Method for evaluating the detection capability of a single-photon laser ranging system

Abstract

The application discloses a kind of single-photon laser ranging system's detection capability evaluation method, solve the existing single-photon laser ranging system detection capability evaluation technique long period, high cost, poor flexibility problem, the present application uses numerical simulation method, generates the trigger time sequence of each light emission, data generation process, based on detection model from starting timing moment start to obtain the cumulative distribution of system, ensure that the trigger time sequence generated is subject to detection model distribution, after generating at each trigger time, update the starting time of cumulative probability distribution, generate cumulative probability distribution from new starting time, slide traversal covers the entire gate, realize the method of cumulative distribution is applied to free asynchronous mode;Simultaneously introduce the influence of post-pulse rate in the trigger time sequence generation process, make the trigger time sequence generated by simulation consistent with actual detection result response, improve the accuracy of evaluation result.

Description

Technical Field

[0001] This invention relates to single-photon laser ranging systems, and more specifically to a method for evaluating the detection capability of a single-photon laser ranging system. Background Technology

[0002] In the field of optoelectronic measurement technology, with the continuous expansion of long-distance, high-precision target trajectory and distance measurement scenarios, the target to be measured is showing a trend of miniaturization and long detection distance. The industry's requirements for the detection range and detection accuracy of laser ranging technology continue to increase, and the working range of laser ranging has gradually extended from the traditional several kilometers to hundreds or even thousands of kilometers.

[0003] Traditional laser ranging systems are mostly based on linear APD (avalanche photodiode) detectors. However, this detection method has inherent technical defects, such as high overall system power consumption and large equipment size. It is difficult to adapt to ultra-long-distance laser ranging scenarios of hundreds of kilometers and above, and cannot meet the current application requirements of remote photoelectric measurement.

[0004] To address the challenge of long-range detection, GM-APD (Geiger-mode avalanche photodiode) detectors have seen rapid development and application. These devices possess ultra-high detection sensitivity, enabling them to capture weak laser echo signals transmitted over extremely long distances, significantly enhancing the long-range detection capabilities of laser ranging systems and making them suitable for ultra-long-distance laser ranging scenarios. However, the high sensitivity of GM-APD devices also makes them highly susceptible to triggering responses from weak noise signals in the environment. This results in single-photon laser ranging systems being greatly affected by ambient light noise, with system detection performance fluctuating significantly with changes in ambient light intensity, leading to poor environmental adaptability.

[0005] Therefore, accurately assessing the detection capability of single-photon laser ranging systems under different environmental noise conditions, and clarifying the effective detection conditions and required number of echo photons for specific noise environments, is of great guiding significance for optimizing the structural design of laser ranging systems and ensuring stable system operation.

[0006] Currently, the industry's evaluation methods for the detection capabilities of single-photon laser ranging systems are mainly divided into two categories: experimental measurement evaluation method and numerical simulation analysis evaluation method based on counting method. However, both existing technologies have obvious defects and shortcomings.

[0007] Among them, the experimental evaluation method relies on physical test prototypes to complete performance testing and capability evaluation. It requires a series of processes such as prototype development, test setup, and actual testing and debugging. The overall evaluation cycle is long, the R&D and testing costs are high, the flexibility is extremely poor, and it cannot quickly adapt to the detection capability evaluation needs under different system parameters and different environmental conditions.

[0008] Numerical simulation evaluation methods based on probability density are extremely inefficient at generating simulated detection data and are time-consuming, requiring multiple repetitions to bring the results close to the true values ​​of the detection model. This makes it difficult to guarantee evaluation efficiency and accuracy. Furthermore, existing probability density simulation methods do not consider the afterpulse effect during the operation of single-photon laser ranging systems, leading to discrepancies between the simulation evaluation model and the actual system operating conditions. Consequently, the evaluation results are inaccurate and fail to accurately reflect the true detection capability of free-running single-photon laser ranging systems under real-world environmental noise conditions.

