A time delay interferometry based absolute distance measurement method and apparatus

Abstract

The application belongs to the field of laser ranging, and particularly relates to an absolute distance measurement method and device based on time delay interference, which comprises the following steps: introducing an arbitrary light source, first injecting a frequency modulation signal into the light source to prepare a frequency period jitter modulation note, then splitting the light with period jitter and injecting different frequencies, which are used to form heterodyne interference, one of the lights is used as reference light, the other light is processed twice by time delay, the reference light and the light processed by time delay are combined to realize twice heterodyne interference, and the first time delay processing contains distance information to be measured. The application uses the frequency period jitter modulation note of heterodyne interference light, combines the time delay interference method, calculates the time delay time, and calculates the absolute distance information contained in the time delay time, realizes low-cost and large-scale absolute distance measurement, and realizes the time delay interference algorithm, and the ranging reliability is high.

Description

TECHNICAL FIELD

[0001] The present application belongs to the field of laser ranging, and more particularly relates to an absolute distance measurement method and device based on time delay interference. BACKGROUND

[0002] High-precision absolute distance measurement has played an important role in scientific research and engineering practice, and directly determines the position of a country in the fields of equipment manufacturing, space science, large scientific devices, and metrology. For example, in equipment manufacturing, high-precision ranging technology is needed to provide real-time spatial coordinate information for digital docking assembly of large aircraft. In space science, real-time distance information between satellites is needed for space gravitational wave detection programs. In large scientific devices, a spherical radio telescope is composed of 4450 reflective panels, and the manufacture and assembly of large-diameter mirrors require accurate measurement of the size of the reflective panels. As can be seen, among various distance measurement methods, laser distance measurement has become an indispensable important measurement means in many industries due to its high precision, large scale, and good universality.

[0003] Methods of laser distance measurement can be divided into two categories: incremental distance measurement and absolute distance measurement. Incremental distance measurement relies on a continuous wave light source to measure the continuous movement of a mirror along the direction of outgoing measurement light, thereby obtaining the change in distance. During the entire measurement process, a photodetector needs to continuously receive the echo signal of the measurement mirror, and once the light is interrupted, the measurement needs to be restarted from the starting position. However, in many practical application scenarios, such as stepped platforms, it is difficult to ensure that the echo signal of the measurement mirror is uninterrupted. Absolute distance measurement technology can solve this problem and directly obtain the distance information between the reference mirror and the measurement mirror.

[0004] Existing laser absolute distance measurement techniques can be divided into two categories: one is absolute distance measurement based on pulsed light, and the other is absolute distance measurement based on continuous light. Absolute distance measurement based on pulsed light measures the time of flight of light pulses to achieve absolute distance measurement, which can achieve large-scale distance measurement but has low precision. Absolute distance measurement based on optical comb can achieve large-scale and high-precision absolute distance measurement, but traditional optical comb light sources are expensive and bulky, making it difficult to meet the needs of large-scale industrial site measurement. The main principle of absolute distance measurement based on continuous light is frequency-modulated continuous wave interference, which modulates the optical frequency of a tunable laser, then measures the real-time beat frequency of the reference light and the returned light, and then realizes absolute distance measurement. However, the frequency-modulated continuous wave distance measurement method requires a wideband tunable laser source, which is expensive, and requires high linearity of optical frequency scanning.

[0005] Therefore, it is of great significance to study a low-cost distance measurement method suitable for large scales. SUMMARY

[0006] In view of the defects of the prior art and the demand for improvement, the present application provides an absolute distance measurement device based on time delay interference, which aims to realize large-scale absolute distance measurement by using an arbitrary continuous wave light source with low cost.

