Single photon detection array laser tracking angle measurement and communication distance measurement device and method

Abstract

The single-photon detection array laser tracking angle measurement and communication ranging device and method disclosed in the present invention belong to the technical field of laser signal detection and satellite communication ranging. The single-photon detection array laser tracking angle measurement and communication ranging device disclosed in the present invention includes an optical telescope, a piezoelectric deflection mirror, a piezoelectric controller, a single-photon detection array, a signal amplification and distribution network, a signal acquisition and processing module, a low phase noise frequency synthesizer, an edge detection and multi-channel synthesizer. The present invention uses a highly sensitive single-photon detection array to replace the CCD camera angle measurement subsystem. Based on the single-photon detection array, the signal can be tracked and angled while completing signal reception, simplifying the laser tracking angle measurement and communication ranging system structure, and improving the utilization rate of received signals and the system receiving sensitivity. The present invention can enable all signal energy to be received by the single-photon detection array, improve the energy utilization rate of the laser signal, and can increase the signal receiving area.

Description

Technical Field

[0001] The invention relates to a single-photon detection array laser tracking angle measurement and communication distance measurement device and method, belonging to the technical field of laser signal detection and satellite communication distance measurement. Background Art

[0002] Currently, satellite communications are limited by spectrum and orbital resources. Laser measurement and control technology has the advantages of good confidentiality and high transmission rate, and has become an effective means to solve high-speed space transmission. It plays an important role in major engineering projects such as high-resolution space mapping, manned spacecraft rendezvous and docking, and space station construction. It is a key link in precise single-point positioning, space-based monitoring, and anti-interference positioning.

[0003] Satellite laser measurement and control systems need to complete angle measurement, distance measurement, and data transmission tasks. In-orbit satellite measurement and control requires the ground end to quickly search a large field of view during the satellite transit time to capture satellite signals and continuously adjust the alignment angle for tracking. In existing laser measurement and control systems, the angle measurement hardware subsystem used for signal capture and tracking and the hardware subsystem used for communication and ranging are two independent sets of optical receiving devices, and a spectroscope is required to divide the received laser signal into two parts. One part is received by a CCD (charge coupled device) camera, which captures and tracks the satellite signal through the imaging position of the signal on the photosensitive surface; the other part is received by a laser signal receiver, converted into an electrical signal, and uses a digital signal processing algorithm to achieve communication and ranging.

[0004] Since the power of the satellite-to-ground downlink laser signal is extremely weak, the ground end needs to use a single-photon detector to receive the signal at the photon level. The spectroscope is difficult to achieve ideal spectroscopic effect when the number of photons is extremely small. At the same time, the sensitivity of the CCD camera is much lower than that of the single-photon detector. In order for the CCD camera to work properly, more energy needs to be allocated to the angle measurement hardware subsystem, which greatly weakens the signal energy used to achieve communication ranging, and reduces the communication ranging performance and the success rate of link establishment. Summary of the invention

[0005] In order to solve the problem that the hardware subsystems of angle measurement and communication ranging are separated and the low sensitivity of CCD camera affects the system performance and the success rate of link establishment, the main purpose of the present invention is to provide a single-photon detection array laser tracking angle measurement and communication ranging device and method, using a high-sensitivity single-photon detection array to replace the CCD camera angle measurement subsystem, based on the single-photon detection array, the signal can be tracked and angled while completing signal reception, simplifying the laser tracking angle measurement and communication ranging system structure, and improving the utilization rate of received signals and the system receiving sensitivity. The high sensitivity means that only a few photons / pulses are needed to receive the signal, and the number of photons required for a single pulse response reaches single digits.

[0006] The objective of the present invention is achieved through the following technical solutions:

[0007] The single-photon detection array laser tracking angle measurement and communication distance measurement device disclosed in the present invention comprises an optical telescope, a piezoelectric deflection mirror, a piezoelectric controller, a single-photon detection array, a signal amplification and distribution network, a signal acquisition and processing module, a low phase noise frequency synthesizer, and an edge detection and multi-channel synthesizer.

