A garden plant health condition detection and early warning system based on spectral analysis

Abstract

The application discloses a kind of garden plant health condition detection and early warning system based on spectral analysis, including adjustable frequency excitation light source, fluorescence detector, quadrature phase-locked demodulation module, phase frequency characteristic analysis module, early warning control unit and early warning output terminal, adjustable frequency excitation light source emits broadband sweep frequency modulation perturbation excitation light, quadrature phase-locked demodulation module executes operation filtering natural background stray light to the electric signal collected, phase frequency characteristic analysis module extracts characteristic relaxation frequency parameter when absolute phase delay parameter reaches forty-five degrees phase angle, early warning control unit sends instruction lock frequency and applies saturated light flash pulse, system calculates dynamic apparent electron transfer rate parameter, and according to temperature drift compensation baseline, executes double tolerance threshold comparison determination plant physiological stress state.The application avoids the defect of detection frequency band misplacement, eliminates the interference of strong background light and air temperature fluctuation, realizes the multi-dimensional joint early warning of early physiological stress.

Description

Technical Field

[0001] This invention relates to the field of garden plant monitoring technology, specifically to a garden plant health status detection and early warning system based on spectral analysis. Background Technology

[0002] Garden plants are the core carriers for the construction of urban ecosystems and the maintenance of landscape functions. Their healthy growth directly affects the city's ecological service capacity, the quality of the living environment, and the long-term stability of the garden green space system. As urban garden management models develop towards refinement and intelligence, higher requirements are placed on in-situ, non-destructive, and early detection technologies for the health status of garden plants. Detection technologies that can identify the internal physiological stress state of plants before visible changes occur in their appearance have become a core research and application direction in the field of garden plant management.

[0003] Currently, pulse-modulated fluorescence detection technology based on the principle of chlorophyll fluorescence dynamics has become the mainstream non-destructive detection method for plant physiological status and has been widely used in the field of garden plant health monitoring. To improve the environmental adaptability and physiological parameter acquisition capabilities of the detection process, the industry commonly employs excitation light control strategies such as multi-frequency flash, continuous frequency sweep, and variable frequency modulation. By adjusting the modulation frequency of the excitation light, plant light response curves and photosynthetic physiological parameters are obtained. For example, the technical solution disclosed in CN121164276A uses ambient light detection to regulate the PWM variable frequency signal driving the laser source, achieving dynamic adjustment of the excitation light frequency. Simultaneously, the industry also commonly combines multispectral laser excitation and hyperspectral imaging technologies. For instance, CN120668875A uses hyperspectral stimulated Raman scattering imaging technology to achieve quantitative detection of plant physiological indicators. All of these technologies provide data support for the assessment of the health status of garden plants.

[0004] However, in practical applications of in-situ detection of garden plants in the field, existing fluorescence detection technologies based on frequency conversion and sweep frequency modulation use an open-loop control mode for adjusting and scanning the excitation light frequency, which is unrelated to the real-time biochemical relaxation state of the plant's own photosynthetic system. This makes it impossible to locate the characteristic response frequency that is completely matched with the plant's current physiological state by analyzing the phase frequency characteristics of the plant's fluorescence response, and even more impossible to form an adaptive closed-loop matching mechanism between the excitation light modulation frequency and the biochemical relaxation characteristics of the plant's photosynthetic system. This systemic defect makes the excitation light frequency easily deviate from the sensitive response range of the plant's photosynthetic system. This not only makes it difficult to accurately capture the subtle changes in biochemical characteristics that occur when plants suffer early physiological stress, but also further exacerbates the problems of insufficient signal-to-noise ratio and parameter drift in the complex environment of strong background stray light and frequent temperature fluctuations in gardens in the field. Ultimately, it is impossible to achieve high-sensitivity, high-reliability detection and stable early warning of early physiological stress in garden plants. Summary of the Invention

[0005] The technical problem to be solved by this invention is the omission of biochemical response information of target garden plants caused by strong outdoor background light interference and fixed frequency detection.

[0006] A system for detecting and warning the health status of garden plants based on spectral analysis includes an tunable excitation light source, a fluorescence detector, an orthogonal phase-locked demodulation module, a phase-frequency characteristic analysis module, an early warning control unit, and an early warning output terminal.

[0007] A frequency-tunable excitation source emits broadband swept-frequency modulated perturbation excitation light with continuously varying frequency towards the target garden plants. A fluorescence detector collects the mixed light signal, which includes dynamic fluorescence response signals and stray light from the natural background, after the target garden plants are stimulated, and converts the mixed light signal into an electrical signal. The quadrature phase-locked demodulation module uses the digital reference clock signal output from the early warning control unit to perform phase-locked demodulation on the electrical signal, filtering out the interference components of stray light from the natural background, and outputting in-phase and quadrature component signals.

[0008] As a further improvement of the present invention, the early warning control unit sets the impedance characteristic threshold condition to a 45-degree phase angle; when the physical condition that the tangent of the absolute phase delay parameter is equal to one is met, the phase frequency characteristic analysis module defines the extracted instantaneous excitation frequency value as the characteristic relaxation frequency parameter; the value of the characteristic relaxation frequency parameter is equal to the reciprocal of the product of the biochemical relaxation time parameter of the target garden plant, the constant of pi, and the constant 2.

[0009] The early warning control unit sends a frequency locking command to the tunable excitation source based on the calculated characteristic relaxation frequency parameter, forming an adaptive closed-loop feedback control loop. The tunable excitation source outputs constant-frequency perturbation excitation light with a modulation frequency fixed at the characteristic relaxation frequency parameter value, and applies a saturation flash pulse at a specific time node.

[0010] As a further improvement of the present invention, the system also includes an ambient photosynthetically active radiation sensor. The phase-frequency characteristic analysis module extracts the mean value of the fluorescence response amplitude parameter sequence during the constant-frequency perturbation excitation light irradiation stage, defining it as the normal locked demodulation amplitude parameter. It extracts the maximum value from the transient fluorescence response amplitude parameter sequence during the saturated flash pulse irradiation stage, defining it as the transient maximum demodulation amplitude parameter. The phase-frequency characteristic analysis module establishes a dynamic apparent electron transport rate calculation model. The value of the dynamic apparent electron transport rate parameter is equal to the product of the photosynthetically active radiation parameter collected by the ambient photosynthetically active radiation sensor, the standard absorption coefficient pre-stored in the system, and the quotient of the difference between the transient maximum demodulation amplitude parameter and the normal locked demodulation amplitude parameter divided by the transient maximum demodulation amplitude parameter.

