CN110031865B - Vegetation detection binary channels fluorescence laser radar system - Google Patents

Abstract

The invention provides a vegetation detection double-channel fluorescent laser radar system, which comprises a laser emission unit, a ranging unit, a scanning unit, a receiving detection unit and a time sequence control unit, wherein the laser emission unit emits ultraviolet laser and is used as excitation light of vegetation fluorescence and ranging laser of the ranging unit; the laser emission unit generates ultraviolet laser and emits the ultraviolet laser through the scanning unit, the receiving and detecting unit separates and outputs the ultraviolet laser echo to the ranging unit, and the receiving and detecting unit processes the fluorescent signal by itself; the receiving and detecting unit adopts an optical telescope to realize optical condensation, adopts a dichroic lens to separate ultraviolet laser echoes and transmit fluorescent signals, and respectively enters two photoelectric detectors corresponding to vegetation fluorescent characteristic wave bands through an optical beam splitting module after being coupled by a coupling optical fiber. The invention supports the synchronous acquisition of the laser point cloud space information and the fluorescence dual-channel information of the vegetation target, and completes the integrated monitoring of the vegetation space structure and the physiological state.

Description

A Dual-channel Fluorescent LiDAR System for Vegetation Detection

technical field

The invention belongs to the technical field of surveying and mapping remote sensing, in particular to a dual-channel fluorescent laser radar system for vegetation detection.

Background technique

Lidar technology has outstanding advantages in the field of earth observation, especially in the rapid detection of three-dimensional spatial structure of vegetation. Point cloud data formed by lidar echo signals can provide spatial distribution information of vegetation, but limited to a single wavelength, it is difficult to obtain the spectral characteristics of vegetation.

The application of active laser-induced fluorescence technology on vegetation can produce fluorescence characteristic peaks, and the generation of fluorescence comes from the radiative energy level transition of photosynthetic sites inside vegetation. As an important physiological activity of vegetation, photosynthesis of vegetation is closely related to its physiological state. Therefore, fluorescence can be used as an early "probe" for vegetation photosynthesis and health status, indicating the physiological status of vegetation growth, biochemical parameter stress, and pests and diseases. Monitoring the physiological and growth status of vegetation is of great significance to vegetation ecological research and precision agriculture applications.

However, the current detection and imaging of plant fluorescence signals has not been able to explain the distribution of fluorescence signals in the form of point clouds, that is, it has failed to combine the advantages of lidar spatial detection with the advantages of fluorescence spectroscopy. Through the present invention, the dual-channel fluorescent laser radar system uses ultraviolet laser light sources for vegetation detection targets, and its reflected echoes are used for space ranging, and at the same time, plant fluorescence is induced for biochemical state monitoring, realizing the dual detection mechanism of reflection ranging and laser-induced fluorescence. The system uses a single-band ultraviolet laser as the ranging light and the excitation light of vegetation fluorescence at the same time. On the basis of single-band ranging, two channels are added to receive the fluorescence characteristic peak signals of plants in the 685nm and 740nm bands, so as to realize the detection of vegetation target points. Simultaneous observation of cloud and fluorescence dual-channel characteristics, thereby realizing integrated monitoring of the spatial structure and physiological state of vegetation targets.

Contents of the invention

The purpose of the present invention is to provide a dual-channel fluorescence laser radar system for vegetation detection, which can realize the integrated monitoring of the spatial three-dimensional structure and fluorescence characteristics of vegetation targets.

In order to achieve the above object, the present invention adopts the following technical solutions:

A dual-channel fluorescent laser radar system for vegetation detection, including a laser emitting unit, a distance measuring unit, a scanning unit, a receiving detection unit, and a timing control unit, and the timing control unit is respectively connected to the laser emitting unit, the ranging unit, the scanning unit, and the receiving detection unit , the laser emitting unit emits ultraviolet laser light, which is simultaneously used as the excitation light of vegetation fluorescence and the ranging laser of the ranging unit;

The laser emitting unit generates ultraviolet laser and emits it through the scanning unit, the receiving and detecting unit separates and outputs the ultraviolet laser echo to the distance measuring unit, and the receiving and detecting unit processes the fluorescent signal by itself;

The receiving and detecting unit includes an optical telescope, a dichroic lens, a coupling fiber, an optical splitting module and a corresponding photodetector that provides dual-channel detection. The optical telescope is used to achieve optical concentration, and the dichroic lens is used to separate the ultraviolet laser echo and The transmitted fluorescence signal is coupled by the coupling fiber, and enters the photodetectors corresponding to the two vegetation fluorescence characteristic bands respectively through the optical spectroscopic module.

