Airborne hyperspectral laser radar scanning system and method, upper computer and storage medium

Abstract

The invention relates to the technical field of scanning imaging, in particular to an airborne hyperspectral laser radar scanning system and method, an upper computer and a storage medium, and the system comprises airborne hyperspectral laser radar equipment which comprises an equipment body, a scanning mirror unit, a photoelectric detection unit and an angle coding unit, the scanning mirror unit reflects scanning laser to a target, the photoelectric detection unit is used for detecting a ground echo signal reflected by the target, and the angle coding unit obtains an angle coding signal in the scanning process of the scanning mirror unit; and the upper computer comprises a time synchronizer and a controller, the time synchronizer is used for processing the ground echo signals and the angle coding signals into time synchronization frame data of angles and waveforms, and the controller controls the scanning mirror unit to execute scanning actions according to the target scanning parameters. Therefore, the problems that time sequence deviation exists between angle coding information of an airborne hyperspectral laser radar scanning system and ground echo signal measurement in the prior art, and post-scanning imaging is affected are solved.

Description

Technical Field

[0001] The present application relates to the field of scanning imaging technology, and in particular to an airborne hyperspectral laser radar scanning system, method, host computer and storage medium. Background Art

[0002] Hyperspectral LiDAR is a new type of LiDAR technology. Based on the hardware of traditional single-wavelength LiDAR, it uses supercontinuum laser as a light source to greatly expand the spectral width of the transmitter, and specifically increases the number of receiving wavelengths at the detection end of the system. It interprets the distance and reflectivity properties from the reflected pulse echo waveform signals of different wavelengths obtained from each channel, thereby realizing the synchronous integrated acquisition of spatial three-dimensional information and multi-band reflection spectrum information at the foot point based on single laser foot point measurement. Compared with ground-based hyperspectral LiDAR, airborne hyperspectral LiDAR periodically changes the incident posture of the laser through a scanning device during flight, thereby achieving coverage measurement and imaging of ground targets, thereby achieving higher operating efficiency, wider range and more timely surveying and mapping tasks.

[0003] However, the hyperspectral lidar performs independent channel spectroscopic detection on the received signal light, and each spectral detection channel detects and collects the laser emission pulse and the target backscattered echo at the same time. This results in that the echo information and the angle coding information are not completely synchronized in timing. Therefore, there is a timing offset between the detection echo of the same target point and the angle coding information of the scanning unit, which in turn affects the quality of subsequent scanning imaging. This offset manifests itself in two forms: the existence of the timing of the echo waveform and the angle coding, the absolute timing offset of a single laser trigger cycle, and the cumulative offset under multiple laser trigger conditions.

[0004] Compared with traditional large ground-based hyperspectral lidar, the detection distance of airborne hyperspectral lidar has been increased from less than 100m to more than 500m, which makes the waveform signal at long distance on the ground and the scanning angle encoding information on the aircraft increase significantly due to the increase of the optical path of signal transmission, thereby amplifying the timing deviation between the two. In addition, in the long-distance application scenario of airborne detection, the measurement error of the timing error caused by the propagation time difference of the fixed-length optical path of multiple spectral channels inside the instrument, the response of the multi-channel photoelectric detector, analog-to-digital conversion and other factors will be more complicated by the significant increase in detection distance. Summary of the invention

[0005] The present application provides an airborne hyperspectral laser radar scanning system, method, host computer and storage medium to solve the problem that there is a timing deviation between the angle coding information and the ground echo signal measurement of the airborne hyperspectral laser radar scanning system in the related art, thereby affecting the subsequent scanning and imaging.

[0006] The first aspect of the present application provides an airborne hyperspectral lidar scanning system, comprising: an airborne hyperspectral lidar device, wherein the device comprises a device body, a scanning mirror unit, a photoelectric detection unit and an angle encoding unit arranged on the device body, the scanning mirror unit reflects scanning laser to a target, the photoelectric detection unit is used to detect a ground echo signal reflected by the target, and the angle encoding unit obtains an angle encoding signal of a scanning process of the scanning mirror unit; a host computer, wherein the host computer comprises a time synchronizer and a controller, the time synchronizer is used to process a ground echo signal and an angle encoding signal into time-synchronized frame data of an angle and a waveform, and the controller controls the scanning mirror unit to perform a scanning action according to target scanning parameters.

