A high-speed denoising method and equipment for airborne area array Geiger avalanche diode radar

Abstract

A high-speed denoising method and equipment suitable for airborne area array Geiger avalanche diode radar, including: a radar image acquisition control module realizes area array Geiger avalanche diode radar data acquisition, and performs effective pixel and noise pixel segmentation processing on the acquired 64*64 image; adaptive denoising is added by analyzing radar equations and equipment parameters; signal threshold is automatically set according to the distribution of avalanche diode data in a single frame; signal proportion is increased by using matched filtering; and signal is extracted and noise is removed by using time and space correlation method. The present invention performs real-time denoising processing on the collected radar data by combining the inherent characteristics of the area array Geiger avalanche diode radar, data distribution in a single frame, time and space correlation method and matched filtering algorithm, improves the data drowning problem of Geiger avalanche diode radar under extremely low synthetic frame number, can effectively reduce background noise interference in the image, and quickly obtain the pixel signal centroid.

Description

Technical Field

[0001] The invention belongs to the field of real-time image processing, and in particular relates to a high-speed denoising method and equipment suitable for an airborne area array Geiger avalanche diode radar. Background Art

[0002] Field Geiger-Mode of Avalanche Photodiodes Focal Plane Array Lidar (GM-APD FPA Lidar) is a flash scanning Lidar system. The system uses a high-repetition-rate, high-energy laser as an active light source, and has the advantages of long measurement distance, strong anti-interference ability, and strong concealment. Secondly, the Geiger-Mode Avalanche Focal Plane Array Lidar system uses Geiger-Mode Avalanche Photodiodes to realize flight time counting and obtain the distance information corresponding to the echo signal with high time resolution. The system realizes the output of detection distance image through specific trigger signals and output signals.

[0003] Geiger mode avalanche focal plane array laser radar has played an important role in application fields such as terrain detection and target search. With the development of optoelectronic devices, the performance of Geiger mode avalanche focal plane array laser radar system has gradually improved, and the measurement accuracy and speed of the system have been greatly improved. At present, after the Geiger mode avalanche focal plane array detector collects image data, it is connected to the server through storage devices such as disk arrays for data processing. Due to the fast acquisition speed of the Geiger mode avalanche focal plane array radar system, it is greatly affected by noise and has a large output data volume. When the detector acquisition time is long, the amount of acquired output distance image data is too large, which occupies more storage resources, and the data processing is difficult, which reduces the flexibility of the laser radar system. Therefore, in order to improve the data acquisition and processing efficiency of the Geiger mode avalanche focal plane array laser radar, it is necessary to study the real-time noise processing of the Geiger mode avalanche focal plane array laser radar range image, and propose a high-speed denoising method and equipment suitable for airborne Geiger mode avalanche focal plane array laser radar to meet the high-speed and high-precision measurement requirements of the Geiger mode avalanche focal plane array laser radar. Summary of the invention

[0004] The purpose of the present invention is to solve the shortcomings of the existing Geiger mode avalanche focal plane array laser radar, such as low data processing efficiency and low system flexibility, caused by excessive data volume and noise affecting the data. A real-time processing method for distance image of a Geiger mode avalanche focal plane array laser radar is provided. The Geiger mode avalanche focal plane array laser radar is connected with an image data acquisition and processing module, and the image data acquisition and processing module realizes high-speed acquisition and processing of image data based on an FPGA chip.

[0005] To achieve the above purpose, the technical solution adopted by the present invention is as follows:

[0006] A high-speed denoising method suitable for airborne area array Geiger avalanche diode radar, the method comprising:

[0007] Step 1: Setting the area array Geiger avalanche diode image acquisition and processing parameters, obtaining the image acquisition parameters through the area array Geiger avalanche diode image acquisition control unit, and setting the preliminary global noise threshold parameters;

[0008] Step 2: Acquisition of area array Geiger avalanche diode image acquisition data, obtaining image signals and synchronization signals through an image acquisition control unit, obtaining distance image pixel data according to an acquisition mode and image acquisition parameters, and obtaining image synchronization data according to the acquisition parameters;

[0009] Step 3: Single frame data dark noise removal operation, calculate the noise distribution of each pixel according to the area array Geiger avalanche diode image acquisition and processing parameters, and obtain preliminary area array signal data;

