Method for judging distance square correction signal of laser radar background noise
By deducting background noises of different sizes from the lidar echo signal, comparing the signal shape, and determining the true value of the background noise of the lidar background noise in the prior art, the problem of background noise affecting data quality is solved, and the accuracy and reliability of lidar data are improved.
Patent Information
- Application Number
- CN202510399923.7
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-04-01
- Publication Date
- 2025-07-04
AI Technical Summary
The prior art is difficult to effectively and directly determine the exact value of lidar background noise, resulting in inaccurate data quality, especially under the influence of solar radiation background light during the day, the noise intensity significantly increases.
By collecting lidar echo signals, deducting background noise of different sizes, comparing the lidar distance square correction signal shape after deducting noise, using signal waveform changes to determine the real background noise value, and using electronic devices and computer-readable storage media to implement this method.
It realizes effective, direct and accurate judgment of lidar background noise, and improves the accuracy and reliability of data signal processing.
Smart Images
Figure CN120254818A_ABST
Abstract
Description
Technical Field
[0001] The present invention relates to the technical field of lidar atmospheric detection, and particularly relates to a method for determining a distance-squared correction signal of lidar background noise. Background Art
[0002] As an active remote sensing detection technology, lidar has been widely used in the fields of atmospheric environment monitoring, meteorological observation, target recognition, etc. Lidar background noise is an important issue affecting the quality of lidar detection data. The existence of lidar background noise brings great uncertainty errors to the inversion of lidar data, and has been affecting the data quality of lidar. Background noise is the most common type of lidar noise. Especially during daytime experimental observations, the continuous presence of background light such as solar radiation leads to a significant increase in the intensity of background noise.
[0003] How to determine the magnitude of background noise is a key step in removing noise. How to remove noise, solve the noise problem, and improve data quality have always been problems that researchers engaged in lidar detection research want to solve. The existence of noise, especially background noise, with excessive errors, leads to the distortion of echo signals and inaccurate detection data, making it difficult to ensure the "accuracy, representativeness, and reliability" of the observed data. This is also the main confusion or problem in the field of lidar atmospheric detection research. Although existing technologies have proposed various noise suppression algorithms, such as wavelet denoising, adaptive filtering, etc., their core still relies on empirical assumptions about the statistical characteristics of noise and fails to fundamentally solve the physical mechanism problem related to distance of background noise.
[0004] Therefore, there is an urgent need for a correction method based on the physical characteristics of lidar noise to establish a dynamic noise determination model to improve the accuracy of signal processing and the reliability of data inversion. Summary of the Invention
[0005] The problem to be solved by the present invention is: to provide a method for determining a distance-squared correction signal of lidar background noise, which can effectively, directly, and accurately determine the accurate value or true value of lidar background noise.
[0006] The present invention adopts the following technical solution: A method for determining a distance-squared correction signal of lidar background noise, comprising the following steps:
[0007] Step S1: Collect lidar echo signal data and generate a lidar echo signal P(r), where r represents the echo signal distance;
[0008] Step S2: Subtract background noises Δ of different magnitudes from the lidar echo signal i , and generate a lidar echo signal P(r) - Δ after subtracting different background noises i ;
[0009] Step S3: Based on the lidar echo signal data, generate the lidar distance squared correction signal P(r)r 2 ;
[0010] Step S4: Subtract background noises Δ of different magnitudes from the lidar echo signal, and generate the lidar distance squared correction signal [P(r) - Δ i , after subtracting background noises of different magnitudes i r 2 ;
[0011] Step S5: Compare the shapes of the lidar distance squared correction signals after subtracting background noises of different magnitudes to obtain the true background noise value.
[0012] Preferably, in Step S1, the lidar echo signal is: the lidar echo signal P(r) under the conditions of clean air quality, uniform atmospheric molecule distribution, no aerosol or uniform aerosol distribution.
[0013] Preferably, in Step S2, the background noises Δ of different magnitudes i , where i = 1, 2,..., N, use the signal intensity detected under different weather backgrounds by blocking the laser light source and opening the telescope skylight as the background noise.