[0007] Optionally, the time synchronizer is also used to: after detecting a ground echo signal, send a first time instruction to a waveform acquisition card, wherein the waveform acquisition card performs a signal threshold judgment on the ground echo signal based on the first time instruction, and returns the first instruction if the ground echo signal exceeds the signal threshold; send a second time instruction to the waveform acquisition card based on the first instruction, and process the angle coding signal based on the second time instruction to obtain angle coding information, wherein the waveform acquisition card is used to store the data of the ground echo signal; and generate time synchronization frame data of the angle and waveform based on the timing information and angle coding information of the second time instruction.

[0008] Optionally, the scanning mirror unit includes: a scanning mirror, a scanning mirror shaft and a motor, wherein the scanning mirror is used to reflect the scanning laser to the target, and reflect the ground echo signal reflected by the target to the photoelectric detection unit; the scanning mirror shaft is used to connect the scanning mirror and the motor, and change the spatial posture of the normal vector on the scanning mirror by rotation to change the emission direction of the scanning laser; the motor is used to drive the scanning mirror shaft and the scanning mirror to realize rotational scanning.

[0009] Optionally, the angle encoding unit includes: a grating ruler and a grating encoding reading head, wherein the grating ruler is used to mark and distinguish the angles of the scanning laser scanning target; the grating encoding reading head is used to read the angle markings generated during the scanning process and output a counting signal for each angle marking.

[0010] Optionally, the controller is further configured to store time synchronization frame data.

[0011] Optionally, the host computer further includes: a waveform acquisition card, which is used to acquire ground echo signals and perform signal threshold judgment on the ground echo signals.

[0012] The second aspect of the present application provides a control method for an airborne hyperspectral lidar scanning system, including: obtaining target scanning parameters of a scanning laser; controlling a scanning mirror unit to perform a scanning action based on the target scanning parameters, and obtaining a ground echo signal detected by a photoelectric detection unit and an angle coding signal by an angle coding unit; and using a time synchronizer to process the ground echo signal and the angle coding signal into time-synchronized frame data of angle and waveform.

[0013] Optionally, a time synchronizer is used to process the ground echo signal and the angle coding signal into time-synchronized frame data of angle and waveform, including: after detecting the ground echo signal, sending a first time instruction to a waveform acquisition card, wherein the waveform acquisition card performs a signal threshold judgment on the ground echo signal based on the first time instruction, and returns the first instruction if the ground echo signal exceeds the signal threshold; sending a second time instruction to the waveform acquisition card based on the first instruction, and processing the angle coding signal based on the second time instruction to obtain angle coding information, wherein the waveform acquisition card is used to store the data of the ground echo signal; and generating time-synchronized frame data of angle and waveform based on the timing information and angle coding information of the second time instruction.

[0014] The third aspect of the present application provides a host computer, including: a memory, a processor, and a computer program stored in the memory and executable on the processor, and the processor executes the program to perform the airborne hyperspectral lidar scanning method as described in the above embodiment.

[0015] The fourth aspect embodiment of the present application provides a computer-readable storage medium having a computer program or instructions stored thereon, and the computer program or instructions are executed by a processor to perform an airborne hyperspectral lidar scanning method.

[0016] Therefore, this application has at least the following beneficial effects:

[0017] The embodiment of the present application can process the ground echo signal and the angle-coded signal into time-synchronized frame data of angle and waveform based on the time synchronizer, that is, to achieve accurate time synchronization of the echo signal and the angle-coded signal, and solve the problem of timing deviation between the scanning system and the ground echo signal measurement under the condition of long-distance detection of the airborne hyperspectral laser radar, thereby improving the quality of subsequent scanning imaging. Thus, the technical problem that the angle-coded information of the airborne hyperspectral laser radar scanning system has timing deviation between the ground echo signal measurement, which in turn affects the subsequent scanning imaging, is solved in the related art.

