shall find hostile optical systems in a large space angle (field of regard) and through longer distances in short time. The field of regard of such a system may cover as an example 90° to 120° in azimuth and 15° to 45° in elevation for a symmetric war scenario or even much more in an asymmetric conflict in an urban scenario. The distance range may run from a few 100 m (for example a hostile fire attack) up to several kilometers (for example a missile attack). The scanning time needed to find any hostile optical system within above defined space angle shall be a few seconds only or even better a fraction of a second. Such systems need huge laser power within wavelength bands such as VIS (visual spectral range), NIR (near infra-red) and/or SWIR (short wave infra-red) offering higher atmospheric transmission. The sensitivity of the system detector shall be very high as the laser signal is running two times through the atmosphere starting from the optic detection system to the hostile optic systems and back to the detector. Consequentially, the retro-reflected signal to be detected may be for large distances several orders of magnitude lower than the laser signal emitted following a distance dependency that scales at least with distance to the power of minus 4 (here atmospheric attenuation is neglected). Conventional optic detection systems as described above show the following drawbacks: appropriate lasers are non-eye safe lasers coming around with a hazard area of several 100 m or even more,these laser wavelengths are detectable by standard laser warner systems and thus the optic detection system is detectable when in operation,fast scanning prevents the system from an inherent false alarm reduction mechanism that would need longer integration times per angular direction (therefore, such systems may not be used when too many false alarms are detected which in turn results in an unacceptable workload/stress for the operator crew),a scanning electro-optical system providing high power laser and very sensitive detection capabilities at the same time have at least two apertures that is large in size and weight and, therefore, provides integration difficulties into a platform as the system requires an elevated position free of obstacles to cover the wide field of regard. Therefore, there is a demand for an optic detection system that allows the integration into ground-based, flying or swimming platforms by means of a very compact design that is optimized in terms of size, weight and power (SWaP) and offers sufficient agility to demonstrate its performance under respective platform dynamic conditions. BRIEF DESCRIPTION OF THE INVENTION At least some of the above-mentioned problems are solved by an optical detection system according to claim 1 and a method for detecting according to claim 14. The dependent claims refer to further advantageous realizations for the subject matters of the independent claims. The present invention relates to an optical detection system for detecting a hostile optical component without exposing the surrounding to unnecessary hazards. The system comprises a laser unit, a (single) aperture for an optical path, a detector, and a camera (e.g. a surveillance camera). The laser unit is configured to provide an adjustable laser beam along the optical path to scan for the hostile optical component or to act as a jammer by providing a target spoofing. The detector is configured to detect through the single aperture retroreflections of the laser beam at the hostile optical component. The camera is configured for detecting through the single aperture potential candidates for the hostile optical component. The detector may then verify the candidates. Therefore, the laser unit irradiates a laser beam into the field of interest that eventually may be reflected by the optical component (e.g. by a lens or a glass panel). These retroreflection can be detected by the detector (or the camera) by analyzing the used frequency or signal signature or a signal modulation (e.g. a particular pulse pattern). The adjustments in the laser unit may relate to different parameters. Likewise, the camera may be suitable to