Airborne hyperspectral lidar scanning system, method, host computer and storage medium

Abstract

This application relates to the field of scanning imaging technology, and particularly to an airborne hyperspectral lidar scanning system, method, host computer, and storage medium. The system includes: an airborne hyperspectral lidar device, comprising a device body, a scanning mirror unit, a photoelectric detection unit, and an angle encoding unit mounted on the device body. The scanning mirror unit reflects scanning laser light towards the target, the photoelectric detection unit detects the ground echo signal reflected by the target, and the angle encoding unit acquires the angle encoding signal during the scanning process of the scanning mirror unit; the host computer includes a time synchronizer and a controller. The time synchronizer processes the ground echo signal and the angle encoding signal into time-synchronized frame data of angle and waveform, and the controller controls the scanning mirror unit to perform scanning actions according to the target scanning parameters. This solves the problem of timing discrepancies between the angle encoding information and the ground echo signal measurement in related airborne hyperspectral lidar scanning systems, which affects subsequent scanning imaging.

Description

Technical Field

[0001] This application relates to the field of scanning imaging technology, and in particular to an airborne hyperspectral lidar scanning system, method, host computer, and storage medium. Background Technology

[0002] Hyperspectral lidar is a novel lidar technology that, based on the hardware of traditional single-wavelength lidar, uses supercontinuum lasers as the light source to significantly extend the spectral width of the transmitter. It also specifically increases the number of receiving wavelengths at the system's detector end. By interpreting the distance and reflectivity attributes from the reflected pulse echo waveforms of different wavelengths acquired from various channels, it achieves simultaneous and integrated acquisition of three-dimensional spatial information and multi-spectral reflectance spectral information based on measurements at a single laser footpoint. Compared to ground-based hyperspectral lidar, airborne hyperspectral lidar, through its scanning device, periodically and continuously changes the incident attitude of the laser during flight, thereby achieving comprehensive measurement and imaging of ground targets. This results in higher operational efficiency, wider coverage, and faster mapping tasks.

[0003] However, hyperspectral lidar performs independent channel-based beam splitting detection on the received signal light, with each spectral detection channel simultaneously detecting and acquiring both the laser emission pulse and the target backscattered echo. This results in the echo information and angle encoding information not being completely synchronized in time. Consequently, there is a temporal offset between the detected echo and the angle encoding information of the scanning unit for the same target point, thus affecting the quality of subsequent scanning imaging. This offset manifests in two forms: an absolute temporal offset between the echo waveform and the angle encoding under a single laser trigger cycle, and a cumulative offset under multiple laser trigger conditions.

[0004] Compared to traditional large-scale ground-based hyperspectral lidar, airborne hyperspectral lidar increases the detection range from less than 100m to more than 500m. This significantly increases the amplitude of the waveform signal at long distances on the ground and the scanning angle encoding information on the airborne lidar due to the increased optical path length, thus amplifying the timing discrepancies between the two. Furthermore, in long-range airborne detection applications, the measurement errors caused by factors such as the propagation time differences of fixed-length optical paths in multiple spectral channels within the instrument, the response of multi-channel photodetectors, and analog-to-digital conversion become even more complex due to the significantly increased detection distance. Summary of the Invention

[0005] This application provides an airborne hyperspectral lidar scanning system, method, host computer, and storage medium to solve the problem in related technologies where there is a timing deviation between the angle encoding information and the ground echo signal measurement in the airborne hyperspectral lidar scanning system, which in turn affects subsequent scanning imaging.

[0006] The first aspect of this application provides an airborne hyperspectral lidar scanning system, comprising: an airborne hyperspectral lidar device, wherein the device includes a device body, a scanning mirror unit, a photoelectric detection unit, and an angle encoding unit disposed on the device body; the scanning mirror unit reflects scanning laser light toward a target; the photoelectric detection unit is used to detect ground echo signals reflected by the target; and the angle encoding unit acquires angle encoding signals during the scanning process of the scanning mirror unit; and a host computer, wherein the host computer includes a time synchronizer and a controller; the time synchronizer is used to process the ground echo signals and angle encoding signals into time synchronization frame data of angle and waveform; and the controller controls the scanning mirror unit to perform scanning actions according to the target scanning parameters.