[0011] As a further improvement of the present invention, the system also includes an ambient temperature sensor. Based on the ambient temperature values ​​collected by the sensor, the early warning control unit performs temperature drift compensation calculations on the pre-written reference characteristic frequency values ​​and reference electron transport rate values ​​under standard temperature conditions, and outputs the temperature-compensated characteristic frequency baseline and the temperature-compensated electron transport baseline. The early warning control unit extracts the frequency offset value of the characteristic relaxation frequency parameter from the temperature-compensated characteristic frequency baseline, and extracts the rate attenuation value of the dynamic apparent electron transport rate parameter below the temperature-compensated electron transport baseline. When the frequency offset value is greater than the frequency tolerance threshold and the rate attenuation value is greater than the rate tolerance threshold, the target garden plant is determined to be under physiological stress, and a diagnostic report is output through the early warning output terminal.

[0012] As a further improvement of the present invention, the fluorescence detector is connected to a signal conditioning circuit including a DC cancellation loop. The DC cancellation loop extracts the DC voltage component at the output node of the transimpedance amplifier and converts it into a reverse compensation current injected into the transimpedance amplifier to cancel the DC photocurrent component in the electrical signal. The quadrature phase-locked demodulation module has a phase compensation reference loop connected in series. This loop pre-stores the hardware phase offset caused by the system's physical links and performs phase lead pre-compensation on the initial in-phase reference signal. The phase-frequency characteristic analysis module embeds a coordinate rotating digital computer hardware logic core, employing a shift-addition iterative arithmetic architecture to perform arctangent and square root calculations at the hardware level. The system is configured with a multi-rotor UAV as a mobile detection platform, equipped with a three-axis mechanical anti-shake gimbal, an independent transient energy storage power supply module, and an edge computing motherboard. The tunable excitation light source and the fluorescence detector are fixed to the three-axis mechanical anti-shake gimbal. The quadrature phase-locked demodulation module and the phase-frequency characteristic analysis module are integrated into the edge computing motherboard to complete local computation.

[0013] The present invention, by adopting the above technical solution, can bring the following beneficial effects:

[0014] 1. This invention drives a frequency-adjustable excitation light source to emit broadband swept-frequency modulated perturbation excitation light through an early warning control unit. When the absolute phase delay parameter reaches a 45-degree phase angle, the phase frequency characteristic analysis module extracts the characteristic relaxation frequency parameter and feeds it back to the frequency-adjustable excitation light source for frequency locking. This constructs an adaptive closed-loop feedback control loop, avoiding the technical defects of fixed-frequency detection that leads to misalignment of the sensitive response frequency band. It achieves dynamic tracking and physical impedance matching of the relaxation characteristics of target garden plants under different physiological states.

[0015] 2. This invention utilizes a DC cancellation circuit connected in parallel within a signal conditioning circuit comprising an avalanche photodiode and a transimpedance amplifier. This DC cancellation circuit extracts the DC voltage component at the output node of the transimpedance amplifier and converts it into a reverse compensation current injected into the input node of the transimpedance amplifier. This cancels the DC photocurrent component generated by stray light from the natural background in the hardware circuit, preventing the transimpedance amplifier from overloading under strong background light illumination. This achieves stable extraction and signal conditioning of AC fluorescence response signals in complex outdoor lighting environments.

[0016] 3. This invention uses a baseline temperature compensation logic core to perform temperature drift compensation calculations on pre-written reference characteristic frequency values ​​and reference electron transfer rate values ​​based on the ambient temperature values ​​collected by the ambient temperature sensor, and outputs two sets of temperature compensation baselines. By using a state discriminator to perform a double tolerance threshold comparison in combination with the frequency offset value and the rate attenuation value, the interference of single parameter data fluctuations caused by non-physiological stress environmental factors such as temperature fluctuations is eliminated, and a multi-dimensional joint early warning and discrimination effect for early physiological stress of target garden plants is achieved. Attached Figure Description

[0017] Figure 1 This is a block diagram of the overall physical architecture of the system of the present invention;

[0018] Figure 2 This is a flowchart illustrating the overall workflow of the present invention.

[0019] Figure 3 This is a diagram of the closed-loop optimization mechanism and feature frequency adaptive locking logic of the present invention.

[0020] Figure 4 This is a schematic diagram of the configuration structure of the detection platform of the present invention. Detailed Implementation

[0021] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0022] See attached document Figure 1 , Figure 1 This is an architectural diagram of a garden plant health status detection and early warning system based on spectral analysis according to an embodiment of the present invention. The present invention provides a garden plant health status detection and early warning system based on spectral analysis, including a tunable excitation light source, a fluorescence detector, an orthogonal phase-locked demodulation module, a phase-frequency characteristic analysis module, an early warning control unit, and an early warning output terminal.

[0023] A frequency-tunable excitation source is located at the signal transmitting end of the system, and its emitted light path is directed towards the target garden plant. A fluorescence detector is located at the signal receiving end of the system, and its optical field of view covers the area of ​​the target garden plant illuminated by the frequency-tunable excitation source.

[0024] The signal input terminal of the quadrature phase-locked demodulation module is connected to the signal output terminal of the fluorescence detector, and the synchronization reference terminal of the quadrature phase-locked demodulation module is connected to the reference signal output terminal of the early warning control unit.

[0025] The signal input terminal of the phase-frequency characteristic analysis module is connected to the data output terminal of the quadrature phase-locked demodulation module. The first port of the early warning control unit is connected to the output terminal of the phase-frequency characteristic analysis module, the second port of the early warning control unit is connected to the modulation control terminal of the tunable excitation light source, and the third port of the early warning control unit is connected to the early warning output terminal. A feedback loop is formed in the system physical architecture through the tunable excitation light source, fluorescence detector, quadrature phase-locked demodulation module, phase-frequency characteristic analysis module, early warning control unit, and early warning output terminal.

[0026] See attached document Figure 2 , Figure 2 This is a system flowchart according to an embodiment of the present invention. After the system is initially started and the detection parameters are configured, the early warning control unit outputs a sweep frequency control command to the tunable frequency excitation light source. The tunable frequency excitation light source emits broadband sweep frequency modulated perturbation excitation light with continuously varying frequency to the target garden plants according to the sweep frequency control command.

