阅读说明：本技术 一种光子级自适应高灵敏度空间微弱目标探测系统及探测方法 (Photon-level self-adaptive high-sensitivity space weak target detection system and detection method ) 是由 代京京 赵思思 王智勇 张景豪 郑永超 于 2020-07-27 设计创作，主要内容包括：本发明公开了一种光子级自适应高灵敏度空间微弱目标探测系统及探测方法,包括：激光发射单元,用于向目标探测区域发射自适应调频单模激光,辐照目标探测区域中的空间微弱目标；目标反射激光脉冲,产生反射回波光信号；探测单元,用于对回波光信号进行滤波聚焦后分成若干路信号,分别对各路信号进行光电转换得到与各路信号对应的电信号；数据采集处理单元,用于根据若干路电信号区分探测目标的类型和大小信息以及目标的距离信息；控制单元,用于根据目标的类型和大小信息以及目标的距离信息自适应调节激光发射单元的激光脉冲的频率、功率、脉冲宽度。本发明可进一步提升信号光与噪声的区分度,达到精准探测目标的目的。(The invention discloses a photon-level self-adaptive high-sensitivity space weak target detection system and a detection method, which comprises the following steps: the laser emission unit is used for emitting adaptive frequency modulation single-mode laser to a target detection area and irradiating a spatial weak target in the target detection area; the target reflects the laser pulse to generate a reflected echo optical signal; the detection unit is used for filtering and focusing the echo optical signal, dividing the echo optical signal into a plurality of paths of signals, and respectively carrying out photoelectric conversion on each path of signal to obtain an electric signal corresponding to each path of signal; the data acquisition and processing unit is used for distinguishing the type and size information of the detected target and the distance information of the target according to the plurality of paths of electric signals; and the control unit is used for adaptively adjusting the frequency, the power and the pulse width of the laser pulse of the laser emitting unit according to the type and the size information of the target and the distance information of the target. The invention can further improve the discrimination of signal light and noise and achieve the aim of accurately detecting the target.)

1. A photon-level adaptive high-sensitivity spatial weak target detection system, comprising:

the laser emission unit is used for emitting adaptive frequency modulation single-mode laser to a target detection area and irradiating a spatial weak target in the target detection area; the target reflects the laser pulse to generate a reflected echo optical signal;

the detection unit is used for receiving the echo optical signals, filtering and focusing the echo optical signals, dividing the echo optical signals into a plurality of paths of signals, and respectively carrying out photoelectric conversion on each path of signals to obtain electric signals corresponding to each path of signals;

the data acquisition and processing unit is used for receiving a plurality of paths of electric signals and distinguishing the type and size information of a detected target and the distance information of the target according to the plurality of paths of electric signals;

and the control unit is used for receiving the type and size information of the target and the distance information of the target and adaptively adjusting the frequency, the power and the pulse width of the laser pulse of the laser emission unit according to the type and size information of the target and the distance information of the target.

2. A detection system according to claim 1, wherein the spatially weak targets are spatial debris with a diameter < 100 μm.

3. The detection system of claim 1, wherein the laser emitting unit comprises: the device comprises a single-mode laser, an optical conversion device, a scanning galvanometer, a variable frequency power supply, a photoelectric Q-switching device and a power supply controller, wherein the scanning galvanometer is connected with the photoelectric Q-switching device; wherein the content of the first and second substances,

the single-mode laser is used for generating single-mode laser;

the optical conversion device consists of a plurality of telescope system lens groups and is used for automatically adjusting the optical focal length of the system to achieve the function of adjusting the size of an output light spot;

the scanning galvanometer is used for rotating the emission direction of the power supply and scanning a target in a space;

the photoelectric Q-switch device and the variable frequency light source are used for adjusting the output pulse width of the single-mode laser from microsecond to nanosecond;

and the power supply controller is used for controlling the laser emission frequency and power through the power supply.

4. The detection system of claim 1, wherein the detection unit comprises: the device comprises an optical conversion component, a light filtering component, a focusing lens, an optical beam splitting component and a photoelectric conversion module, wherein the optical conversion component is connected with the light filtering component, the light filtering component is connected with the focusing lens, the focusing lens is connected with the optical beam splitting component, and the optical beam splitting component is connected with the photoelectric conversion module; wherein the content of the first and second substances,

the optical conversion component consists of a plurality of telescope system lens groups and is used for receiving the echo light signals;

the filtering component comprises a band-pass filter and a narrow-band filter and is used for filtering stray light and background light out of a signal wave band in the echo optical signal;

the focusing lens is used for focusing the filtered echo optical signals;

the optical beam splitting assembly is arranged at the light outlet of the focusing lens and is used for dividing the filtered and focused echo optical signal into a plurality of paths of signals;

the photoelectric conversion module comprises a single photon avalanche photodiode and is used for respectively carrying out photoelectric conversion on each path of signal to obtain an electric signal corresponding to each path of signal.