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

[0008] Optionally, the scanning mirror unit includes: a scanning mirror, a scanning mirror shaft, and a 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 to change the spatial attitude of the normal vector on the scanning mirror by rotation, thereby changing the emission direction of the scanning laser. The motor is used to drive the scanning mirror shaft and the scanning mirror to achieve 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 engrave and distinguish the angles of the target scanned by the scanning laser; the grating encoding reading head is used to read the angle engravings generated during the scanning process and output a counting signal for each angle engraving.

[0010] Optionally, the controller is also used to store time synchronization frame data.

[0011] Optionally, the host computer may also include a waveform acquisition card for acquiring ground echo signals and performing signal threshold judgment on the ground echo signals.

[0012] The second aspect of this application provides a control method for an airborne hyperspectral lidar scanning system, comprising: acquiring target scanning parameters of the scanning laser; controlling a scanning mirror unit to perform a scanning action based on the target scanning parameters, and acquiring ground echo signals detected by a photoelectric detection unit and angle encoding signals from an angle encoding unit; and using a time synchronizer to process the ground echo signals and angle encoding signals 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-coded signal into time-synchronized frame data of angle and waveform, including: after detecting the ground echo signal, sending a first time command 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 command, and if the ground echo signal exceeds the signal threshold, returns the first command; sending a second time command to the waveform acquisition card based on the first command, and processing the angle-coded signal based on the second time command to obtain angle-coded information, wherein the waveform acquisition card is used to store the ground echo signal data; and generating time-synchronized frame data of angle and waveform based on the timing information and angle-coded information of the second time command.

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

[0015] A fourth aspect of this application provides a computer-readable storage medium having a computer program or instructions stored thereon, which are executed by a processor to perform an airborne hyperspectral lidar scanning method, such as the one described above.

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

[0017] This application's embodiments can process ground echo signals and angle-coded signals into time-synchronized frame data of angle and waveform based on a time synchronizer, thus achieving precise time synchronization between the echo signals and angle-coded signals. This solves the timing deviation problem between the scanning system and ground echo signal measurement under long-range detection conditions of airborne hyperspectral lidar, thereby improving the quality of subsequent scanning imaging. Therefore, it resolves the technical problem in related technologies where timing deviation exists between angle-coded information and ground echo signal measurement in airborne hyperspectral lidar scanning systems, affecting subsequent scanning imaging.

[0018] Additional aspects and advantages of this application will be set forth in part in the description which follows, and in part will be obvious from the description, or may be learned by practice of this application. Attached Figure Description

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

[0020] Figure 1 This is a schematic diagram of an airborne hyperspectral lidar scanning system provided according to an embodiment of this application;

[0021] Figure 2 This is a structural diagram of an airborne hyperspectral lidar scanning system according to a specific embodiment of this application;

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

[0023] Figure 4 This is a schematic diagram of an angle encoding unit provided according to a specific embodiment of this application;

[0024] Figure 5 This is a flowchart of an airborne hyperspectral lidar scanning method provided according to an embodiment of this application;

[0025] Figure 6 This is a schematic diagram of the structure of the host computer provided according to an embodiment of this application. Detailed Implementation

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

[0027] The following description, with reference to the accompanying drawings, outlines an airborne hyperspectral lidar scanning system, control method, host computer, and medium according to embodiments of this application. Addressing the issue mentioned in the background art where hyperspectral lidar performs independent channel-based beam splitting detection of the received signal light, with each spectral detection channel simultaneously detecting and acquiring both the laser emission pulse and the target backscattered echo, this results in a lack of complete synchronization between the echo information and the angle encoding information. Consequently, a temporal offset exists between the detected echo and the angle encoding information of the scanning unit for the same target point, affecting the quality of subsequent scanning imaging. This application provides an airborne hyperspectral lidar scanning system in which a time synchronizer processes the ground echo signal and the angle encoding signal into time-synchronized frame data of angle and waveform, achieving precise time synchronization between the echo signal and the angle encoding signal. This resolves the temporal deviation between the angle encoding information and the ground echo signal measurement in related technologies, thus affecting subsequent scanning imaging.