[0027] The fluorescence detector collects optical signals within its field of view. These signals include the dynamic fluorescence response signal generated by the target garden plant under broadband swept-frequency modulated perturbation excitation light, as well as stray light from the natural background in the environment. The fluorescence detector converts the received mixed optical signal, containing the dynamic fluorescence response signal and stray light from the natural background, into an electrical signal, which is then transmitted to the quadrature phase-locked demodulation module.

[0028] The quadrature phase-locked loop (QPL) demodulation module receives the electrical signal generated from the mixed optical signal. It then performs multiplication and integration operations on the electrical signal using a digital reference clock signal obtained from the early warning control unit. The QPL demodulation module filters out stray light interference components from the electrical signal that are not at the same frequency as the digital reference clock signal in its hardware circuitry. Subsequently, the QPL demodulation module outputs in-phase and quadrature component signals to the phase-frequency characteristic analysis module.

[0029] The phase-frequency characteristic analysis module calculates the fluorescence amplitude parameter and absolute phase delay parameter under the instantaneous excitation frequency condition based on the received in-phase and quadrature component signals. The module then compares the calculated absolute phase delay parameter with a preset impedance characteristic threshold condition.

[0030] When the absolute phase delay parameter does not reach the impedance characteristic threshold condition, the system maintains the frequency sweep state, and the tunable excitation light source continues to perform frequency conversion.

[0031] When the absolute phase delay parameter reaches the impedance characteristic threshold condition, the phase frequency characteristic analysis module extracts the excitation frequency value corresponding to the instant the absolute phase delay parameter reaches the impedance characteristic threshold condition. The phase frequency characteristic analysis module uses the extracted excitation frequency value as the current characteristic relaxation frequency of the target garden plant. The early warning control unit receives the characteristic relaxation frequency and sends a frequency locking command to the tunable excitation light source.

[0032] The tunable excitation source terminates the broadband sweep sequence according to the frequency locking command, and continuously excites the output optical signal with the modulation frequency fixed at the characteristic relaxation frequency value. In the frequency-locked state, the tunable excitation source applies saturation flash pulses superimposed at specific preset time nodes.

[0033] The phase-frequency characteristic analysis module calculates the dynamic apparent electron transport rate parameter based on the fluorescence amplitude parameter data output by the quadrature phase-locked demodulation module in the frequency-locked state and during the saturation flash pulse.

[0034] The early warning control unit retrieves the pre-stored reference frequency and calculates the offset of the current characteristic relaxation frequency value relative to the reference frequency. Combining the characteristic relaxation frequency offset with the attenuation value of the dynamic apparent electron transport rate parameter, the early warning control unit determines the plant stress state. Based on the plant stress state determination result, the early warning control unit outputs a diagnostic report and alarm prompt through the early warning output terminal.

[0035] The tunable excitation light source provided by the present invention includes an array of light-emitting units, a high-frequency driving circuit board, an optical lens group, and a heat dissipation substrate.

[0036] The light-emitting unit array is composed of monochromatic light-emitting diodes arranged in a matrix. The emission spectrum of the array covers the photosynthetically active radiation band of plants. The array includes red light-emitting diodes emitting wavelengths in the red light band and blue light-emitting diodes emitting wavelengths in the blue light band. The center wavelength of the red light band is set in the range of 620 nm to 680 nm. The center wavelength of the blue light band is set in the range of 450 nm to 480 nm. The emission wavelength ranges of the red and blue light-emitting diodes coincide with the absorption peak band of plant chlorophyll.

[0037] Red and blue light-emitting diodes (LEDs) are arranged in an alternating array on the substrate surface of the light-emitting unit array. The LED array is mounted on the heat-conducting surface of a heat-dissipating substrate. The heat-dissipating substrate dissipates the heat generated by the red and blue LEDs during operation and maintains the stability of their emission wavelengths. An optical lens group is located on the light-emitting side of the LED array. The optical lens group focuses the light beam generated by the LED array. The optical lens group shapes the light beam into a surface light source with uniform irradiance and projects it onto the canopy area of ​​the target garden plant. The surface light source ensures that the excitation photon flux density received by the leaves within the canopy area of ​​the target garden plant is consistent.

[0038] The power output terminal of the high-frequency drive circuit board is connected to the input terminal of the light-emitting unit array. The high-frequency drive circuit board embeds high-speed power switching devices. It receives frequency sweep control commands from the early warning control unit. Based on these commands, the high-frequency drive circuit board adjusts the drive current parameters input to the light-emitting unit array.

[0039] The drive current output from the high-frequency driver circuit board includes a DC bias current component and an AC modulation current component. The DC bias current component drives the light-emitting unit array to generate background excitation light with a constant intensity. This background excitation light is projected onto the target garden plants to maintain their basic photosynthesis. The AC modulation current component drives the light-emitting unit array to generate modulated light with intensity fluctuating over time. The frequency of the AC modulation current component changes continuously over time according to a sweep frequency control command, driving the light-emitting unit array to generate broadband sweep frequency modulation perturbation excitation light with continuously changing frequency. This broadband sweep frequency modulation perturbation excitation light is input into the photosynthetic electron transport chain of the target garden plants. The red and blue light-emitting diodes embedded in the light-emitting unit array have microsecond-level optical power switching response rates to meet the signal response requirements of the system's broadband sweep frequency excitation.

[0040] The system provided by this invention includes a signal generation module inside the early warning control unit and a current regulation circuit inside the high-frequency drive circuit board.

[0041] The signal generation module incorporates a direct digital frequency synthesizer (DDP). The DDP generates a digital waveform sequence of a swept-frequency modulated signal based on the global system clock. The DDP has two independent, parallel synchronous output channels: a first synchronous output channel and a second synchronous output channel. The first synchronous output channel converts the digital waveform sequence into a continuous analog voltage control signal via a digital-to-analog converter (DAC). This analog voltage control signal is then output to the high-frequency driver circuit board. The second synchronous output channel outputs a digital reference clock signal to the quadrature phase-locked demodulation (QLL) module. The digital reference clock signal is strictly synchronized with the analog voltage control signal and is phase-locked. The digital reference clock signal provides the physical time reference for the phase resolution operation of the QLL module.