[0010] Step 4: Setting the adaptive threshold of the single frame data, obtaining the threshold for the matched filtered data according to the distribution state of the image data in the single frame;

[0011] Step 5: Single frame data spatial correlation operation, according to the area array Geiger avalanche diode image acquisition and processing parameters and scanning system parameters, to obtain the spatial correlation data between pixels in a specific area;

[0012] Step 6: Single frame data time correlation operation, according to the laser parameters used and the area array Geiger avalanche diode image acquisition and processing parameters, the data in the specified area is correlated to obtain the time correlation data in the specific area;

[0013] Step 7: Matched filtering operation of single-frame correlation data, according to the laser parameters used and the area array Geiger avalanche diode image acquisition and processing parameters, to obtain the distribution data of each pixel in the single frame;

[0014] Step 8: Centroid calculation of single frame data, based on the automatic threshold setting of matched filtered data and the pixel distribution data after matched filtering, the centroid data in the image is obtained.

[0015] The high-speed denoising method of the present invention is implemented by computer software or programmable logic devices in an image data processing module to perform corresponding functions.

[0016] Furthermore, in step one, the image acquisition and processing parameter settings of the area array Geiger avalanche diode include: setting the bias voltage, temperature, delay, acquisition system operating frequency, measurement gate width, laser pulse width, laser waveform, laser wavelength, laser single pulse energy, overall efficiency of the optical system, receiving lens aperture, receiving lens focal length, filter transmittance, filter center wavelength, and filter half-width parameters of the area array Geiger avalanche diode according to acquisition requirements.

[0017] Furthermore, in step 2, the acquisition of the area array Geiger avalanche diode image acquisition data includes: obtaining the area array Geiger avalanche diode image pixel flight time data and image data valid signal through the area array Geiger avalanche diode image acquisition unit.

[0018] Furthermore, in step three, the single-frame data dark noise removal operation includes: calculating the noise distribution of each pixel according to the area array Geiger avalanche diode image acquisition and processing parameters, setting the area array avalanche diode global noise filtering threshold according to the noise distribution, and obtaining the area array data after preliminary filtering of dark noise.

[0019] Furthermore, in step five, the single-frame data spatial correlation operation includes: performing pixel spatial correlation processing according to scanning system parameters and radar parameters in combination with pixel spatial weights, sequentially obtaining spatial correlation data of each pixel of the single-frame image, and sequentially obtaining cumulative spatial correlation statistical data of each pixel in the single frame.

[0020] Furthermore, in step six, the single frame data time correlation operation includes: performing time correlation convolution processing on the spatial correlation accumulated data according to the radar matching laser parameters and radar parameters, and obtaining dual correlation data of each pixel in the single frame in turn.

[0021] A high-speed denoising device suitable for an airborne area array Geiger avalanche diode radar, the device comprising an area array Geiger avalanche diode image imaging unit and an area array Geiger avalanche diode image acquisition and processing unit;

[0022] The area array Geiger avalanche diode image imaging unit is mainly composed of an optical lens, an area array Geiger avalanche diode detector, a power control unit and a timing control unit. The optical lens is used to collect the reflected echo laser signal of the target to be measured, and the area array Geiger avalanche diode detector realizes flight time counting and outputs a distance image.

[0023] The main functional modules of the area array Geiger avalanche diode image acquisition and processing unit include a detector control module, an image data acquisition module and an image data processing module, which are responsible for the acquisition control of the area array Geiger avalanche diode detector, and cache and calculate the high-speed image data stream output by the area array Geiger avalanche diode detector to achieve real-time multiple denoising and centroid position calculation of the distance image.

[0024] Furthermore, the optical lens includes a filter lens, a collection aperture, a focus adjustment lens and a converging lens to achieve convergent reception of the echo laser signal.

[0025] Furthermore, the detector control module controls the bias, trigger, temperature, delay, acquisition system operating frequency, and measurement gate width acquisition functions of the planar array Geiger avalanche diode detector by setting the detector configuration parameters;

[0026] The image data acquisition module acquires and outputs distance image pixel grayscale data and synchronization signals according to a set camera acquisition protocol;

[0027] The image data processing module performs real-time noise removal and centroid extraction processing of the image according to the collected distance image data, synchronization signal and threshold parameters.