[0018] Additional aspects and advantages of the present application will be given in part in the description below, and in part will become apparent from the description below, or will be learned through the practice of the present application. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] The above and / or additional aspects and advantages of the present application will become apparent and easily understood from the following description of the embodiments in conjunction with the accompanying drawings, in which:

[0020] Figure 1 A schematic diagram of an airborne hyperspectral laser radar scanning system provided according to an embodiment of the present application;

[0021] Figure 2 A structural diagram of an airborne hyperspectral laser radar scanning system provided according to a specific embodiment of the present application;

[0022] Figure 3 is a schematic diagram of a scanning mirror unit provided according to an embodiment of the present application;

[0023] Figure 4 A schematic diagram of an angle encoding unit provided according to a specific embodiment of the present application;

[0024] Figure 5 A flowchart of an airborne hyperspectral laser radar scanning method provided according to an embodiment of the present application;

[0025] Figure 6 It is a schematic diagram of the structure of a host computer provided according to an embodiment of the present application. DETAILED DESCRIPTION

[0026] Embodiments of the present application are described in detail below, and examples of the embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals throughout represent the same or similar elements or elements having the same or similar functions. The embodiments described below with reference to the accompanying drawings are exemplary and are intended to be used to explain the present application, and should not be construed as limiting the present application.

[0027] The following describes the airborne hyperspectral laser radar scanning system, control method, host computer and medium of the embodiment of the present application with reference to the accompanying drawings. The hyperspectral laser radar mentioned in the background technology center performs independent channel spectroscopic detection on the received signal light, and each spectral detection channel simultaneously detects and collects the laser emission pulse and the target backscattered echo. This causes the echo information and the angle coding information to be not completely synchronized in timing, so there is a timing offset between the detection echo of the same target point and the angle coding information of the scanning unit, which in turn affects the quality of subsequent scanning and imaging. The present application provides an airborne hyperspectral laser radar scanning system, in which the ground echo signal and the angle coding signal are processed into time synchronization frame data of angle and waveform based on a time synchronizer, that is, accurate time synchronization of the echo signal and the angle coding signal is achieved. As a result, the problem of the timing deviation between the angle coding information and the ground echo signal measurement of the airborne hyperspectral laser radar scanning system in the related art, which in turn affects the subsequent scanning and imaging.

[0028] Specifically, Figure 1 A schematic diagram of an airborne hyperspectral lidar scanning system provided in an embodiment of the present application.

[0029] like Figure 1 As shown, the airborne hyperspectral laser radar scanning system 10 includes: an airborne hyperspectral laser radar device 11 and a host computer 12.

[0030] Among them, the airborne hyperspectral lidar device 11 includes a device body, a scanning mirror unit, a photoelectric detection unit and an angle encoding unit arranged on the device body. The scanning mirror unit reflects the scanning laser to the target, the photoelectric detection unit is used to detect the ground echo signal reflected by the target, and the angle encoding unit obtains the angle encoding signal of the scanning process of the scanning mirror unit; the host computer 12 includes a time synchronizer and a controller. The time synchronizer is used to process the ground echo signal and the angle encoding signal into time synchronization frame data of the angle and waveform, and the controller controls the scanning mirror unit to perform the scanning action according to the target scanning parameters.

[0031] Among them, the target scanning parameters can be set according to the specific situation, mainly including the scanning frequency repetition rate, the laser emission repetition rate, the energy power, etc.

[0032] It can be understood that the embodiment of the present application can control the scanning mirror unit to perform a scanning action according to the target scanning parameters through the controller of the host computer. The time synchronizer in the host computer synchronizes the ground echo signal detected by the photoelectric detection unit and the angle coding information generated during the scanning process of the scanning mirror unit to generate time synchronization frame data of the angle and waveform, thereby avoiding the ground waveform and the onboard angle coding time deviation under realistic conditions of long-distance detection by the airborne hyperspectral lidar.

[0033] Specifically, the working process of the scanning system of the embodiment of the present application is: the controller controls the scanning mirror unit to perform the scanning action according to the target scanning parameters, the scanning mirror unit reflects the scanning laser, the photoelectric detection unit is used to detect the ground echo signal reflected by the ground target, the angle encoding unit obtains the angle encoding information during the scanning process of the scanning mirror unit, and the time synchronizer synchronizes the ground echo signal and the angle encoding information to obtain time synchronization frame data.