[0008] The optical telescope is used to receive the space laser signal transmitted by the satellite, complete the capture and tracking of the laser signal, and focus the space laser signal and transmit it to the piezoelectric deflection mirror during the satellite transit.

[0009] The piezoelectric deflection mirror is used to reflect the laser signal received by the optical telescope and adjust the direction of the optical path so that the signal is accurately aligned with the center position of the single photon detection array.

[0010] The piezoelectric controller is used to control the two-dimensional deflection angle of the piezoelectric deflection mirror, thereby controlling the transmission direction of the light path.

[0011] The highly sensitive single-photon detection array is used to track and measure the angle of the signal while receiving the signal. The use of multiple single-photon detectors to form a single-photon detection array increases the signal receiving area and improves the signal receiving stability compared to a single single-photon detector. The single-photon detection array detects extremely weak downlink laser signals at the level of a single photon, and converts the signal into an electrical pulse signal with a fast rising edge and an exponential decay on the falling edge. The array pixel that receives the photon outputs an electrical pulse signal, and the pixel that does not receive the photon outputs a low level. The position of the light spot in the array is calculated using the signal energy difference received by the pixel in the single-photon detection array, and the angle information of the incident laser signal is further obtained to achieve signal angle measurement, and then the signal is tracked and measured while the signal is received. The high sensitivity means that only a few photons / pulses are required to receive the signal, and the number of photons required for a single pulse response reaches single digits. The extremely weak downlink laser signal refers to a light pulse in a laser signal containing less than 100 photons.

[0012] The signal amplification and distribution network is used to receive the multi-channel electrical signal output from the single-photon detection array, first amplify the signal amplitude, and then divide the amplified signal into two groups. One group of signals is sent to the edge detection and multi-channel synthesizer for electrical pulse rising edge detection and multi-channel signal synthesis, and the other group of signals is sent to the signal acquisition and processing module for spot position calculation, and the laser signal incident angle is calculated by the spot position.

[0013] The signal acquisition and processing module realizes angle measurement based on the multi-channel electrical pulse signal output by the signal amplification and distribution network on the one hand, and realizes communication data demodulation and ranging time information measurement according to the synthesized signal on the other hand.

[0014] The low phase noise frequency synthesizer is used to generate the working clock of the signal acquisition and processing module, the edge detection and the multi-channel synthesizer.

[0015] The edge detection and channel synthesizer is used to extract the edges of the multi-channel electrical pulse signal after amplification processing by the signal conditioning and distribution network, to shape the signal with a fast rising edge and an exponential decay of the falling edge, and to synthesize the shaped multi-channel signals into one modulated signal, which is sent to the signal acquisition and processing module for communication and ranging information processing.

[0016] The present invention also discloses a method for laser tracking angle measurement and communication ranging based on a single photon detection array. The method is implemented based on the device for laser tracking angle measurement and communication ranging. The method comprises the following steps:

[0017] Step 1: The optical telescope receives the laser signal sent by the satellite and focuses it on the piezoelectric deflection mirror. The piezoelectric controller controls the piezoelectric deflection mirror to scan in a two-dimensional plane, and quickly searches for the satellite-to-ground laser signal incident on the optical telescope. During the search phase, the rotation of the optical telescope is independent of the piezoelectric deflection mirror. During the tracking phase, the optical telescope rotates in coordination with the piezoelectric deflection mirror with the focus as the origin. The angle of rotation of the optical telescope is twice the rotation angle of the piezoelectric deflection mirror.

[0018] Step 2: The N×M single-photon detection array receives the laser signal reflected by the piezoelectric deflection mirror with high sensitivity. The detection sensitivity is at the single photon level, and the photoelectric conversion of the satellite downlink laser signal is completed to output multiple electrical signals. N and M are the number of row and column pixels of the single-photon detection array, respectively. The signal receiving area of ​​the N×M single-photon detection array is NM times the receiving area of ​​a single single-photon detector, achieving more reliable reception of the signal.