[0009] In summary, the industry currently lacks an efficient, accurate, and widely adaptable evaluation method that can assess the detection capabilities of single-photon laser ranging systems in free-running mode under actual environmental noise conditions, making it difficult to meet the design optimization and performance testing needs of current long-range laser ranging systems. Summary of the Invention

[0010] This invention aims to address the technical problems in existing single-photon laser ranging system detection capability evaluation technologies, such as long experimental measurement evaluation methods, high cost, poor flexibility, low efficiency and limited applicability of traditional probability density simulation evaluation, and failure to consider the system's afterpulse effect, which leads to large deviations between the evaluation results and actual operating conditions and makes it impossible to accurately evaluate the actual detection capability of the system in free-running mode. Therefore, this invention proposes a new method for evaluating the detection capability of single-photon laser ranging systems.

[0011] To achieve the above-mentioned objectives, the present invention adopts the following technical solution:

[0012] A method for evaluating the detection capability of a single-photon laser ranging system, wherein the single-photon laser ranging system is a single-photon laser ranging system based on a free asynchronous Geiger APD detector, and its special feature is that it includes the following steps:

[0013] Step 1: Obtain the system parameters of the single-photon laser ranging system to be evaluated, and calculate the dead time value of the APD detector. and the maximum timing value of the detection gate width ;

[0014] Step 2: Generate the trigger time sequence of a single-photon laser ranging system to be evaluated for one ranging process. , This represents the total number of laser beams emitted in one ranging process. For the first The trigger timing subsequence generated by the next light emission;

[0015] Step 2.1: Calculate the total number of laser emission cycles required for the single-photon laser ranging system to be evaluated to complete one ranging process using the system parameters. ;

[0016] Step 2.2: Count the laser output. The initial value is 1;

[0017] Step 2.3: Set the trigger timer value The initial value is 1, and the number of triggers is... The initial value is 1;

[0018] Step 2.4, Calculate [ , Each timing point within the range Trigger probability And based on the trigger probability calculate[ , Time intervals within the range Cumulative probability distribution ;

[0019] Step 2.5: Generate a random number a in the range [0,1] based on uniform probability;

[0020] Step 2.6: Compare the current trigger timer value. With maximum timing value ;like Less than If so, proceed to step 2.7; otherwise, end the generation of the current trigger time sequence and proceed to step 2.13.

[0021] Step 2.7, in the cumulative probability distribution Iterate through the data to find the trigger time corresponding to the random number 'a'. and set the current trigger timer value satisfy Set the current trigger timer value Assign the value to the current light output count Current number of triggers Triggering time To the current number of triggers Add 1, and proceed to step 2.8;

[0022] Step 2.8: Set the current trigger timer value. Increase dead time value To update the trigger timer value Compare the updated trigger timer value With maximum timing value ;like Less than If so, proceed to step 2.9; otherwise, end the generation of this trigger time sequence and proceed to step 2.13.

[0023] Step 2.9: Generate a random number b within the range [0,1] based on uniform probability, and compare the random number b with the afterpulse rate s of the single-photon laser ranging system to be evaluated; if b is less than s, proceed to step 2.10; otherwise, based on the updated trigger timing value... Return to step 2.4;

[0024] Step 2.10: Update the trigger timer value Assign the value to the current light output count Current number of triggers Triggering time To the current number of triggers Increment by 1, and simultaneously add 1 to the current trigger timer value. Increase dead time value ;

[0025] Step 2.11: Compare the updated trigger timer value. With maximum timing value ;like Less than If not, return to step 2.4; otherwise, end the generation of the current trigger time sequence and execute step 2.13.

[0026] Step 2.12: Determine the trigger time from Step 2.7 or Step 2.7 and Step 2.10. The merger constitutes the first The trigger time subsequence of the next light emission ;

[0027] Step 2.13: Count the current light output. Increment by 1 to update the light output count. The updated light emission count Total number of light emission Compare; if Greater than If the trigger time sequence generation ends, proceed to step 3; otherwise, proceed based on the updated light output count. Return to step 2.3 to generate the next trigger time sequence, until... Greater than ;

[0028] Step 2.14, The trigger time subsequence of secondary light generation The combined trigger time sequence constitutes a ranging process. ;

[0029] Step 3: Based on the trigger time sequence Complete the evaluation of the detection capability of the single-photon laser ranging system to be evaluated.