[0014] Preferably, in Step S4, the lidar distance squared correction signal is P(r)r 2 , after subtracting background noises of different magnitudes, the lidar distance squared correction signal is expressed as [P(r) - Δ i r 2 .
[0015] Preferably, in Step S5, when comparing the shapes of the lidar distance squared correction signals after subtracting background noises of different magnitudes, the tail shape of the distance squared correction signal after subtracting background noises of different magnitudes is upturned. Different amounts of background noise subtraction result in different degrees of upturn of the tail of the distance squared correction signal: the smaller the noise subtracted, the larger the upturn amplitude of the signal tail; the larger the background noise subtracted, the smaller the upturn amplitude of the signal tail. As the background noise subtraction gradually increases, the signal tail becomes flatter as the distance increases.
[0016] Preferably, in Step S5, obtaining the true background noise value includes the following sub-steps:
[0017] Step S5.1: Establish a coordinate system with the distance r as the abscissa and the distance squared correction signal intensity as the ordinate to obtain the distance squared correction signal curve;
[0018] Step S5.2: In the distance squared correction signal curve, as the value of the subtracted background noise Δ i increases, the distance squared correction signal P(r)r2 The waveform gradually flattens as the distance r increases;
[0019] Step S5.3. When the deducted background noise Δ i reaches the maximum value, the distance-squared correction signal [P(r) - Δ i r 2 The waveform is parallel to the coordinate axis of the distance r as the distance increases, and the maximum value of the background noise is obtained;
[0020] Step S5.4. Use the maximum value of the lidar background noise as the true background noise value.
[0021] The technical solution of the present invention also provides: an electronic device, including:
[0022] One or more processors;
[0023] A storage device having one or more programs stored thereon;
[0024] When the one or more programs are executed by the one or more processors, the one or more processors implement the determination method of the distance-squared correction signal of the lidar background noise described in any one of the above.
[0025] The technical solution of the present invention also provides a computer-readable storage medium having a computer program stored thereon, and when the program is executed by a processor, the steps in the determination method of the distance-squared correction signal of the lidar background noise described in any one of the above are implemented.
[0026] Compared with the prior art, the present invention adopts the above technical solution and has the following technical effects:
[0027] The determination method of the present invention deducts background noises of different magnitudes from the lidar echo signal, and makes corresponding lidar distance-squared correction signals of different shapes. According to the differences in the waveform shapes of the lidar distance-squared correction signals after deducting different background noises, the accurate value or true value of the lidar background noise can be effectively, directly, and accurately determined. Description of the Drawings
[0028] Figure 1 It is a lidar echo signal diagram of the present invention for deducting different background noises;
[0029] Figure 2 It is a diagram of the far echo signal and background noise after amplifying the distance-squared correction signal of the present invention;
[0030] Figure 3 It is the amplification factor of the distance-squared correction signal of the present invention for the echo signal and background noise;
[0031] Figure 4Lidar distance correction signal diagram for deducting different background noises in the present invention;
[0032] Figure 5 Flowchart of background noise deduction operation for lidar echo signal in the present invention. Detailed implementation manners
[0033] To make the objectives, technical solutions and advantages of the present invention clearer, the technical solutions of the application will be further elaborated in detail below with reference to the accompanying drawings. The described embodiments are only a part of the embodiments involved in the present invention. All non-innovative embodiments made by other researchers in the field based on this embodiment fall within the protection scope of the present invention. At the same time, for the step numbers in the embodiments of the present invention, they are only set for the convenience of elaboration and explanation, and no limitation is imposed on the order between the steps. The execution order of each step in the embodiment can be adaptively adjusted according to the understanding of those skilled in the art.
[0034] In an embodiment of the present invention, through the determination method of the present invention, based on the waveform shape differences of the lidar distance squared correction signals after deducting background noises of different magnitudes, an effective determination of the true background noise value is performed.
[0035] When the lidar echo signal has very low laser energy and very poor air quality, the laser echo signals and background noises in the distance are generally very small, and it is difficult to study the fine structures of the lidar echo signals and background noises in the distance. Based on this, in this embodiment, through the lidar distance squared correction signal, the fine structures of the lidar echo signals and background noises at long-distance positions are amplified, and the fine structures of the signals and background noises are further studied.