[0019] Step three: The signal amplification and distribution network amplifies the multi-channel electrical signals output by the single-photon detection array and distributes them into two groups of signals. One group of signals is sent to the edge detection and multi-channel synthesizer for electrical pulse rising edge detection and multi-channel signal synthesis, and the other group of signals is sent to the signal acquisition and processing module for spot position calculation, and the laser signal incident angle is calculated based on the spot position.

[0020] Step 4: The signal acquisition and processing module collects the multi-channel signals output by the signal amplification and distribution network, and counts the pulses in each signal. When the light pulse count value received at a certain scanning dwell point exceeds the threshold value, the centroid position of the light spot is calculated as the starting point of signal tracking, and the deflection angle is calculated through the centroid position of the light spot, and the angle control signal is output to the piezoelectric controller.

[0021] Spot centroid position (xi ,y i ) is the coordinate of the i-th pixel, N is the number of pixels in the single-photon detection array, the center of the array is the origin of the coordinate, and I i is the number of pulses received by the i-th pixel during the measurement period.

[0022] The angle (θ) between the optical path between the piezoelectric deflection mirror and the single photon detection array and the centroid position of the light spot at the origin of the array x ,θ y )for: L is the distance between the piezoelectric deflection mirror and the single photon detection array.

[0023] In order to move the center of mass of the light spot to the center of the array, it is necessary to control the deflection angle (Δθ x ,Δθ y )for:

[0024]

[0025] Step 5: The piezoelectric deflection mirror adjusts the deflection angle of the lens according to the control signal of the piezoelectric controller, so that the laser signal is located at the center of the single-photon detection array after being reflected by the piezoelectric deflection mirror.

[0026] Step six: if the light pulse count value received at this dwell point is less than the threshold value, return to step one and control the piezoelectric deflection mirror to search for the laser signal again; if the light pulse count value received at the scanning dwell point of this deflection angle exceeds the threshold value, continue to update the deflection angle through the center position of the light spot, so that the center of mass of the light spot continues to be located at the center position of the single-photon receiving array, thereby realizing tracking and angle measurement of the laser signal.

[0027] Step 7: The signal acquisition and processing module acquires the analog electrical signals synthesized by the edge detection and channel synthesizer, completes the digital quantization of the analog electrical signals, and captures, tracks, synchronously demodulates and decodes the digital signals to extract the communication data and ranging information to achieve communication. The signal sent by the satellite contains the sending time information. When the ground end receives the signal, it records the receiving time information. The signal transmission time is obtained by subtracting the receiving time information from the demodulated sending time information, and then the signal transmission distance is calculated to achieve ranging.

[0028] The synthetic signal r(t) is expressed as: r i (t) is the output signal of the i-th pixel; τ is the signal delay, which is designed according to the pulse width required to be output.

[0029] The transmitted signal s(t) is expressed as: Where T is the symbol period, N is the position of the pulse within the symbol, and information is transmitted through the position of the pulse within the symbol.

[0030] Step 8. According to steps 4 to 6, the position of the light spot in the array is calculated using the signal energy difference received by the pixels in the single-photon detection array, and the angle information of the incident laser signal is further obtained to realize signal angle measurement. According to step 7, the electrical pulse signal output by the single-photon detection array is used to realize communication and ranging. That is, based on the single-photon detection array, the signal is tracked and angled while completing signal reception, which simplifies the structure of the laser tracking angle measurement and communication ranging system, and improves the utilization rate of the received signal and the detection sensitivity of the system.