[0007] To achieve the above-mentioned purpose, according to one aspect of the present application, an absolute distance measurement method based on time delay interference is provided, comprising:

[0008] A signal source is used to generate signal light, a frequency modulation signal is injected into the signal light, so that the signal light is periodically dithered at a center frequency, and a modulated note with periodic dithering is generated;

[0009] The signal light with periodic dithering is divided into two beams and injected into different frequencies, obtaining two beams of light with different center frequencies; one of the beams is introduced with a time delay t1 relative to the other beam and divided into a first time delay light and a measurement light; at the same time, the other beam is divided into a reference light;

[0010] The first time delay light is combined with one of the reference lights to form a first heterodyne interference light; at the same time, the measurement light is controlled to pass through a circulator and a collimator, and then pass through a distance L1 to be measured to reach a measurement mirror, and is reflected back to the collimator and the circulator, and a second time delay light is output from the circulator, which is combined with the other reference light to form a second heterodyne interference light, the second time delay light is delayed by t1+2*L1 / c relative to the other reference light; the measurement mirror is installed on the object to be measured;

[0011] The actual frequency periodic dithering modulated note data of the first heterodyne interference light and the second heterodyne interference light is detected and collected; time delay interference algorithm is used to perform data translation on two modulated note data in time dimension, and the difference value of the two modulated note data before and after translation is calculated, and the minimum value of the difference value at each sampling point is taken as the target to determine the translation time of each modulated note data, which is taken as the delay time t1 of the first time delay light and the delay time t1+2*L1 / c of the second time delay light, and the distance L1 to be measured is calculated.

[0012] The present application also provides an absolute distance measurement device based on time delay interference, comprising: a laser source, a first acousto-optic modulator, a first beam splitter, a second acousto-optic modulator, a third acousto-optic modulator, an optical fiber, a second beam splitter, a third beam splitter, a first combiner, a first photodetector, a circulator, a collimator, a measurement mirror, a second combiner, a second photodetector, an oscilloscope and a processor; the measurement mirror is installed on the object to be measured, and the distance to be measured is the distance from the object to be measured to the collimator;

[0013] The laser source is used to generate signal light; the first acousto-optic modulator is used to inject a frequency modulation signal into the signal light, so that the signal light is periodically jittered at a center frequency, generating a modulation note with a periodically jittered frequency; the first beam splitter is used to split the periodically jittered signal light into two beams; the second acousto-optic modulator and the third acousto-optic modulator are used to inject different frequencies into the two beams of light split by the first beam splitter respectively, obtaining two beams of light with different center frequencies; the optical fiber is connected to the second acousto-optic modulator, used to transmit a beam of light modulated and output by the second acousto-optic modulator, so as to introduce a time delay t1 relative to a beam of light modulated and output by the third acousto-optic modulator, and the second beam splitter is used to split the beam of light output by the optical fiber, serving as a first time-delayed light and a measurement light respectively; the third beam splitter is used to split the light modulated and output by the third acousto-optic modulator, both serving as reference light.

[0014] The first beam combiner is used to combine the first time-delayed light with one of the beams of reference light, forming a first heterodyne interference light, which is detected by the first photodetector; the measurement light passes through the circulator and the collimator, and then passes through the distance L1 to be measured to reach the measurement mirror, is reflected back to the collimator and the circulator by the measurement mirror, and the second time-delayed light is output by the circulator, and the second beam combiner is used to combine the second time-delayed light with the other beam of reference light, forming a second heterodyne interference light, which is detected by the second photodetector, and the second time-delayed light is delayed by t1+2*L1 / c relative to the other beam of reference light.

[0015] The oscilloscope is used to detect and collect modulation note data of actual frequency periodic jitter of the first heterodyne interference light and the second heterodyne interference light; and the processor is used to perform data translation on the two modulation note data in the time dimension respectively by using a time delay interference algorithm, calculate the difference values of the two modulation note data before and after translation, and determine the translation time of each modulation note data as the delay time t1 of the first time-delayed light and the delay time t1+2*L1 / c of the second time-delayed light, so as to calculate the distance L1 to be measured.

[0016] Further, the sampling frequency of the oscilloscope is 1GHz-50GHz, and the sampling time is 200us to 1ms.