Moreover, the emission optical axis of the ultraviolet laser coincides with the central axis of the optical telescope in the receiving and detecting unit.

Furthermore, a rotating mirror is provided in the scanning unit.

Moreover, the rotating mirror adopts an aluminum film total reflection mirror.

Moreover, the dichroic lens is placed behind the converging port of the optical telescope and placed at an angle of 135 degrees to the central axis of the optical telescope.

Moreover, the two characteristic wavelength bands of vegetation fluorescence are 685nm and 740nm.

Moreover, the distance measuring unit is externally triggered by the timing control unit to receive the ultraviolet laser echo, and the optical telescope in the receiving and detecting unit receives and separates the ultraviolet ranging echo and outputs it to the distance measuring unit. The turntable where the rotating mirror is located rotates to realize scanning, and the distance data of the ranging unit and the scanning angle pulse of the scanning unit together constitute the three-dimensional spatial structure data of the vegetation.

Moreover, the timing control unit outputs digital pulse signals, completes distance detection, rotating mirror scanning and dual-channel detector photoelectric conversion actions in time series, and records vegetation target distance, rotating mirror movement step length and integrated intensity of dual-wavelength fluorescent signals.

The difference and effect between the present invention and the prior art are: the dual-channel fluorescence laser radar system breaks through the limitation of the single space detection capability of the traditional single-band laser radar, and simultaneously realizes the detection of the dual-wavelength fluorescence characteristics of vegetation on the basis of single-band laser ranging. Detection, using the dual detection mechanism of reflection ranging and laser-induced fluorescence, can support the simultaneous acquisition of laser point cloud spatial information and fluorescence dual-channel information of vegetation targets, and realize integrated monitoring of the spatial structure and physiological state of vegetation targets, which can be widely used in Digital surveying and mapping, vegetation remote sensing and other fields.

Description of drawings

FIG. 1 is a schematic diagram of a system structure in an embodiment of the present invention.

Fig. 2 is a schematic diagram of coaxial design of system optical paths in an embodiment of the present invention.

Fig. 3 is a schematic structural diagram of a ranging unit in an embodiment of the present invention.

Fig. 4 is a schematic diagram of the optical path design of the spectroscopic detection in the embodiment of the present invention.

Detailed ways

The technical solution of the present invention will be described in detail below in conjunction with the drawings and embodiments.

The present invention provides a dual-channel fluorescence laser radar system for vegetation detection. The laser emission unit uses a pump tunable laser to pump frequency-doubled ultraviolet laser light, and simultaneously serves as the excitation light for vegetation fluorescence and the distance measurement laser for the distance measurement unit. The system is composed of a laser emitting unit, a distance measuring unit, a scanning unit, a receiving and detecting unit and a timing control unit, similar to the existing single-channel laser radar system, but the present invention improves each unit to realize the pumping tunable laser The frequency-doubled ultraviolet laser is pumped and used as the ranging laser for the distance measurement of the ranging unit. At the same time, the ultraviolet laser is used as the excitation light to act on the vegetation to generate characteristic fluorescence based on the vegetation laser-induced fluorescence mechanism. The invention completes a vegetation detection dual-channel fluorescence laser radar system for actively imaging vegetation fluorescence point clouds through system construction, optical design and timing control. The distance measuring unit is externally triggered by the timing control unit to receive the ultraviolet laser echo. The optical telescope in the receiving detection unit receives and separates the ultraviolet ranging echo and outputs it to the distance measuring unit. The turntable rotates to realize scanning, and the distance data of the ranging unit and the scanning angle pulse of the scanning unit together constitute the three-dimensional spatial structure data of the vegetation.

Referring to FIG. 1 , the structural distribution of a dual-channel fluorescence laser radar system for vegetation detection according to an embodiment of the present invention mainly includes a laser emitting unit 1 , a scanning unit 2 , a ranging unit 3 , a receiving and detecting unit 4 and a timing control unit 5 .

As shown in FIG. 1 , the laser emitting unit 1 generates ultraviolet laser light and emits it through the scanning unit 2 , the receiving and detecting unit 4 separates and outputs the ultraviolet laser echo to the distance measuring unit 3 , and the receiving and detecting unit 4 itself processes the fluorescence signal. The timing control unit 5 is connected to the laser emitting unit 1, the scanning unit 2, the distance measuring unit 3 and the receiving and detecting unit 4 through a communication line at the same time, and scans and detects through a multi-channel timing pulse control system.