[0028] Specifically, Figure 1 This is a schematic diagram of an airborne hyperspectral lidar scanning system provided in an embodiment of this application.

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

[0030] The airborne hyperspectral lidar device 11 includes a device body, a scanning mirror unit, a photoelectric detection unit, and an angle encoding unit mounted on the device body. The scanning mirror unit reflects scanning laser light to the target, the photoelectric detection unit detects the ground echo signal reflected by the target, and the angle encoding unit acquires the angle encoding signal during the scanning process of the scanning mirror unit. The host computer 12 includes a time synchronizer and a controller. The time synchronizer processes 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 scanning actions according to the target scanning parameters.

[0031] The target scanning parameters can be set according to specific circumstances, mainly including the scanning frequency repetition rate, the repetition rate of the emitted laser, and the energy power.

[0032] It is understood that, in the embodiments of this application, the scanning mirror unit can be controlled by the controller of the host computer to perform scanning actions according to the target scanning parameters. The time synchronizer in the host computer synchronizes the ground echo signal detected by the photoelectric detection unit and the angle encoding information generated by the scanning mirror unit during the scanning process, and generates time synchronization frame data of angle and waveform, thereby avoiding the time deviation between the ground waveform and the on-board angle encoding under the real conditions of long-distance detection by airborne hyperspectral lidar.

[0033] Specifically, the scanning system of this application embodiment works as follows: the controller controls the scanning mirror unit to perform scanning actions 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 this embodiment, the time synchronizer is further configured to: after detecting a ground echo signal, send a first time command 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 command, and if the ground echo signal exceeds the signal threshold, return the first command; send a second time command to the waveform acquisition card based on the first command, and process the angle-coded signal based on the second time command to obtain angle-coded information, wherein the waveform acquisition card is used to store the ground echo signal data; and generate time synchronization frame data of angle and waveform based on the timing information and angle-coded information of the second time command.

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

[0036] After detecting the ground echo signal, the first time command O1 is sent to the waveform acquisition card. The waveform acquisition card performs threshold judgment on the ground echo, and collects the ground echo signal according to the judgment, and returns the first command 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 begins to store the ground echo signal data;

[0038] The time synchronizer processes the angle-encoded signal based on the second time instruction O2 to obtain angle-encoded information, and combines the timing information of the second time instruction O2 with the angle-encoded information to store the time synchronization frame data D1 of the angle and waveform.

[0039] In this embodiment, the scanning mirror unit includes a scanning mirror, a scanning mirror shaft, and a motor.

[0040] 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 to change the spatial attitude 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 achieve rotational scanning.

[0041] It is understood that the scanning mirror unit in this application embodiment 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 changes the spatial attitude of the normal vector on the scanning mirror by rotation, so as to change the emission direction of the scanning laser. The motor can be a high-power motor to drive the scanning mirror shaft and the scanning mirror to achieve rotational scanning.

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

[0043] The grating ruler is used to engrave and distinguish the angles of the target scanned by the scanning laser; the grating encoder reading head is used to read the angle engravings generated during the scanning process and output the counting signal for each angle engraving.

[0044] It is understood that the angle encoding unit in this application embodiment includes a grating ruler and a grating encoding reading head. The grating ruler is responsible for precisely engraving and distinguishing the angle of the entire scanning cycle, so as to realize the high-resolution angle resolution capability during the scanning process. The grating encoding reading head is responsible for reading the angle engraving generated during scanning rotation and outputting the technical signal of each engraving.

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

[0046] It is understood that the controller in this application embodiment is also used to store time synchronization frame data.

[0047] In this embodiment of the application, the host computer further includes: a waveform acquisition card, used to acquire ground echo signals and perform signal threshold judgment on the ground echo signals.

[0048] It is understood that the host computer in this application embodiment also includes a waveform acquisition card, which is used to acquire ground echo signals and perform signal threshold judgment on the ground echo signals.