[0031] Beneficial effects:

[0032] 1. The single-photon detection array laser tracking angle measurement and communication ranging device and method disclosed in the present invention use a highly sensitive single-photon detection array to replace the CCD camera angle measurement subsystem to achieve integrated signal reception and angle measurement tracking, that is, the signal energy difference received by the pixels in the single-photon detection array is used to calculate the position of the light spot in the array, and further obtain the angle information of the incident laser signal to achieve signal angle measurement, and then track and measure the angle of the signal while receiving the signal, thereby simplifying the structure of the laser tracking angle measurement and communication ranging system. Compared with the replaced CCD camera angle measurement subsystem, it has the advantages of simple structure and small size.

[0033] 2. The single-photon detection array laser tracking angle measurement and communication ranging device and method disclosed in the present invention use a highly sensitive single-photon detection array to replace the CCD camera angle measurement subsystem, so that all signal energy is received by the single-photon detection array and used for communication ranging and angle tracking, thereby improving the laser signal energy utilization rate.

[0034] 3. Using a CCD camera for measurement requires at least several hundred photons / pulses. The laser tracking angle measurement and communication ranging device and method of the single-photon detection array disclosed in the present invention use highly sensitive single-photon detectors and only require a few photons / pulse to receive signals. The number of photons required for a single pulse response reaches single digits, thereby improving the detection sensitivity of the laser tracking angle measurement and communication ranging system.

[0035] 4. The single-photon detection array laser tracking angle measurement and communication ranging device and method disclosed in the present invention use multiple single-photon detectors to form a detection array to receive signals, increase the signal receiving area, and further expand the receiving field of view of the laser tracking angle measurement and communication ranging device, which can more reliably receive signals compared to using a single single-photon detector. BRIEF DESCRIPTION OF THE DRAWINGS

[0036] Figure 1 It is a schematic diagram of the structure of the device for laser tracking angle measurement and communication ranging based on single photon detection array in the present invention;

[0037] Figure 2 It is a schematic diagram of the hardware structure of the signal acquisition and processing module in the present invention;

[0038] Figure 3 It is a flow chart of the method for laser tracking angle measurement and communication ranging based on single photon detection array in the present invention;

[0039] Figure 4 It is a signal processing flow chart of the signal acquisition and processing module in the present invention. DETAILED DESCRIPTION

[0040] The invention is further described and described in detail below with reference to the accompanying drawings and examples.

[0041] Embodiment 1:

[0042] like Figure 1 As shown, the device for laser tracking angle measurement and communication ranging based on single-photon detection array disclosed in this embodiment includes: an optical telescope, a piezoelectric deflection mirror, a piezoelectric controller, a single-photon detection array, a signal amplification and distribution network, a signal acquisition and processing module, a low phase noise frequency synthesizer, and an edge detection and multi-channel synthesizer. The piezoelectric deflection mirror reflects the laser signal received by the optical telescope to the single-photon detection array, and the signal acquisition and processing module is connected to the piezoelectric deflection mirror through the piezoelectric controller; the signal amplification and distribution network is respectively connected to the single-photon detection array, the signal acquisition and processing module, and the edge detection and multi-channel synthesizer; the low phase noise frequency synthesizer is connected to the signal acquisition and processing module, and the edge detection and multi-channel synthesizer.

[0043] The optical telescope is used to receive space laser signals, capture and track the laser signals, and transmit the space laser signals to the piezoelectric deflection mirror during the satellite transit.

[0044] The piezoelectric deflection mirror is used to reflect the laser signal received by the optical telescope and adjust the direction of the optical path so that the signal is accurately aligned with the center position of the single photon detection array.

[0045] The piezoelectric controller is used to control the two-dimensional deflection angle of the piezoelectric deflection mirror, thereby controlling the transmission direction of the light path.

