All-weather reconnaissance and warning device

Abstract

This invention discloses an all-weather reconnaissance and alarm device, comprising a laser illumination component, an ICCD / ICMOS gating component, and an integrated processor. The laser illumination component uses high peak power pulsed laser light for illumination assistance, enhancing target brightness. The ICCD / ICMOS gating component is used to achieve high-gain photoelectric conversion of weak optical signals. Specifically, the ICCD / ICMOS gating component eliminates or reduces the influence of sunlight through "ultrafast adaptive imaging + light decay," enabling the component to operate in the linear region with the optimal signal-to-noise ratio for the target. Simultaneously, the ICCD / ICMOS gating component integrates a high-speed CCD / CMOS image sensor. Without changing the delay time, a higher image intensifier repetition frequency results in a smaller increase in delay time. Through ultra-high-speed image acquisition, it fully utilizes the energy of each laser pulse, enabling imaging of targets at different distances and high-speed moving targets. The integrated processing component focuses on controlling the ultrafast adaptive adjustment duration, the interval between auxiliary illumination and gating opening, and high-precision gain control.

Description

Technical Field

[0001] This invention belongs to the field of photoelectric detection, specifically relating to an all-weather reconnaissance and alarm device. Background Technology

[0002] In backlit areas of space, strong light from the sun and other sources can cause large-area pixel saturation, submerging targets in the field of view in the background and preventing them from being imaged. This severely limits the detection capability and efficiency of photoelectric detection systems. Therefore, backlit detection in space applications is a critical problem that urgently needs to be solved.

[0003] Traditional solutions mainly employ "avoidance" and "elimination," which can mitigate the challenges of backlight imaging to some extent, but they also create blind spots in the detection field of view, failing to fundamentally solve the problem of backlight detection in space. Currently, existing methods, both domestically and internationally, cannot fundamentally solve the problem of backlight imaging.

[0004] The paper "Development of an All-Weather Laser Imaging System" proposes a range-gated synchronization control technology. This technology utilizes a pulsed laser and an ICCD / ICMOS gating camera to synchronize, separating scattered and reflected light at different distances by timing. This ensures that the pulsed light reflected from the observed target falls within the gating range of the ICCD / ICMOS camera for imaging. However, while this system claims all-weather imaging, it neglects detection capabilities in backlight and strong light backgrounds. Furthermore, existing range-gated imaging technologies use ordinary CCD / ICMOS detectors with frame rates typically in the tens of hertz range. With a fixed delay time, they can only detect targets at specific distances, requiring adjustments to the delay time to obtain information on targets at different distances and high-speed moving targets. This results in slow system response times and a high risk of target information loss.

[0005] Therefore, there is an urgent need to develop a new type of all-weather reconnaissance and warning device that can not only meet the requirements of all-weather reconnaissance and detection, but also take into account the detection and identification of targets at different distances and high-speed moving targets, so as to realize multi-scenario, all-weather detection of space targets. Summary of the Invention

[0006] This invention proposes an all-weather reconnaissance and alarm device that can meet the needs of multiple scenarios such as backlight areas and shadow areas, and realize the imaging detection of targets at different distances, providing necessary technical support for our space platform.

[0007] The technical solution for achieving this invention is as follows: an all-weather reconnaissance and alarm device. When the target is in a backlit or shadowed area, a 532nm narrow-pulse high-peak-value laser is emitted through a laser illumination component to illuminate key information areas of the target, increasing the target's brightness in the laser band. The laser illumination component integrates a scanning galvanometer to achieve scanning illumination within a 30°×30° wide field of view. When the target appears within the detection field of view of the ICCD / ICMOS gated imaging component, ultra-short-time gating exposure technology and filtering technology are used to reduce strong light background interference. Through a matching design with the laser illumination component, high efficiency is achieved. Utilizing the energy of each laser pulse, the ICCD / ICMOS gated imaging component is used for optical signal convergence and reception, enabling imaging of targets at different distances and high-speed moving targets. The integrated processing unit uses an adaptive exposure algorithm to control the ultrafast adaptive adjustment time. An ultrafast exposure-based readout architecture is adopted to realize laser emission, nanosecond-level shutter, and image sensor trigger control. After receiving the target signal, the ICCD / ICMOS gated imaging component amplifies it with high gain to improve the target signal-to-noise ratio. To prevent target loss, the laser illumination component and the ICCD / ICMOS gated imaging component share the same field of view.

[0008] Compared with the prior art, the significant advantages of this invention are:

[0009] 1) It meets the application needs of multiple scenarios such as backlight areas and shadow areas, and achieves the purpose of all-weather observation of targets.