[0017] Further, the oscilloscope uses the same external clock reference as the first acousto-optic modulator, the second acousto-optic modulator and the third acousto-optic modulator.

[0018] Further, the modulation frequency of the frequency modulation signal injected by the first acousto-optic modulator into the signal light is between 10kHz and 50kHz, and the generated periodic jitter frequency is less than half of the smaller one of the first heterodyne interference light frequency and the second heterodyne interference light frequency.

[0019] Further, the heterodyne frequency of the first heterodyne interference light and the second heterodyne interference light is between 10MHz and 20MHz.

[0020] Further, the length of the optical fiber is between 10km and 100km.

[0021] Overall, the above technical solutions conceived by the present application can achieve the following beneficial effects:

[0022] (1) The present application first injects a frequency modulation signal into an arbitrary light source to prepare a frequency period jitter modulation note p(t), then splits and injects different frequencies, one beam of light as reference light, the other beam of light is processed twice, and the reference light and the delayed light are combined to realize twice heterodyne interference, and the frequency period jitter modulation note of the heterodyne interference light is combined with the time delay interference method to complete low-cost and large-scale absolute distance measurement, realize the practicality of the time delay interference algorithm, and has high reliability.

[0023] (2) The present embodiment also proposes an absolute distance measurement device, which can realize the absolute distance measurement method proposed by the present application; in addition, based on the device, the calibration and evaluation of the method are realized by changing the absolute distance, and the reliability of the method of the present application is verified. BRIEF DESCRIPTION OF DRAWINGS

[0024] Figure 1 A flow chart of an absolute distance measurement method based on time delay interference is provided for the embodiment of the present application;

[0025] Figure 2 A schematic diagram of an absolute distance measurement device based on time delay interference is provided for the embodiment of the present application;

[0026] Figure 3 A measurement precision calibration diagram is provided for the embodiment of the present application.

[0027] In all the drawings, the same reference signs are used to represent the same elements or structures, wherein:

[0028] 1 is a first acousto-optic modulator, 2 is a first beam splitter, 3 is a second acousto-optic modulator, 4 is a third acousto-optic modulator, 5 is an optical fiber, 6 is a second beam splitter, 7 is a circulator, 8 is a collimator, 9 is a measurement mirror, 10 is a third beam splitter, 11 is a first beam combiner, 12 is a first photodetector, 13 is a second beam combiner, 14 is a second photodetector, and 15 is an oscilloscope. DETAILED DESCRIPTION

[0029] In order to make the purpose, technical scheme and advantages of the present application more clear, the present application is further described in detail below in combination with the drawings and examples. It should be understood that the specific examples described herein are only used to explain the present application and do not limit the present application. In addition, the technical features involved in each embodiment of the present application described below can be combined with each other as long as they do not conflict with each other.

[0030] Embodiment one

[0031] An absolute distance measurement method based on time delay interference, as shown in Figure 1 , comprises:

[0032] A laser source is used to generate signal light, a frequency modulation signal is injected into the signal light, so that the signal light is periodically dithered at the center frequency to generate a frequency periodic dithering modulation note p(t);

[0033] The periodically dithered signal light is divided into two beams and injected into different frequencies to obtain two beams of light with different center frequencies; one of the beams is introduced into a time delay t1 relative to the other beam and divided into a first time delay light and a measurement light, and the corresponding frequency periodic dithering modulation notes are both p(t-t1); at the same time, the other beam is divided into a reference light;

[0034] The first time delay light and one of the reference lights are combined to form a first heterodyne interference light, and the frequency periodic dithering modulation note of the first heterodyne interference light is p(t)-p(t-t1); at the same time, the measurement light is controlled to pass through a circulator, a collimator and a distance to be measured L1, and then reaches a measurement mirror, and is reflected back to the collimator and the circulator, and the second time delay light is output from the circulator, and the second time delay light is combined with the other reference light to form a second heterodyne interference light; wherein the frequency periodic dithering modulation note of the second time delay light is p(t-t1-2*L1 / c), and the frequency periodic dithering adjustment note of the second heterodyne interference light is p(t)-p(t-t1-2*L1 / c); the measurement mirror is installed on the object to be measured;