[0030] Furthermore, step 1 specifically includes:

[0031] Step 1.1: Obtain the system parameters of the single-photon laser ranging system to be evaluated; the system parameters include the ranging refresh rate. Laser repetition rate Gate width T, dead time Detection timing resolution and the subsequent pulse rate s;

[0032] Step 1.2: Using the dead time of the APD detector Gating gate width T and APD detection timing resolution Calculate the dead time value of the APD detector and the maximum timing value of the detection gate width .

[0033] Furthermore, step 2.1 specifically includes:

[0034] Based on the ranging refresh frequency and laser repetition frequency Calculate the total number of laser beams required for the single-photon laser ranging system under evaluation to complete one ranging cycle. :

[0035] .

[0036] Further, in step 2.4, calculate [ , Each timing point within the range Trigger probability Specifically:

[0037] Calculations based on the detection model of the single-photon laser ranging system to be evaluated [ , Time intervals within the range Trigger probability :

[0038] ;

[0039] in, The initial noise carrier number, , To preset the average noise carrier rate or identify the average noise carrier rate; The initial signal carrier number; The timing value for the laser flight time corresponding to the distance to the target.

[0040] Furthermore, in step 2.4, the timing value The following formula is used to calculate:

[0041] ;

[0042] Where D is the distance between the target and the single-photon laser ranging system to be evaluated, and c is the speed of light.

[0043] Furthermore, in step 2.4, based on the trigger probability... calculate[ , Cumulative probability distribution of time interval i within the range Specifically:

[0044] Based on trigger probability calculate[ , Cumulative probability distribution of time interval i within the range :

[0045] ;

[0046] Where l is the cumulative variable, l∈[1,i].

[0047] Furthermore, in step 2.4, the average noise carrier rate is identified. The method to obtain it is as follows:

[0048] Step A1: Place the single-photon laser ranging system to be evaluated in the working environment and turn off the laser source. Use a signal generator to generate a synchronization signal with the same frequency as the laser source to synchronize the free asynchronous Geiger APD detector of the single-photon laser ranging system under test, and turn on the laser source.

[0049] Step A2: Determine the trigger sequence {R} of each pixel of the free asynchronous Geiger APD detector in the single-photon laser ranging system to be evaluated within the detection gate width range;

[0050] Step A3: Count the number of triggering sequences {R} within the detection gate width. And calculate the average noise carrier rate. :

[0051] ;

[0052] Among them, t n The average time interval for noise triggering. .

[0053] Furthermore, in step 2.7, the method for traversing and searching is as follows:

[0054] judge Is it true or false?

[0055] If true, then trigger time. satisfy: Set the current trigger timer value Assign the value to the current light output count Current number of triggers Triggering time To the current number of triggers Add 1, and proceed to step 2.8;

[0056] If not, then the current trigger timer value is set. Add 1 and return to step 2.6.

[0057] Furthermore, in step 1.2, the dead time value... The following formula is used to calculate:

[0058] .

[0059] Furthermore, in step 1.2, the maximum timing value The following formula is used to calculate:

[0060] .

[0061] The beneficial effects of this invention are:

[0062] 1. This invention provides a method for evaluating the detection capability of a single-photon laser ranging system. For a single-photon laser ranging system based on a free-asynchronous Geiger APD, a numerical simulation method is used to generate a sequence of trigger times for each light emission. During data generation, the cumulative distribution of the system is obtained from the initial timing based on the detection model, ensuring that the generated trigger time sequence conforms to the detection model distribution. After each trigger time is generated, the starting time of the cumulative probability distribution is updated, and a new cumulative probability distribution is generated from the new starting time. This cumulative probability distribution is then traversed and covered within the entire gate, thus applying the cumulative distribution method to the free-asynchronous mode. Simultaneously, the influence of the afterpulse rate is introduced during the trigger time sequence generation process, making the simulated trigger time sequence consistent with the actual detection result response, resulting in more accurate simulation and significantly improving the accuracy of the evaluation results.