[0034] In an embodiment of the present application, the time synchronizer is also used to: after detecting a ground echo signal, send a first time instruction to a waveform acquisition card, wherein the waveform acquisition card performs a signal threshold judgment on the ground echo signal based on the first time instruction, and returns the first instruction if the ground echo signal exceeds the signal threshold; send a second time instruction to the waveform acquisition card based on the first instruction, and process the angle coding signal based on the second time instruction to obtain angle coding information, wherein the waveform acquisition card is used to store the data of the ground echo signal; generate time synchronization frame data of the angle and waveform based on the timing information and angle coding information of the second time instruction.

[0035] It can be understood that the specific execution process of the time synchronizer in the embodiment of the present application is as follows:

[0036] After detecting the ground echo signal, the first time instruction O1 is sent to the waveform acquisition card, the waveform acquisition card makes a threshold judgment on the ground echo, collects the ground echo signal according to the judgment, and returns the first instruction A1 to the time synchronizer;

[0037] The time synchronizer receives the first instruction A1 from the acquisition card, and sends the second time instruction O2 to the waveform acquisition card, and the waveform acquisition card starts to store the data of the ground echo signal;

[0038] The time synchronizer processes the angle coding signal based on the second time instruction O2 to obtain angle coding information, and stores the angle and waveform time synchronization frame data D1 in combination with its own timing information and angle coding information of the second time instruction O2.

[0039] In an embodiment of the present application, the scanning mirror unit includes: a scanning mirror, a scanning mirror shaft and a motor.

[0040] Among them, the scanning mirror is used to reflect the scanning laser to the target, and reflect the ground echo signal reflected by the target to the photoelectric detection unit; the scanning mirror shaft is used to connect the scanning mirror and the motor, and change the spatial posture of the normal vector on the scanning mirror by rotation to change the emission direction of the scanning laser; the motor is used to drive the scanning mirror shaft and the scanning mirror to realize rotational scanning.

[0041] It can be understood that the scanning mirror unit of the embodiment of the present application includes a scanning mirror, a scanning mirror shaft and a motor. The scanning mirror shaft is located between the scanning mirror and the motor. The scanning mirror is used to reflect the scanning laser to the target, and reflect the ground echo signal reflected by the target to the photoelectric detection unit. The scanning mirror shaft is used to connect the scanning mirror and the motor, and change the spatial posture of the normal vector on the scanning mirror by rotation to change the emission direction of the scanning laser. The motor can be a high-power motor, which is used to drive the scanning mirror shaft and the scanning mirror to realize rotational scanning.

[0042] In an embodiment of the present application, the angle encoding unit includes: a grating scale and a grating encoding reading head.

[0043] Among them, the grating ruler is used to mark and distinguish the angles of the scanning laser scanning target; the grating encoding reading head is used to read the angle markings generated during the scanning process and output a counting signal for each angle marking.

[0044] It can be understood that the angle encoding unit of the embodiment of the present application includes a grating scale and a grating encoding reading head. The grating scale is responsible for precisely engraving and distinguishing the angles of the entire scanning cycle to achieve high-resolution angle resolution during the scanning process. The grating encoding reading head is responsible for reading the angle lines generated during the scanning rotation and outputting the technical signal of each engraving.

[0045] In an embodiment of the present application, the controller is also used to store time synchronization frame data.

[0046] It can be understood that the controller of the embodiment of the present application is also used to store time synchronization frame data.

[0047] In the embodiment of the present application, the host computer also includes: a waveform acquisition card, which is used to collect ground echo signals and perform signal threshold judgment on the ground echo signals.

[0048] It can be understood that the host computer of the embodiment of the present application also includes a waveform acquisition card for acquiring ground echo signals and performing signal threshold judgment on the ground echo signals.

[0049] The following is an explanation of the airborne hyperspectral lidar scanning system of the present application through a specific implementation. The device can achieve high-speed laser scanning of more than 10 Hz for an airborne hyperspectral lidar with an optical aperture of 300 mm, and achieve high-precision time synchronization matching, transmission and storage of the angle-coded information and laser pulses produced during the scanning through a high-precision clock unit (40 MHz), thereby solving the problem of time synchronization scanning of ground waveforms and on-board angle codes under realistic conditions for long-distance detection by airborne hyperspectral lidar.