[0010] 2) High-speed CCD / CMOS image sensors are used to achieve imaging detection of targets at different distances.

[0011] 3) The use of "ultrafast adaptive imaging + light decay" greatly weakens or reduces the impact of sunlight. Attached Figure Description

[0012] Figure 1 This is a schematic diagram of the composition of an all-weather reconnaissance and alarm device according to the present invention.

[0013] Figure 2 This is a schematic diagram of the structure of an all-weather detection and alarm device according to the present invention.

[0014] Figure 3 This is a flowchart illustrating the operation of an all-weather detection and alarm device according to the present invention.

[0015] Figure 4 This is a schematic diagram of a target detection device for all-weather reconnaissance and alarm according to the present invention at different distances under strong light background. Detailed Implementation

[0016] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of the present invention, and not all of them. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of the present invention.

[0017] The following section will further introduce the specific implementation method, as well as the technical difficulties and inventive points of this invention, using this design example as an example.

[0018] Combination Figure 1 , Figure 2 and Figure 3 A 24 / 7 reconnaissance and alarm device includes a laser illumination component 1, an ICCD / ICMOS gating component 2, and a processing unit 3. The laser illumination component 1 operates at a wavelength of 532nm, and the ICCD / ICMOS gating component 2 is located on the top surface of the laser illumination component 1. The processing unit 3 is located on one side of the ICCD / ICMOS gating component 2 and is connected to both the laser illumination component 1 and the ICCD / ICMOS gating component 2. When the target is in a backlit or shadowed area, the laser illumination component 1 emits a narrow-pulse, high-peak-value laser to illuminate key information areas of the target, increasing the target's brightness in the laser wavelength range. The laser illumination component 1 integrates a scanning galvanometer to achieve scanning illumination within a large 30°×30° field of view. When a target appears within the detection field of view of the ICCD / ICMOS gating component 2, ultra-short time gating exposure technology and filtering technology are used to reduce strong light background interference. Through matching design with the laser illumination component 1, the energy of each laser pulse is efficiently utilized. The high-speed CCD / ICCD image sensor 208 is used for optical signal convergence and reception, realizing imaging of targets at different distances and high-speed moving targets. The integrated processing unit 3 completes the control of ultra-fast adaptive adjustment time through an adaptive exposure algorithm. A readout architecture based on ultra-fast exposure is adopted to realize laser emission, nanosecond-level shutter, and image sensor trigger control. After the gating camera receives the target signal, it improves the target signal-to-noise ratio through high-gain amplification. To prevent target loss, the laser illumination component 1 and the ICCD / ICMOS gating component 2 are in the same field of view.

[0019] like Figure 2As shown, the laser illumination component 1 of the all-weather reconnaissance and alarm device of the present invention includes a laser 101, an optical emission system 102, a scanning mirror 103, and a motor 104. The laser 101 operates at a wavelength of 532nm, generating a laser pulse sequence with high beam quality and high peak power. After being expanded and collimated by the optical emission system 102, the pulse is transmitted to the scanning mirror 103. The scanning mirror 103 performs two-dimensional high-frequency motion driven by the motor 104, realizing rapid pointing control of the laser emission optical axis and completing a large field-of-view search of the target.

[0020] like Figure 3 As shown, the ICCD / ICMOS gating component 2 of the all-weather detection and alarm device of this invention includes an adjustable attenuator 201, an optical imaging system 202, a 532nm±2nm narrowband filter 203, a photocathode 204, a microchannel plate 205, a fluorescent screen 206, a light cone 207, a high-speed CCD / CMOS image sensor 208, and a gated power supply 209. The light passes sequentially through the adjustable attenuator 201, optical imaging system 202, photocathode 204, microchannel plate 205, fluorescent screen 206, and high-speed CCD / CMOS image sensor 208 along the incident light direction. The narrowband filter 203 is placed in the optical imaging system 202, and the two share a common optical axis; the gated power supply 209 is electrically connected to the photocathode 204; the fluorescent screen 206 is coupled to the high-speed CCD / CMOS image sensor 208 through the light cone. The adjustable attenuator 201 controls the attenuation ratio of light incident on the optical imaging system 202. When the target is in a strong light background, adjusting the attenuator greatly reduces background stray light incident on the optical system. When the target is in a shadow area, the luminous flux of the attenuator is maximized to increase the energy of the reflected echo from the target. The optical imaging system 202 completes the convergence and reception of incident optical signals. The narrowband filter 203 is used to receive light in the 532nm band from the laser illumination component and to deeply cut off light in the non-532nm±2nm band. The gated power supply 209 is mainly responsible for generating a high-speed voltage pulse with adjustable gate width. The image intensifier (ICI) controls the opening and closing of the photocathode 204, with a repetition frequency reaching up to hundreds of kHz, an integer multiple of the frame rate of the laser illumination component 1 and the high-speed CCD / CMOS image sensor 208. This enables nanosecond-level rapid gating and converts the light radiation input to it into photoelectrons. The photoelectrons are multiplied in the microchannel plate 205, and the phosphor screen 206 completes the electro-optical conversion. The phosphor screen 206 is coupled to the high-speed CCD / CMOS image sensor 208 via the light cone 207, with a frame rate as high as tens of kHz. The frame rate of the CCD / CMOS gating camera 2 is determined by the frame rate of the image sensor. With a fixed gating time and without changing the delay time, a higher repetition frequency of the image intensifier results in a smaller increase in delay time. Through ultra-high-speed image acquisition, the energy of each laser pulse is fully utilized, enabling imaging of targets at different distances and high-speed moving targets.