[0063] 2. The background noise photon count is closely related to the ambient light characteristics, stray light in the optical system, and the dark count of the pulse rate after the detector. Therefore, it is difficult to obtain the background noise by calculation. This invention uses an identification method to obtain the identified average noise carrier rate. This identification method is simple and fast to calculate, and can be used for both detection capability simulation evaluation and laser signal detection algorithm design, making it highly applicable.

[0064] 3. The present invention provides a method for evaluating the detection capability of a single-photon laser ranging system. This method can be used to evaluate whether a single-photon laser ranging system can achieve target detection under specific environmental noise conditions. It can also be used to analyze how many echo photons a single-photon laser ranging system needs to be configured to achieve target detection under specific environmental noise conditions, thus guiding the design of the laser ranging system. Attached Figure Description

[0065] Figure 1 This is a flowchart of an embodiment of step 2, generating a ranging process trigger sequence, in the detection capability evaluation method of a single-photon laser ranging system of the present invention.

[0066] Figure 2 This is a timing diagram of a single ranging process in an embodiment of the present invention;

[0067] Figure 3 These are the data generation result diagram and the measured data of the single-photon laser ranging system to be evaluated in the embodiments of the present invention, where a) is the measured data and b) is the generation result diagram. Detailed Implementation

[0068] The technical solution of the present invention will be clearly and completely described below with reference to the accompanying drawings and embodiments. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0069] This invention provides a method for evaluating the detection capability of a single-photon laser ranging system, applicable to a single-photon laser ranging system based on a free asynchronous Geiger APD detector.

[0070] The single-photon laser ranging system described in this embodiment includes a fiber laser, a laser collimating lens, a laser receiving lens, and a Geiger APD laser receiving unit (including a receiving lens and an APD detector). The fiber laser periodically transmits laser pulses, which are reflected by the target and received by the Geiger APD laser receiving unit via a laser transceiver system. The Geiger APD laser receiving unit operates in asynchronous free-running mode. The system's detection model is as follows: if the system is in a non-dead-time condition, then... The detection probability within the time range is:

[0071]

[0072] in, ,in, for The initial number of signal carriers within a time period. The initial noise carrier number. Including afterpulse, ambient noise carriers, and dark counting. ,in, for Average noise carrier rate over time. The detection capability evaluation method provided in this embodiment includes the following steps:

[0073] Step 1: Obtain the system parameters of the single-photon laser ranging system to be evaluated, and calculate the dead time value of the APD detector. and the maximum timing value of the detection gate width Specifically, it includes:

[0074] Step 1.1: Obtain the system parameters of the single-photon laser ranging system to be evaluated; these system parameters include the ranging refresh rate. Laser repetition rate Gate width T, dead time Detection timing resolution and the subsequent pulse rate s;

[0075] In this embodiment, the gate width T is 200µs, and the dead time is... The detection timing resolution is 110 ns. It is 10 ns;

[0076] Step 1.2: Using the dead time of the APD detector Gating gate width T and APD detection timing resolution Calculate the dead time value of the APD detector and the maximum timing value of the detection gate width :

[0077] =11;

[0078] =20000.

[0079] Step 2, as follows Figure 1 As shown, the trigger time sequence of a single-photon laser ranging system to be evaluated is generated. , This represents the total number of laser beams emitted in one ranging process. For the first The trigger timing subsequence generated by the secondary light emission; specifically including the following steps:

[0080] Step 2.1: Based on the ranging refresh frequency and laser repetition frequency Calculate the total number of laser beams required for the single-photon laser ranging system under evaluation to complete one ranging cycle. :

[0081] ;

[0082] This embodiment calculates the total number of light outputs in a single ranging process. It is 200.