[0028] The beneficial effects of the present invention compared to the prior art are:

[0029] 1. The present invention uses a Geiger mode avalanche focal plane array imaging unit to achieve high-speed range image data acquisition and output, and collect high-precision time information of the echo light signal;

[0030] 2. In the present invention, after obtaining high-speed range image data through the range image acquisition and processing unit, the centroid calculation accuracy of each pixel of the Geiger mode avalanche focal plane array laser radar image is improved after preprocessing such as dark noise filtering;

[0031] 3. In the present invention, the distance image acquisition and processing unit performs a double correlation operation on the data set with the dark noise filtered out, thereby improving the accuracy of extracting the centroid of each pixel in the Geiger mode avalanche focal plane array laser radar image;

[0032] 4. In the present invention, the range image acquisition and processing unit performs matched filtering operation on the data set from which dark noise is filtered, thereby improving the signal-to-noise ratio of each pixel data of the Geiger mode avalanche focal plane array laser radar image;

[0033] 5. The modeling distance image acquisition and processing unit of the present invention realizes the preprocessing, dark noise filtering, dual correlation operation and centroid calculation of a single frame distance image based on the parallel pipeline processing of programmable logic devices, realizes the real-time processing of the acquired distance image data, effectively filters the noise in the input distance image, and improves the signal extraction efficiency and subsequent data processing efficiency of the Geiger mode avalanche focal plane array lidar distance image. BRIEF DESCRIPTION OF THE DRAWINGS

[0034] In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the drawings required for use in the description of the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative labor.

[0035] Figure 1 A schematic diagram of a Geiger mode avalanche focal plane array laser radar image acquisition and processing equipment according to an embodiment of the present invention;

[0036] Figure 2 This is a schematic diagram of the structure of a Geiger mode avalanche focal plane array laser radar image acquisition and processing equipment according to an embodiment of the present invention;

[0037] Figure 3 A schematic diagram of a Geiger mode avalanche focal plane array laser radar image acquisition and processing flow according to an embodiment of the present invention;

[0038] Figure 4 It is a structural schematic diagram of a Geiger mode avalanche focal plane array laser radar image acquisition module according to an embodiment of the present invention;

[0039] Figure 5 It is a schematic diagram of the operation of a dark noise filtering module in a Geiger mode avalanche focal plane array laser radar image processing unit according to an embodiment of the present invention;

[0040] Figure 6 It is a flow chart of TTC calculation of single-frame range image weight threshold of Geiger mode avalanche focal plane array laser radar image according to one embodiment of the present invention;

[0041] Figure 7 It is a flow chart for obtaining a single-frame dual-correlation data set of a Geiger mode avalanche focal plane array laser radar image according to an embodiment of the present invention;

[0042] Figure 8 It is a flow chart of real-time single-frame high-speed dual-correlation matched filtering denoising and centroid extraction of Geiger mode avalanche focal plane array lidar images described in one embodiment of the present invention. DETAILED DESCRIPTION

[0043] In order to make the purpose, technical scheme and advantages of the present invention clearer, the present invention will be further described in detail below with reference to the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, rather than all the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0044] In the Geiger mode avalanche focal plane array laser radar system, the Geiger mode avalanche focal plane array detector in the Geiger mode avalanche focal plane array laser radar converts the echo light signal into distance image data. The output image data rate is determined by the data transmission protocol of the Geiger mode avalanche focal plane array detector, which can be set by configuring the acquisition frame rate. The image data processing module processes the high-speed image data stream output by the camera and is responsible for the preprocessing and storage of the image data. The data processing rate is set by the image acquisition card FPGA chip, and the data processing module can be designed to meet the actual image processing requirements. In order to achieve noise removal and centroid extraction of the distance image, the present invention optimizes the processing method of the distance image, and the processing flow includes the setting of the array Geiger avalanche diode image acquisition processing parameters, the acquisition of the array Geiger avalanche diode image acquisition data, the dark noise removal operation of the single frame data, the spatial correlation operation of the single frame data, the time correlation operation of the single frame data, the matched filtering operation of the single frame correlation data, the adaptive threshold setting of the single frame data, and the centroid operation of the single frame data.