[0035] The actual frequency periodic dithering modulation note data of the first heterodyne interference light and the second heterodyne interference light is detected and collected; time delay interference algorithm is used to perform data translation on the two modulation note data in the time dimension, and the difference values of the two modulation note data before and after translation are calculated, and the minimum value of the difference values at each sampling point is taken as the target to determine the translation time of each modulation note data, which corresponds to the delay time t1 of the first time delay light and the delay time t1+2*L1 / c of the second time delay light, and the distance to be measured L1 is calculated.

[0036] This embodiment uses an arbitrary light source, performs acousto-optic modulation and two delay processes, performs two heterodyne interference processes, collects two heterodyne interference lights, and uses the frequency periodic jitter of the heterodyne interference lights as modulation notes. Combined with the interferometry and time-of-flight method, and utilizing the time delay interferometry method, it completes low-cost, large-scale absolute distance measurement.

[0037] Specifically, in determining the shift time of each modulated note data, the interference signal is acquired using a high-speed oscilloscope. Then, the first and second interference signals are bandpass filtered at a frequency equal to the frequency of the periodically jittering modulated note. The two filtered data are then shifted, and the variance of the deviation between each sampling point is calculated. The variance is minimized when the shift time is equal to the delay time of the first and second time-delayed light, respectively. The distance to be measured is determined based on the delay time, as follows:

[0038] The modulation note of the frequency periodic jitter of the first heterodyne interference light is: p(t)-p(t-t1). If it is shifted by time t2, the frequency jitter of the first interference light after shifting is: p(t-t2)-p(t-t1-t2).

[0039] The modulation note of the frequency period jitter of the second heterodyne interference light is: p(t)-p(t-t1-2*L2 / c). If it is shifted by time t3, the frequency jitter of the second interference light after shifting is: p(t-t3)-p(t-t1-2*L1 / c-t3).

[0040] Subtracting the second heterodyne interference frequency jitter from the first heterodyne interference frequency jitter yields the first time delay processing data: [p(t)-p(t-t1)]-[p(t)-p(t-t1-2*L1 / c)]

[0041] Subtracting the jitter of the second heterodyne interference light after shifting the first heterodyne interference light frequency jitter yields the second time delay processing data: [p(t-t2)-p(t-t1-t2)]-[p(t-t3)-p(t-t1-2*L1 / c-t3)].

[0042] Subtracting the second time-delayed data from the first time-delayed data yields the third time-delayed data:

[0043] X = [p(t) - p(t - t1)] - [p(t) - p(t - t1 - 2 * L1 / c)] - [p(t - t2) - p(t - t1 - t2)] - [p(t - t3) - p(t - t1 - 2 * L1 / c - t3)]. Calculate the variance of the data processed with the third time delay:

[0044] σ 2 =var(X)

[0045] When t2=t1+2*L1 / c and t3=t1, the variance of the third time-delayed processing data is minimum:

[0046] σ 2 =0

[0047] Therefore, time search is performed on t2 and t3, and when the minimum variance is found, the above t2 minus t3 can obtain the distance to be measured:

[0048] L1=(t2-t3)*c / 2

[0049] Based on the method of the embodiment, the device as Figure 2 described is proposed, and the method reliability verification is performed, as follows:

[0050] As Figure 2As shown, a distance measuring device is given, which comprises a light source, a first acousto-optic modulator 1, a first beam splitter 2, a second acousto-optic modulator 3, a third acousto-optic modulator 4, a long distance optical fiber 5, a second beam splitter 6, a circulator 7, a collimator 8, a measurement mirror 9, a third beam splitter 10, a first beam combiner 11, a first photodetector 12, a second beam combiner 13, a second photodetector 14 and a high-speed oscilloscope 15. Among them, the signal light emitted by the light source passes through the first acousto-optic modulator 1, and a signal source injects a frequency modulation signal into the signal light through the first acousto-optic modulator 1, so that the signal light periodically dithers at the center frequency to generate a frequency periodically dithering modulation note p(t) (signal preparation), then the signal light with periodic dithering passes through the first beam splitter 2 to be divided into two beams, and the two beams of light pass through the second acousto-optic modulator 3 and the third acousto-optic modulator 4 respectively, and different frequencies are injected at the second acousto-optic modulator 3 and the third acousto-optic modulator 4 to obtain two beams of light with different center frequencies, which facilitates the formation of heterodyne interference at the photodetectors 12 and 14. The light passing through the second acousto-optic modulator 3 passes through the long distance optical fiber 5 again, and introduces a time delay t1 of the optical fiber length relative to the light passing through the acousto-optic modulator 4, and the light passing through the optical fiber enters the second beam splitter 6 to be divided into two beams, and since both beams have introduced a delay t1 by passing through the long distance optical fiber, the frequency periodically dithering modulation note becomes p(t-t1), one of which enters the beam combiner 11 as the first time delay light, and the other passes through the circulator 7 and the collimator 8 to become the measurement light. The measurement light passes through the collimator 8 and reaches the measurement mirror 9 after passing through the distance to be measured L1, and then is reflected by the measurement mirror 9 back to the collimator 8 and the circulator 7 to form the second time delay light, and the frequency periodically dithering modulation note of the second time delay light is p(t-t1-2*L1 / c). The other beam of light divided by the first beam splitter 2 serves as the reference light, and after the modulation of the reference light by the third acousto-optic modulator 4, the reference light is divided into two beams of reference light by the third beam splitter 10. Since the reference light does not pass through the long optical fiber 5, the frequency periodically dithering modulation note of the reference light is p(t). One of the two beams of reference light and the first time delay light enters the first beam combiner 11 to form the first heterodyne interference light, and the frequency periodically dithering modulation note of the first heterodyne interference light is p(t)-p(t-t1). The first heterodyne interference light enters the first photodetector 12, and the other beam of reference light divided by the third beam splitter 10 and the second time delay light enter the second beam combiner 13 to form the second heterodyne interference light, and the frequency periodically dithering modulation note of the second heterodyne interference light is p(t)-p(t-t1-2*L1 / c). The second heterodyne interference light enters the second photodetector 14, and the high-speed oscilloscope 15 simultaneously collects the frequency periodically dithering modulation note of the first heterodyne interference light and the frequency periodically dithering modulation note of the second heterodyne interference light. After calculation, the time delay t1 and L1 / c are obtained, and the distance to be measured L1 is determined accordingly.

[0051] The frequency modulation signal injected by the first acousto-optic modulator to the signal light has a modulation frequency between 10 kHz and 50 kHz, and the generated periodic jitter frequency is less than half of the smaller one of the first heterodyne interference light frequency and the second heterodyne interference light frequency, so as to prevent the modulation frequency from aliasing the heterodyne interference frequency. The heterodyne frequency of the first heterodyne interference light and the second heterodyne interference light is between 10 MHz and 20 MHz, which is mainly limited by the bandwidth of the acousto-optic modulator.

[0052] The long-distance optical fiber has a length between 10 km and 100 km. If the distance is too long, the light loss is large, and if the distance is too short, the delay is not long enough.

[0053] The high-speed oscilloscope uses the same external clock reference as the first acousto-optic modulator, the second acousto-optic modulator, and the third acousto-optic modulator. The sampling frequency of the high-speed oscilloscope is between 1 GHz and 50 GHz, and the sampling time is between 200 us and 1 ms. The higher the sampling rate, the higher the ranging accuracy. The sampling time needs to be moderate. Too short sampling time cannot collect complete modulation notes, and too long sampling time increases the calculation complexity.

