Methods, apparatus, equipment and storage media for differential absorption lidar correction

Abstract

This application discloses a method, apparatus, device, and storage medium for differential absorption lidar correction, relating to the field of lidar technology. The method includes: acquiring echo signal intensity curves and a first beam divergence map of multiple angular intervals of the lidar to be processed; the multiple angular intervals include a first angular interval and multiple second angular intervals, and the echo signal intensity curves include echo signal intensity curves of emitted beams of multiple wavelengths; for each wavelength of emitted beam, the following operations are performed: determining a first height corresponding to the echo signal intensity curve of the first angular interval and a second height corresponding to the echo signal intensity curve of each second angular interval; generating a second beam divergence map using a preset generation algorithm based on the first height and the angular interval corresponding to the first height, and each second height and the angular interval corresponding to each second height; and performing correction processing on the lidar based on the first beam divergence map and the second beam divergence map.

Description

Technical Field

[0001] This application relates to the field of lidar technology, specifically to atmospheric composition detection lidar technology, gas detection technology, and other technical fields, and particularly to a method, apparatus, equipment, and storage medium for differential absorption lidar correction. Background Technology

[0002] Differential absorption lidar is primarily used for measuring the atmospheric composition concentration profile of a target. However, the output optical characteristics of large pulse energy, small wavelength difference, and small divergence angle make it difficult to determine the beam morphology of the differential wavelength pair, especially in the radar operating environment. Furthermore, maintenance of radar optical components, particularly the transmitting system, inevitably alters the output optical characteristics of the differential pair.

[0003] Therefore, even if the radar equipment has undergone algorithmic correction for the near-range inversion results when it leaves the factory, the beam output characteristics of the differential pair have changed after the optical components of the lidar equipment have been maintained, and the original correction algorithm can no longer play a corrective role at close range.

[0004] Therefore, there is an urgent need for a differential absorption lidar calibration method to effectively calibrate the lidar after maintenance. Summary of the Invention

[0005] This application provides a method, apparatus, device, and storage medium for differential absorption lidar calibration, which can solve the problem of poor calibration effect of differential absorption lidar after maintenance. The technical solution is as follows:

[0006] In a first aspect, a method for correcting a differential absorption lidar is provided, the method comprising:

[0007] The echo signal intensity curves and the first beam divergence diagram of the lidar to be processed are obtained for multiple angular intervals; the multiple angular intervals include a first angular interval and multiple second angular intervals, the echo signal intensity curves include the echo signal intensity curves of the emitted beams of at least two wavelengths, and the first beam divergence diagram is a reference beam divergence diagram, which is obtained by calibration before leaving the factory.

[0008] For each wavelength of the emitted beam, the following operations are performed: determine the first height corresponding to the echo signal intensity curve of the first angular interval and the second height corresponding to the echo signal intensity curve of each second angular interval;

[0009] Based on the first height and the angle interval corresponding to the first height, each second height and the angle interval corresponding to each second height, a second beam divergence pattern is generated using a preset generation algorithm;

[0010] Based on the first beam divergence pattern and the second beam divergence pattern, the lidar to be processed is corrected.

[0011] In one possible implementation, acquiring the echo signal intensity curves of multiple angular intervals of the lidar to be processed includes: using a triangulation measurement tool to acquire the echo signal intensity values ​​and corresponding detection heights of multiple angular intervals of the emitted beams of at least two wavelengths.

[0012] For each wavelength of the emitted beam, the following operation is performed: based on the echo signal intensity of each angle interval and the corresponding detection height, echo signal intensity curves for multiple angle intervals are obtained.

[0013] In one possible implementation, determining the first height corresponding to the echo signal intensity curve of the first angle interval and the second height corresponding to the echo signal intensity curve of each second angle interval includes:

[0014] Based on the echo signal intensity curve of the first angle interval, the detection height corresponding to the maximum value of the first echo signal intensity is obtained;

[0015] The detection height corresponding to the maximum value of the first echo signal intensity is determined as the first height;

[0016] Based on the echo signal intensity curve of each second angle interval, the detection height corresponding to the maximum value of each second echo signal intensity is obtained;

[0017] The detection height corresponding to the maximum value of each second echo signal intensity is determined as the second height.

[0018] In one possible implementation, generating a second beam divergence pattern based on the first height and the angle interval corresponding to the first height, each second height and the angle interval corresponding to each second height, using a preset generation algorithm, includes:

[0019] Based on the first height and each second height, multiple radial values ​​are obtained;

[0020] Based on the angle range corresponding to the first height, each radial value, and the angle range corresponding to each second height, determine the angle corresponding to each radial value;

[0021] A second beam divergence pattern is generated based on each radial value and the angle corresponding to each radial value.

[0022] In one possible implementation, the lidar to be processed is corrected based on the first beam divergence pattern and the second beam divergence pattern, including:

[0023] The first beam divergence pattern and the second beam divergence pattern are compared.

[0024] If the result of the comparison process does not meet the preset matching conditions, a correction strategy is determined based on the first beam divergence pattern and the second beam divergence pattern.

[0025] Based on the aforementioned correction strategy, the lidar to be processed is corrected until the comparison result of the corrected lidar meets the preset matching conditions.

[0026] In one possible implementation, the first beam divergence pattern includes a first beam curve and a first beam curve area, the second beam divergence pattern includes a second beam curve and a second beam curve area, and a comparison process is performed between the first beam divergence pattern and the second beam divergence pattern, including:

[0027] Based on the first beam divergence diagram, the first beam curve and the area of ​​the first beam curve for each wavelength of the emitted beam are obtained.

[0028] Based on the second beam divergence pattern, the second beam curve and the area of ​​the second beam curve for each wavelength of the emitted beam are obtained.

[0029] Based on the first beam curve and the second beam curve of the emitted beam for each wavelength, the correlation coefficient of the first beam curve and the second beam curve of the emitted beam for each wavelength is calculated using a preset correlation algorithm.

[0030] Based on the area of ​​the first beam curve and the area of ​​the second beam curve, the area ratio of the area of ​​the first beam curve and the area of ​​the second beam curve for each wavelength of the emitted beam is calculated.

[0031] The comparison process results are obtained based on the correlation coefficient and area ratio of the emitted beam at each wavelength.

[0032] Secondly, a differential absorption lidar correction device is provided, the device comprising:

[0033] The acquisition unit is used to acquire echo signal intensity curves and a first beam divergence diagram of multiple angle intervals of the lidar to be processed; the multiple angle intervals include a first angle interval and multiple second angle intervals, the echo signal intensity curves include echo signal intensity curves of at least two wavelengths of emitted beams, and the first beam divergence diagram is a reference beam divergence diagram.

[0034] The determining unit is used to perform the following operations for the emitted beam of each wavelength: determining a first height corresponding to the echo signal intensity curve of a first angle interval and a second height corresponding to the echo signal intensity curve of each second angle interval;

[0035] The generation unit is used to generate a second beam divergence pattern based on the first height and the angle interval corresponding to the first height, each second height and the angle interval corresponding to each second height, using a preset generation algorithm.