[0045] Embodiment 1:

[0046] (1) Range image data flow and parameter acquisition

[0047] The image data output by the distance image acquisition module is input in the form of a pixel serial data stream, and the pixel grayscale range is 0 to 4096; image control signals such as line head, line end, frame head, frame end and data valid signal provide synchronization and address information of image data; image processing parameters such as image size parameters and processing threshold parameters such as dark noise threshold Thr dn , weight threshold Thr weight and probability threshold Thr proba ;

[0048] (2) Single-frame data extraction of range image

[0049] The distance image processing module obtains single-frame distance image data and corresponding data synchronization signals according to the collected distance image data and the collected frame synchronization signals;

[0050] (3) Dark noise separation of single-frame range image

[0051] In the range image processing module, the dark noise threshold parameter Thr is calculated based on the detector parameters, optical transmitting and receiving system parameters, laser output parameters and approximate working height. dn . Calculate the data distribution in a single frame and filter out the dark noise;

[0052] (4) Single-frame image spatiotemporal dual correlation operation

[0053] In the range image processing module, the spatial correlation pixel threshold Thr is calculated based on the approximate flight altitude, field of view parameters, and detector inherent parameters.srp and pixel weights Wgt at different relative positions ppos For each pixel position in a single frame, a spatial correlation pixel threshold Thr is implemented. srp and pixel weight Wgt ppos The adaptive weight spatial correlation pixel data statistics. In the distance image processing module, the pixel time correlation threshold Thr is calculated according to the laser output parameters. trp For each spatial correlation data set in a single frame, a pixel-based temporal correlation threshold Thr is implemented. trp Adaptive dual correlation dataset.

[0054] (5) Matched filtering and adaptive thresholding of dual correlation data in a single frame image

[0055] In the range image processing module, the template function and weight threshold Thr for matched filtering are calculated according to the laser output parameters, optical transmitting and receiving system parameters, and detector parameters. weight Calculate the probability threshold Thr according to the distance distribution characteristics in a single frame proba For each dual-correlation data set in a single frame, signal extraction based on matched filtering is implemented, and the weight threshold Thr is used to extract the signal. weight The extracted signal is judged, combined with the probability threshold Thr proba Obtain the largest possible signal data set.

[0056] (6) Determining the signal centroid in a single frame image

[0057] According to the acquired signal data set, the signal centroid is obtained.

[0058] Embodiment 2:

[0059] See also Figures 1-2 The embodiment of the present disclosure provides an airborne area array Geiger avalanche diode radar range image acquisition and processing equipment, including:

[0060] A Geiger mode avalanche focal plane array imaging unit, wherein the Geiger mode avalanche focal plane array imaging unit is mainly composed of an optical lens and a Geiger mode avalanche focal plane array detector; the Geiger mode avalanche focal plane array imaging unit receives an echo laser signal through the optical lens, and obtains the echo signal photon flight time through the Geiger mode avalanche focal plane array detector; and serially outputs distance image data according to the CameraLinkBase protocol;

[0061] See also Figure 1 , the optical elements inside the optical lens assembly include:

[0062] L101: a filter lens, which can select the wavelength of the transmitted light, thereby improving the anti-interference ability of the imaging unit;

[0063] L102: Collection aperture, which can limit the intensity of light irradiated on the detector and optimize the working conditions of the imaging unit;

[0064] L103: a focal length adjustment lens, which is used to adjust the focal length of the imaging unit to meet the working height and obtain a clear distance image;

[0065] L104: Converging lens, which is used to converge the light passing through elements L101 to L103 so that the light converges on the sensor plane in the detector.

[0066] The distance image acquisition processing unit is composed of an FPGA interface card and an interface cable. The distance image acquisition processing unit is connected to a Geiger mode avalanche focal plane array detector via an SDR26_90 interface cable to send detector control signals and receive collected image data signals; RAM storage resources are configured in the FPGA interface card to cache collected image data; and the functions of each module of the distance image acquisition processing unit are realized through a programmable logic device in the FPGA interface card.