[0083] Step 2.2: Count the laser output. The initial value is 1;

[0084] Step 2.3: Set the trigger timer value The initial value is 1, and the number of triggers is... The initial value is 1;

[0085] Step 2.4: Calculation of the detection model based on the single-photon laser ranging system to be evaluated. Each timing point within the range Trigger probability :

[0086] ;

[0087] in, The initial noise carrier number, , To preset the average noise carrier rate or identify the average noise carrier rate; The initial signal carrier number; The timing value for the laser flight time corresponding to the target distance:

[0088] ;

[0089] Where D is the distance between the target and the single-photon laser ranging system to be evaluated, and c is the speed of light;

[0090] Then based on the trigger probability calculate Each time point within the range Cumulative probability distribution :

[0091] ;

[0092] Where l is the cumulative variable, l∈[1,i].

[0093] Step 2.5, based on uniform probability in Generate a random number 'a' within the range;

[0094] Step 2.6: Compare the current trigger timer value. With maximum timing value :

[0095] like Proceed to step 2.7;

[0096] If , the generation of the current trigger time sequence is ended, and step 2.13 is performed;

[0097] Step 2.7: Traverse the cumulative probability distribution described above to search for the trigger time corresponding to the random number a , and make the current trigger timing value satisfy , assign the current trigger timing value to the trigger time of the current light output count and the current number of triggers , add 1 to the current number of triggers , and perform step 2.8;

[0098] The above traversal search method is as follows:

[0099] Determine whether holds:

[0100] If it holds, the trigger time satisfies: , assign the current trigger timing value to the trigger time of the current light output count and the current number of triggers , add 1 to the current number of triggers , and perform step 2.8;

[0101] If it does not hold, add 1 to the current trigger timing value , and return to step 2.6.

[0102] Step 2.8: Add the dead time timing value to the current trigger timing value to update the trigger timing value ; compare the updated trigger timing value with the maximum timing value :

[0103] If , perform step 2.9;

[0104] If , end the generation of the current trigger time sequence, and perform step 2.13;

[0105] Step 2.9: Generate a random number b within the range based on uniform probability , and compare the random number b with the afterpulse rate s:

[0106] If b<s, perform step 2.10;​​

[0107] If b ≥ s, then based on the updated trigger timing value Return to step 2.4;

[0108] Step 2.10: Update the trigger timer value Assign the value to the current light output count Current number of triggers Triggering time To the current number of triggers Increment by 1, and simultaneously add 1 to the current trigger timer value. Increase dead time value ;

[0109] Step 2.11: Compare the updated trigger timer value. With maximum timing value :

[0110] like Return to step 2.4;

[0111] like If so, the generation of the current trigger time sequence ends, and step 2.13 is executed;

[0112] Step 2.12: Determine the trigger time from Step 2.7 or Step 2.7 and Step 2.10. The merger constitutes the first The trigger time subsequence of the next light emission ;

[0113] Step 2.13: Count the current light output. Increment by 1 to update the light output count. The updated light emission count Total number of light emission Comparison:

[0114] like If the trigger time sequence generation ends, proceed to step 3.

[0115] like Then based on the updated light output count Return to step 2.3 to generate the next trigger time sequence, until... ;

[0116] Step 2.14, The trigger time sequence of secondary light generation The combined trigger time sequence constitutes a ranging process. The generation process timing principle is as follows: Figure 2 As shown.

[0117] Step 3: Based on the trigger time sequence After histogram statistics, as follows Figure 3 As shown in b), Figure 3 (a) This paper also shows the histogram of the measured sequence of the single-photon laser ranging system. It can be seen that the detection capability evaluation method proposed in this embodiment generates trigger time positions, signal trigger times, and noise trigger times that are comparable to the measured data. By analyzing the signal-to-noise ratio of the target echo signal and noise, the detection capability of the single-photon laser ranging system under specific lighting conditions can be evaluated. Furthermore, based on the trigger time sequence histogram, the detection capability of the single-photon laser ranging system under specific noise carrier conditions can be assessed. Next, adjust the initial signal carriers. Data is generated until the desired signal-to-noise ratio is achieved. This is based on the adjusted initial signal carrier... The laser ranging equation guides the design of parameters such as laser source energy and system aperture in single-photon ranging systems.