[0036] The correction unit is used to perform correction processing on the lidar to be processed based on the first beam divergence pattern and the second beam divergence pattern.

[0037] Thirdly, a computer-readable storage medium is provided, wherein at least one instruction is stored therein, the at least one instruction being loaded and executed by a processor to implement the aspects and any possible implementations described above.

[0038] Fourthly, an electronic device is provided, comprising:

[0039] At least one processor; and

[0040] A memory communicatively connected to the at least one processor; wherein,

[0041] The memory stores instructions that can be executed by the at least one processor to enable the at least one processor to perform the methods described above and any possible implementations.

[0042] The beneficial effects of the technical solution provided in this application include at least the following:

[0043] As can be seen from the above technical solution, the embodiments of this application can obtain the echo signal intensity curves and the first beam divergence map of multiple angle intervals of the lidar to be processed; the multiple angle intervals include a first angle interval and multiple second angle intervals, the echo signal intensity curves include the echo signal intensity curves of at least two wavelengths of emitted beams, and the first beam divergence map is a reference beam divergence map. Then, the following operations can be performed for each wavelength of emitted beam: determine the first height corresponding to the echo signal intensity curve of the first angle interval and the second height corresponding to the echo signal intensity curve of each second angle interval; based on the first height and the angle interval corresponding to the first height, and each second height and the angle interval corresponding to each second height, generate a second beam divergence map using a preset generation algorithm; finally, based on the first beam divergence map and the second beam divergence map of each wavelength of emitted beam, the lidar to be processed is corrected. Since the second beam divergence map can be compared and matched with the first beam divergence map as a reference, the correction strategy for the lidar to be processed can be determined according to the comparison result, and the lidar can be adjusted to the reference state, the complexity of lidar correction is reduced while ensuring the reliability of lidar correction.

[0044] It should be understood that the description in this section is not intended to identify key or essential features of the embodiments of this application, nor is it intended to limit the scope of this application. Other features of this application will become readily apparent from the following description. Attached Figure Description

[0045] To more clearly illustrate the technical solutions in the embodiments of this application, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the accompanying drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0046] Figure 1 This is a schematic flowchart of a differential absorption lidar correction method provided in one embodiment of this application;

[0047] Figure 2 This is a schematic diagram of the flow of a differential absorption lidar correction method provided in another embodiment of this application;

[0048] Figure 3 This is a schematic diagram illustrating the working principle of the angle measurement tool for differential absorption lidar provided in another embodiment of this application;

[0049] Figure 4 This is a schematic diagram of the echo signal curves of an emitted beam of one wavelength in different angle ranges in a differential absorption lidar correction method provided in another embodiment of this application;

[0050] Figure 5 This is a schematic diagram of the beam divergence pattern in a differential absorption lidar correction method provided in another embodiment of this application;

[0051] Figure 6 This is a schematic diagram of the first beam divergence pattern in a differential absorption lidar correction method provided in another embodiment of this application;

[0052] Figure 7 This is a schematic diagram of the second beam divergence pattern in a differential absorption lidar correction method provided in another embodiment of this application;

[0053] Figure 8 This is a schematic diagram comparing a new second beam divergence pattern with a first beam divergence pattern in a differential absorption lidar correction method provided in another embodiment of this application;

[0054] Figure 9 This is a structural block diagram of a differential absorption lidar correction device provided in another embodiment of this application;

[0055] Figure 10This is a block diagram of an electronic device used to implement the differential absorption lidar correction method of the embodiments of this application. Detailed Implementation

[0056] The following description, in conjunction with the accompanying drawings, illustrates exemplary embodiments of this application, including various details to aid understanding. These should be considered merely exemplary. Therefore, those skilled in the art will recognize that various changes and modifications can be made to the embodiments described herein without departing from the scope and spirit of this application. Similarly, for clarity and brevity, descriptions of well-known functions and structures are omitted in the following description.

[0057] Obviously, the described embodiments are only some, not all, of the embodiments in this application. All other embodiments obtained by those skilled in the art based on the embodiments in this application without inventive effort are within the scope of protection of this application.

[0058] It should be noted that the hardware observation equipment terminal involved in the embodiments of this application may include, but is not limited to, equipment in meteorological observation stations such as receivers, integrated processors, remote control devices, and base measurement boxes.

[0059] Furthermore, the term "and / or" in this article is merely a description of the relationship between related objects, indicating that three relationships can exist. For example, A and / or B can represent: A existing alone, A and B existing simultaneously, or B existing alone. Additionally, the character " / " in this article generally indicates that the preceding and following related objects have an "or" relationship.

[0060] Typically, differential absorption lidar needs to emit multiple (at least two) wavelengths of laser light into the atmosphere. These wavelengths are often generated through beam combining or conversion within the light source system and then emitted via the same transmission system. However, due to optical chromatic aberration, optical deviations in the beam combining or conversion process, and the inconsistency of the light source itself, lasers of different wavelengths cannot be ideally combined (maintaining perfect overlap), often resulting in different divergence angles and emission positions. Since differential absorption lidar inverts target component concentration by synchronously changing differential wavelength pairs, non-ideal beam combining affects the accuracy of the inversion results. Especially at close range, where the receiving field of view cannot completely cover the emitted beam, the inversion error caused by non-ideal beam combining is greatly amplified. Therefore, separate correction based on beam deviation algorithms is needed for this distance range to ensure the accuracy of the inversion results. The maximum height requiring beam deviation algorithm correction is h0, called the algorithm threshold range, which is mainly affected by the transmitting and receiving field of view and the relative positions of the transmitter and receiver.

[0061] Differential absorption lidar is primarily used for measuring the atmospheric composition concentration profile of targets. Therefore, it often features a large pulse light energy, such as 20 millijoules (mJ). Furthermore, because the wavelength pairs in differential absorption need to minimize the influence of non-target atmospheric components on the test results, the wavelength pairs are often close together, such as 289 nanometers (nm) and 316 nm. To achieve longer detection distances, its beam divergence angle is often on the order of milliradians (mrad). The output optical characteristics of large pulse energy, small wavelength difference, and small divergence angle make it difficult to determine the beam morphology of the differential wavelength pairs, especially in the field of differential absorption lidar operation. Maintenance of the differential absorption lidar optical components, particularly the transmitting system, inevitably alters the output optical characteristics of the differential pairs. Therefore, even if the equipment has undergone algorithmic correction for near-range inversion results at the factory, the beam output characteristics of the differential pairs have changed after maintenance of the optical components, rendering the original correction algorithm ineffective at near range.

[0062] In traditional solutions, a dual-telescope approach is typically used to ensure the accuracy of the inversion results. In a differential absorption lidar, telescope one corresponds to the first receiving field of view, and its large receiving angle allows for coverage of the transmitted beam at relatively close range. This significantly reduces the algorithm threshold range h0, which can usually be designed below the required detection height. For example, if the detection height is 150-6000 meters (m), a threshold range h0 of 100m can be designed, eliminating the need for beam deviation correction. However, an excessively large receiving angle increases optical noise, significantly reducing the signal-to-noise ratio and detection range. Therefore, a second telescope is also necessary, with a smaller receiving angle for long-distance signal measurement.