[0042] The high-frequency driver circuit board receives analog voltage control signals. Based on these signals, the circuit board adjusts the drive current parameters output to the LED array in real time. The system employs a linear broadband frequency sweep mode. The starting frequency for the linear broadband frequency sweep is set to... The rate of change of frequency The time-domain model of the excitation light intensity output by the light-emitting unit array is expressed as:

[0043]

[0044] In the formula, This represents the instantaneous excitation light intensity output by the light-emitting unit array; Indicates DC bias light intensity parameters; This represents the amplitude parameter of the AC-modulated light intensity. This represents the perturbation scan time variable. The frequency value of the instantaneous excitation light intensity increases linearly with the perturbation scan time variable.

[0045] The high-frequency drive circuit board independently controls the output ratio of the DC bias light intensity parameter and the AC modulation light intensity amplitude parameter. The DC bias light intensity parameter provides a steady-state irradiation background for the target garden plants. The AC modulation light intensity amplitude parameter forms an AC modulation current component with continuously varying frequency. The AC modulation current component drives the light-emitting unit array to output continuous broadband swept-frequency modulated perturbation excitation light. The broadband swept-frequency modulated perturbation excitation light covers the biochemical response frequency band of the photosynthetic electron transport chain of the target garden plants in the frequency domain. The broadband swept-frequency modulated perturbation excitation light provides continuous physical excitation input for the phase frequency characteristic analysis module to find characteristic relaxation frequencies.

[0046] The system provided by this invention includes a fluorescence detector and a signal conditioning circuit connected to the fluorescence detector. The fluorescence detector includes a narrowband interference filter, an avalanche photodiode, and a semiconductor cooling component. The signal conditioning circuit includes a transimpedance amplifier and a DC cancellation circuit.

[0047] A narrowband interference filter is placed on the light-receiving side of the avalanche photodiode. The transmission center wavelength of the narrowband interference filter is set at the peak of chlorophyll fluorescence emission in plants. The narrowband interference filter blocks reflected light emitted by the tunable excitation source and ambient sunlight from entering the avalanche photodiode.

[0048] The avalanche photodiode is mounted on the cooling surface of a semiconductor cooling system. The semiconductor cooling system maintains the physical operating temperature of the avalanche photodiode at a set value. This system prevents the avalanche gain coefficient from drifting due to temperature fluctuations in the outdoor environment, ensuring the stability of the photoelectric conversion rate of the avalanche photodiode.

[0049] An avalanche photodiode receives an optical signal passing through a narrowband interference filter. The avalanche photodiode converts the optical signal into a photocurrent signal. The optical signal contains natural background stray light and an AC fluorescence response signal. The photocurrent signal contains a DC photocurrent component, an AC perturbation photocurrent component, and a system noise current component. The DC photocurrent component is induced by both natural background stray light and DC bias excitation light. The AC perturbation photocurrent component is induced by broadband swept-frequency modulated perturbation excitation light.

[0050] The input of the transimpedance amplifier is connected to the signal output of the avalanche photodiode. The outdoor solar illuminance is much greater than the illuminance of the AC fluorescence response signal, and the DC photocurrent component of the photocurrent signal is much greater than the AC perturbation photocurrent component. Directly amplifying the photocurrent signal would cause the transimpedance amplifier to reach output saturation.

[0051] A DC-DC cancellation circuit is connected in parallel between the input and output terminals of the transimpedance amplifier. The DC-DC cancellation circuit extracts the DC voltage component at the output node of the transimpedance amplifier. The DC-DC cancellation circuit converts this DC voltage component into a reverse compensation current. The DC-DC cancellation circuit injects this reverse compensation current into the input node of the transimpedance amplifier.

[0052] The reverse compensation current cancels the DC photocurrent component at the input of the transimpedance amplifier. The transimpedance amplifier only amplifies the AC perturbation photocurrent component and the system noise current component. The DC cancellation loop prevents the signal conditioning circuit from overloading under ambient sunlight. The transimpedance amplifier outputs the amplified AC voltage signal to the quadrature phase-locked demodulation module.

[0053] The quadrature phase-locked demodulation module provided by the present invention includes a reference signal generation sub-circuit, a phase shifter, a first multiplier, a second multiplier, a first low-pass filter, a second low-pass filter, and a phase compensation reference circuit.

[0054] The signal input terminal of the quadrature phase-locked loop (QPL) demodulation module is connected to the transimpedance amplifier within the signal conditioning circuit. The transimpedance amplifier transmits an AC voltage signal to the signal input terminal of the QPL demodulation module. The synchronization reference terminal of the QPL demodulation module is connected to the signal generation module within the early warning control unit. The synchronization reference terminal of the QPL demodulation module receives the digital reference clock signal emitted by the signal generation module.

[0055] The reference signal generation sub-circuit generates an initial in-phase reference signal based on a digital reference clock signal. There is a hardware propagation time difference when the AC voltage signal flows through the avalanche photodiode and the transimpedance amplifier; this hardware propagation time difference introduces a fixed hardware phase offset.

[0056] A phase compensation reference circuit is connected in series between the reference signal generation sub-circuit and the subsequent multiplication unit. The phase compensation reference circuit pre-stores the hardware phase offset caused by the system's physical link. The phase compensation reference circuit extracts the initial in-phase reference signal. Based on the hardware phase offset, the phase compensation reference circuit performs phase lead pre-compensation on the initial in-phase reference signal. The phase compensation reference circuit outputs a compensated in-phase reference signal. The compensated in-phase reference signal eliminates the static transmission error caused by the system's physical link in the time domain.

[0057] The input of the phase shifter receives a compensating in-phase reference signal. The phase shifter delays the phase of the compensating in-phase reference signal by 90 degrees, and outputs a quadrature reference signal.

[0058] The first multiplier receives an AC voltage signal and a compensated in-phase reference signal at its inputs. It performs a multiplication operation on the AC voltage signal and the compensated in-phase reference signal. The first multiplier outputs a first mixer signal. The second multiplier receives an AC voltage signal and a quadrature reference signal at its inputs. It performs a multiplication operation on the AC voltage signal and the quadrature reference signal. The second multiplier outputs a second mixer signal.

[0059] The input of the first low-pass filter is connected to the output of the first multiplier. The first low-pass filter performs integration on the first mixer signal. The first low-pass filter blocks the harmonic components and interference components that are not at the same frequency as the digital reference clock signal in the first mixer signal. The first low-pass filter outputs a DC in-phase component signal to the subsequent module.