[0050] Combination Figure 2 Specifically describe the airborne hyperspectral laser radar scanning system of the present application, Figure 2 The host computer control unit is equivalent to the host computer of this application. The overall scanning system is divided into a scanning mirror unit that changes the laser emission direction and reflects the ground echo to the optical receiving system; an angle coding synchronization unit that produces angle coding information during the scanning process and synchronizes and transmits it with the laser emission pulse time; and a host computer control unit that controls the scanning mirror unit and the angle coding synchronization unit.

[0051] The scanning mirror unit is composed of a reflective medium film reflective mirror 1 (also called a scanning mirror), a scanning mirror rotating shaft 2 and a high-power motor 3. Figure 3As shown, the reflective dielectric film reflector 1 is responsible for reflecting the horizontal laser emitted by the laser, reflecting it to the surface of the observed object, and reflecting the echo signal from the ground into the optical receiving telescope (i.e., the photodetector unit). The scanning mirror shaft 2 is responsible for connecting the high-power motor 3 and the reflective dielectric film reflector 1, and the spatial posture of the mirror normal vector is changed by the clockwise rotation of the scanning mirror shaft 2, thereby periodically changing the emission posture vector of the laser. The high-power motor 3 is responsible for driving the scanning mirror shaft 2 and the mirror surface of the reflective dielectric film reflector 1 connected thereto to rotate. The fixed base fixes the scanning mirror unit on the airborne platform so that the angle between the short axis direction generated by the scanning and the flight direction is 0.

[0052] First, the angle between the scanning mirror plane and the rotation axis is 7.5°, and the scanning mirror rotation axis is driven by a high-power motor. The laser emission vector direction is horizontal, and the angle between it and the normal vector of the scanning mirror plane is 45°. The incident point of the laser on the scanning mirror plane is designed to be the geometric center of the intersection of the rotation axis plane and the scanning mirror plane. Figure 2 As shown, since there is a fixed angle of 7.5° between the rotation axis and the normal vector of the scanning mirror plane, according to formula (1) and the auxiliary rotation matrix (2), it can be obtained that during the scanning rotation process, the normal vector of the scanning mirror plane forms a cone plane equation (3) around the rotation axis. According to the reflection law (4) and the angle constraint relationship (5), it can be obtained that the scanning curve when the aircraft is stationary is an oval curve (6). According to (1)-(6), the computer simulation scanning result is an oval two-dimensional scanning trajectory. Compared with one-dimensional scanning methods such as galvanometers and polyhedron rotating mirrors, it has the advantages of not losing scanning points and the high-frequency components (acceleration and deceleration components) of the motor.

[0053]

[0054] The angle encoding synchronization unit (equivalent to the angle encoding unit of the present application) is composed of a grating ruler 4 and a grating encoding reading head 5. Figure 4 The grating ruler 4 is responsible for precisely engraving and distinguishing the angles of the entire scanning cycle, realizing the ability of high-resolution angle resolution during scanning. The grating encoding reading head 5 is responsible for reading the angle engravings generated during the scanning rotation and outputting the counting signal of each engraving.

[0055] The host control unit is composed of a chassis controller 6, a clock synchronization card 7 (40MHz high-precision clock, equivalent to the time synchronizer of this application), a waveform acquisition card 8 and a chassis 9 containing a PXIE backplane. The clock synchronization card 7 receives the trigger pulse signal from the laser and the high-precision coding information from the angle encoding unit, and synchronizes and transmits the angle coding information with the laser pulse time, and stores the angle synchronization frame data on the chassis controller 6. The chassis controller 6 is responsible for controlling the scanning frequency of the scanning mirror unit, and receiving and storing the angle synchronization frame data transmitted from the clock synchronization card 7.

[0056] According to the airborne hyperspectral lidar scanning system proposed in the embodiment of the present application, the ground echo signal and the angle coding signal can be processed into time-synchronized frame data of angle and waveform based on a time synchronizer, that is, accurate time synchronization of the echo signal and the angle coding signal is achieved, which solves the problem of timing deviation in the measurement of the scanning system and the ground echo signal under the long-distance detection conditions of the airborne hyperspectral lidar, thereby improving the quality of subsequent scanning imaging.

[0057] Next, the airborne hyperspectral lidar scanning method proposed according to the embodiment of the present application is described with reference to the accompanying drawings.

[0058] Figure 5 It is a flow chart of the airborne hyperspectral lidar scanning method of an embodiment of the present application.