[0063] The main problem with this approach is the increased complexity it introduces in terms of hardware structure. As the demand for exploration increases, the number of telescopes needs to be increased accordingly, which not only increases equipment costs but also requires fine-tuning of the docking points between the telescopes' fields of view.

[0064] Therefore, there is an urgent need for a differential absorption lidar calibration method to effectively calibrate the lidar after maintenance.

[0065] Please refer to Figure 1 This document illustrates a flowchart of a differential absorption lidar correction method according to an embodiment of this application. Specifically, the differential absorption lidar correction method may include:

[0066] Step 101: Obtain the echo signal intensity curves and the first beam divergence diagram of the lidar to be processed in multiple angular intervals; the multiple angular intervals include a first angular interval and multiple second angular intervals, the echo signal intensity curves include the echo signal intensity curves of the emitted beams of at least two wavelengths, and the first beam divergence diagram is a reference beam divergence diagram.

[0067] Step 102: Perform the following operations for the emitted beam of each wavelength: determine the first height corresponding to the echo signal intensity curve of the first angle interval and the second height corresponding to the echo signal intensity curve of each second angle interval.

[0068] Step 103: Based on the first height and the angle interval corresponding to the first height, and each second height and the angle interval corresponding to each second height, generate a second beam divergence pattern using a preset generation algorithm.

[0069] Step 104: Based on the first beam divergence pattern and the second beam divergence pattern of the emitted beam for each wavelength, perform correction processing on the lidar to be processed.

[0070] It should be noted that the lidar to be processed can be a lidar that needs to be calibrated after equipment maintenance.

[0071] It should be noted that the first beam divergence pattern can be a beam divergence pattern generated by atmospheric detection based on the differential absorption lidar after factory calibration. This first beam divergence pattern can be used as a standard, that is, a reference beam divergence pattern.

[0072] It should be noted that the size of each angular interval can be the same. For example, the size of each angular interval can be 20 degrees.

[0073] It should be noted that after obtaining the corrected differential absorption lidar, since the differential absorption lidar has been corrected to the reference state, the beam deviation algorithm can continue to be used to perform algorithm correction processing on the inversion results at close range where the received field of view cannot completely cover the emitted beam.

[0074] In this way, by comparing and matching the second beam divergence pattern with the first beam divergence pattern as a reference, the correction strategy for the lidar to be processed can be determined based on the comparison result, and the lidar can be adjusted to the reference state. This reduces the complexity of lidar correction while ensuring the reliability of lidar correction.

[0075] Optionally, in one possible implementation of this embodiment, in step 101, firstly, an angle measurement tool can be used to obtain the echo signal intensity values ​​and corresponding detection heights for multiple angular intervals of the emitted beams of at least two wavelengths. Secondly, for each wavelength of the emitted beam, the following operation can be performed: based on the echo signal intensity values ​​and corresponding detection heights of each angular interval, an echo signal intensity curve for multiple angular intervals can be obtained.

[0076] In this implementation, the angle measurement tool can divide the working area of ​​the lidar receiving telescope into multiple angle intervals.

[0077] In one specific implementation of this method, for an angular range of a transmitted beam of a certain wavelength, an echo signal intensity curve can be generated based on multiple detection heights within that angular range and the echo signal intensity value corresponding to each detection height.

[0078] In this way, echo signal intensity curves in different angle ranges can be obtained through the angle measurement tool, and the divergence of the output light in various directions can be analyzed. The divergence at different angles under a certain wavelength and the divergence at different wavelengths can be understood, so as to effectively correct the lidar based on these conditions.

[0079] Optionally, in one possible implementation of this embodiment, in step 102, firstly, the detection height corresponding to the maximum value of the first echo signal intensity can be obtained based on the echo signal intensity curve of the first angle interval. Secondly, the detection height corresponding to the maximum value of the first echo signal intensity is determined as the first height. Thirdly, the detection height corresponding to the maximum value of each second echo signal intensity is obtained based on the echo signal intensity curve of each second angle interval. Thirdly, the detection height corresponding to the maximum value of each second echo signal intensity is determined as the second height.

[0080] In this implementation, the first angle interval can be an angle interval based on a reference direction and a preset angle range. For example, with 0° as the reference direction and a preset angle range of 20°, the first angle interval is 0°-20°. The second angle interval is the angle interval following the initial measured angle interval. For example, the second angle interval includes 20°-40°, 40°-60°, 60°-80°, ..., 340°-360°.

[0081] Understandably, the preset angle range here can be determined based on the measurement time and detection height of the actual application scenario.

[0082] In this implementation, there can be multiple second angle intervals and multiple second heights. One second height can correspond to one second angle interval.

[0083] In one specific implementation of this method, based on the echo signal intensity curve of the first angle interval, the detection height corresponding to the maximum value of the echo signal intensity in the echo signal intensity curve is obtained, and then the detection height corresponding to the maximum value of the echo signal intensity is determined as the first height.

[0084] In another specific implementation of this method, for any second angle interval, based on the echo signal intensity curve of the second angle interval, the detection height corresponding to the maximum value of the echo signal intensity in the echo signal intensity curve is obtained, and then the detection height corresponding to the maximum value of the echo signal intensity is determined as the second height.

[0085] In this way, effective information that can be used to generate a beam divergence pattern can be obtained by determining the detection height corresponding to the maximum value of the echo signal intensity, which facilitates the improvement of the effectiveness of the generated beam divergence pattern in the future.

[0086] It should be noted that the specific implementation process provided in this embodiment can be combined with various specific implementation processes provided in the foregoing implementation methods to realize the differential absorption lidar correction method of this embodiment. Detailed descriptions can be found in the relevant content of the foregoing implementation methods, and will not be repeated here.

[0087] Optionally, in one possible implementation of this embodiment, in step 103, firstly, multiple radial values ​​can be obtained based on the first height and each second height. Secondly, based on the angle interval corresponding to the first height, each radial value, and the angle interval corresponding to each second height, the angle corresponding to each radial value is determined. Thirdly, a second beam divergence pattern is generated based on each radial value and the angle corresponding to each radial value.

[0088] In this implementation, the beam divergence pattern can be represented as: , Radial value, This represents the angle corresponding to the radial value.

[0089] here, The angle corresponding to the radial value can be at least one value selected from the angle range corresponding to the radial value.

[0090] For example, It can be the midpoint of the angle range corresponding to the radial value, for example, for the second angle range of 20° to 40°. It can be 30°; These can be the maximum and minimum values ​​within the angular range corresponding to the radial value; for example, for the second angular range of 20° to 40°, The number can be two, and it can be 20° or 40°. These two... It can correspond to the same radial value, that is, the radial value corresponding to the second angle range of 20° to 40°.