[0060] The input of the second low-pass filter is connected to the output of the second multiplier. The second low-pass filter performs integration on the second mixer signal. It blocks harmonic components and interference components that are not at the same frequency as the digital reference clock signal in the second mixer signal. The second low-pass filter outputs a DC quadrature component signal to the subsequent module.

[0061] The first and second low-pass filters, based on the principle of orthogonality, remove residual noise components from natural background stray light in the frequency domain. The voltage value of the DC in-phase component signal is directly proportional to the amplitude of the in-phase component in the AC voltage signal. The voltage value of the DC quadrature component signal is directly proportional to the amplitude of the quadrature component in the AC voltage signal.

[0062] The signal outputs of the first and second low-pass filters are connected to the phase-frequency characteristic analysis module. The quadrature phase-locked demodulation module synchronously transmits the DC in-phase component signal and the DC quadrature component signal to the phase-frequency characteristic analysis module. The quadrature phase-locked demodulation module provides the extracted demodulated data for the impedance characteristic calculation step of the phase-frequency characteristic analysis module.

[0063] The phase frequency characteristic analysis module provided by this invention includes a data sampling unit, a phase frequency calculation unit, and a sliding filter unit.

[0064] The input of the data sampling unit is connected to the signal output of the quadrature phase-locked demodulation module. The data sampling unit receives the DC in-phase component signal and the DC quadrature component signal transmitted from the quadrature phase-locked demodulation module. The data sampling unit performs analog-to-digital conversion on the DC in-phase component signal and the DC quadrature component signal. The data sampling unit then transmits the converted digital in-phase component signal and digital quadrature component signal to the phase frequency calculation unit.

[0065] The phase-frequency calculation unit embeds a coordinate-rotating digital computer hardware logic core. The phase-frequency calculation unit inputs the digital in-phase component signal and the digital quadrature component signal into the coordinate-rotating digital computer hardware logic core. The coordinate-rotating digital computer hardware logic core employs a shift-addition iterative operation architecture. Replacing floating-point multiplier hardware resources, the coordinate-rotating digital computer hardware logic core can perform arctangent and square root calculations at the hardware level.

[0066] The phase-frequency decoding unit processes the received digital in-phase and digital quadrature component signals using a coordinate-rotating digital computer hardware logic core. The unit extracts the sum of squares of the in-phase and quadrature component signals. It then performs a square root operation on this sum. Finally, the unit obtains the fluorescence response amplitude parameter under the instantaneous excitation frequency condition through this square root operation.

[0067] The phase-frequency decoding unit extracts the numerical ratio of the digital quadrature component signal to the digital in-phase component signal. The phase-frequency decoding unit then performs an arctangent calculation on this numerical ratio. Through the arctangent calculation, the phase-frequency decoding unit obtains the absolute phase delay parameter of the target garden plant under the instantaneous excitation frequency condition.

[0068] Shot noise interference exists in the photoelectric conversion process, causing numerical jitter in the fluorescence response amplitude parameter sequence and the absolute phase delay parameter sequence. The sliding filter unit is connected to the data output of the phase-frequency calculation unit. The sliding filter unit receives the continuously calculated fluorescence response amplitude parameter sequence and absolute phase delay parameter sequence.

[0069] The sliding filter unit has a fixed-capacity data update window. It moves the latest calculated parameter data into the update window and simultaneously removes the oldest parameter data from it. The sliding filter unit then performs an arithmetic mean operation on the set of values ​​within the update window.

[0070] The sliding filter unit smooths the fluorescence response amplitude parameter sequence and the absolute phase delay parameter sequence through arithmetic averaging. The sliding filter unit removes high-frequency abrupt changes in the parameter sequences. The phase-frequency characteristic analysis module outputs the smoothed fluorescence response amplitude parameter and absolute phase delay parameter. The phase-frequency characteristic analysis module continuously provides filtered phase-frequency data to the early warning control unit.

[0071] See attached document Figure 3 The early warning control unit provided by this invention includes a threshold comparator, a digital phase-locked loop control logic core, and a frequency generation register. The data output terminal of the phase-frequency characteristic analysis module is connected to the data input terminal of the early warning control unit.

[0072] The phase-frequency characteristic analysis module continuously transmits a smoothed sequence of absolute phase delay parameters to the early warning control unit. The photosynthetic electron transport chain within the target garden plant is equivalent to a first-order low-pass biochemical relaxation system in the kinetic model. This first-order low-pass biochemical relaxation system possesses a biochemical relaxation time parameter. This biochemical relaxation time parameter characterizes the time-dependent physical quantity of electron transfer from the primary quinone acceptor to the secondary quinone acceptor.

[0073] As the instantaneous excitation frequency of the broadband swept-frequency modulated perturbation excitation light increases, the absolute phase delay parameter output by the phase-frequency characteristic analysis module undergoes a nonlinear deflection. The characteristic phase threshold value is pre-written into the memory of the early warning control unit. Based on a first-order low-pass biochemical relaxation system model, the early warning control unit sets the characteristic phase threshold value to a quarter of pi in radians (i.e., a 45-degree phase angle). The characteristic phase threshold value characterizes the physical impedance boundary of the photosynthetic electron transport chain of the target garden plant.

[0074] The threshold comparator compares the received absolute phase delay parameter with the characteristic phase threshold value in real time. When the absolute phase delay parameter reaches the characteristic phase threshold value, i.e., when the physical condition that the tangent of the absolute phase delay parameter equals one is met, the threshold comparator extracts the instantaneous excitation frequency value corresponding to the moment of successful comparison. The early warning control unit defines the extracted instantaneous excitation frequency value as the characteristic relaxation frequency parameter.

[0075] The characteristic relaxation frequency parameter and the biochemical relaxation time parameter within the target garden plant satisfy the following algebraic correlation model:

[0076]

[0077] In the formula, This represents the characteristic relaxation frequency parameter obtained from the solution; This parameter represents the current biochemical relaxation time of the photosynthetic electron transport chain. This represents the constant value of pi.

[0078] When the absolute phase delay parameter reaches the characteristic phase threshold value, the early warning control unit generates a hardware interrupt trigger signal. This signal activates the digital phase-locked loop (PLL) control logic core. The PLL control logic core writes the control word corresponding to the characteristic relaxation frequency parameter to the frequency generation register. The frequency generation register then blocks the initial broadband frequency sweep control command issued by the early warning control unit.