5. The detection system of claim 1, wherein the data acquisition processing unit comprises: a single photon technologist and an analysis processing module;

the single photon technologist is used for receiving a plurality of paths of electric signals;

and the analysis processing module is used for distinguishing the type and size information of the detection target and the distance information of the target according to the plurality of paths of electric signals.

6. A detection method of a detection system according to any one of claims 1 to 5, comprising:

emitting adaptive frequency modulation single-mode laser to a target detection area, and irradiating a spatial weak target in the target detection area; the target reflects the laser pulse to generate a reflected echo optical signal;

receiving the echo optical signal, filtering and focusing the echo optical signal, dividing the echo optical signal into a plurality of paths of signals, and respectively carrying out photoelectric conversion on each path of signal to obtain an electric signal corresponding to each path of signal;

receiving a plurality of paths of electric signals, and distinguishing the type and size information of a detection target and the distance information of the target according to the plurality of paths of electric signals;

receiving the type and size information of the target and the distance information of the target, and adaptively adjusting the frequency, the power and the pulse width of the laser pulse of the laser emission unit according to the type and size information of the target and the distance information of the target.

Technical Field

The invention relates to the technical field of space weak target detection, in particular to a photon-level self-adaptive high-sensitivity space weak target detection system and a detection method.

Background

The number of tiny space fragments is large and the frequency of collisions with the spacecraft is high, and although such collisions do not have a direct impact or catastrophic failure on the structure of the spacecraft, their cumulative effect may have an impact on the performance of the surface materials and components of the spacecraft. The small size of the space debris (diameter < 100 μm) makes direct detection on the ground impossible, so on-track detection becomes an important means for grasping the environment of the space debris.

In the space background, the single photon ranging technology is adopted to obtain signals of long-distance space debris at present, however, as long as noise photons and signal photons have in-phase response pulses, a signal processing and analyzing system can generate misjudgment, and the detection of the signal photon pulses causes huge interference. Especially, in sunny weather, the noise of the solar background light cannot be completely eliminated through measures such as filtering, and the like, so that a large amount of false alarms are generated by the single photon laser radar.

Disclosure of Invention

Aiming at the problems in the prior art, the invention provides a photon-level adaptive high-sensitivity space weak target detection system and a detection method, and the detection system can further improve the discrimination of signal light and noise.

The invention discloses a photon-level self-adaptive high-sensitivity space weak target detection system, which comprises:

the laser emission unit is used for emitting adaptive frequency modulation single-mode laser to a target detection area and irradiating a spatial weak target in the target detection area; the target reflects the laser pulse to generate a reflected echo optical signal;

the detection unit is used for receiving the echo optical signals, filtering and focusing the echo optical signals, dividing the echo optical signals into a plurality of paths of signals, and respectively carrying out photoelectric conversion on each path of signals to obtain electric signals corresponding to each path of signals;

the data acquisition and processing unit is used for receiving a plurality of paths of electric signals and distinguishing the type and size information of a detected target and the distance information of the target according to the plurality of paths of electric signals;

and the control unit is used for receiving the type and size information of the target and the distance information of the target and adaptively adjusting the frequency, the power and the pulse width of the laser pulse of the laser emission unit according to the type and size information of the target and the distance information of the target.

As a further development of the invention, the spatially weak targets are spatial fragments with a diameter < 100 μm.

As a further improvement of the present invention, the laser emitting unit includes: the device comprises a single-mode laser, an optical conversion device, a scanning galvanometer, a variable frequency power supply, a photoelectric Q-switching device and a power supply controller, wherein the scanning galvanometer is connected with the photoelectric Q-switching device; wherein the content of the first and second substances,

the single-mode laser is used for generating single-mode laser;

the optical conversion device consists of a plurality of telescope system lens groups and is used for automatically adjusting the optical focal length of the system to achieve the function of adjusting the size of an output light spot;

the scanning galvanometer is used for rotating the emission direction of the power supply and scanning a target in a space;

the photoelectric Q-switch device and the variable frequency light source are used for adjusting the output pulse width of the single-mode laser from microsecond to nanosecond;

and the power supply controller is used for controlling the laser emission frequency and power through the power supply.