[0046] The high-sensitivity single-photon detection array is used to track and measure the angle of the signal while receiving the signal. The use of multiple single-photon detections to form a single-photon detection array increases the signal receiving area and improves the signal receiving stability compared to a single single-photon detector. The single-photon detection array detects extremely weak downlink laser signals at the level of a single photon, and converts the signal into an electrical pulse signal with a fast rising edge and an exponential decay on the falling edge. The array pixel that receives the photon outputs an electrical pulse signal, and the pixel that does not receive the photon outputs a low level. The position of the light spot in the array is calculated using the signal energy difference received by the pixel in the single-photon detection array, and the angle information of the incident laser signal is further obtained to achieve signal angle measurement, and then the signal is tracked and measured while the signal is received. The high sensitivity means that only a few photons / pulses are required to receive the signal, and the number of photons required for a single pulse response reaches single digits. The extremely weak downlink laser signal refers to a light pulse in a laser signal containing less than 100 photons.

[0047] The signal amplification and distribution network is used to receive the multi-channel electrical signal output from the single-photon detection array, first amplify the signal amplitude, and then divide the amplified signal into two groups. One group of signals is sent to the edge detection and multi-channel synthesizer for electrical pulse rising edge detection and multi-channel signal synthesis, and the other group of signals is sent to the signal acquisition and processing module for spot position calculation, and the laser signal incident angle is calculated by the spot position.

[0048] The signal acquisition and processing module, on the one hand, completes the angle measurement function through the multi-channel electrical pulse signal, and on the other hand, realizes communication data demodulation and ranging time information measurement according to the synthetic signal.

[0049] The low phase noise frequency synthesizer is used to generate the working clock of the signal acquisition and processing module, the edge detection and the multi-channel synthesizer.

[0050] The edge detection and channel synthesizer is used to extract the edges of the multi-channel electrical pulse signal after amplification processing by the signal conditioning and distribution network, to shape the signal with a fast rising edge and an exponential decay of the falling edge, and to synthesize the shaped multi-channel signals into one modulated signal, which is sent to the signal acquisition and processing module for communication and ranging information processing.

[0051] The piezoelectric deflection mirror adopts a piezoelectric deflection mirror of model S37.T4SF produced by Xin Mingtian Company.

[0052] The piezoelectric controller adopts a piezoelectric controller of model E70.D3S produced by Xin Ming Tian Company.

[0053] like Figure 2The figure shows the hardware structure diagram of the signal acquisition and processing module. The signal acquisition and processing module includes: angle measurement signal acquisition ADC (chip model AD9695-625), XC7VX485T master control FPGA chip, synthetic signal acquisition ADC chip ADC12DJ5200RF, clock management unit and Gigabit network port. The clock management unit (chip model LMX2594) provides a reference clock for the FPGA chip and the ADC chip; the N-channel angle measurement signal acquisition ADC is responsible for collecting the signal output by the single-photon detection array after being amplified by the signal amplification and distribution network, and then the XC7VX485T master FPGA counts the electrical pulses of each channel, and uses the count value of each channel to calculate the position of the center of mass of the light spot in the single-photon detection array, and then converts the position information into the angle information of the piezoelectric deflection mirror to obtain the angle measurement result; at the same time, the high-speed signal acquisition chip ADC12DJ5200RF collects the N-in-one signal output by the edge detection and channel synthesizer, and the XC7VX485T master FPGA processes the collected digital signal to complete the communication and ranging information solution; the angle measurement, communication and ranging results are calculated and demodulated by the FPGA and transmitted to the computer through the gigabit network port for result display.

[0054] Example 2

[0055] like Figure 3 The specific implementation process of the present invention is described by taking a 4×4 single-photon detection array and a laser detection system with a light wavelength of 1550nm as an example.

[0056] Based on the laser tracking angle measurement and communication ranging device based on a single photon detection array, this embodiment also discloses a laser tracking angle measurement and communication ranging method based on a single photon detection array, and the specific implementation steps are as follows:

[0057] Step 1: The optical telescope receives the laser signal sent by the satellite and focuses the laser signal onto the piezoelectric deflection mirror.

[0058] The transmitted signal s(t) can be expressed as: Where T is the symbol period, N is the position of the pulse within the symbol, and information is transmitted through the position of the pulse within the symbol.