The laser emitting unit 1 includes a laser module, a frequency doubling module, a spectroscopic module, an ultraviolet high reflection mirror, a first total reflection mirror 6 and a second total reflection mirror 7 .

In an embodiment, the dual-channel fluorescent laser radar system for vegetation detection is pumped to emit ultraviolet laser light by pumping a tunable laser. The laser includes a laser module, a frequency doubling module and a light splitting module. The laser module pumps out the 1064nm fundamental frequency laser with a certain repetition frequency, and the laser with the wavelength of 532nm and 355nm is output through the frequency doubling crystal of the frequency doubling module, and then input into the spectroscopic module. The light splitting module separates the 355nm laser light source, and then further filters out the excess laser light through the ultraviolet high reflection lens. The 355nm ultraviolet laser emitted by the laser emitting unit is used as the fluorescence excitation light and the ranging laser at the same time.

The scanning unit 2 includes a rotary table, an electric control box and a rotating mirror 8 . The electric control box is connected with the rotary table, and the rotating mirror 8 is installed on the rotary table of the scanning unit, and can rotate along with the rotary table. The rotating mirror 8 preferably adopts an aluminum film total reflection mirror, which has a large receiving field of view and a wide range of reflection wavelengths. The reflectivity is less affected by wavelength and incident angle, and the reflectivity is high and cheap.

Referring to Fig. 2 , the ultraviolet laser emission optical axis of a vegetation detection dual-channel fluorescence lidar system according to an embodiment of the present invention coincides with the central axis of the optical telescope in the receiving and detecting unit, forming a coaxial design. The coaxial optical design specifically includes a first total reflection mirror 6 , a second total reflection mirror 7 , a rotating mirror 8 , an optical telescope 9 and a dichroic mirror 10 . Wherein the first total reflection lens 6 is placed at an angle of 45 degrees with the incident ultraviolet laser, the second total reflection lens 7 is placed at the center of the receiving field of view of the optical telescope of the receiving and detection unit and is at an angle of 45 degrees with the central axis of the telescope, and the rotating mirror 8 is connected with the center axis of the telescope from the first total reflection lens 7. The second total reflection lens 7 is placed at an angle of 45 degrees and the angle can be changed with the rotation of the bottom turntable. The central axis of the optical telescope 9 coincides with the optical axes of the second total reflection lens 7 to the rotating mirror 8 to form an optical coaxial, which can receive ultraviolet rays at the same time. Laser echo and vegetation fluorescence, support single-point synchronous acquisition of distance and dual-wavelength fluorescence, which can effectively improve the signal-to-noise ratio. The dichroic lens 10 is placed behind the converging port of the optical telescope 9 and placed at 135 degrees to the central axis of the optical telescope 9 .

During specific implementation, the laser emitting unit pumps and emits ultraviolet laser light, which passes through the first total reflection mirror 6 and the second total reflection mirror 7 successively at an incident angle of 45 degrees in the optical structure of the system, and also reaches the rotating mirror at an incident angle of 45 degrees. 8 centers. The turntable connected to the rotating mirror 8 receives the digital signal emitted by the timing control unit, completes the step-by-step scanning of the laser beam in both horizontal and vertical directions in space, and returns the step-length pulse signal to the system.

The ultraviolet laser is received in the vegetation scene, and the characteristic fluorescence is produced based on the laser-induced fluorescence mechanism in the photoreaction center inside the vegetation. The optical signal received by the rotating mirror 8 includes the echo of the ultraviolet excitation light and the characteristic continuum fluorescence signal of the vegetation. The rotating mirror 8 focuses on the focal plane of the mirror by reflecting and receiving the optical signal entering the field of view of the optical telescope 9 through a large field of view. At the receiving exit of the optical telescope, based on the reflection and transmission characteristics of the dichroic lens 10 in different wavelength bands, the ultraviolet laser echo signal is separated and output to the distance measuring unit, and the fluorescence continuum signal is transmitted to the coupling fiber.