[0021] The integrated processing unit 3 synchronizes the laser illumination component 1 and the ICCD / ICMOS gating component 2 with high precision, focusing on controlling the ultra-fast adaptive adjustment time, the interval between auxiliary illumination and gating opening, and high-precision gain control. It achieves ultra-fast adaptive adjustment time control through an adaptive exposure algorithm; employs an ultra-fast exposure-based readout architecture to realize laser emission, nanosecond-level shutter, and image sensor trigger control; after the camera receives the target signal, it uses high-gain amplification to improve the target signal-to-noise ratio. The integrated processing unit 3 performs detection and extraction processing on the acquired images, analyzes the target's azimuth and distance information, sends guidance information, completes all-day target photoelectric detection in strong light backgrounds and shadow areas, and issues alarm information.

[0022] The adaptive exposure algorithm calculates the average grayscale value of the image and determines the lighting conditions based on this value, identifying whether the target is in a backlit area. When the target is in a shadow area, the optimal exposure time is automatically calculated based on the grayscale level and exposure parameters. When the target is in a backlit area, the attenuator 201 is adjusted to reduce background stray light incident on the ICCD / ICMOS gate component 2, and the optimal gate time is determined based on the grayscale level and the upper limit adjustment of the image intensifier energy. The relationship between the ideal exposure time and the current exposure time is as follows:

[0023]

[0024] In the formula, T1 and T2 correspond to the current image exposure time and the ideal image exposure time, respectively; DN1 and DN2 correspond to the current image statistical average gray value and the ideal gray value, respectively; G1 and G2 correspond to the current image gain and the ideal image gain, respectively; and N is the highest gray value of the image. Given the current exposure parameters and the image statistical average, the ideal exposure time T2 can be calculated based on the target brightness.

[0025] This invention possesses the capability for all-weather photoelectric detection in various scenarios, including strong light backgrounds and shadow areas. The steps for using an all-weather reconnaissance and alarm device are as follows:

[0026] Step 1: When the target is in a bright background or shadow area, the laser illumination component 1 emits a pulsed laser and scans and illuminates the target within a large field of view through a scanning galvanometer, thus completing the auxiliary illumination of the target in the designated airspace.

[0027] Step 2: When the delay time of the laser illumination component 1 and the ICCD / ICMOS gating component 2 is reached, the gating gate opens, and the high-speed CCD / CMOS image sensor 208 performs image acquisition.

[0028] Step 3: If the laser illumination component 1 successfully illuminates the target, the laser pulse information reflected back from the target enters the high-speed CCD / CMOS image sensor 208. An image of the target is then acquired.

[0029] Step 4: If the laser illumination component 1 fails to illuminate the target, change the delay time and continue to scan and illuminate the target by scanning mirror to perform distance traversal.

[0030] Step 5: The integrated processing unit 3 detects and extracts the acquired images, analyzes the target's location and distance information, and sends guidance information.

[0031] like Figure 4 The image shown is a test result of the all-weather reconnaissance and warning device, conducted on a clear day during an outdoor UAV test. The device utilizes "ultrafast adaptive imaging + light decay" to eliminate or reduce the influence of sunlight. Simultaneously, laser illumination component 1 provides auxiliary illumination, increasing target brightness. A high-speed CCD / CCD image sensor 208 is used for optical signal convergence and reception, enabling target imaging at different distances.