As a further improvement of the present invention, the detection unit includes: the device comprises an optical conversion component, a light filtering component, a focusing lens, an optical beam splitting component and a photoelectric conversion module, wherein the optical conversion component is connected with the light filtering component, the light filtering component is connected with the focusing lens, the focusing lens is connected with the optical beam splitting component, and the optical beam splitting component is connected with the photoelectric conversion module; wherein the content of the first and second substances,

the optical conversion component consists of a plurality of telescope system lens groups and is used for receiving the echo light signals;

the filtering component comprises a band-pass filter and a narrow-band filter and is used for filtering stray light and background light out of a signal wave band in the echo optical signal;

the focusing lens is used for focusing the filtered echo optical signals;

the optical beam splitting assembly is arranged at the light outlet of the focusing lens and is used for dividing the filtered and focused echo optical signal into a plurality of paths of signals;

the photoelectric conversion module comprises a single photon avalanche photodiode and is used for respectively carrying out photoelectric conversion on each path of signal to obtain an electric signal corresponding to each path of signal.

As a further improvement of the present invention, the data acquisition processing unit includes: a single photon technologist and an analysis processing module;

the single photon technologist is used for receiving a plurality of paths of electric signals;

and the analysis processing module is used for distinguishing the type and size information of the detection target and the distance information of the target according to the plurality of paths of electric signals.

The invention also discloses a photon-level self-adaptive high-sensitivity space weak target detection method, which comprises the following steps:

emitting adaptive frequency modulation single-mode laser to a target detection area, and irradiating a spatial weak target in the target detection area; the target reflects the laser pulse to generate a reflected echo optical signal;

receiving the echo optical signal, filtering and focusing the echo optical signal, dividing the echo optical signal into a plurality of paths of signals, and respectively carrying out photoelectric conversion on each path of signal to obtain an electric signal corresponding to each path of signal;

receiving a plurality of paths of electric signals, and distinguishing the type and size information of a detection target and the distance information of the target according to the plurality of paths of electric signals;

receiving the type and size information of the target and the distance information of the target, and adaptively adjusting the frequency, the power and the pulse width of the laser pulse of the laser emission unit according to the type and size information of the target and the distance information of the target.

Compared with the prior art, the invention has the beneficial effects that:

after the data acquisition processing unit measures the reflection signal of the target, the control unit can further adjust the self-adaption of the laser to change the frequency, the pulse width, the power and the single pulse energy of the emitted laser so as to adjust the contrast ratio of the signal light and the background light, and the data acquisition processing unit analyzes the stray light and the signal light; the discrimination of signal light and noise can be further improved, and the purpose of accurately detecting the target is achieved.

Drawings

FIG. 1 is a block diagram of a photonic-grade adaptive high-sensitivity spatial weak target detection system according to an embodiment of the present invention;

FIG. 2 is a block diagram of a laser emitting unit according to an embodiment of the present invention;

FIG. 3 is a block diagram of a probe unit according to an embodiment of the present invention;

FIG. 4 is a block diagram of a data acquisition and processing unit according to an embodiment of the present invention;

FIG. 5 is a comparison diagram of photon-level adaptive high-sensitivity spatial debris detection target signal extraction according to an embodiment of the present invention;

fig. 6 is a flowchart of a photon-level adaptive high-sensitivity spatial weak target detection method according to an embodiment of the present invention.

Detailed Description

In order to make the objects, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the drawings in the embodiments of the present invention, and it is obvious that the described embodiments are some, but not all, embodiments of the present invention. All other embodiments, which can be obtained by a person skilled in the art without any inventive step based on the embodiments of the present invention, are within the scope of the present invention.

The invention is described in further detail below with reference to the attached drawing figures:

as shown in fig. 1, the present invention provides a photon-level adaptive high-sensitivity spatial weak target detection system, which includes: the device comprises a laser emission unit, a detection unit, a data acquisition and processing unit and a control unit, wherein the laser emission unit is connected with the detection unit, the detection unit is connected with the data acquisition and processing unit, the data acquisition and processing unit is connected with the control unit, and the control unit is connected with the laser emission unit; wherein the content of the first and second substances,

the laser emission unit is used for emitting self-adaptive frequency modulation single-mode laser to a target detection area and irradiating a spatial weak target in the target detection area; the target reflects the laser pulse to generate a reflected echo optical signal; wherein the space weak target is a space fragment with the diameter less than 100 mu m;

specifically, as shown in fig. 2, the laser emitting unit of the present invention includes: the device comprises a single-mode laser, an optical conversion device, a scanning galvanometer, a variable frequency power supply, a photoelectric Q-switching device and a power supply controller, wherein the scanning galvanometer is connected with the photoelectric Q-switching device; the single-mode laser is used for generating single-mode laser; the optical conversion device consists of a plurality of telescope system lens groups and is used for automatically adjusting the optical focal length of the system to achieve the function of adjusting the size of an output light spot; the scanning galvanometer is used for rotating the emission direction of the power supply and scanning a target in a space; the device comprises an optoelectronic modulation Q device and a variable frequency light source, wherein the optoelectronic modulation Q device and the variable frequency light source are used for adjusting the output pulse width of single-mode laser from microsecond to nanosecond; and the power supply controller is used for controlling the laser emission frequency and power through the power supply.