The ultraviolet laser from the laser emitting unit acts on the surface of the vegetation to produce characteristic fluorescence, and the spatial transmission of the ultraviolet laser echo and fluorescence signal is not unidirectional. The backscattering of echo signals and the scattering characteristics of fluorescence are regular in spatial distribution. Echo signals in all directions will be received by the large field of view of the rotating mirror 8 and reflected into the field of view of the optical telescope 9 . The total reflection mirror 7 is just in the center of the field of view of the optical telescope 9, but the small circular field in the center of the receiving field of view on the side of the telescope is itself opaque, so placing the total reflection mirror 7 in front has no effect. The function of focusing is to facilitate fiber coupling later.

The receiving and detecting unit 4 includes an optical telescope 9 , a dichroic lens 10 , a coupling fiber, an optical splitting module and photodetectors 19 and 23 . The optical splitting module includes a first splitting filter 16 , a second splitting filter 20 , a first narrowband filter 17 , a second narrowband filter 21 , a first focusing lens 18 and a second focusing lens 22 .

Referring to Fig. 4, a receiving and detecting unit of a vegetation detection dual-channel fluorescence laser radar system according to an embodiment of the present invention includes an optical telescope 9 in Fig. 2, a dichroic lens 10, a coupling optical fiber, and an optical splitting module and a corresponding dual-channel detection Photodetector. The optical spectroscopic module comprises the first spectroscopic filter 16, the second spectroscopic filter 20, the first narrowband filter 17, the second narrowband filter 21, the first focusing lens 18 and the second focusing lens 22; The device includes a first photodetector 19 and a second photodetector 23.

The optical telescope 9 focuses on the coupling entrance of the coupling fiber, and the dichroic lens 10 is arranged between the optical telescope 9 and the coupling entrance of the coupling fiber, and the ultraviolet light echo is reflected by the dichroic lens 10 between the optical telescope 9 and the coupling fiber The output is sent to the distance measuring unit, which also prevents strong light from damaging the detector. The continuum fluorescent signal is coupled by the coupling fiber, transmitted through the first spectroscopic filter 16 and filtered into the first narrow-band filter 17 to obtain 685nm wavelength fluorescence, which enters the first photodetector 19 through the first focusing lens 18; The light reflected by a spectroscopic filter 16 enters the second spectroscopic filter 20 , reflects and enters the second narrowband filter 21 to filter out 740nm fluorescence, and enters the second photodetector 23 through the second focusing lens 22 . The first photodetector 19 and the second photodetector 23 collect and output the photoelectric analog-to-digital conversion of the two-channel single-band signal. The ranging unit 3 includes an avalanche photodiode 12, a narrowband filter 13, a high-speed collector 14 and a counter 15, wherein the avalanche photodiode 12, the high-speed collector 14 and the counter 15 are connected in sequence, and the ultraviolet laser echo is filtered by a narrowband The slice 13 is incident on the avalanche photodiode 12 . The avalanche photodiode 12 is called APD for short.

Referring to FIG. 3 , a distance measuring unit of a dual-channel fluorescence laser radar system for vegetation detection according to an embodiment of the present invention includes an avalanche photodiode 12 , a narrowband filter 13 , a high-speed collector 14 and a counter 15 . The third-party digital delay generator 11 is connected to the avalanche photodiode 12 to trigger photoelectric detection, and at the same time the avalanche photodiode 12 receives the ultraviolet light echoes separated and reflected by the dichroic mirror 10 in the detection receiving unit 4 and filtered by the narrow-band filter 13 . The avalanche photodiode 12 is connected to a high-speed collector 14 and a counter 15 to collect and record the laser pulse waveform.

Described timing control unit 5 comprises, third-party digital delay generator 11 and BNC connection, the third-party digital delay generator 11 of timing control unit outputs 4 channels TTL amplitude pulse signals by BNC connection, is connected to respectively The laser module of the laser emitting unit 1 , the electric control box of the scanning unit 2 , the avalanche photodiode 12 of the ranging unit 3 and the photodetectors 19 and 23 in the receiving and detecting unit 4 . It can be connected to the external interface of each part, output digital pulse signal, complete system distance detection, rotating mirror scanning and dual-channel detector photoelectric conversion system action in time series, and record vegetation target distance, rotating mirror movement step size and 685nm, Integrated intensity of the 740nm dual-wavelength fluorescence signal.