[0079] The early warning control unit outputs a frequency lock command to the tunable excitation source via the frequency generation register. The frequency lock command fixes the modulation frequency parameter of the tunable excitation source at the characteristic relaxation frequency parameter value. The tunable excitation source terminates continuous frequency changing operations. The tunable excitation source outputs constant-frequency perturbation excitation light with a fixed modulation frequency.

[0080] The modulation frequency of the constant-frequency perturbation excitation light achieves physical impedance matching with the internal biochemical response rate of the photosynthetic electron transport chain of the target garden plant. The digital phase-locked loop control logic core, the tunable excitation light source, and the phase-frequency characteristic analysis module constitute an adaptive closed-loop feedback control loop at the system architecture level. This adaptive closed-loop feedback control loop maintains the modulation frequency parameter of the tunable excitation light source consistent with the reciprocal of the biochemical relaxation time parameter.

[0081] The system provided by this invention also includes an ambient photosynthetically active radiation sensor. The phase-frequency characteristic analysis module also integrates a data buffer register, a transient saturation control logic core, and a dynamic parameter calculation logic core.

[0082] The tunable frequency excitation source receives a frequency locking command from the early warning control unit. The tunable frequency excitation source outputs constant-frequency perturbation excitation light. The modulation frequency of the constant-frequency perturbation excitation light is equal to the characteristic relaxation frequency parameter. During the constant-frequency perturbation excitation light irradiation phase, the phase-frequency characteristic analysis module continuously receives the fluorescence response amplitude parameter transmitted by the quadrature phase-locked demodulation module.

[0083] The data buffer register records the fluorescence response amplitude parameter sequence. The kinetic parameter calculation logic core performs mean calculation on the fluorescence response amplitude parameter sequence. The kinetic parameter calculation logic core extracts the mean calculation result and defines it as the normal-locked demodulated amplitude parameter. The normal-locked demodulated amplitude parameter characterizes the basic photochemical response state of the target garden plant under the characteristic relaxation frequency condition.

[0084] The transient saturation control logic core sends a pulse trigger request to the early warning control unit. The early warning control unit receives the pulse trigger request and outputs a control level to the tunable excitation light source. Simultaneously emitting constant-frequency perturbation excitation light, the tunable excitation light source superimposes saturation flash pulses onto the target garden plants. The photon flux density of the saturation flash pulses is higher than the light saturation point of the target garden plants.

[0085] The saturated flash pulse forces the photosystem II reaction centers inside the target garden plant into a closed state. During the saturated flash pulse irradiation phase, the quadrature phase-locked demodulation module outputs transient fluorescence response amplitude parameters to the phase-frequency characteristic analysis module. A data buffer register stores the sequence of transient fluorescence response amplitude parameters. The kinetic parameter calculation logic core extracts the maximum value from the transient fluorescence response amplitude parameter sequence. The kinetic parameter calculation logic core defines the maximum value as the transient maximum demodulation amplitude parameter.

[0086] An environmental photosynthetically active radiation (EPA) sensor collects the effective photon flux density under test conditions. The EPA sensor converts the effective photon flux density into photosynthetically active radiation parameters. The EPA sensor then transmits these parameters to a kinetic parameter calculation logic core. The kinetic parameter calculation logic core retrieves the standard absorption coefficient from the system memory. The kinetic parameter calculation logic core then establishes a dynamic apparent electron transport rate calculation model.

[0087]

[0088] In the formula, This represents the dynamic apparent electron transport rate parameter obtained from the solution; Indicates the standard absorption coefficient; Indicates the photosynthetically active radiation parameter; This represents the parameter indicating the maximum transient demodulation amplitude. This indicates the normal locking demodulation amplitude parameter.

[0089] The dynamic apparent electron transport rate parameter characterizes the photochemical electron transport capacity of the target garden plant under the current characteristic relaxation frequency conditions. The kinetic parameter calculation logic kernel transmits the dynamic apparent electron transport rate parameter to the early warning control unit. Upon receiving the dynamic apparent electron transport rate parameter, the early warning control unit executes the subsequent stress state discrimination procedure.

[0090] The early warning control unit also integrates a storage medium, a baseline temperature compensation logic core, a deviation calculation logic core, and a status discriminator. The system also includes an ambient temperature sensor. The signal output of the ambient temperature sensor is connected to the early warning control unit. The communication port of the early warning control unit is connected to the early warning output terminal.

[0091] The phase frequency characteristic analysis module continuously transmits characteristic relaxation frequency parameters and dynamic apparent electron transfer rate parameters to the early warning control unit. The storage medium contains pre-written reference characteristic frequency values ​​and reference electron transfer rate values ​​of the target garden plants under standard temperature conditions.

[0092] An ambient temperature sensor collects the ambient temperature data of the environment in which the target garden plants are located. The sensor transmits this data to a baseline temperature compensation logic core. This core retrieves the reference characteristic frequency and reference electron transport rate values. Based on the ambient temperature data, the core performs temperature drift compensation calculations on the reference characteristic frequency and electron transport rate values. Finally, the core outputs the temperature-compensated characteristic frequency baseline and the temperature-compensated electron transport rate baseline.

[0093] The deviation calculation logic core retrieves the characteristic relaxation frequency parameter and the temperature-compensated characteristic frequency baseline. It then performs an absolute difference calculation on the characteristic relaxation frequency parameter and the temperature-compensated characteristic frequency baseline. Finally, the deviation calculation logic core extracts the frequency offset value of the characteristic relaxation frequency parameter from the temperature-compensated characteristic frequency baseline.

[0094] The deviation calculation logic core retrieves the dynamic apparent electron transport rate parameter and the temperature-compensated electron transport baseline. It then performs a subtraction operation between the temperature-compensated electron transport baseline and the dynamic apparent electron transport rate parameter. Finally, the deviation calculation logic core extracts the rate attenuation value where the dynamic apparent electron transport rate parameter is lower than the temperature-compensated electron transport baseline.

[0095] The state discriminator has internally set frequency tolerance thresholds and rate tolerance thresholds. It receives the frequency offset and rate attenuation values ​​output by the deviation calculation logic core. The state discriminator compares the frequency offset value with the frequency tolerance threshold, and simultaneously compares the rate attenuation value with the rate tolerance threshold.