[0049] The following is a specific implementation of the airborne hyperspectral lidar scanning system of this application. This device can achieve high-speed laser scanning of more than 10 Hz for airborne hyperspectral lidar with an optical aperture of 300 mm. It also achieves high-precision time synchronization matching, transmission and storage of angle encoding information and laser pulses generated during scanning through a high-precision clock unit (40 MHz), thus solving the problem of time synchronization scanning of ground waveforms and on-board angle encoding under real-world conditions for long-distance detection by airborne hyperspectral lidar.

[0050] Combination Figure 2 This application provides a detailed description of its airborne hyperspectral lidar scanning system. 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 encoding synchronization unit that generates angle encoding information during the scanning process, synchronizes it with the laser emission pulse time, and transmits it; and a host computer control unit that controls the scanning mirror unit and the angle encoding synchronization unit.

[0051] The scanning mirror unit consists of a reflective dielectric film mirror 1 (also called a scanning mirror), a scanning mirror shaft 2, and a high-power motor 3. For example... Figure 3As shown, the reflective dielectric film mirror 1 reflects the horizontal laser emitted by the laser, directing it to the surface of the observed object and reflecting the echo signal from the ground into the optical receiving telescope (i.e., the photoelectric detection unit). The scanning mirror shaft 2 connects the high-power motor 3 and the reflective dielectric film mirror 1. The clockwise rotation of the scanning mirror shaft 2 changes the spatial attitude of the mirror's normal vector, thus periodically changing the laser's emission attitude vector. The high-power motor 3 drives the scanning mirror shaft 2 and the mirror surface of the reflective dielectric film mirror 1 connected to it to achieve rotation. The fixed base secures the scanning mirror unit to the airborne platform, ensuring that the angle between the minor 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 is horizontal, and the angle between it and the normal vector of the scanning mirror plane is 45°. The laser incident point on the scanning mirror plane is designed as the geometric center where the rotation axis plane and the scanning mirror plane intersect. For example... 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), we can obtain the equation (3) of a conical plane formed by the normal vector of the scanning mirror plane around the rotation axis during the scanning rotation process. According to the law of reflection (4) and the angle constraint relationship (5), we can obtain 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 galvanometer and polyhedral rotating mirror, it has the advantages of not losing scanning points and high-frequency components of the motor (acceleration and deceleration components).

[0053]

[0054] The angle encoding synchronization unit (equivalent to the angle encoding unit of this application) consists of a grating ruler 4 and a grating encoding reading head 5, such as... Figure 4 As shown. The grating ruler 4 is responsible for precisely marking and distinguishing the angles of the entire scanning cycle, achieving high-resolution angle resolution during scanning. The grating encoder reading head 5 is responsible for reading the angle markings generated during scanning rotation and outputting a count signal for each marking.

[0055] The host computer control unit consists of a chassis controller 6, a clock synchronization card 7 (a 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 trigger pulse signals from the laser and high-precision encoded information from the angle encoding unit, synchronizes and transmits the angle encoded information with the laser pulse time, and stores the angle synchronization frame data in 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 embodiments of this application, the ground echo signal and angle-coded signal can be processed into time-synchronized frame data of angle and waveform based on a time synchronizer, that is, the echo signal and angle-coded signal are accurately synchronized in time. This solves the problem of timing deviation between the scanning system and the ground echo signal measurement under the long-distance detection conditions of airborne hyperspectral lidar, thereby improving the quality of subsequent scanning imaging.

[0057] Next, referring to the accompanying drawings, the airborne hyperspectral lidar scanning method proposed according to the embodiments of this application is described.

[0058] Figure 5 This is a flowchart of an airborne hyperspectral lidar scanning method according to an embodiment of this application.

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

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

[0061] The target scanning parameters can be set according to specific circumstances, mainly including the scanning frequency repetition rate, the repetition rate of the emitted laser, and the energy power.

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

[0063] It is understood that the embodiments of this application can control the scanning mirror unit to perform scanning actions based on the target scanning parameters, and acquire the ground echo signal detected by the photoelectric detection unit and the angle encoding signal acquired by the angle encoding unit during the scanning process in the airborne hyperspectral lidar equipment, so as to perform time synchronization later.