[0036] In this embodiment, a method for determining the distance squared correction signal of lidar background noise is as Figure 5 shown, and includes the following steps:
[0037] Step S1: Based on the lidar echo signal data, generate the lidar echo signal P(r).
[0038] Step S2: Deduct background noises of different magnitudes from the lidar echo signal, and respectively generate the lidar echo signals after deducting different background noises.
[0039] Change the magnitude of the background noise to obtain different magnitudes of background noise Δ i , i = 1, 2,..., N, calculate the lidar echo signal P(r) - Δ i after deducting different background noises. After deducting the background noise, the waveform of the lidar distance squared correction signal changes, and different background noises correspond to background-deduced lidar distance squared correction signals with different shapes.
[0040] As Figure 1 shown, the deducted background noises are respectively: 0.001, 0.002, 0.003, and the lidar echo signals after deducting different background noises are respectively: Original Radar Signal, Original Signal–bg0.001, Original Signal–bg 0.002, Original Signal–bg 0.003;
[0041] By comparing the waveform shapes of the lidar echo signals after deducting different background noises, it can be seen that the waveform shapes of the echo signals after deducting the noises are very similar and it is difficult to distinguish them.
[0042] Step S3: Based on the echo signal (containing background noise) at the far distance of the lidar, make the corresponding distance-squared correction signal P(r)r 2 .
[0043] At this time, the distance-squared correction signal is much larger than the echo signal (including background noise), amplifying the fine structures of the far-distance echo signal and background noise as Figure 2 and Figure 3 shown.
[0044] Step S4: Deduct different magnitudes of background noise from the lidar echo signal, and respectively make the lidar distance-squared correction signals after deducting different background noises.
[0045] By changing the background noise of the lidar echo signal, different background noises Δ i are deducted from the lidar echo signal. Perform distance-squared correction on the lidar echo signal after deducting the background noise to obtain the lidar distance-squared correction signal [P(r)-Δ i r 2 .
[0046] Step S5: Compare the shapes of the lidar distance-squared correction signals after deducting different magnitudes of background noise. The waveform shapes of the lidar distance-squared correction signals [P(r)-Δ i r 2 are significantly different.
[0047] When the background noise gets closer and closer to the true value, the waveform of the distance-squared correction signal after deducting the background becomes flatter and flatter. When the waveform of the high-altitude part of the lidar distance-squared correction signal after deducting the background noise is close to being parallel to the horizontal coordinate axis, the background noise corresponding to the distance-squared correction signal after deducting the background at this time is the most accurate and close to the true value.
[0048] Specifically, as Figure 4As shown, the lidar distance squared correction signals after deducting different background noises are respectively: Original Signal, Original Signal-bg 0.001, Original Signal-bg 0.002, Original Signal-bg 0.003.
[0049] From Figure 4 it can be seen that the waveform of the original distance squared correction signal without deducting the background noise warps most severely as the distance increases, such as Figure 4 Original Signal in Figure 4 . The waveform of the distance squared correction signal after deducting the noise warps less as the distance increases compared to the original signal, such as Original Signal–bg 0.001, Original Signal–bg 0.002, Original Signal–bg 0.003 in
[0050] . Further, as the value of the deducted background noise gradually increases, the waveform of the distance squared correction signal becomes flatter as the distance increases. When the deducted background noise reaches the maximum value, the waveform of the distance squared correction signal after deducting the background noise becomes parallel to the distance coordinate axis as the distance increases, such as Figure 4 Original Signal–bg0.003 in
[0051] Figure 4 In this case (such as
[0052] background noise bg, the true value is 0.003), the background noise reaches the maximum value, is close to the true background noise value, and is the most accurate.
[0053] In an embodiment of the present invention, an electronic device is further provided, including: one or more processors; a storage device on which one or more programs are stored; when the one or more programs are executed by the one or more processors, the one or more processors implement the determination method of the distance squared correction signal of the lidar background noise described in any one of the above embodiments.