Further, the single mode laser may include a DFB semiconductor single mode laser that may directly output light or may be fiber coupled to output light.

Furthermore, the optical conversion system can also be composed of micro lens groups.

Further, the photoelectric Q-switching device can be SESEM or laser switch crystal.

The detection unit is used for receiving the echo optical signals, filtering and focusing the echo optical signals, dividing the echo optical signals into a plurality of paths of signals, and respectively carrying out photoelectric conversion on each path of signals to obtain electric signals corresponding to each path of signals;

specifically, as shown in fig. 3, the detection unit of the present invention includes: the photoelectric conversion device comprises an optical conversion component, a filtering component, a focusing lens, an optical beam splitting component and a photoelectric conversion module, wherein the optical conversion component is connected with the filtering component, the filtering component is connected with the focusing lens, the focusing lens is connected with the optical beam splitting component, and the optical beam splitting component is connected with the photoelectric conversion module; the optical conversion component consists of a plurality of telescope system lens groups and is used for receiving echo optical signals; the filtering component comprises a band-pass filter and a narrow-band filter and is used for filtering stray light and background light out of a signal wave band in the echo optical signal; the focusing lens is used for focusing the filtered echo optical signals; the optical beam splitting component is arranged at the light outlet of the focusing lens and is used for dividing the filtered and focused echo optical signal into a plurality of paths of signals; the photoelectric conversion module comprises a single photon avalanche photodiode and is used for respectively carrying out photoelectric conversion on each path of signal to obtain an electric signal corresponding to each path of signal.

Further, the optical splitting assembly may employ a fiber optic splitter.

The data acquisition and processing unit is used for receiving a plurality of paths of electric signals and distinguishing the type and size information of a detected target and the distance information of the target according to the plurality of paths of electric signals;

specifically, as shown in fig. 4, the data acquisition processing unit of the present invention includes: the time domain high responsivity single photon technology device comprises a time domain high responsivity single photon technology device and an analysis processing module; the single photon technologist is used for receiving a plurality of paths of electric signals; the analysis processing module is used for distinguishing the type and size information of the detection target and the distance information of the target according to the plurality of paths of electric signals; according to the electric signal, the noise signal generated by the stray light and the echo signal reflected by the target are distinguished.

The control unit is used for receiving the type and size information of the target and the distance information of the target and adaptively adjusting the frequency, the power and the pulse width of the laser pulse of the laser emission unit according to the type and size information of the target and the distance information of the target; the detection system of the invention can further improve the discrimination of signal light and noise, and achieve the purpose of accurately detecting the target, and the photon level self-adaptive high-sensitivity space debris detection target signal is extracted and compared, as shown in fig. 5.

As shown in fig. 6, the present invention also discloses a photon-level adaptive high-sensitivity spatial weak target detection method, which comprises:

s1, emitting adaptive frequency modulation single-mode laser to the target detection area, and irradiating the spatial weak target in the target detection area; the target reflects the laser pulse to generate a reflected echo optical signal;

s2, receiving the echo optical signal, filtering and focusing the echo optical signal, dividing the echo optical signal into a plurality of paths of signals, and respectively carrying out photoelectric conversion on each path of signal to obtain an electric signal corresponding to each path of signal;

s3, receiving a plurality of paths of electric signals, and distinguishing the type and size information of the detected target and the distance information of the target according to the plurality of paths of electric signals;

and S4, receiving the type and size information of the target and the distance information of the target, and adaptively adjusting the frequency, the power and the pulse width of the laser pulse of the laser emitting unit according to the type and size information of the target and the distance information of the target.

The invention has the advantages that:

after the data acquisition processing unit measures the reflection signal of the target, the control unit can further adjust the self-adaption of the laser to change the frequency, the pulse width, the power and the single pulse energy of the emitted laser so as to adjust the contrast ratio of the signal light and the background light, and the data acquisition processing unit analyzes the stray light and the signal light; the discrimination of signal light and noise can be further improved, and the purpose of accurately detecting the target is achieved.

The above is only a preferred embodiment of the present invention, and is not intended to limit the present invention, and various modifications and changes will occur to those skilled in the art. Any modification, equivalent replacement, or improvement made within the spirit and principle of the present invention should be included in the protection scope of the present invention.