[0059] like Figure 5 As shown, the airborne hyperspectral laser radar scanning method includes the following steps:

[0060] In step S101 , target scanning parameters of the scanning laser are acquired.

[0061] Among them, the target scanning parameters can be set according to the specific situation, mainly including the scanning frequency repetition rate, the laser emission repetition rate, the energy power, etc.

[0062] In step S102, the scanning mirror unit is controlled to perform a scanning action based on the target scanning parameter, and a ground echo signal detected by the photoelectric detection unit and an angle encoding signal of the angle encoding unit are acquired.

[0063] It can be understood that the embodiments of the present application can control the scanning mirror unit to perform a scanning action based on the target scanning parameters, and obtain the ground echo signal detected by the photoelectric detection unit in the airborne hyperspectral lidar device and the angle coding signal obtained by the angle coding unit during the scanning process, so as to perform subsequent time synchronization.

[0064] In step S103, a time synchronizer is used to process the ground echo signal and the angle encoding signal into time synchronized frame data of angle and waveform.

[0065] It can be understood that the embodiments of the present application can utilize a time synchronizer to process the ground echo signal and the angle coding signal into time synchronization frame data of the angle and waveform to achieve time synchronization, as follows.

[0066] In an embodiment of the present application, a time synchronizer is used to process a ground echo signal and angle coding information into time-synchronized frame data of angle and waveform, including: after detecting a ground echo signal, sending a first time instruction to a waveform acquisition card, wherein the waveform acquisition card performs a signal threshold judgment on the ground echo signal based on the first time instruction, and returns the first instruction if the ground echo signal exceeds the signal threshold; sending a second time instruction to the waveform acquisition card based on the first instruction, and processing the angle coding signal based on the second time instruction to obtain angle coding information, wherein the waveform acquisition card is used to store data of the ground echo signal; and generating time-synchronized frame data of angle and waveform based on the timing information and angle coding information of the second time instruction.

[0067] Specifically, the time synchronization process is as follows:

[0068] The time synchronizer receives the square wave signal triggered by the laser emission pulse, and judges it by the rising edge of the signal, and generates an internal high-precision time instruction O1 to the waveform acquisition card to identify the waveform;

[0069] The waveform acquisition card receives the time instruction O1 sent by the clock card and performs threshold crossing identification on the echo waveform signal entering the card. If the threshold is crossed, the instruction A1 is returned to the clock card.

[0070] The time synchronizer receives the instruction A1 from the acquisition card and generates a high-precision clock instruction O2 to the acquisition card to start storing the echo waveform data;

[0071] The time synchronizer itself processes the angle coding signal according to the O2 instruction and generates angle coding information, and stores the angle-waveform coded time synchronization frame data D1 in combination with the timing information of the O2 instruction itself.

[0072] It should be noted that the aforementioned explanation of the embodiment of the airborne hyperspectral laser radar scanning system is also applicable to the airborne hyperspectral laser radar scanning method of this embodiment, and will not be repeated here.

[0073] The following is a description of the airborne hyperspectral laser radar scanning method of the present application embodiment through a specific embodiment, which is as follows:

[0074] Step 1: Set the signal trigger source of the clock synchronization card to the square wave trigger signal of the laser through the host computer, and set the rising edge of the square wave signal as the synchronization card signal recognition trigger condition;

[0075] Step 2: After identifying the trigger conditions of the laser, the clock synchronization card requests the threshold discrimination result from the waveform acquisition card. If an echo waveform is detected by the hyperspectral laser radar at this time, a trigger instruction is sent to the clock synchronization card. The clock synchronization card generates a clock synchronization trigger instruction to collect laser multi-channel echo waveform data for all waveform acquisition cards, and generates trigger numbers (1, 2, 3, ..., n) in sequence according to the accumulation rule starting from 1. The clock synchronization card uses each clock synchronization instruction cycle as the acquisition frame cycle, records the scanning angle code, trigger number and high-precision clock time data issued by the angle encoding unit, and transmits it to the host computer through the PXIe backplane interface as the fixed synchronization frame data and stores it on the fixed path of the local hard disk of the host computer.