[0054] In an embodiment of the present invention, a computer-readable storage medium is further provided, on which a computer program is stored, and when the program is executed by a processor, the steps in the determination method of the distance squared correction signal of the lidar background noise in any one of the above embodiments are implemented.
[0055] The above are only the preferred embodiments of the present invention. It should be noted that for those of ordinary skill in the art, without departing from the principle of the present invention, several improvements and modifications can be made, and these improvements and modifications should also be regarded as the protection scope of the present invention.
Claims
1. A method for determining a distance-squared correction signal of the background noise of a lidar, characterized in that, It includes the following steps: Step S1: Collect the lidar echo signal data and generate the lidar echo signal P(r), where r represents the echo signal distance; Step S2: Subtract background noises Δ of different magnitudes from the lidar echo signal i , and generate the lidar echo signal P(r) - Δ after subtracting different background noises i ; Step S3: Based on the lidar echo signal data, generate the lidar range squared correction signal P(r)r 2 ; Step S4: Subtract background noises Δ of different magnitudes from the lidar echo signal i , and generate the lidar range squared correction signal [P(r) - Δ i r 2 ; Step S5: Compare the shapes of the lidar distance squared correction signals after subtracting background noises of different magnitudes to obtain the true background noise value.
2. The method for determining the distance-squared correction signal of the background noise of a lidar according to claim 1, characterized in that, In Step S1, the lidar echo signal is the lidar echo signal P(r) under the conditions of clean air quality, uniform distribution of atmospheric molecules, no aerosol or uniform distribution of aerosol.
3. The method for determining the distance-squared correction signal of the background noise of the lidar according to claim 1, wherein In step S2, background noises Δ of different magnitudes i , where i = 1, 2,..., N, the signal intensities detected under different weather backgrounds by blocking the laser light source and opening the telescope skylight are used as background noises.
4. The determination method of the distance-squared correction signal for the background noise of the lidar according to claim 1, wherein In step S4, the lidar distance squared correction signal is P(r)r 2 , after deducting different background noises, the lidar distance squared correction signal is expressed as [P(r) - Δ i r 2 .
5. The method for determining the distance-squared correction signal of the background noise of a lidar according to claim 4, wherein In Step S5, when comparing the shapes of the lidar distance squared correction signals after subtracting background noises of different magnitudes, the tail shapes of the distance squared correction signals after subtracting background noises of different magnitudes are upturned. With different amounts of background noise subtracted, the degree of upturn of the signal tails is different: the smaller the noise subtracted, the larger the upturn amplitude of the signal tail; the larger the background noise subtracted, the smaller the upturn amplitude of the signal tail. As the subtracted background noise gradually increases, the signal tail becomes flatter as the distance increases.
6. The method for determining the distance-squared correction signal of the background noise of a lidar according to claim 5, wherein In Step S5, obtaining the true background noise value includes the following sub-steps: Step S5.1: Establish a coordinate system with the distance r as the abscissa and the intensity of the distance squared correction signal as the ordinate to obtain the distance squared correction signal curve; Step S5.
2. In the distance squared correction signal curve, as the subtracted background noise Δ i value increases, the waveform of the distance squared correction signal P(r)r 2 gradually flattens out as the distance r increases; Step S5.
3. When the deducted background noise Δ i reaches the maximum value, the distance squared correction signal [P(r) - Δ i r 2 waveform increases with the distance and is parallel to the coordinate axis of the distance r, indicating that the background noise reaches the maximum value; Step S5.4: Take the maximum value of the lidar background noise as the true background noise value.
7. An electronic device, characterized in that, It includes: One or more processors; A storage device on which one or more programs are stored; When the one or more programs are executed by the one or more processors, the one or more processors implement the method for determining the distance squared correction signal of the lidar background noise as described in any one of Claims 1 to 6.
8. A computer-readable storage medium, characterized in that, A computer program is stored thereon, and when the program is executed by a processor, it implements the steps in the method for determining the distance squared correction signal of the lidar background noise as described in any one of Claims 1 to 6.