[0059] Step 2: The piezoelectric deflection mirror adjusts the two-dimensional deflection angle under the control of the piezoelectric controller to reflect the laser signal from the optical telescope to the 4×4 single-photon detection array.

[0060] Step 3: The 4×4 single-photon detection array performs photoelectric conversion on the received laser signal and outputs 16 electrical signals to the signal amplification and distribution network. The signal amplification and distribution network amplifies the 16 signals and divides them into two groups of signals, which are output to the signal acquisition and processing module and the edge detection and multi-channel synthesizer respectively.

[0061] Step 4: The signal acquisition and processing module collects 16 angle measurement signals through a 16-channel ADC, counts the electrical pulses of the 16 signals, obtains the grayscale imaging of the light spot, and calculates the position of the center of mass of the light spot in the 4×4 single-photon detection array, and converts it into angle information and outputs it to the piezoelectric controller.

[0062] Spot centroid position (x i ,y i ) is the coordinate of the i-th pixel, N is the number of pixels in the single-photon detection array, the center of the array is the origin of the coordinate, and I i is the number of pulses received by the i-th pixel during the measurement period.

[0063] The angle (θ) between the optical path between the piezoelectric deflection mirror and the single photon detection array and the centroid position of the light spot at the origin of the array x ,θ y )for: L is the distance between the piezoelectric deflection mirror and the single photon detection array.

[0064] In order to move the center of mass of the light spot to the center of the array, it is necessary to control the deflection angle (Δθ x ,Δθ y )for:

[0065]

[0066] Step 5: The piezoelectric controller controls the angle of the piezoelectric deflection mirror so that the centroid of the light spot formed by the laser signal emitted by the deflection mirror on the 4×4 single-photon detection array is located at the center of the receiving array.

[0067] Step 6: The edge detection and multi-channel synthesizer extracts the edges of the 16 signals, combines the 16 signals into one and outputs a shaped and synthesized signal to the signal acquisition and processing module.

[0068] The synthetic signal r(t) can be expressed as: r i (t) is the output signal of the i-th pixel, ∩ represents the logical AND operation, and τ is the signal delay, which is designed according to the pulse width required to be output.

[0069] Step 7: The signal acquisition and processing module acquires the synthesized signal through the 10Gsps high-speed signal acquisition ADC chip, and completes the synchronization of the synthesized signal through the capture tracking synchronization algorithm. The synchronization signal is demodulated, decoded and distance-measured to obtain communication data and ranging data.

[0070] Step 8: The display monitoring module updates and displays the communication data, ranging results and light spot centroid position information in real time.

[0071] like Figure 4 The figure shows the signal processing flow chart of the signal acquisition and processing module. The original communication data includes telemetry data and ranging data. Every 7136-bit original data is subjected to CRC check and RS (223, 255) error correction coding to obtain 8160-bit coded data. The coded data is supplemented with 64-bit frame header data and 776-bit padding data to form a frame of 9000-bit data, and the 9000-bit data is mapped into 2250 pulse position modulation symbols through time slot mapping. The 16-channel angle measurement signals output by the 4×4 single-photon detection array are sampled by AD9695-625 and transmitted to FPGA for electrical pulse counting to obtain the grayscale imaging of the light spot and calculate the position of the center of mass of the light spot in the 4×4 array, and further obtain the angle information to control the piezoelectric deflection mirror. The high-speed signal synthesized from the 16-channel signal output by the 4×4 single-photon detection array is sampled and quantized by ADC12DJ5200RF. The FPGA performs sliding correlation capture on the sampled data and achieves stable tracking through the early-late gate algorithm. Furthermore, the data is error-corrected and decoded for communication data demodulation and ranging result calculation to achieve communication and ranging.

[0072] The specific description above further illustrates the purpose, technical solutions and beneficial effects of the invention in detail. It should be understood that the above is only a specific embodiment of the present invention and is not intended to limit the scope of protection of the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included in the scope of protection of the present invention.