[0091] In a specific implementation of this method, for any wavelength of emitted beam, firstly, the ratio of each second height to the first height is calculated, and each ratio is used as a radial value. Secondly, based on the angle interval corresponding to the first height, each radial value, and the angle interval corresponding to each second height, the angle interval corresponding to each radial value is determined. Thirdly, at least one angle is selected from the angle interval corresponding to each radial value as the angle corresponding to that radial value. Fourthly, based on each pair of radial values ​​and angles, a second beam curve for the emitted beam of that wavelength is generated. Fifthly, the second beam curve for the emitted beam of each wavelength is obtained. Sixthly, based on the second beam curve for the emitted beam of each wavelength, a second beam divergence pattern is generated.

[0092] In another specific implementation of this method, the first height can be updated based on a preset period, and then the corresponding radial value can be calculated based on the updated first height and the subsequent second height.

[0093] Understandably, in order to reduce the impact of atmospheric state changes on test results, after determining the radial values ​​of several angle intervals, for example, every 16 or 30 minutes, the angular measuring tool can be switched back to the first angle interval to measure the minimum first height, and the latest first height is used to replace the original first height for subsequent calculation of the radial values ​​of the second angle interval.

[0094] In this way, the reliability and effectiveness of the generated second beam divergence pattern can be further improved by calculating multiple radial values ​​based on the first height and each second height, as well as the angle corresponding to each radial value.

[0095] It should be noted that the specific implementation process provided in this embodiment can be combined with various specific implementation processes provided in the foregoing implementation methods to realize the differential absorption lidar correction method of this embodiment. Detailed descriptions can be found in the relevant content of the foregoing implementation methods, and will not be repeated here.

[0096] Optionally, in one possible implementation of this embodiment, in step 104, the first beam divergence pattern and the second beam divergence pattern are compared. Then, in response to the result of the comparison process not meeting the preset matching conditions, a correction strategy is determined based on the first beam divergence pattern and the second beam divergence pattern. Based on the correction strategy, the lidar to be processed is corrected until the result of the comparison process of the corrected lidar meets the preset matching conditions.

[0097] In this implementation, the first beam divergence pattern includes a first beam curve and a first beam curve area, and the second beam divergence pattern includes a second beam curve and a second beam curve area.

[0098] Here, the first beam curve may include the beam curve of the emitted beam at each wavelength in the first beam divergence pattern. There may be multiple first beam curves. The area of ​​the first beam curve may include the area enclosed by the beam curves of the emitted beam at each wavelength in the first beam divergence pattern.

[0099] Simultaneously, the second beam profile may include the beam profile of the emitted beam at each wavelength in the second beam divergence diagram. There may be multiple second beam profiles. The area of ​​the second beam profile may include the area enclosed by the beam profiles of the emitted beams at each wavelength in the second beam divergence diagram.

[0100] In a specific implementation of this method, firstly, based on the first beam divergence diagram, the first beam curve and the area of ​​the first beam curve for each wavelength of the emitted beam can be obtained. Secondly, based on the second beam divergence diagram, the second beam curve and the area of ​​the second beam curve for each wavelength of the emitted beam can be obtained. Thirdly, based on the first beam curve and the second beam curve for each wavelength of the emitted beam, a preset correlation algorithm is used to calculate the correlation coefficient of the first beam curve and the second beam curve for each wavelength of the emitted beam. Fourthly, based on the area of ​​the first beam curve and the area of ​​the second beam curve, the area ratio of the first beam curve area and the second beam curve area for each wavelength of the emitted beam is calculated. Finally, based on the correlation coefficient and the area ratio of the emitted beam for each wavelength, the result of the comparison processing is obtained.

[0101] In this implementation, the preset matching conditions can be that the correlation coefficient of the emitted beam of each wavelength exceeds a preset correlation threshold, and the area ratio of the emitted beam of each wavelength is within a preset area ratio value range.

[0102] Preferably, the preset correlation threshold can be 0.8, and the preset area ratio value range can be from 0.8 to 1.2. The preset value range can indicate that the deviation of the areas of the two curves is less than 20%.

[0103] In this implementation, the preset correlation algorithm can be the Pearson correlation algorithm.

[0104] In another specific implementation of this method, a reference direction and a deviation angle are determined based on the first beam divergence pattern and the second beam divergence pattern. Then, a correction strategy is determined based on the reference direction and the deviation angle, and the lidar is adjusted based on the determined correction strategy.

[0105] It is understandable that the beam divergence diagram contains angular information, which can be used to obtain the overall direction of the beam. By comparing the overall directions of the two beams in the two beam divergence diagrams, the reference direction and deviation angle used for correction can be determined.

[0106] In this implementation, the correction strategy may include an adjustment method for the differential absorption lidar. This correction strategy may be determined based on the difference between the first beam divergence pattern and the second beam divergence pattern. Here, the correction strategy aims to maintain a substantially consistent second beam divergence pattern of the corrected lidar with the first beam divergence pattern, which serves as a reference.

[0107] It should be noted that the specific implementation process provided in this embodiment can be combined with various specific implementation processes provided in the foregoing implementation methods to realize the differential absorption lidar correction method of this embodiment. Detailed descriptions can be found in the relevant content of the foregoing implementation methods, and will not be repeated here.

[0108] To better illustrate the differential absorption lidar correction method in this application, and in conjunction with the application scenarios of the differential absorption lidar correction method, the method will be described in detail.

[0109] Figure 2 This illustration shows a schematic diagram of the flow of a differential absorption lidar correction method provided in another embodiment of this application, as shown below. Figure 2 As shown. In this embodiment, the differential absorption lidar correction method can be specifically implemented as follows:

[0110] Step 201: Obtain the first beam divergence pattern generated in advance based on the detection information of the reference lidar.

[0111] In this embodiment, the reference lidar can be a lidar that has undergone factory calibration and algorithm correction.

[0112] It is understandable that, when generating the first beam divergence map, a reference lidar can be used to detect the echo signal intensity values ​​and corresponding detection heights in multiple angle intervals. Then, based on the echo signal intensity values ​​and corresponding detection heights in multiple angle intervals, the first beam divergence map can be generated and stored.

[0113] Step 202: Using a triangulation measuring tool, obtain the echo signal intensity values ​​and corresponding detection heights for multiple angular intervals of at least two wavelengths of the emitted beam.

[0114] In this embodiment, Figure 3 This is a schematic diagram illustrating the principle of the angle measurement tool for differential absorption lidar provided in another embodiment of this application, as shown below. Figure 3 As shown, the arbitrariness measuring tool operates on the receiving telescope of the differential absorption lidar. The receiving telescope is a circularly symmetrical optical device, and its working area can be divided into multiple fan-shaped regions with a total angle of 360°. The arbitrariness measuring tool can selectively preserve the fan-shaped regions within a certain angular range of the receiving telescope, while the remaining areas are blocked by the arbitrariness measuring tool, i.e., the non-working area of ​​the telescope, and therefore cannot participate in the reception of echo signals. Figure 3 As shown, the angular measuring tool allows a specific angular range of the receiving telescope to participate in the detection process. By continuously changing the detection angular range retained by the angular measuring tool, the echo signal situation within 360° can be measured. Using the angular measuring tool, the echo signal intensity value and corresponding detection height under different receiving areas can be measured.