In the embodiment, the third-party digital delay generator 11 in the timing control unit emits a pulse signal to trigger the avalanche photodiode 12 in the ranging unit to start detection. The ultraviolet laser is emitted to the vegetation target through the system optical structure and the scanning unit, and its backscattering signal enters the receiving and detecting unit and is reflected by the dichroic mirror 10 to the distance measuring unit. The ultraviolet echo enters the avalanche photodiode 12 through the narrow-band filter 13 . The high-speed collector 14 connected to the avalanche photodiode 12 collects the photoelectric signal, and converts the time interval of the ultraviolet echo signal into distance information through the counter 15 to complete the distance measurement of a single point.

During specific implementation, the timing control unit 5 connects the laser emitting unit 1, the scanning unit 2, the distance measuring unit 3, and the receiving and detecting unit 4 to transmit digital signals to complete the purpose of controlling system actions in a certain time sequence. The timing control unit relies on a third-party digital delay generator 11 to construct multi-channel timing control, and the control system detects and records the distance of a single point in the vegetation scene and the fluorescence intensity of two channels in sequence. The third-party digital delay generator 11 of the timing control unit outputs 4 channels of TTL amplitude pulse signals to each unit through the BNC connection. When the system scans to a single point, the laser module in the laser emitting unit receives the channel 1 pulse signal to pump and frequency multiplies and splits to emit ultraviolet laser light. Channels 2 and 3 are connected to the distance measuring unit and the receiving detection unit. After a short time delay, the avalanche photodiode 12 and the photodetectors 19 and 23 simultaneously detect the ultraviolet echo signal and the fluorescence dual-channel signal respectively. Channel 4 is connected to the electric control box in the scanning unit. After another period of delay, the output pulse triggers the electric control box to control the rotation of the turntable, so that the system scans to the next point. The point-by-point distance values returned by each unit controlled by the timing control unit, the dual-channel fluorescence intensity value, and the step-length value of the stepping motion of the rotating mirror are all recorded and output to the system.

The recommended and preferred product models for each part are: the laser includes a laser module, a frequency doubling module and a light splitting module, and the preferred model is Surelite I-20. Avalanche photodiode 11 preferred part number: Thorlabs APD410A2/M. The preferred model of the high-speed collector 13: Teledyne SP Devices ADQ412. Counter 14 preferred model: National Instruments PXIe-6612. The preferred model of the photodetectors 18 and 20 is Licel SP32-200-2758. Preferred models of rotary table: Zolix Rauk100, Rauk200. The preferred model of electric control box: Zolix MC600-2B. The preferred model of the third-party digital delay generator 11 is Stanford Research Systems DG645. The preferred model of rotating mirror 8: Zolix TFAEFL-300S06-P.

The present invention can realize integrated monitoring of spatial structure and physiological state information of vegetation by adopting the above scheme, and can form fluorescence imaging of vegetation in the form and basis of point cloud. This dual-channel fluorescence lidar system for vegetation detection forms vegetation point cloud fluorescence data that integrates three-dimensional spatial features and dual-wavelength fluorescence spectral features. characterization.

The above-mentioned embodiments are only descriptions of the preferred implementation modes of the invention, and are not intended to limit the scope of the present invention. Variations and improvements should fall within the scope of protection defined by the claims of the present invention.

Claims (7)

1. The utility model provides a vegetation detection binary channels fluorescence laser radar system, includes laser emission unit, range unit, scanning unit, receives detection unit and time sequence control unit, and time sequence control unit connects laser emission unit, range unit, scanning unit and receives detection unit, its characterized in that respectively: the laser emission unit emits ultraviolet laser, and simultaneously serves as excitation light of vegetation fluorescence and ranging laser of the ranging unit, so that the reflection echo of the ultraviolet laser light source is used for space ranging, and the vegetation fluorescence is induced to be monitored in a biochemical state, and a reflection ranging and laser-induced fluorescence dual-detection mechanism is provided; on the basis of single-band ranging, two channels are added to receive fluorescence characteristic peak signals of plants in different bands, so that synchronous observation of vegetation target point cloud and fluorescence double-channel characteristics is realized, and further integrated monitoring of the spatial structure and physiological state of vegetation targets is realized;

the laser emission unit generates ultraviolet laser and emits the ultraviolet laser through the scanning unit, the receiving and detecting unit separates and outputs the ultraviolet laser echo to the ranging unit, and the receiving and detecting unit processes the fluorescent signal by itself;