[0118] The initial signal carrier number in the trigger probability model in step 2.4 The background noise photon count can be calculated based on the ranging equation. However, the background noise photon count is closely related to the ambient light characteristics, stray light in the optical system, and the dark count of the pulse rate after the detector. Therefore, it is difficult to obtain the background noise using calculation methods. In this embodiment, an identification method is used to obtain the average noise carrier rate. The initial noise carrier number is then obtained, and the identification steps are as follows:

[0119] Step A1: Place the single-photon laser ranging system to be evaluated in the working environment and turn off the laser source of the single-photon laser ranging system to be evaluated. Use a signal generator to generate a synchronization signal with the same frequency as the laser source to synchronize the free asynchronous Geiger APD detector of the single-photon laser ranging system to be evaluated, and turn on the laser source of the single-photon laser ranging system to be evaluated.

[0120] Step A2: Determine the trigger sequence {R} of each pixel of the free asynchronous Geiger APD detector in the single-photon laser ranging system to be evaluated within the detection gate width range;

[0121] Step A3: Count the number of triggering sequences {R} within the detection gate width. And calculate the average noise carrier rate. :

[0122] ;

[0123] Among them, t n The average time interval for noise triggering. .

[0124] The above description is merely a specific embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any changes or substitutions within the technical scope disclosed in the present invention should be covered within the scope of protection of the present invention. Therefore, the scope of protection of the present invention should be determined by the scope of the claims.

Claims

1. A method for evaluating the detection capability of a single-photon laser ranging system, wherein the single-photon laser ranging system is a single-photon laser ranging system based on a free asynchronous Geiger APD detector, characterized in that, Includes the following steps: Step 1: Obtain the system parameters of the single-photon laser ranging system to be evaluated, and calculate the dead time value of the APD detector. and the maximum timing value of the detection gate width ; Step 2: Generate the trigger time sequence of a single-photon laser ranging system to be evaluated for one ranging process. , This represents the total number of laser beams emitted during one ranging process. For the first The trigger timing subsequence generated by the next light emission; Step 2.1: Calculate the total number of laser emission cycles required for the single-photon laser ranging system to be evaluated to complete one ranging process using the system parameters. ; Step 2.2: Count the laser output. The initial value is 1; Step 2.3: Set the trigger timer value The initial value is 1, and the number of triggers is... The initial value is 1; Step 2.4, Calculate [ , Each timing point within the range Trigger probability And based on the trigger probability calculate[ , Each timing point within the range Cumulative probability distribution ; Step 2.5: Generate a random number a in the range [0,1] based on uniform probability; Step 2.6: Compare the current trigger timer value. With maximum timing value ;like Less than If so, proceed to step 2.7; otherwise, end the generation of the current trigger time sequence and proceed to step 2.

13. Step 2.7, in the cumulative probability distribution Iterate through the data to find the trigger time corresponding to the random number 'a'. and set the current trigger timer value satisfy Set the current trigger timer value Assign the value to the current light output count Current number of triggers Triggering time To the current number of triggers Add 1, and proceed to step 2.8; Step 2.8: Set the current trigger timer value. Increase dead time value To update the trigger timer value Compare the updated trigger timer value With maximum timing value ;like Less than If so, proceed to step 2.9; otherwise, end the generation of this trigger time sequence and proceed to step 2.

13. Step 2.9: Generate a random number b in the range [0,1] based on uniform probability, and compare the random number b with the afterpulse rate s of the single-photon laser ranging system to be evaluated; if b is less than s, then proceed to step 2.

10. Otherwise, based on the updated trigger timing value Return to step 2.4; Step 2.10: Update the trigger timer value Assign the value to the current light output count Current number of triggers Triggering time To the current number of triggers Increment by 1, and simultaneously add 1 to the current trigger timer value. Increase dead time value ; Step 2.11: Compare the updated trigger timer value. With maximum timing value ;like Less than If not, return to step 2.4; otherwise, end the generation of the current trigger time sequence and execute step 2.