[0115] Step 203: Perform the following operation for the emitted beam of each wavelength: Based on the echo signal intensity value of each angle interval and the corresponding detection height, obtain the echo signal intensity curve of multiple angle intervals, including the first angle interval and multiple second angle intervals.

[0116] Step 204: Determine the first height corresponding to the echo signal intensity curve of the first angle interval and the second height corresponding to the echo signal intensity curve of each second angle interval.

[0117] In this embodiment, for any wavelength of emitted beam, the detection height corresponding to the maximum value of the first echo signal intensity can be obtained based on the echo signal intensity curve of the first angle interval, and the detection height corresponding to the maximum value of the first echo signal intensity is determined as the first height. Based on the echo signal intensity curve of each second angle interval, the detection height corresponding to the maximum value of each second echo signal intensity is obtained, and the detection height corresponding to the maximum value of each second echo signal intensity is determined as the second height.

[0118] Here, the first angle interval can be the initial angle interval for angle measurement. The first angle interval can be an angle interval based on a reference direction and a preset angle range. For example, with 0° as the reference direction and a preset angle range of 20°, the first angle interval is 0° to 20°. The second angle interval is the angle interval following the initial measurement angle interval. For example, the second angle interval includes 20° to 40°, 40° to 60°, 60° to 80°, ..., 340° to 360°.

[0119] In this embodiment, Figure 4 This is a schematic diagram of the echo signal curves of a emitted beam of one wavelength in different angle ranges in a differential absorption lidar correction method provided in another embodiment of this application, as shown below. Figure 4 As shown, there are deviations between the echo signal curves in different angle ranges. This is mainly due to the influence of the beam output characteristics at different angles and the atmospheric conditions at different times. Here, the detection height corresponding to the maximum signal strength is, i.e., the distance is... , Exemplary The detection height corresponds to the maximum echo signal intensity in the first angular interval (0° to 20°), i.e., the first height. The second height is the detection height corresponding to the maximum echo signal intensity in a second set of angle intervals (20° to 40°).

[0120] Step 205: Based on the first height and the angle interval corresponding to the first height, and each second height and the angle interval corresponding to each second height, a second beam curve of the emitted beam for each wavelength is generated using a preset generation algorithm. Based on the second beam curve of the emitted beam for each wavelength, a second beam divergence map is obtained.

[0121] In this embodiment, firstly, multiple radial values ​​are obtained based on a first height and each second height. Secondly, based on the angle interval corresponding to the first height, each radial value, and the angle interval corresponding to each second height, the angle corresponding to each radial value is determined. Thirdly, based on each radial value and the angle corresponding to each radial value, a second beam curve is generated to obtain the second beam curve of the emitted beam for each wavelength. Finally, the second beam curve of the emitted beam for each wavelength is used to obtain a second beam divergence pattern.

[0122] Preferably, for an emitted beam of any wavelength, firstly, the ratio of each second height to the first height is calculated, and each ratio is used as a radial value. Secondly, based on the angle interval corresponding to the first height, each radial value, and the angle interval corresponding to each second height, the angle interval corresponding to each radial value is determined. Thirdly, at least one angle is selected from the angle interval corresponding to each radial value as the angle corresponding to that radial value. Fourthly, based on each pair of radial values ​​and angles, a second beam curve for the emitted beam of that wavelength is generated. Finally, based on the second beam curve of the emitted beam for each wavelength, a second beam divergence pattern is generated.

[0123] Here, the beam divergence diagram can be represented as: Radial value , Take as ,in, The first height corresponds to the maximum echo signal intensity in the first set of angle intervals. The second height corresponding to the maximum echo signal intensity in a second set of angular intervals, this radial value Corresponding angle . Figure 5 This is a schematic diagram of the beam divergence pattern in a differential absorption lidar correction method provided in another embodiment of this application, as shown below. Figure 5 As shown, the beam divergence diagram includes the beam divergence curve for wavelength 1 and the beam divergence curve for wavelength 2.

[0124] In this embodiment, the first height can be updated based on a preset period, and then the corresponding radial value can be calculated based on the updated first height and the subsequent second height.

[0125] Preferably, the preset period can be 30 minutes. Here, the detection can be performed again based on the first angle interval every 30 minutes to obtain the echo signal intensity value and detection height of the first angle interval, so as to obtain the detection height corresponding to the new maximum echo signal intensity value and obtain the new first height.

[0126] It is understandable that here, the detection height corresponds to the maximum value of the echo signal intensity of the emitted beam. The threshold range of the beam deviation algorithm Closely related. When When the value is smaller, it means that the beam has a greater divergence intensity in that direction with the center of the telescope as the origin. Therefore, using different angle ranges... Parameters to plot beam divergence For easier comparison, each radial value can be... Standardize, Take the second height of the corresponding second angle interval divided by the first height of the first angle interval, i.e., take it as... .

[0127] Step 206: Compare the first beam divergence pattern and the second beam divergence pattern.

[0128] Step 207: Determine whether the comparison processing result meets the preset matching conditions.

[0129] Step 208: If the comparison processing result does not meet the preset matching conditions, a correction strategy is determined based on the first beam divergence map and the second beam divergence map. The lidar is then adjusted based on the correction strategy, and the process returns to step 202 based on the adjusted lidar.

[0130] In this embodiment, a reference direction and a deviation angle are determined based on the first beam divergence pattern and the second beam divergence pattern, and then the lidar can be adjusted according to the reference direction and the deviation angle.

[0131] In this embodiment, after adjustment, a new beam divergence pattern is obtained through retesting, and it is determined whether it meets the preset matching conditions, i.e., whether it conforms to the consistency standard, with the first beam divergence pattern used as a reference. If it does, the correction and debugging are completed, and the original beam deviation algorithm can then be used to effectively correct the inversion results at close range. If it does not conform, the correction and debugging need to be performed again based on the comparison results until the consistency standard is met.

[0132] Step 209: If the comparison processing results meet the preset matching conditions, the lidar is not adjusted to obtain a calibrated lidar.

[0133] In this embodiment, for example, the differential absorption lidar can be an ozone lidar with emission wavelengths of 266nm, 289nm, and 316nm. The receiving telescope is of the Cassegrain type, consisting of a primary mirror and a secondary mirror. The echo signal first reaches the primary mirror, and then is captured by the photodetector under the combined reflection and focusing effect of the primary and secondary mirrors, so that the differential absorption lidar data processing unit obtains the echo signal intensity value and the corresponding detection height.

[0134] First, the LiDAR, after being calibrated at the factory, is measured using a triangulation measuring tool. Figure 6 This is a schematic diagram of the first beam divergence pattern in a differential absorption lidar correction method provided in another embodiment of this application, as shown below. Figure 6As shown, the emission wavelengths are 266nm, 289nm, and 316nm. A reference direction of 350° (angle range 340° to 360°) can be used. Data is measured every 2 minutes, and after 4 sets of measurements, the reference direction angle range (i.e., the first angle range) is remeasured and updated. The value is determined using the methods in steps 202 to 205 to determine the beam divergence pattern. Parameters, and plot the generated beam divergence diagram, such as Figure 6 As shown, the beam divergence pattern is the first beam divergence pattern used as a reference.