[0064] In step S103, the ground echo signal and angle-coded signal are processed into time-synchronized frame data of angle and waveform using a time synchronizer.

[0065] It is understood that the embodiments of this application can use a time synchronizer to process the ground echo signal and the angle-encoded signal into time-synchronized frame data of angle and waveform, so as to achieve time synchronization, as follows.

[0066] In this embodiment, a time synchronizer is used to process ground echo signals and angle encoding information into time-synchronized frame data of angle and waveform. This includes: after detecting a ground echo signal, sending a first time command 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 command; if the ground echo signal exceeds the signal threshold, it returns the first command; sending a second time command to the waveform acquisition card based on the first command, and processing the angle encoding signal based on the second time command to obtain angle encoding information, wherein the waveform acquisition card is used to store the ground echo signal data; and generating time-synchronized frame data of angle and waveform based on the timing information and angle encoding information of the second time command.

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

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

[0069] The waveform acquisition card receives the time command O1 sent by the clock card and performs threshold recognition on the echo waveform signal entering the card. If the threshold is exceeded, it returns the clock card command A1.

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

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

[0072] It should be noted that the foregoing explanation of the airborne hyperspectral lidar scanning system embodiment also applies to the airborne hyperspectral lidar scanning method of this embodiment, and will not be repeated here.

[0073] The airborne hyperspectral lidar scanning method of this application is described below through a specific embodiment:

[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 trigger condition for the synchronization card signal recognition.

[0075] Step 2: After recognizing the laser trigger conditions, the clock synchronization card requests the threshold judgment result from the waveform acquisition card. If an echo waveform is detected by the hyperspectral lidar at this time, a trigger command is sent to the clock synchronization card. The clock synchronization card generates a clock synchronization trigger command to acquire laser multi-channel echo waveform data from all waveform acquisition cards, and generates trigger numbers (1,2,3,...,n) sequentially according to the accumulation rule starting from 1. The clock synchronization card uses each clock synchronization command 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 as synchronization frame data to the host computer through the PXIE backplane interface and stores it on a fixed path on the host computer's local hard drive.

[0076] According to the airborne hyperspectral lidar scanning method proposed in the embodiments of this application, the airborne hyperspectral lidar can be controlled to operate based on target scanning parameters, and the ground echo signal and angle coded signal are processed into time-synchronized frame data of angle and waveform based on a time synchronizer, that is, the echo signal and angle coded signal are accurately synchronized in time, which solves the problem of timing deviation between the scanning system and the ground echo signal measurement under the long-distance detection conditions of airborne hyperspectral lidar, thereby improving the quality of subsequent scanning imaging.

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

[0078] The memory 601, the processor 602, and the computer program stored on the memory 601 and capable of running on the processor 602.

[0079] When the processor 602 executes the program, it implements the airborne hyperspectral lidar scanning method provided in the above embodiments.

[0080] Furthermore, the host computer also includes:

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

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

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

[0084] If the memory 601, processor 602, and communication interface 603 are implemented independently, then the communication interface 603, memory 601, and processor 602 can be interconnected via a bus to complete communication between them. The bus can be an Industry Standard Architecture (ISA) bus, a Peripheral Component Interconnect (PCI) bus, or an Extended Industry Standard Architecture (EISA) bus, etc. The bus can be divided into address bus, data bus, control bus, etc. For ease of representation, Figure 6 The bus is represented by a single 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, processor 602, and communication interface 603 are integrated on a single chip, then the memory 601, processor 602, and communication interface 603 can communicate with each other through an internal interface.

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

[0087] This application also provides a computer-readable storage medium storing a computer program or instructions thereon, which, when executed by a processor, implements the above-described airborne hyperspectral lidar scanning method.

[0088] In the description of this specification, the description with reference to the terms "one embodiment", "some embodiments", "example", "specific example", or "some examples" 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 can be combined in any one or N embodiments or examples in a suitable manner. In addition, those skilled in the art can combine and combine different embodiments or examples described in this specification and features of different embodiments or examples without contradiction.