[0067] Embodiment 3:

[0068] See also Figure 3 , a schematic diagram of the range profile acquisition and processing flow of the airborne area array Geiger avalanche diode radar in the embodiment of the present disclosure includes:

[0069] S1: Geiger mode avalanche focal plane array imaging, after configuring the timing and working parameters of the Geiger mode avalanche focal plane array detector, the Geiger mode avalanche focal plane array detector outputs the echo laser signal photon flight time image;

[0070] S2: echo signal photon flight time data output, the high-speed camera outputs high-speed image data stream through the CameraLinkBase image acquisition protocol, and the image data is serially output to the FPGA interface card of the distance image acquisition processing unit through the SDR26_90 cable;

[0071] S3: Output and cache of parallel data of distance image. The FPGA interface card in the distance image acquisition processing unit converts serial image data into parallel image data according to the acquisition protocol to obtain image data and image acquisition synchronization signal. After obtaining valid frame data according to the acquisition synchronization signal, it is cached into the memory of the FPGA interface card.

[0072] S4: Real-time high-performance denoising algorithm for distance images. The distance image processing unit in the FPGA interface card reads the image data through DMA and performs multi-stage noise removal operations; the distance image after noise removal is output to the subsequent storage processing module.

[0073] Embodiment 4:

[0074] In the embodiment of the present disclosure, a method for denoising a range image of an airborne area array Geiger avalanche diode radar is implemented in parallel by programmable logic devices in an FPGA interface card in a range image processing unit. By setting multiple parallel units to match the speed of reading cache image data and the speed of algorithm operation, real-time filtering of noise in the collected image is achieved, thereby improving the denoising efficiency of the range image. Please refer to Figure 4 , the functional modules in the distance image processing unit include:

[0075] M101: A parallel control module, in which a counter parallel control logic unit and a plurality of pixel signal centroid extraction modules are arranged. After the image data is read from the cache, the pixel signal centroid extraction module is selected through the parallel control logic unit to match the data reading rate with the pixel signal centroid extraction module rate.

[0076] M102: A dark noise filtering module, which performs probability-based dark noise filtering on a single-frame range image by reading system parameters.

[0077] M103: TTC operation module, which realizes the adaptive noise filtering intensity after matched filtering by calculating specific parameters in a single-frame range image.

[0078] M104: pixel signal centroid extraction module, the centroid calculation module can realize the airborne area array Geiger avalanche diode radar range image denoising processing method, the calculation module includes:

[0079] M201: Single pixel dual correlation data acquisition module. The laser pulse width and other parameters are acquired by the board providing the parameter values ​​required for the operation. The single frame distance image is read out from the cache and used to expand the data volume of a specific pixel area according to the time correlation and space correlation, improve the denoising accuracy, and be used for subsequent matching filtering and centroid extraction operations.

[0080] M202: Dual-correlation matched filtering denoising module. The matched filtering denoising implements matched filtering of the dual-correlation data based on the laser pulse waveform, dual-correlation data obtained by M201 and the TTC data obtained by M103, thereby improving the signal ratio and implementing an adaptive signal threshold based on the triggering conditions of this frame for subsequent centroid extraction operations.

[0081] M203: Signal centroid extraction module, which extracts the signal centroid of a specific pixel based on dual-correlation matched filtering data and intra-frame adaptive threshold TTC to obtain a high-precision photon flight time value.

[0082] See also Figure 5 , the dark noise filtering module operation processing flow includes:

[0083] (1) Initializing dark noise related parameters, which include dark noise coefficient Dark_NCp, laser power Energy_Laser, working height Working_Height, receiving mirror aperture Rec_Dim, total optical system efficiency Ef_Sys, detector dark count rate Dark_NCR, solar spectrum irradiance E at 1064 nm si , filter lens bandwidth δ λ , detector time resolution δ t , optical lens field of view FOV, detector quantum efficiency ρ, one-way atmospheric transmittance Ef_atm, target scattering solid angle Ω s ;

[0084] (2) Calculate the system dark noise number, which includes calculating the average dark count noise number per frame Dark_NCnt=Dark_NCR*64*64, the average solar noise number per frame

[0085] (3) Setting a single-frame system dark noise threshold, the system dark noise threshold Thr dn Its value TC_Threshold is set by the dark count noise number Dark_NCnt per frame and the average solar noise number Solar_NCnt per frame, TC_threshold = Dark_NCp*(Dark_NCnt+Solar_NCnt);

[0086] (4) single-frame flight time data statistics, wherein the single-frame flight time data statistics generates a flight time data distribution function Fo(t) within the frame by counting the data distribution within the single frame;

[0087] (5) Data dark noise screening and data output after screening. The data dark noise screening is performed by traversing the single-frame flight time distribution function Fo(t) and comparing it with the system dark noise threshold TC_Threshold, retaining only the function part with a function value higher than the system dark noise threshold, and setting the rest to zero; then the processed remaining image is output.