[0135] Secondly Figure 7 This is a schematic diagram of the second beam divergence pattern in a differential absorption lidar correction method provided in another embodiment of this application, as shown below. Figure 7 As shown, after the optical components of the lidar are maintained, a new set of optical components is obtained again using the methods in steps 202 to 205. The parameters are determined, and the beam divergence diagram, i.e., the second beam divergence diagram, is plotted.

[0136] Next, the first and second beam divergence maps can be compared and analyzed. The data from both analyses are compared with preset matching conditions. Here, the first beam divergence map includes the first beam curve for each wavelength. The second beam divergence map includes the second beam curve for each wavelength. The correlation coefficient for each wavelength can be the Pearson correlation coefficient between the first and second beam curves for each wavelength. When the correlation coefficient for each wavelength is greater than 80% and the deviation of the curve area is less than 20%, i.e., the curve area ratio is between 0.8 and 1.2, the comparison result can be determined to meet the preset matching conditions; otherwise, the comparison result is determined not to meet the preset matching conditions.

[0137] Here, it can be determined that the comparison results do not meet the preset matching conditions, as shown in Table 1 below.

[0138] Table 1: Comparison results and matching conditions of the first and second beam divergence patterns

[0139]

[0140] Here, as Figure 6 and 7 As shown, firstly, it can be seen that the curves for 289nm and 316nm change more drastically, while the curve for 266nm changes less. This is because the output light at 266nm has a larger divergence angle and output spot size. Analyzing the comparison between 289nm and 316nm, their curve areas differ significantly, mainly due to the direction of the reference angle range. This is due to changes. A larger total area means the beam direction is more biased towards the reference angle range, i.e., the 350° direction. Secondly, it can be seen from the reference beam divergence diagram, i.e., the first beam divergence diagram, that the beam in this state is biased towards the 210° direction, while after optical element maintenance, the beam in the second beam divergence diagram state is biased towards the 120° direction. Therefore, the correction strategy is determined to be an adjustment tilt from 120° to 210°, with the reference direction being from 120° to 210°, and the reference angle, i.e., the deviation angle, can be 90°.

[0141] Furthermore, by adjusting the lidar based on the correction strategy and repeating the measurements, a new beam divergence pattern, namely the new second beam divergence pattern, can be obtained. This new beam divergence pattern can then be compared with the first beam divergence pattern. Figure 8 This is a schematic diagram comparing the new beam divergence pattern and the first beam divergence pattern in a differential absorption lidar correction method provided in another embodiment of this application, as shown below. Figure 8 As shown, the new beam divergence curve corresponding to each wavelength and the first beam divergence curve corresponding to each wavelength and the reference are shown. Figure 8 Based on the comparison results calculated in Table 2, it can be seen that the consistency meets the standard. Thus, the calibration process for the lidar is complete, and a calibrated lidar is obtained.

[0142] Table 2: Comparison results and matching conditions between the first beam divergence pattern and the new beam divergence pattern

[0143]

[0144] Thus, by adopting the scheme in this embodiment, the second beam divergence pattern can be compared and matched with the first beam divergence pattern as a reference, and the strategy for correcting the lidar to be processed can be determined based on the comparison result, so as to adjust the lidar to the reference state. This reduces the complexity of lidar correction while ensuring the reliability of lidar correction.

[0145] Furthermore, by adopting the scheme in this embodiment, the divergence of the output light of the differential wavelength in various directions can be quantitatively analyzed, and the divergence at different angles under a certain wavelength and the divergence at different wavelengths can be understood.

[0146] Furthermore, the solution in this embodiment can effectively address the impact of optical path changes caused by on-site debugging on the correction of near-range inversion results, enabling the correction algorithm to function better and improving the near-range detection performance of the lidar.

[0147] Furthermore, the solution described in this embodiment can reduce the number and complexity of lidar receiving telescopes.

[0148] It should be noted that, for the sake of simplicity, the foregoing method embodiments are all described as a series of actions. However, those skilled in the art should understand that this application is not limited to the described order of actions, as some steps may be performed in other orders or simultaneously according to this application. Furthermore, those skilled in the art should also understand that the embodiments described in the specification are preferred embodiments, and the actions and modules involved are not necessarily essential to this application.

[0149] In the above embodiments, the descriptions of each embodiment have different focuses. For parts not described in detail in a certain embodiment, please refer to the relevant descriptions in other embodiments.

[0150] Figure 9 This invention provides a structural block diagram of a differential absorption lidar correction apparatus according to an embodiment of the present application, as shown below. Figure 9 As shown. The differential absorption lidar correction device 900 of this embodiment may include an acquisition unit 901, a determination unit 902, a generation unit 903, and a correction unit 904. The acquisition unit 901 is used to acquire echo signal intensity curves and a first beam divergence map of multiple angular intervals of the lidar to be processed; the multiple angular intervals include a first angular interval and multiple second angular intervals, the echo signal intensity curves include echo signal intensity curves of at least two wavelengths of emitted beams, and the first beam divergence map is a reference beam divergence map; the determination unit 902 is used to perform the following operations for each wavelength of emitted beam: determine a first height corresponding to the echo signal intensity curve of the first angular interval and a second height corresponding to the echo signal intensity curve of each second angular interval; the generation unit 903 is used to generate a second beam divergence map based on the first height and the angular interval corresponding to the first height, and each second height and the angular interval corresponding to each second height, using a preset generation algorithm; the correction unit 904 is used to perform correction processing on the lidar to be processed based on the first beam divergence map and the second beam divergence map.

[0151] Optionally, in one possible implementation of this embodiment, the acquisition unit 901 is used to acquire the echo signal intensity values ​​and corresponding detection heights of multiple angular intervals of the emitted beams of at least two wavelengths using an angle measurement tool; and to perform the following operation for each wavelength of the emitted beam: based on the echo signal intensity values ​​and corresponding detection heights of each angular interval, obtain echo signal intensity curves of multiple angular intervals.

[0152] Optionally, in one possible implementation of this embodiment, the determining unit 902 is configured to obtain the detection height corresponding to the maximum value of the first echo signal intensity based on the echo signal intensity curve of the first angle interval; determine the detection height corresponding to the maximum value of the first echo signal intensity as the first height; obtain the detection height corresponding to the maximum value of each second echo signal intensity based on the echo signal intensity curve of each second angle interval; and determine the detection height corresponding to the maximum value of each second echo signal intensity as the second height.

[0153] Optionally, in one possible implementation of this embodiment, the generation unit 903 is configured to obtain multiple radial values ​​based on the first height and each second height; determine the angle corresponding to each radial value based on the angle interval corresponding to the first height, each radial value and the angle interval corresponding to each second height; and generate a second beam divergence pattern based on each radial value and the angle corresponding to each radial value.

[0154] Optionally, in one possible implementation of this embodiment, the correction unit 904 is used to perform comparison processing on the first beam divergence pattern and the second beam divergence pattern; in response to the result of the comparison processing not meeting the preset matching conditions, a correction strategy is determined based on the first beam divergence pattern and the second beam divergence pattern; based on the correction strategy, the lidar to be processed is corrected until the comparison processing result of the corrected lidar meets the preset matching conditions.