[0054] The method of embodiment one is executed by using the device to realize absolute distance measurement of the measured object from the collimator. By translating the measurement mirror, the absolute distance of the measured object from the collimator is changed, and the absolute distance measurement method of the present embodiment is re-executed to obtain the measurement distance of the measurement mirror from the collimator at each position, thereby evaluating the reliability of the method of the present embodiment. The related verification data are shown in Figure 3 Figure 3 The abscissa shows the reference step length of the displacement table driving the movement of the measurement mirror. The measurement mirror moves 0.2±0.00001 m each time and stays for a period of time. Then at least 5 groups of data are measured by using the absolute distance measurement method of the present embodiment. The ordinate shows the mean value and error of the distance measurement of the present method relative to the reference step length. The results show that the distance measurement accuracy of the present method is better than 0.1 m.

[0055] Those skilled in the art will readily understand that the above description is only a preferred embodiment of the present application and is not intended to limit the present application. Any modification, equivalent replacement, and improvement made within the spirit and principle of the present application shall be included in the protection scope of the present application.​

Claims

1. A method of absolute distance measurement based on time delay interferometry, characterized in that, The application relates to a frequency-modulated continuous wave (FMCW) laser radar system. The signal light is divided into two beams, and different frequencies are injected into the two beams to obtain two beams of light with different center frequencies; one of the two beams of light is introduced into a time delay t1 relative to the other beam of light through a long-distance optical fiber and is divided into a first time-delayed light and a measurement light; meanwhile, the other beam of light is divided into a reference light. The application relates to a frequency-modulated continuous wave (FMCW) laser radar system. The first time-delayed light is combined with one of the reference lights to form first heterodyne interference light; meanwhile, the measurement light passes through a circulator and a collimator and then passes through the distance L1 to be measured to reach a measurement mirror, is reflected by the measurement mirror back to the collimator and the circulator, and the second time-delayed light is output by the circulator, the second time-delayed light is combined with the other reference light to form second heterodyne interference light, and the second time-delayed light is delayed by t1+2 relative to the other reference light L1 / c; the measurement mirror is installed on the object to be measured The modulation pitch data of actual frequency period jitter of the first heterodyne interference light and the second heterodyne interference light is collected; time delay interference algorithm is used to perform data shift on two modulation pitch data in time dimension respectively, the difference value of two modulation pitch data before and after corresponding shift is calculated, and the shift time of each modulation pitch data is determined as the delay time t1 of the first time delay light and the delay time t1+2 of the second time delay light, with the minimum value of variance of the difference value at each sampling point as the target L1 / c, and the distance to be measured L1 is calculated.

2. An absolute distance measuring device based on time delay interferometry, characterized in that The application relates to a frequency-modulated continuous wave (FMCW) laser radar system. The application relates to a frequency-modulated continuous wave (FMCW) laser radar system. The application relates to a frequency-modulated continuous wave (FMCW) laser radar system. The application relates to a frequency-modulated continuous wave (FMCW) laser radar system. The first beam combiner is configured to combine the first time-delayed light with one of the reference lights to form first heterodyne interference light, which is detected by the first photodetector; the measurement light passes through the circulator and the collimator, and then passes through the distance L1 to be measured to reach the measurement mirror, is reflected by the measurement mirror to the collimator and the circulator, and is output by the circulator as second time-delayed light; the second beam combiner is configured to combine the second time-delayed light with the other reference light to form second heterodyne interference light, which is detected by the second photodetector; and the second time-delayed light is delayed by t1+2 relative to the other reference light. L1 / c; The application relates to a frequency-modulated continuous wave (FMCW) laser radar system. The processor is configured to perform data translation on the two modulation tone data in a time dimension respectively by using a time delay interference algorithm, calculate a difference value of the two modulation tone data before and after translation, and determine a translation time of each modulation tone data by taking a minimum value of a variance of the difference value at each sampling point as a target, which corresponds to a delay time t1 of the first time delay light and a delay time t1+2 of the second time delay light. L1 / c, and the distance to be measured L1 is calculated.