[0096] When the frequency offset value is greater than the frequency tolerance threshold and the rate attenuation value is greater than the rate tolerance threshold, the state discriminator determines that the target garden plant is in a state of physiological stress.

[0097] After the state discriminator outputs the physiological stress state determination result, the early warning control unit generates a physiological stress early warning command. The early warning control unit transmits the physiological stress early warning command to the early warning output terminal. The early warning output terminal receives the physiological stress early warning command. The early warning output terminal outputs a diagnostic data report containing frequency offset and rate attenuation values. The early warning output terminal simultaneously triggers an audible and visual alarm signal.

[0098] See attached document Figure 4 The garden plant health status detection and early warning system based on spectral analysis provided by this invention is equipped with a mobile detection platform and a fixed detection platform.

[0099] The mobile detection platform utilizes a multi-rotor drone. The multi-rotor drone is equipped with a three-axis mechanically stabilized gimbal and an independent transient energy storage and power supply module. A frequency-adjustable excitation light source and a fluorescence detector are fixedly mounted on the equipment carrier end of the three-axis mechanically stabilized gimbal.

[0100] The three-axis mechanical gimbal counteracts the mechanical vibrations generated by the multi-rotor drone while hovering. It maintains the transmitted light path of the tunable excitation source aligned with the canopy area of ​​the target garden plants. The three-axis mechanical gimbal prevents spatial displacement of the transmitted light path and avoids the introduction of spatial phase noise into the optical signal transmission path.

[0101] The independent transient energy storage power supply module incorporates a supercapacitor component. This module provides instantaneous high-current support for the tunable excitation light source when emitting saturated flash pulses. It also isolates the system's test load circuit from the flight control power supply of the multi-rotor UAV.

[0102] The fixed detection platform includes a mounting pole, a dual-axis stepping gimbal, and a solar power supply. The dual-axis stepping gimbal is fixed to the top of the mounting pole. An adjustable frequency excitation source and a fluorescence detector are mounted on the dual-axis stepping gimbal. The dual-axis stepping gimbal performs horizontal rotation and pitch adjustment movements according to the scanning sequence issued by the early warning control unit. The dual-axis stepping gimbal guides the adjustable frequency excitation source to scan the target garden plants. The solar power supply provides power to the fixed detection platform.

[0103] Both mobile and fixed detection platforms are equipped with an edge computing motherboard and a wireless data transceiver terminal. The quadrature phase-locked demodulation module and phase-frequency characteristic analysis module are integrated into the edge computing motherboard. The electrical signal output from the fluorescence detector undergoes local phase-locked demodulation and phase-frequency characteristic calculation within the edge computing motherboard. The phase-frequency characteristic analysis module converts the calculated characteristic relaxation frequency parameter and dynamic apparent electron transport rate parameter into digital signals. Both mobile and fixed detection platforms transmit these digital signals to the ground control workstation via the wireless data transceiver terminal.

[0104] The early warning control unit is integrated into the ground control workstation. It receives digital signals and executes a stress state assessment procedure. After generating a physiological stress early warning command, the early warning control unit outputs a diagnostic report through the early warning output terminal connected to the ground control workstation.

[0105] The UAV flight control logic, solar charging and discharging management circuit, wireless data communication protocol principle, power supply and voltage regulation circuit of basic components, analog-to-digital conversion underlying algorithm, and machining process of supporting structural components involved in the embodiments of this invention can be implemented by those skilled in the art using existing technical solutions. The specific implementation methods of the aforementioned physical structure and software control logic are well-known technologies in the field and will not be described in detail here.

Claims

1. A system for detecting and warning the health status of garden plants based on spectral analysis, characterized in that, It includes an early warning control unit, a frequency-tunable excitation source, a fluorescence detector, a quadrature phase-locked demodulation module, a phase-frequency characteristic analysis module, and an early warning output terminal; A frequency-tunable excitation light source is used to emit broadband swept-frequency modulated perturbation excitation light with continuously varying frequency to target garden plants, and outputs constant-frequency perturbation excitation light and superimposed saturated flash pulse after receiving a frequency locking command; A fluorescence detector is used to collect a mixed light signal containing dynamic fluorescence response signal and natural background stray light after the target garden plant is stimulated, and to convert the mixed light signal into an electrical signal; The quadrature phase-locked demodulation module is connected to the fluorescence detector and is used to receive the digital reference clock signal output by the early warning control unit, and to perform phase-locked demodulation operation on the electrical signal using the digital reference clock signal to filter out the natural background stray light interference components and output the in-phase component signal and the quadrature component signal. The phase frequency characteristic analysis module, connected to the quadrature phase-locked demodulation module, is used to calculate the absolute phase delay parameter based on the in-phase component signal and the quadrature component signal. When the absolute phase delay parameter reaches the impedance characteristic threshold condition, the corresponding excitation frequency value is extracted as the characteristic relaxation frequency parameter. During the constant frequency perturbation excitation light and saturated flash pulse irradiation stages, the dynamic apparent electron transport rate parameter is calculated based on the parameters output by the quadrature phase-locked demodulation module. The early warning control unit, connected to the phase frequency characteristic analysis module and the tunable excitation light source, is used to output the digital reference clock signal to the quadrature phase-locked demodulation module and output a frequency sweep control command, and to send the frequency locking command to the tunable excitation light source when the characteristic relaxation frequency parameter is received, thereby forming an adaptive closed-loop feedback control loop between the early warning control unit, the tunable excitation light source and the phase frequency characteristic analysis module; and to determine the plant stress state based on the characteristic relaxation frequency parameter and the dynamic apparent electron transport rate parameter. The early warning output terminal is connected to the early warning control unit and is used to output diagnostic reports and alarm prompts based on the plant stress status determination results.

2. The garden plant health status detection and early warning system based on spectral analysis according to claim 1, characterized in that, The early warning control unit integrates a signal generation module with a built-in direct digital frequency synthesizer. The direct digital frequency synthesizer outputs an analog voltage control signal to the tunable excitation light source through a first synchronous output channel, and outputs a digital reference clock signal to the quadrature phase-locked demodulation module through a second synchronous output channel to provide a physical time base. The tunable excitation light source includes an array of light-emitting units attached to the heat-conducting surface of a heat dissipation substrate, and a high-frequency driving circuit board that receives the analog voltage control signal. The high-frequency driving circuit board outputs a driving current containing a DC bias current component and an AC modulation current component, and the frequency of the AC modulation current component changes continuously with time to drive the light-emitting unit array to generate the broadband swept-frequency modulated perturbation excitation light.