[0076] According to the airborne hyperspectral lidar scanning method proposed in the embodiment of the present application, the airborne hyperspectral lidar can be controlled to work based on the target scanning parameters, and the ground echo signal and the angle coding signal can be processed into time-synchronized frame data of the angle and the waveform based on the time synchronizer, that is, the precise time synchronization of the echo signal and the angle coding signal is achieved, which solves the timing deviation problem in the measurement of the scanning system and the ground echo signal under the long-distance detection conditions of the airborne hyperspectral lidar, thereby improving the quality of subsequent scanning imaging.

[0077] Figure 6 A schematic diagram of the structure of the host computer provided in the embodiment of the present application. The host computer may include:

[0078] A memory 601 , a processor 602 , and a computer program stored in the memory 601 and executable on the processor 602 .

[0079] When the processor 602 executes the program, the airborne hyperspectral laser radar scanning method provided in the above embodiment is implemented.

[0080] Furthermore, the host computer also includes:

[0081] The communication interface 603 is used for communication between the memory 601 and the processor 602 .

[0082] The memory 601 is used to store computer programs that can be executed on the processor 602 .

[0083] The memory 601 may include a high-speed RAM memory, and may also include a non-volatile memory (non-volatile memory), such as at least one disk memory.

[0084] If the memory 601, the processor 602 and the communication interface 603 are implemented independently, the communication interface 603, the memory 601 and the processor 602 can be connected to each other through a bus and communicate with each other. The bus can be an Industry Standard Architecture (ISA) bus, a Peripheral Component Interconnect (PCI) bus or an Extended Industry Standard Architecture (EISA) bus. The bus can be divided into an address bus, a data bus, a control bus, etc. For ease of representation, Figure 6 The bus is represented by only one thick line, but this does not mean that there is only one bus or one type of bus.

[0085] Optionally, in a specific implementation, if the memory 601, the processor 602 and the communication interface 603 are integrated on a chip, the memory 601, the processor 602 and the communication interface 603 can communicate with each other through an internal interface.

[0086] The processor 602 may be a central processing unit (CPU), or an application specific integrated circuit (ASIC), or one or more integrated circuits configured to implement the embodiments of the present application.

[0087] An embodiment of the present application also provides a computer-readable storage medium on which a computer program or instruction is stored. When the computer program or instruction is executed by a processor, the above-mentioned airborne hyperspectral lidar scanning method is implemented.

[0088] In the description of this specification, the description with reference to the terms "one embodiment", "some embodiments", "example", "specific example", or "some examples" etc. means that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present application. In this specification, the schematic representations of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described may be combined in any one or N embodiments or examples in a suitable manner. In addition, those skilled in the art may combine and combine the different embodiments or examples described in this specification and the features of the different embodiments or examples, without contradiction.

[0089] In addition, the terms "first" and "second" are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Therefore, a feature defined as "first" or "second" may explicitly or implicitly include at least one of the features. In the description of this application, "N" means at least two, such as two, three, etc., unless otherwise clearly and specifically defined.

[0090] Any process or method description in a flowchart or otherwise described herein may be understood to represent a module, fragment or portion of code comprising one or N executable instructions for implementing the steps of a custom logical function or process, and the scope of the preferred embodiments of the present application includes alternative implementations in which functions may not be performed in the order shown or discussed, including performing functions in a substantially simultaneous manner or in reverse order depending on the functions involved, which should be understood by technicians in the technical field to which the embodiments of the present application belong.

[0091] It should be understood that the various parts of the present application can be implemented by hardware, software, firmware or a combination thereof. In the above embodiment, the N steps or methods can be implemented by software or firmware stored in a memory and executed by a suitable instruction execution system. For example, if implemented by hardware, as in another embodiment, it can be implemented by any one or a combination of multiple of the following technologies known in the art: a discrete logic circuit having a logic gate circuit for implementing a logic function for a data signal, a dedicated integrated circuit having a suitable combination of logic gate circuits, a programmable gate array (PGA), a field programmable gate array (FPGA), etc.

[0092] A person skilled in the art may understand that all or part of the steps in the method for implementing the above-mentioned embodiment may be completed by instructing related hardware through a program, and the program may be stored in a computer-readable storage medium, which, when executed, includes one or a combination of the steps of the method embodiment.