[0088] See also Figure 6 , the calculation process of single-frame distance image weight threshold TTC is as follows:

[0089] (1) Calculate the average pixel trigger probability of the frame, calculate the number of triggers in the frame based on the dark noise-free range image data, and obtain the single pixel trigger probability TTC_D0;

[0090] (2) Obtaining the noise filter strength: Obtain the noise filter strength TTC_Index according to the system settings;

[0091] (3) The frame weight threshold Thr weight Get, its value TTC = TTC_D0*TTC_Index.

[0092] See also Figure 7 ,The process of acquiring single frame dual correlation data set includes:

[0093] (1) Time-dependent convolution kernel generation: Generate a uniform one-dimensional convolution kernel with a length of 2*Tts according to the input laser data waveform, where Tts = Thr trp ;

[0094] (2) Generate spatial weight matrix. Define the matrix type according to the input selection. Type 1 is a uniform square matrix of size MatrixSize, and type 2 is a Gaussian square matrix of size MatrixSize.

[0095] (3) Spatial correlation operation: weighted statistics are performed on the surrounding data of a certain pixel in a single frame according to the spatial correlation matrix to generate a spatial correlation histogram Value_SR;

[0096] (4) Time correlation operation: the spatial correlation histogram Value_SR is accumulated by sliding on the time axis, that is, convolution is performed using the time-correlated convolution kernel to obtain the spatial-temporal correlation histogram Value_STR of a certain pixel.

[0097] See also Figure 8 , the single-frame high-speed dual-correlation matching denoising process includes:

[0098] (5) Value_STR peak selection: select the pixel value MWV with the largest weight and the corresponding weight MW according to Value_STR, and judge the relationship between MW and the TTC of the frame. When MW>TTC, enter the centroid calculation step, otherwise it is considered as noise;

[0099] (6) Matched filtering within MWV±Tts: Generate a matched filter template Templete_MF based on the input laser waveform parameters such as the standard deviation, and convolve Value_STR within the range of MWV±Tts in the time domain;

[0100] (7) The centroid is obtained from the convolution result as the signal value DP_DS of the pixel position. If it is determined to be noise, DP_DS=0. SDM_TOF is used as a 64*64 matrix to store the DP_DS of each pixel, and then the calculation of the next pixel is carried out;

[0101] After the signal values ​​of all pixels in a single frame are calculated, the 64*64 SDM_TOF is output as the signal value of each pixel in the frame.

Claims

1. A high-speed denoising method for airborne area array Geiger avalanche diode radar, characterized in that: The method is: Step 1: Setting the area array Geiger avalanche diode image acquisition and processing parameters, obtaining the image acquisition parameters through the area array Geiger avalanche diode image acquisition control unit, and setting the preliminary global noise threshold parameters; Step 2: Acquisition of area array Geiger avalanche diode image acquisition data, obtaining image signals and synchronization signals through an image acquisition control unit, obtaining distance image pixel data according to an acquisition mode and image acquisition parameters, and obtaining image synchronization data according to the acquisition parameters; Step 3: Single frame data dark noise removal operation, calculate the noise distribution of each pixel according to the area array Geiger avalanche diode image acquisition and processing parameters, and obtain preliminary area array signal data; Step 4: Setting the adaptive threshold of the single frame data, obtaining the threshold for the matched filtered data according to the distribution state of the image data in the single frame; Step 5: Single frame data spatial correlation operation, according to the area array Geiger avalanche diode image acquisition and processing parameters and scanning system parameters, to obtain the spatial correlation data between pixels in a specific area; Step 6: Single frame data time correlation operation, according to the laser parameters used and the area array Geiger avalanche diode image acquisition and processing parameters, the data in the specified area is correlated to obtain the time correlation data in the specific area; Step 7: Matched filtering operation of single frame correlation data, according to the laser parameters used and the area array Geiger avalanche diode image acquisition and processing parameters, to obtain the distribution data of each pixel in the single frame; Step 8: Centroid calculation of single frame data, based on the automatic threshold setting of matched filtered data and the pixel distribution data after matched filtering, the centroid data in the image is obtained.