Claims

1. A 24 / 7 reconnaissance and alarm device, characterized in that: The system includes a laser illumination component (1), an ICCD / ICMOS gated imaging component (2), and a comprehensive processing unit (3). When the target is in a backlight or shadow area, the laser illumination component (1) emits a 532nm narrow-pulse high-peak-value laser to illuminate the key information parts of the target, thereby increasing the brightness of the target in the laser band. The laser illumination component (1) integrates a scanning galvanometer to achieve scanning illumination within a 30°×30° wide field of view. When the target appears within the detection field of view of the ICCD / ICMOS gated imaging component (2), ultra-short-time gating exposure technology and filtering technology are used to reduce strong light background interference. The system is then compared with the laser illumination component (1) through a matching process. The design efficiently utilizes the energy of each laser pulse; the ICCD / ICMOS gated imaging component (2) is used for optical signal convergence and reception to achieve imaging of targets at different distances and high-speed moving targets; the integrated processing unit (3) completes the control of ultra-fast adaptive adjustment time through an adaptive exposure algorithm; the readout architecture based on ultra-fast exposure is adopted to realize laser emission, nanosecond-level shutter and image sensor trigger control; after receiving the target signal, the ICCD / ICMOS gated imaging component (2) amplifies the target signal-to-noise ratio through high gain; in order to prevent target loss, the laser illumination component (1) and the ICCD / ICMOS gated imaging component (2) are in the same field of view.

2. The all-weather reconnaissance and alarm device according to claim 1, characterized in that: The laser illumination assembly (1) includes a laser (101), an optical emission system (102), a scanning galvanometer (103), and a motor (104) to complete scanning illumination within a large field of view of 30°×30°, thereby increasing the light energy of the returned signal.

3. The all-weather reconnaissance and alarm device according to claim 2, characterized in that: The ICCD / ICMOS gated imaging component (2) includes an adjustable attenuator (201), an optical imaging system (202), a narrowband filter (203), a photocathode (204), a microchannel plate (205), a fluorescent screen (206), a light cone (207), a high-speed CCD / CMOS image sensor (208), and a gated power supply (209), used to receive the target reflected echo signal; the adjustable attenuator (201) is fixed in front of the optical imaging system (202) to adjust the amount of light incident on the optical imaging system (202). When the target is in a strong light background, the background stray light incident on the optical system is greatly reduced by adjusting the attenuator. When the target is in a shadow area, the light flux of the attenuator is adjusted to the maximum to increase the light energy of the reflected echo from the target. The optical imaging system (202) completes the convergence and reception of the incident optical signal. The filter (203) is connected to the optical imaging system (202) on the same optical axis to receive the 532nm wavelength light generated by the laser illumination component (1) and to cut off the light depth of non-532nm±2nm wavelength bands. The gate power supply (209) is mainly responsible for generating high-speed voltage pulses with adjustable gate width to realize the opening and closing of the photocathode (204). The photocathode (204) has a gating function, and its repetition frequency is up to hundreds of kHz, which is an integer multiple of the frame rate of the laser illumination component (1) and the high-speed CCD / CMOS image sensor (208). It can realize nanosecond-level fast gating and convert the light radiation input to it into photoelectrons. The photoelectrons are multiplied in the microchannel plate (205), and the fluorescent screen (206) completes the electro-optic conversion. The fluorescent screen (206) is coupled to the high-speed CCD / CMOS image sensor (208) through the light cone (207).

4. The all-weather reconnaissance and alarm device according to claim 3, characterized in that: The ICCD / ICMOS gated imaging component (2) uses a high-speed CCD / CMOS image sensor (208) with a frame rate of up to tens of kHz. Through matching design, the repetition frequency of the image intensifier gate is made to be an integer multiple of that of the CCD / CMOS. Each frame image is an image intensifier shutter superposition imaging of 1-10 times. Without changing the delay time, the higher the repetition frequency of the image intensifier, the shorter the delay time. Through ultra-high-speed image acquisition, imaging of targets at different distances and high-speed moving targets can be achieved.

5. The all-weather reconnaissance and alarm device according to claim 4, characterized in that: The integrated processing unit (3) realizes ultra-fast adaptive adjustment duration control, interval of auxiliary lighting and gate opening, high-precision gain control; and performs detection and extraction processing on the acquired images, analyzes the target orientation and distance information, sends guidance information, completes all-day photoelectric detection of targets in strong light background and shadow area, and issues alarm information.

6. The all-weather reconnaissance and alarm device according to claim 5, characterized in that: An adaptive exposure algorithm is used to achieve ultra-fast adaptive adjustment of exposure time, as follows: First, the average gray value of the image is calculated. Based on the average gray value, the lighting conditions are determined, and the optimal exposure time is automatically calculated to create conditions for target detection. The relationship between the ideal exposure time and the current exposure time is as follows: In the formula, T1 and T2 correspond to the current image exposure time and the ideal image exposure time, respectively; DN1 and DN2 correspond to the current image statistical average value and the ideal gray value, respectively; G1 and G2 correspond to the current image gain and the ideal image gain, respectively; and N is the highest gray value of the image.

Images