[0155] Optionally, in one possible implementation of this embodiment, the first beam divergence map includes a first beam curve and a first beam curve area, and the second beam divergence map includes a second beam curve and a second beam curve area. The correction unit 904 is used to: obtain the first beam curve and the first beam curve area of ​​the emitted beam for each wavelength based on the first beam divergence map; obtain the second beam curve and the second beam curve area of ​​the emitted beam for each wavelength based on the second beam divergence map; calculate the correlation coefficient of the first beam curve and the second beam curve of the emitted beam for each wavelength using a preset correlation algorithm based on the first beam curve and the second beam curve of the emitted beam for each wavelength; calculate the area ratio of the first beam curve area and the second beam curve area of ​​the emitted beam for each wavelength based on the first beam curve area and the second beam curve area; and obtain the comparison processing result based on the correlation coefficient and the area ratio of the emitted beam for each wavelength.

[0156] In this embodiment, the acquisition unit can acquire echo signal intensity curves and a first beam divergence map of multiple angular intervals of the lidar to be processed. The multiple angular intervals include a first angular interval and multiple second angular intervals. The echo signal intensity curves include echo signal intensity curves of at least two wavelengths of emitted beams. The first beam divergence map is a reference beam divergence map. The determination unit performs the following operations for each wavelength of emitted beam: determining the first height corresponding to the echo signal intensity curve of the first angular interval and the second height corresponding to the echo signal intensity curve of each second angular interval. The generation unit generates a second beam divergence map based on the first height and the angular interval corresponding to the first height, and each second height and the angular interval corresponding to each second height, using a preset generation algorithm. This allows the correction unit to perform correction processing on the lidar to be processed based on the first beam divergence map and the second beam divergence map. Since the second beam divergence map can be compared and matched with the first beam divergence map as a reference, the correction strategy for the lidar to be processed can be determined based on the comparison result, and the lidar can be adjusted to the reference state. This reduces the complexity of lidar correction while ensuring the reliability of lidar correction.

[0157] The technical solution of this application involves the collection, storage, use, processing, transmission, provision, and disclosure of user personal information, such as user image and attribute data, as well as the collection, storage, use, processing, transmission, provision, and disclosure of meteorological station information, such as station latitude and longitude, altitude, station equipment information, and station business parameters, all of which comply with relevant laws and regulations and do not violate public order and good morals.

[0158] According to embodiments of this application, this application also provides an electronic device, a readable storage medium, and a computer program product.

[0159] Figure 10 A schematic block diagram of an example electronic device 1000 that can be used to implement embodiments of this application is shown. The electronic device is intended to represent various forms of digital computers, such as laptop computers, desktop computers, workstations, personal digital assistants, servers, blade servers, mainframe computers, and other suitable computers. The electronic device may also represent various forms of mobile devices, such as personal digital processors, cellular phones, smartphones, wearable devices, and other similar computing devices. The components shown herein, their connections and relationships, and their functions are merely illustrative and are not intended to limit the implementation of the application described and / or claimed herein.

[0160] like Figure 10As shown, the electronic device 1000 includes a computing unit 1001, which can perform various appropriate actions and processes according to a computer program stored in a read-only memory (ROM) 1002 or a computer program loaded from a storage unit 1008 into a random access memory (RAM) 1003. The RAM 1003 may also store various programs and data required for the operation of the electronic device 1000. The computing unit 1001, ROM 1002, and RAM 1003 are interconnected via a bus 1004. An input / output (I / O) interface 1005 is also connected to the bus 1004.

[0161] Multiple components in electronic device 1000 are connected to I / O interface 1005, including: input unit 1006, such as keyboard, mouse, etc.; output unit 1007, such as various types of displays, speakers, etc.; storage unit 1008, such as disk, optical disk, etc.; and communication unit 1009, such as network card, modem, wireless transceiver, etc. Communication unit 1009 allows electronic device 1000 to exchange information / data with other devices through computer networks such as the Internet and / or various telecommunications networks.

[0162] The computing unit 1001 can be a variety of general-purpose and / or special-purpose processing components with processing and computing capabilities. Some examples of the computing unit 1001 include, but are not limited to, a central processing unit (CPU), a graphics processing unit (GPU), various special-purpose artificial intelligence (AI) computing chips, various computing units running machine learning model algorithms, a digital signal processor (DSP), and any suitable processor, controller, microcontroller, etc. The computing unit 1001 performs the various methods and processes described above, such as the method for differential absorption lidar correction. For example, in some embodiments, the method for differential absorption lidar correction can be implemented as a computer software program tangibly contained in a machine-readable medium, such as storage unit 1008. In some embodiments, part or all of the computer program can be loaded and / or installed on the electronic device 1000 via ROM 1002 and / or communication unit 1009. When the computer program is loaded into RAM 1003 and executed by the computing unit 1001, one or more steps of the differential absorption lidar correction method described above can be performed. Alternatively, in other embodiments, the computing unit 1001 may be configured to perform a method for differential absorption lidar correction by any other suitable means (e.g., by means of firmware).

[0163] Various embodiments of the systems and techniques described above herein can be implemented in digital electronic circuit systems, integrated circuit systems, field-programmable gate arrays (FPGAs), application-specific integrated circuits (ASICs), application-specific standard products (ASSPs), systems-on-a-chip (SoCs), complex programmable logic devices (CPLDs), computer hardware, firmware, software, and / or combinations thereof. These various embodiments may include implementations in one or more computer programs that can be executed and / or interpreted on a programmable system including at least one programmable processor, which may be a dedicated or general-purpose programmable processor, capable of receiving data and instructions from a storage system, at least one input device, and at least one output device, and transmitting data and instructions to the storage system, the at least one input device, and the at least one output device.

[0164] The program code used to implement the methods of this application may be written in any combination of one or more programming languages. This program code may be provided to a processor or controller of a general-purpose computer, special-purpose computer, or other programmable data processing device, such that when executed by the processor or controller, the functions / operations specified in the flowcharts and / or block diagrams are implemented. The program code may be executed entirely on a machine, partially on a machine, as a standalone software package partially on a machine and partially on a remote machine, or entirely on a remote machine or server.

[0165] In the context of this application, a machine-readable medium can be a tangible medium that may contain or store a program for use by or in conjunction with an instruction execution system, apparatus, or device. A machine-readable medium can be a machine-readable signal medium or a machine-readable storage medium. Machine-readable media can be, but is not limited to, electronic, magnetic, optical, electromagnetic, infrared, or semiconductor systems, apparatus, or devices, or any suitable combination of the foregoing. More specific examples of machine-readable storage media include electrical connections based on one or more wires, portable computer disks, hard disks, random access memory (RAM), read-only memory (ROM), erasable programmable read-only memory (EPROM or flash memory), optical fibers, portable compact disk read-only memory (CD-ROM), optical storage devices, magnetic storage devices, or any suitable combination of the foregoing.