Claims

1. Single photon detection array laser tracking angle measurement and communication distance measurement device, characterized in that: It includes optical telescope, piezoelectric deflection mirror, piezoelectric controller, single photon detection array, signal amplification and distribution network, signal acquisition and processing module, low phase noise frequency synthesizer, edge detection and multi-channel synthesizer; The optical telescope is used to receive the space laser signal transmitted by the satellite, complete the capture and tracking of the laser signal, and focus the space laser signal and transmit it to the piezoelectric deflection mirror during the satellite transit; The piezoelectric deflection mirror is used to reflect the laser signal received by the optical telescope and adjust the direction of the optical path so that the signal is accurately aligned with the center position of the single photon detection array; The piezoelectric controller is used to control the two-dimensional deflection angle of the piezoelectric deflection mirror, thereby controlling the transmission direction of the light path; The high-sensitivity single-photon detection array is used to realize tracking and angle measurement of signals while receiving the signals. The single-photon detection array is composed of multiple single-photon detectors to increase the signal receiving area, and improve the signal receiving stability compared with the reception of a single single-photon detector. The single-photon detection array detects extremely weak downlink laser signals at the level of single photons, and converts the signal into an electrical pulse signal with a fast rising edge and an exponential decay on the falling edge. The array pixels that receive the photons output electrical pulse signals, and the pixels that do not receive the photons output low levels. The position of the light spot in the array is calculated using the signal energy difference received by the pixels in the single-photon detection array, and the angle information of the incident laser signal is further obtained to realize signal angle measurement, and then the signal is tracked and angle measured while receiving the signal. The signal amplification and distribution network is used to receive the multi-channel electrical signal output from the single-photon detection array, first amplify the signal amplitude, and then divide the amplified signal into two groups; one group of signals is sent to the edge detection and multi-channel synthesizer for electrical pulse rising edge detection and multi-channel signal synthesis, and the other group of signals is sent to the signal acquisition and processing module for spot position calculation, and the laser signal incident angle is calculated by the spot position; The signal acquisition and processing module realizes angle measurement based on the multi-channel electrical pulse signal output by the signal amplification and distribution network, and realizes communication data demodulation and ranging time information measurement based on the synthesized signal. The low phase noise frequency synthesizer is used to generate the working clock of the signal acquisition and processing module, edge detection and multi-channel synthesizer; The edge detection and multi-channel synthesizer is used to extract the edges of the multi-channel electrical pulse signal after amplification and processing by the signal amplification and distribution network, to shape the signal with a fast rising edge and an exponential decay of the falling edge, and to synthesize the shaped multi-channel signals into one modulated signal, which is sent to the signal acquisition and processing module for communication and ranging information processing.

2. The single photon detection array laser tracking angle measurement and communication distance measurement device according to claim 1, characterized in that: The high sensitivity means that only a few photons / pulses are needed to receive the signal, and the number of photons required for a single pulse response is in the single digit; the extremely weak downlink laser signal means that the number of photons contained in the optical pulse in the laser signal is less than 100.