[0089] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be understood to indicate or imply relative importance or implicitly specify the number of technical features indicated. Thus, a feature specified as "first" or "second" may explicitly or implicitly include at least one such feature. In the description of this application, "N" means at least two, for example, two, three, etc., unless otherwise 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 a custom logical function or process step, and the scope of the preferred embodiments of the present application includes alternative implementations in which functions may be performed in a different order than shown or discussed, including performing functions in a substantially simultaneous manner or in a reverse order depending on the functions involved, which should be understood by those skilled in the art to which the embodiments of the present application pertain.

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

[0092] Those skilled in the art will understand that all or part of the steps of the methods in the above embodiments can be implemented by a program instructing related hardware. The program can be stored in a computer-readable storage medium, and when executed, the program includes one or a combination of the steps of the method embodiments.

Claims

1. An airborne hyperspectral lidar scanning system, characterized in that, include: An airborne hyperspectral lidar device, wherein the device includes a device body, a scanning mirror unit, a photoelectric detection unit and an angle encoding unit disposed on the device body, the scanning mirror unit reflects 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 acquires the angle encoding signal of the scanning process of the scanning mirror unit; The host computer includes a time synchronizer and a controller. The time synchronizer processes the ground echo signal and the angle-encoded signal into time-synchronized frame data of angle and waveform. The controller controls the scanning mirror unit to perform scanning actions according to the target scanning parameters. The time synchronizer is also used for: After detecting the ground echo signal, a first time command is sent to the waveform acquisition card. The waveform acquisition card performs a signal threshold judgment on the ground echo signal based on the first time command. If the ground echo signal exceeds the signal threshold, the first command is returned. Based on the first instruction, a second time instruction is sent to the waveform acquisition card, and the angle-coded signal is processed based on the second time instruction to obtain angle-coded information, wherein the waveform acquisition card is used to store the data of the ground echo signal; Based on the timing information of the second time instruction and the angle encoding information, time synchronization frame data of angle and waveform is generated.

2. The airborne hyperspectral lidar scanning system according to claim 1, characterized in that, 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 changes the spatial orientation of the normal vector on the scanning mirror by rotating it, thereby changing the emission direction of the scanning laser. The motor is used to drive the scanning mirror shaft and the scanning mirror to achieve rotational scanning.

3. The airborne hyperspectral lidar 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 angles at which the scanning laser scans the target; The grating-encoded reading head is used to read the angle markings generated during the scanning process and output a counting signal for each angle marking.

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

5. The airborne hyperspectral lidar scanning system according to claim 1, characterized in that, The host computer also includes a waveform acquisition card, used to acquire the ground echo signal and perform signal threshold judgment on the ground echo signal.

6. A scanning method for an airborne hyperspectral lidar, characterized in that, Includes the following steps: Obtain the target scanning parameters of the scanning laser; Based on the target scanning parameters, the scanning mirror unit is controlled to perform scanning actions and acquire the ground echo signal detected by the photoelectric detection unit and the angle encoding signal of the angle encoding unit. The ground echo signal and the angle-encoded signal are processed into time-synchronized frame data of angle and waveform using a time synchronizer. The step of processing the ground echo signal and the angle-encoded signal into time-synchronized frame data of angle and waveform using a time synchronizer includes: after detecting the ground echo signal, sending a first time command 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 command, and if the ground echo signal exceeds the signal threshold, returns the first command; sending a second time command to the waveform acquisition card based on the first command, and processing the angle-encoded signal to obtain angle-encoded information based on the second time command, 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 of the second time command and the angle-encoded information.

7. A host computer, characterized in that, include: The system includes a memory, a processor, and a computer program stored in the memory and executable on the processor, the processor executing the program to implement the airborne hyperspectral lidar scanning method as described in claim 6.

8. A computer-readable storage medium having a computer program or instructions stored thereon, characterized in that, The computer program or instructions are executed by a processor to implement the airborne hyperspectral lidar scanning method as described in claim 6.

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