2. The high-speed denoising method for airborne area array Geiger avalanche diode radar according to claim 1, characterized in that: In step one, the image acquisition and processing parameter settings of the area array Geiger avalanche diode include: setting the bias voltage, temperature, delay, acquisition system operating frequency, measurement gate width, laser pulse width, waveform, wavelength, single pulse energy, overall efficiency of the optical system, receiving lens aperture, receiving lens focal length, filter transmittance, filter center wavelength, and filter half-width parameters of the area array Geiger avalanche diode according to the acquisition requirements.

3. The high-speed denoising method for airborne area array Geiger avalanche diode radar according to claim 1, characterized in that: In step 2, the acquisition of the area array Geiger avalanche diode image acquisition data includes: obtaining the area array Geiger avalanche diode image pixel flight time data and image data valid signal through the area array Geiger avalanche diode image acquisition unit.

4. The high-speed denoising method for airborne area array Geiger avalanche diode radar according to claim 1, characterized in that: In step three, the single-frame data dark noise removal operation includes: calculating the noise distribution of each pixel according to the area array Geiger avalanche diode image acquisition and processing parameters, setting the area array avalanche diode global noise filtering threshold according to the noise distribution, and obtaining the area array data after preliminary filtering of dark noise.

5. The high-speed denoising method for airborne area array Geiger avalanche diode radar according to claim 1, characterized in that: In step five, the single-frame data spatial correlation operation includes: performing pixel spatial correlation processing according to scanning system parameters and radar parameters in combination with pixel spatial weights, obtaining spatial correlation data of each pixel of the single-frame image in turn, and obtaining cumulative spatial correlation statistical data of each pixel in the single frame in turn.

6. The high-speed denoising method for airborne area array Geiger avalanche diode radar according to claim 1, characterized in that: In step six, the single frame data time correlation operation includes: performing time correlation convolution processing on the spatial correlation accumulated data according to the radar matching laser parameters and radar parameters, and obtaining the dual correlation data of each pixel in the single frame in turn.

7. A high-speed denoising equipment for an airborne area array Geiger avalanche diode radar applicable to the method of claim 1, characterized in that: The equipment includes a planar array Geiger avalanche diode image imaging unit and a planar array Geiger avalanche diode image acquisition and processing unit; The area array Geiger avalanche diode image imaging unit is mainly composed of an optical lens, an area array Geiger avalanche diode detector, a power control unit and a timing control unit. The optical lens is used to collect the reflected echo laser signal of the target to be measured, and the area array Geiger avalanche diode detector realizes flight time counting and outputs a distance image. The main functional modules of the area array Geiger avalanche diode image acquisition and processing unit include a detector control module, an image data acquisition module and an image data processing module, which are responsible for the acquisition control of the area array Geiger avalanche diode detector, and cache and calculate the high-speed image data stream output by the area array Geiger avalanche diode detector to achieve real-time multiple denoising and centroid position calculation of the distance image.

8. The high-speed denoising equipment suitable for airborne area array Geiger avalanche diode radar according to claim 7, characterized in that: The optical lens comprises a filter lens, a collection aperture, a focus adjustment lens and a converging lens, so as to realize the converging reception of the echo laser signal.

9. The high-speed denoising equipment suitable for airborne area array Geiger avalanche diode radar according to claim 7, characterized in that: The detector control module controls the triggering, temperature, delay, acquisition system operating frequency, and measurement gate width acquisition functions of the planar array Geiger avalanche diode detector by setting the detector configuration parameters; The image data acquisition module acquires and outputs distance image pixel grayscale data and synchronization signals according to a set camera acquisition protocol; The image data processing module performs real-time noise removal and centroid extraction processing of the image according to the collected distance image data, synchronization signal and threshold parameters.

Images