3. The garden plant health status detection and early warning system based on spectral analysis according to claim 1, characterized in that, The fluorescence detector includes a narrowband interference filter, a semiconductor cooling component, and an avalanche photodiode attached to the cooling surface of the semiconductor cooling component. The system also includes a signal conditioning circuit, which includes a transimpedance amplifier and a DC cancellation circuit connected in parallel between the input and output terminals of the transimpedance amplifier. The DC cancellation circuit extracts the DC voltage component at the output node of the transimpedance amplifier and converts the DC voltage component into a reverse compensation current that is injected into the input node of the transimpedance amplifier to cancel the DC photocurrent component in the electrical signal.

4. The garden plant health status detection and early warning system based on spectral analysis according to claim 1, characterized in that, The quadrature phase-locked demodulation module includes a reference signal generation sub-circuit, a phase shifter, a first multiplier, a second multiplier, a first low-pass filter, a second low-pass filter, and a phase compensation reference circuit; The phase compensation reference circuit pre-stores the hardware phase offset caused by the system physical link, and performs a phase advance pre-compensation operation on the initial in-phase reference signal according to the hardware phase offset, and outputs a compensated in-phase reference signal; the first multiplier performs a multiplication operation on the electrical signal and the compensated in-phase reference signal, and the second multiplier performs a multiplication operation on the electrical signal and the compensated in-phase reference signal delayed by 90 degrees by the phase shifter.

5. The garden plant health status detection and early warning system based on spectral analysis according to claim 1, characterized in that, The phase frequency characteristic analysis module is embedded with a coordinate rotating digital computer hardware logic core and a sliding filter unit. The coordinate rotation digital computer hardware logic core adopts a shift-addition iterative operation architecture, which is used to perform arctangent calculation on the in-phase component signal and the quadrature component signal at the hardware level to obtain the absolute phase delay parameter, and perform square root calculation to obtain the fluorescence response amplitude parameter; the sliding filter unit performs an arithmetic mean operation on the parameter sequence generated by the solution to remove high-frequency abrupt values.

6. The garden plant health status detection and early warning system based on spectral analysis according to claim 1, characterized in that, The early warning control unit sets the impedance characteristic threshold condition to a 45-degree phase angle; when the physical condition that the tangent of the absolute phase delay parameter equals one is met, the phase frequency characteristic analysis module defines the extracted instantaneous excitation frequency value as the characteristic relaxation frequency parameter; the value of the characteristic relaxation frequency parameter is equal to the reciprocal of the product of the biochemical relaxation time parameter of the target garden plant, the constant of pi, and the constant 2.

7. The garden plant health status detection and early warning system based on spectral analysis according to claim 1, characterized in that, The system also includes an environmental photosynthetically active radiation sensor, and the phase frequency characteristic analysis module includes a data cache register, a transient saturation control logic core, and a dynamic parameter calculation logic core. The mean value of the fluorescence response amplitude parameter sequence extracted by the dynamic parameter calculation logic kernel during the constant frequency perturbation excitation light irradiation stage is defined as the normal locked demodulation amplitude parameter, and the maximum value extracted from the transient fluorescence response amplitude parameter sequence during the saturated flash pulse irradiation stage is defined as the transient maximum demodulation amplitude parameter. The value of the dynamic apparent electron transfer rate parameter is equal to the product of the photosynthetically active radiation parameter collected by the environmental photosynthetically active radiation sensor, the standard absorption coefficient stored in the system, and the quotient of the difference between the transient maximum demodulation amplitude parameter and the normal locked demodulation amplitude parameter divided by the transient maximum demodulation amplitude parameter.

8. The garden plant health status detection and early warning system based on spectral analysis according to claim 1, characterized in that, The system also includes an ambient temperature sensor, and the early warning control unit integrates a storage medium, a baseline temperature compensation logic core, a deviation calculation logic core, and a status discriminator. The baseline temperature compensation logic core performs temperature drift compensation calculations on the reference characteristic frequency value and reference electron transfer rate value under the pre-written standard temperature conditions based on the ambient temperature value collected by the ambient temperature sensor, and outputs the temperature compensation characteristic frequency baseline and the temperature compensation electron transfer baseline. The state discriminator determines that the target garden plant is under physiological stress when the frequency offset of the characteristic relaxation frequency parameter from the temperature-compensated characteristic frequency baseline is greater than the frequency tolerance threshold, and the rate attenuation of the dynamic apparent electron transport rate parameter below the temperature-compensated electron transport baseline is greater than the rate tolerance threshold.

9. A system for detecting and warning the health status of garden plants based on spectral analysis according to claim 1, characterized in that, The system is equipped with a multi-rotor drone as a mobile detection platform. The multi-rotor drone is equipped with a three-axis mechanical anti-shake gimbal, an independent transient energy storage power supply module, an edge computing motherboard, and a wireless data transceiver terminal. The tunable excitation light source and the fluorescence detector are fixedly mounted on the equipment bearing end of the three-axis mechanical anti-shake gimbal to avoid the introduction of spatial phase noise; the independent transient energy storage power supply module has an embedded supercapacitor component to isolate the system test load circuit from the flight control power supply of the multi-rotor UAV; the orthogonal phase-locked demodulation module and the phase frequency characteristic analysis module are integrated on the edge computing motherboard to perform local phase-locked demodulation and phase frequency characteristic calculation, and send the characteristic relaxation frequency parameter and dynamic apparent electron transfer rate parameter converted into digital signals to the ground control workstation integrated with the early warning control unit.

10. A system for detecting and warning the health status of garden plants based on spectral analysis according to claim 1, characterized in that, The system is equipped with a fixed detection platform, which includes a mounting pole, a dual-axis stepping gimbal, a solar power supply component, an edge computing motherboard, and a wireless data transceiver terminal. The tunable excitation light source and the fluorescence detector are mounted on the dual-axis stepping gimbal; the dual-axis stepping gimbal performs horizontal rotation and pitch adjustment movements according to the scanning sequence issued by the early warning control unit to guide the tunable excitation light source to scan the target garden plants; the orthogonal phase-locked demodulation module and the phase frequency feature analysis module are integrated on the edge computing motherboard, and the digital signal is sent to the ground control workstation integrated with the early warning control unit through the wireless data transceiver terminal.

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