the receiving and detecting unit comprises an optical telescope, a dichroic mirror, a coupling optical fiber, an optical light splitting module and a photoelectric detector for providing double-channel detection correspondingly, ultraviolet laser is received in a vegetation scene, characteristic fluorescence is generated in a vegetation internal photoreaction center based on a laser-induced fluorescence mechanism, the received optical signal comprises an ultraviolet excitation light echo and a vegetation characteristic continuous spectrum fluorescence signal, optical focusing is realized by the optical telescope, the ultraviolet laser echo is separated by the dichroic mirror and output to the ranging unit and the fluorescence signal is transmitted, and the transmitted fluorescence signal is coupled by the coupling optical fiber and then respectively enters the photoelectric detectors corresponding to two vegetation fluorescence characteristic wave bands through the optical light splitting module;

the ranging unit comprises an avalanche photodiode, a narrow-band filter, a high-speed collector and a counter, wherein the avalanche photodiode, the high-speed collector and the counter are sequentially connected, and ultraviolet laser echoes are emitted into the avalanche photodiode through the narrow-band filter;

the laser emission unit is used for pumping and emitting ultraviolet laser, sequentially passes through the first total reflection lens and the second total reflection lens at an incidence angle of 45 degrees in the optical structure of the system, and also enters the center of the rotating lens at the incidence angle of 45 degrees; the turntable connected with the turning mirror receives the digital signals transmitted by the time sequence control unit, completes the step-by-step scanning of the laser beam in two directions of space horizontal and vertical, returns step pulse signals and outputs the step pulse signals to the system;

the fluorescence characteristic wave bands of the two vegetation are 685nm and 740nm; the optical beam splitting module comprises a first beam splitting filter, a second beam splitting filter, a first narrow-band filter, a second narrow-band filter, a first focusing lens and a second focusing lens; the photoelectric detector comprises a first photoelectric detector and a second photoelectric detector;

the optical telescope is focused at the coupling entrance of the coupling optical fiber, the dichroic mirror is arranged between the optical telescope and the coupling entrance of the coupling optical fiber, the ultraviolet echo is reflected between the optical telescope and the coupling optical fiber through the dichroic mirror and output to the ranging unit, and the damage of strong light to the detector is prevented; coupling and emitting continuous spectrum fluorescent signals through a coupling optical fiber, and passing through a first light splitting filter; transmitting and entering a first narrow-band filter to obtain 685nm wavelength fluorescence, and entering a first photoelectric detector through a first focusing lens; the reflected light rays passing through the first light splitting filter are incident into the second light splitting filter to be reflected and enter the second narrow-band filter to be filtered to obtain 740nm fluorescence, the fluorescence enters the second photoelectric detector through the second focusing lens, and the first photoelectric detector and the second photoelectric detector acquire and output two-channel single-band signal photoelectric analog-to-digital conversion.

2. The vegetation detection dual channel fluorescent lidar system of claim 1, wherein: the ultraviolet laser emission optical axis coincides with the optical telescope axis in the receiving detection unit.

3. The vegetation detection dual channel fluorescent lidar system of claim 2, wherein: the scanning unit is internally provided with a turning mirror, the backscattering and fluorescence scattering characteristics of echo signals are regular in space distribution, the echo signals in all directions are received by a large view field of the turning mirror and reflected into the view field of the optical telescope, and the total reflection mirror is just positioned at the center of the view field of the optical telescope and is coupled by optical fibers after focusing.

4. The vegetation detection dual channel fluorescent lidar system of claim 3, wherein: the turning mirror adopts an aluminum film total reflection mirror.

5. The vegetation detection dual channel fluorescent lidar system of claim 2, wherein: the dichroic lens is placed at 135 degrees with the central axis of the optical telescope after being placed at the converging port of the optical telescope.

6. The vegetation detection dual channel fluorescent lidar system of claim 3 or 4 or 5, wherein: the distance measuring unit is triggered and received outside through the time sequence control unit, an optical telescope in the receiving and detecting unit receives and separates ultraviolet distance measuring echo and outputs the ultraviolet distance measuring echo to the distance measuring unit, when laser is emitted, the center of an incident scanning rotating mirror reflects to a vegetation target to rotate a turntable where the rotating mirror is located to realize scanning, and distance data of the distance measuring unit and scanning angle pulses of the scanning unit jointly form vegetation three-dimensional space structure data.

7. The vegetation detection dual channel fluorescent lidar system of claim 6, wherein: the time sequence control unit outputs a digital pulse signal, completes distance detection, turning mirror scanning and photoelectric conversion action of the double-channel detector on a time sequence, and records vegetation target distance, turning mirror movement step length and integral intensity of the double-wavelength fluorescent signal.

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