Claims

1. An airborne hyperspectral laser radar scanning system, characterized in that: include: An airborne hyperspectral laser radar device, wherein the device comprises a device body, a scanning mirror unit, a photoelectric detection unit and an angle encoding unit arranged on the device body, the scanning mirror unit reflects scanning laser to a target, the photoelectric detection unit is used to detect a ground echo signal reflected by the target, and the angle encoding unit obtains an angle encoding signal of a scanning process of the scanning mirror unit; A host computer, wherein the host computer includes a time synchronizer and a controller, the time synchronizer is used to process the ground echo signal and the angle encoding signal into time synchronization frame data of angle and waveform, and the controller controls the scanning mirror unit to perform a scanning action according to the target scanning parameters.

2. The airborne hyperspectral laser radar scanning system according to claim 1, characterized in that: The time synchronizer is also used for: After detecting the ground echo signal, sending a first time instruction to the waveform acquisition card, wherein the waveform acquisition card performs a signal threshold judgment on the ground echo signal based on the first time instruction, and returns the first instruction if the ground echo signal exceeds the signal threshold; sending a second time instruction to the waveform acquisition card based on the first instruction, and processing the angle coding signal based on the second time instruction to obtain the angle coding information, wherein the waveform acquisition card is used to store the data of the ground echo signal; Time-synchronized frame data of angle and waveform are generated based on the timing information of the second time instruction and the angle encoding information.

3. The airborne hyperspectral laser radar scanning system according to claim 1, characterized in that: The scanning mirror unit comprises: a scanning mirror, a scanning mirror shaft and a motor, wherein: The scanning mirror is used to reflect the scanning laser to the target, and reflect the ground echo signal reflected by the target to the photoelectric detection unit; The scanning mirror rotating shaft is used to connect the scanning mirror and the motor, and to change the spatial posture of the normal vector on the scanning mirror by rotating, so as to change the emission direction of the scanning laser; The motor is used to drive the scanning mirror shaft and the scanning mirror to realize rotation scanning.

4. The airborne hyperspectral laser radar scanning system according to claim 1, characterized in that: The angle encoding unit includes: a grating ruler and a grating encoding reading head, wherein: The grating ruler is used to engrave and distinguish the angle at which the scanning laser scans the target; The grating encoding reading head is used to read the angle markings generated during the scanning process and output a counting signal for each angle marking.

5. The airborne hyperspectral laser radar scanning system according to claim 1, characterized in that: The controller is also used to store the time synchronization frame data.

6. The airborne hyperspectral laser radar scanning system according to claim 1, characterized in that: The host computer further includes: a waveform acquisition card, which is used to acquire the ground echo signal and perform signal threshold judgment on the ground echo signal.

7. An airborne hyperspectral laser radar scanning method, characterized in that: The following steps are involved: Obtain target scanning parameters of the scanning laser; Controlling the scanning mirror unit to perform a scanning action based on the target scanning parameter, and acquiring a ground echo signal detected by a photoelectric detection unit and an angle coding signal of an angle coding unit; The ground echo signal and the angle-encoded signal are processed into angle and waveform time-synchronized frame data using a time synchronizer.

8. The airborne hyperspectral laser radar scanning method according to claim 7, characterized in that: The method of using the time synchronizer to process the ground echo signal and the angle encoding information into time synchronized frame data of angle and waveform includes: After detecting the ground echo signal, sending a first time instruction to the waveform acquisition card, wherein the waveform acquisition card performs a signal threshold judgment on the ground echo signal based on the first time instruction, and returns the first instruction if the ground echo signal exceeds the signal threshold; sending a second time instruction to the waveform acquisition card based on the first instruction, and processing the angle-encoded signal based on the second time instruction to obtain the angle-encoded information, wherein the waveform acquisition card is used to store data of the ground echo signal; Time-synchronized frame data of angle and waveform are generated based on the timing information of the second time instruction and the angle encoding information.

9. A host computer, characterized in that: include: A memory, a processor, and a computer program stored in the memory and executable on the processor, wherein the processor executes the program to implement the airborne hyperspectral lidar scanning method as claimed in claim 7 or 8.

10. A computer-readable storage medium having a computer program or instruction stored thereon, characterized in that: The computer program or instructions are executed by a processor to implement the airborne hyperspectral lidar scanning method as claimed in claim 7 or 8.

Images