3. A method for laser tracking angle measurement and communication ranging based on a single photon detection array, which is implemented based on the laser tracking angle measurement and communication ranging device as claimed in claim 1 or 2, characterized in that: The following steps are included: Step 1: The optical telescope receives the laser signal sent by the satellite and focuses it on the piezoelectric deflection mirror. The piezoelectric controller controls the piezoelectric deflection mirror to scan in a two-dimensional plane, and quickly searches for the satellite downlink laser signal incident on the optical telescope. During the search phase, the rotation of the optical telescope is independent of the piezoelectric deflection mirror. During the tracking phase, the optical telescope rotates in coordination with the piezoelectric deflection mirror with the focus as the origin. The rotation angle of the optical telescope is twice the rotation angle of the piezoelectric deflection mirror. Step 2: The N×M single-photon detection array performs high-sensitivity reception of the laser signal reflected by the piezoelectric deflection mirror, with a detection sensitivity of a single photon level, completes photoelectric conversion of the satellite downlink laser signal, and outputs multiple electrical signals; N and M are the number of row and column pixels of the single-photon detection array, respectively; the signal receiving area of ​​the N×M single-photon detection array is NM times the receiving area of ​​a single single-photon detector, achieving more reliable reception of the signal; Step 3: The signal amplification and distribution network amplifies the multi-channel electrical signals output by the single-photon detection array and distributes them into two groups of signals, one of which is sent to the edge detection and multi-channel synthesizer for electrical pulse rising edge detection and multi-channel signal synthesis, and the other is sent to the signal acquisition and processing module for spot position calculation, and the incident angle of the laser signal is calculated by the spot position; Step 4: The signal acquisition and processing module collects the multi-channel signals output by the signal amplification and distribution network, and counts the pulses in each channel of the signal. When the light pulse count value received at a certain scanning dwell point exceeds the threshold value, the centroid position of the light spot is calculated as the signal tracking starting point, the deflection angle is calculated by the centroid position of the light spot, and the angle control signal is output to the piezoelectric controller; Step 5: The piezoelectric deflection mirror adjusts the deflection angle of the lens according to the control signal of the piezoelectric controller, so that the laser signal is located at the center of the single-photon detection array after being reflected by the piezoelectric deflection mirror; Step 6: If the light pulse count value received at this dwelling point is less than the threshold value, return to step 1 and control the piezoelectric deflection mirror to search for the laser signal again; if the light pulse count value received at the scanning dwelling point of this deflection angle exceeds the threshold value, the deflection angle is continuously updated through the centroid position of the light spot, so that the centroid of the light spot is continuously located at the center of the single-photon receiving array, thereby realizing the tracking angle measurement of the laser signal; Step 7: The signal acquisition and processing module acquires the analog electrical signal synthesized by the edge detection and channel synthesizer, completes the digital quantization of the analog electrical signal, and captures, tracks, synchronously demodulates and decodes the digital signal to extract the communication data and ranging information to achieve communication; the signal sent by the satellite contains the sending time information, and the ground end records the receiving time information when receiving the signal. The signal transmission time is obtained by subtracting the receiving time information from the demodulated sending time information, and then the signal transmission distance is calculated to achieve ranging; Step 8. According to steps 4 to 6, the position of the light spot in the array is calculated using the signal energy difference received by the pixels in the single-photon detection array, and the angle information of the incident laser signal is further obtained to realize signal angle measurement. According to step 7, the electrical pulse signal output by the single-photon detection array is used to realize communication and ranging. That is, based on the single-photon detection array, the signal is tracked and angled while completing signal reception, which simplifies the structure of the laser tracking angle measurement and communication ranging system, and improves the utilization rate of the received signal and the detection sensitivity of the system.

4. The method for laser tracking angle measurement and communication distance measurement based on single photon detection array as claimed in claim 3, characterized in that: In step four, Spot centroid position (x i ,y i ) is the coordinate of the i-th pixel, N is the number of pixels in the single-photon detection array, the center of the array is the origin of the coordinate, and I i is the number of pulses received by the i-th pixel during the measurement period; The angle (θ) between the optical path between the piezoelectric deflection mirror and the single photon detection array and the centroid position of the light spot at the origin of the array x ,θ y )for: L is the distance between the piezoelectric deflection mirror and the single-photon detection array; In order to move the center of mass of the light spot to the center of the array, it is necessary to control the deflection angle (Δθ x ,Δθ y )for:

5. The method for laser tracking angle measurement and communication distance measurement based on single photon detection array as claimed in claim 4, characterized in that: In step seven, The synthetic signal r(t) is expressed as: r i (t) is the output signal of the i-th pixel; τ is the signal delay, which is designed according to the pulse width required to be output; The transmitted signal s(t) is expressed as: Where T is the symbol period, N is the position of the pulse within the symbol, and information is transmitted through the position of the pulse within the symbol.

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