[0166] To provide interaction with a user, the systems and techniques described herein can be implemented on a computer having: a display device for displaying information to the user (e.g., a CRT (cathode ray tube) or LCD (liquid crystal display) monitor); and a keyboard and pointing device (e.g., a mouse or trackball) through which the user provides input to the computer. Other types of devices can also be used to provide interaction with the user; for example, feedback provided to the user can be any form of sensory feedback (e.g., visual feedback, auditory feedback, or tactile feedback); and input from the user can be received in any form (including sound input, voice input, or tactile input).

[0167] The systems and technologies described herein can be implemented in computing systems that include backend components (e.g., as a data server), or computing systems that include middleware components (e.g., an application server), or computing systems that include frontend components (e.g., a user computer with a graphical user interface or web browser through which a user can interact with implementations of the systems and technologies described herein), or any combination of such backend, middleware, or frontend components. The components of the system can be interconnected via digital data communication of any form or medium (e.g., a communication network). Examples of communication networks include local area networks (LANs), wide area networks (WANs), and the Internet.

[0168] Computer systems can include clients and servers. Clients and servers are generally located far apart and typically interact via communication networks. Client-server relationships are created by computer programs running on the respective computers and having a client-server relationship with each other. Servers can be cloud servers, servers in distributed systems, or servers incorporating blockchain technology.

[0169] It should be understood that the various forms of processes shown above can be used to rearrange, add, or delete steps. For example, the steps described in this invention disclosure can be executed in parallel, sequentially, or in different orders, as long as the desired result of the technical solution disclosed in this application can be achieved, and this is not limited herein.

[0170] The specific embodiments described above do not constitute a limitation on the scope of protection of this application. Those skilled in the art should understand that various modifications, combinations, sub-combinations, and substitutions can be made according to design requirements and other factors. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of this application should be included within the scope of protection of this application.

Claims

1. A method for correcting a differential absorption lidar, characterized in that, The method includes: The echo signal intensity curves and the first beam divergence diagram of the lidar to be processed are obtained for multiple angular intervals; the multiple angular intervals include a first angular interval and multiple second angular intervals, the echo signal intensity curves include the echo signal intensity curves of the emitted beams of at least two wavelengths, and the first beam divergence diagram is a reference beam divergence diagram. For each wavelength of the emitted beam, the following operations are performed: determine the first height corresponding to the echo signal intensity curve of the first angular interval and the second height corresponding to the echo signal intensity curve of each second angular interval; Based on the first height and the angle interval corresponding to the first height, each second height and the angle interval corresponding to each second height, a second beam divergence pattern is generated using a preset generation algorithm; Based on the first beam divergence pattern and the second beam divergence pattern, the lidar to be processed is corrected.

2. The method according to claim 1, characterized in that, The acquisition of echo signal intensity curves for multiple angular intervals of the lidar to be processed includes: Using a triangulation measuring tool, the echo signal intensity values ​​and corresponding detection heights of multiple angular intervals of at least two wavelengths of emitted beams are obtained; For each wavelength of the emitted beam, the following operation is performed: based on the echo signal intensity value of each angle interval and the corresponding detection height, echo signal intensity curves for multiple angle intervals are obtained.

3. The method according to claim 1, characterized in that, The determination of the first height corresponding to the echo signal intensity curve of the first angle interval and the second height corresponding to the echo signal intensity curve of each second angle interval includes: Based on the echo signal intensity curve of the first angle interval, the detection height corresponding to the maximum value of the first echo signal intensity is obtained; The detection height corresponding to the maximum value of the first echo signal intensity is determined as the first height; Based on the echo signal intensity curve of each second angle interval, the detection height corresponding to the maximum value of each second echo signal intensity is obtained; The detection height corresponding to the maximum value of each second echo signal intensity is determined as the second height.

4. The method according to claim 1, characterized in that, The step of generating a second beam divergence pattern based on the first height and the angle interval corresponding to the first height, each second height and the angle interval corresponding to each second height, using a preset generation algorithm, includes: Based on the first height and each second height, multiple radial values ​​are obtained; Based on the angle range corresponding to the first height, each radial value, and the angle range corresponding to each second height, determine the angle corresponding to each radial value; A second beam divergence pattern is generated based on each radial value and the angle corresponding to each radial value.

5. The method according to claim 1, characterized in that, Based on the first beam divergence pattern and the second beam divergence pattern, the lidar to be processed is corrected, including: The first beam divergence pattern and the second beam divergence pattern are compared. If the result of the comparison process does not meet the preset matching conditions, a correction strategy is determined based on the first beam divergence pattern and the second beam divergence pattern. Based on the aforementioned correction strategy, the lidar to be processed is corrected until the comparison result of the corrected lidar meets the preset matching conditions.

6. The method according to claim 5, characterized in that, The first beam divergence pattern includes a first beam curve and a first beam curve area, and the second beam divergence pattern includes a second beam curve and a second beam curve area. A comparison process is performed between the first beam divergence pattern and the second beam divergence pattern, including: Based on the first beam divergence diagram, the first beam curve and the area of ​​the first beam curve for each wavelength of the emitted beam are obtained. Based on the second beam divergence pattern, the second beam curve and the area of ​​the second beam curve for each wavelength of the emitted beam are obtained. Based on the first beam curve and the second beam curve of the emitted beam for each wavelength, the correlation coefficient of the first beam curve and the second beam curve of the emitted beam for each wavelength is calculated using a preset correlation algorithm. Based on the area of ​​the first beam curve and the area of ​​the second beam curve, the area ratio of the area of ​​the first beam curve and the area of ​​the second beam curve for each wavelength of the emitted beam is calculated respectively. The comparison process results are obtained based on the correlation coefficient and area ratio of the emitted beam at each wavelength.

7. A device for differential absorption lidar correction, characterized in that, The device includes: The acquisition unit is used to acquire echo signal intensity curves and a first beam divergence diagram of multiple angle intervals of the lidar to be processed; the multiple angle intervals include a first angle interval and multiple second angle intervals, the echo signal intensity curves include echo signal intensity curves of at least two wavelengths of emitted beams, and the first beam divergence diagram is a reference beam divergence diagram. The determining unit is used to perform the following operations for the emitted beam of each wavelength: determining a first height corresponding to the echo signal intensity curve of a first angle interval and a second height corresponding to the echo signal intensity curve of each second angle interval; The generation unit is used to generate a second beam divergence pattern based on the first height and the angle interval corresponding to the first height, each second height and the angle interval corresponding to each second height, using a preset generation algorithm. The correction unit is used to perform correction processing on the lidar to be processed based on the first beam divergence pattern and the second beam divergence pattern.

8. An electronic device, comprising: At least one processor; as well as A memory communicatively connected to the at least one processor; wherein, The memory stores instructions executable by the at least one processor, which, when executed by the at least one processor, enables the at least one processor to perform the method according to any one of claims 1 to 6.

9. A non-transitory computer-readable storage medium storing computer instructions, wherein, The computer instructions are used to cause the computer to perform the method according to any one of claims 1 to 6.

10. A computer program product comprising a computer program that, when executed by a processor, implements the method according to any one of claims 1-6.

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