3. The absolute distance measuring device according to claim 2, characterized in that The application relates to a frequency-modulated continuous wave (FMCW) laser radar system.

4. The absolute distance measuring device according to claim 2, characterized in that The application relates to a frequency-modulated continuous wave (FMCW) laser radar system.

5. The absolute distance measuring device according to claim 2, characterized in that The application relates to a frequency-modulated continuous wave (FMCW) laser radar system.

6. The absolute distance measuring device according to claim 5, characterized in that The application relates to a frequency-modulated continuous wave (FMCW) laser radar system.

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The application relates to a frequency-modulated continuous wave (FMCW) laser radar system. The application relates to a frequency-modulated continuous wave (FMCW) laser radar system. The application relates to a frequency-modulated continuous wave (FMCW) laser radar system. The application relates to a frequency-modulated continuous wave (FMCW) laser radar system. The application relates to a frequency-modulated continuous wave (FMCW) laser radar system. The application relates to a frequency-modulated continuous wave (FMCW) laser radar system. The application relates to a frequency-modulated continuous wave (FMCW) laser radar system. The application relates to a frequency-modulated continuous wave (FMCW) laser radar system. The application relates to a frequency-modulated continuous wave (FMCW) laser radar system. The application relates to a frequency-modulated continuous wave (FMCW) laser radar system. The application relates to a frequency-modulated continuous wave (FMCW) laser radar system. The application relates to a frequency-modulated continuous wave (FMCW) laser radar system. The application relates to a frequency-modulated continuous wave (FMCW) laser radar system. The application relates to a frequency-modulated continuous wave (FMCW) laser radar system. The application relates to a frequency-modulated continuous wave (FMCW) laser radar system. The application relates to a frequency-modulated continuous wave (FMCW) laser radar system. The application relates to a frequency-modulated continuous wave (FMCW) laser radar system. The application relates to a frequency-modulated continuous wave (FMCW) laser radar system. The application relates to a frequency-modulated continuous wave (FMCW) laser radar system. The application relates to a frequency-modulated continuous wave (FMCW) laser radar system. The application relates to a frequency-modulated continuous wave (FMCW) laser radar system. The application relates to a frequency-modulated continuous wave (FMCW) laser radar system. The application relates to a frequency-modulated continuous wave (FMCW) laser radar system. The application relates to a frequency-modulated continuous wave (FMCW) laser radar system. The application relates to a frequency-modulated continuous wave (FMCW) laser radar system. The application relates to a frequency-modulated continuous wave (FMCW) laser radar system. The application relates to a frequency-modulated continuous wave (FMCW) laser radar system. The application relates to a frequency-modulated continuous wave (FMCW) laser radar system. The application relates to a frequency-modulated continuous wave (FMCW) laser radar system. The application relates to a frequency-modulated continuous wave (FMCW) laser radar system. The application relates to a frequency-modulated continuous wave (FMCW) laser radar system. The application relates to a frequency-modulated continuous wave (FMCW) laser radar system. The application relates to a frequency-modulated continuous wave (FMCW) laser radar system. The application relates to a frequency-modulated continuous wave (FMCW) laser radar system. The application relates to a frequency-modulated continuous wave (FMCW) laser radar system. The application relates to a frequency-modulated continuous wave (FMCW) laser radar system. The application relates to a frequency-modulated continuous wave (FMCW) laser radar system. The application relates to a frequency-modulated continuous wave (FMCW) laser radar system. The application relates to a frequency-modulated continuous wave (FMCW) laser radar system. The application relates to a frequency-modulated continuous wave (FMCW) laser radar system. The application relates to a frequency-modulated continuous wave (FMCW) laser radar system. The application relates to a frequency-modulated continuous wave (FMCW) laser radar system. The application relates to a frequency-modulated continuous wave (FMCW) laser radar system. The application relates to a

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