13. Step 2.12: Determine the trigger time from Step 2.7 or Step 2.7 and Step 2.

10. The merger constitutes the first The trigger time subsequence of the next light emission ; Step 2.13: Count the current light output. Increment by 1 to update the light output count. The updated light emission count Total number of light emission Compare; if Greater than If the trigger time sequence generation ends, proceed to step 3. Otherwise, based on the updated light output count Return to step 2.3 to generate the next trigger time sequence, until... Greater than ; Step 2.14, The trigger time subsequence of secondary light generation The combined trigger time sequence constitutes a ranging process. ; Step 3: Based on the trigger time sequence Complete the evaluation of the detection capability of the single-photon laser ranging system to be evaluated.

2. The method for evaluating the detection capability of a single-photon laser ranging system according to claim 1, characterized in that, Step 1 specifically includes: Step 1.1: Obtain the system parameters of the single-photon laser ranging system to be evaluated; the system parameters include the ranging refresh rate. Laser repetition rate Gate width T, dead time Detection timing resolution and the subsequent pulse rate s; Step 1.2: Using the dead time of the APD detector Gating gate width T and APD detection timing resolution Calculate the dead time value of the APD detector and the maximum timing value of the detection gate width .

3. The method for evaluating the detection capability of a single-photon laser ranging system according to claim 2, characterized in that, Step 2.1 specifically involves: Based on the ranging refresh frequency and laser repetition frequency Calculate the total number of laser beams required for the single-photon laser ranging system under evaluation to complete one ranging cycle. : 。 4. The method for evaluating the detection capability of a single-photon laser ranging system according to claim 3, characterized in that, In step 2.4, calculate [ , Each timing point within the range Trigger probability Specifically: Calculations based on the detection model of the single-photon laser ranging system to be evaluated [ , Each timing point within the range Trigger probability : ； in, The initial noise carrier number, , To preset the average noise carrier rate or identify the average noise carrier rate; The initial signal carrier number; The timing value for the laser flight time corresponding to the distance to the target.

5. The method for evaluating the detection capability of a single-photon laser ranging system according to claim 4, characterized in that, In step 2.4, the timing value The following formula is used to calculate: ； Where D is the distance between the target and the single-photon laser ranging system to be evaluated, and c is the speed of light.

6. The method for evaluating the detection capability of a single-photon laser ranging system according to claim 5, characterized in that, In step 2.4, based on the trigger probability calculate[ , Cumulative probability distribution of time interval i within the range Specifically: Based on trigger probability calculate[ , Cumulative probability distribution of time interval i within the range : ； Where l is the cumulative variable, l∈[1,i].

7. The method for evaluating the detection capability of a single-photon laser ranging system according to claim 6, characterized in that, In step 2.4, the average noise carrier rate is identified. The method to obtain it is as follows: Step A1: Place the single-photon laser ranging system to be evaluated in the working environment and turn off the laser source. Use a signal generator to generate a synchronization signal with the same frequency as the laser source to synchronize the free asynchronous Geiger APD detector of the single-photon laser ranging system under test, and turn on the laser source. Step A2: Determine the trigger sequence {R} of each pixel of the free asynchronous Geiger APD detector in the single-photon laser ranging system to be evaluated within the detection gate width range; Step A3: Count the number of triggering sequences {R} within the detection gate width. And calculate the average noise carrier rate. : ； Among them, t n The average time interval for noise triggering. .

8. The method for evaluating the detection capability of a single-photon laser ranging system according to claim 7, characterized in that, In step 2.7, the method for traversing and searching is as follows: judge Is it true or false? If true, then trigger time. satisfy: Set the current trigger timer value Assign the value to the current light output count Current number of triggers Triggering time To the current number of triggers Add 1, and proceed to step 2.8; If not, then the current trigger timer value is set. Add 1 and return to step 2.

6.

9. The method for evaluating the detection capability of a single-photon laser ranging system according to claim 8, characterized in that, In step 1.2, the dead time value The following formula is used to calculate: 。 10. The method for evaluating the detection capability of a single-photon laser ranging system according to claim 9, characterized in that, In step 1.2, the maximum timing value The following formula is used to calculate: 。

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