Airborne radar transmitter in-situ performance detection and state monitoring device

Abstract

The invention relates to an airborne radar transmitter in-situ performance detection and state monitoring device, and belongs to the technical field of equipment testing. In the aspect of a hardware system, by integrating resource modules such as measurement, operation and power supply, the overall design becomes compact and portable, and the test and guarantee requirements under the external field condition can be better met; in the aspect of a software platform, an advanced algorithm and a data processing technology are adopted, measurement of key performance parameters of time domain and frequency domain of airborne radar signals can be automatically completed in a one-key flow mode, and the current performance state and fault information are visually displayed in a graphical mode. And a tester can quickly know the radar performance condition and timely discover and process potential problems. Generally speaking, the device provided by the invention gives consideration to the comprehensive test capability and the convenient operation mode, effectively simplifies the tedious steps of operating the equipment in the in-situ test process of the airborne radar transmitter, and improves the equipment maintenance guarantee level.

Description

Technical Field

[0001] The invention relates to an in-situ performance detection and state monitoring device for an airborne radar transmitter, belonging to the technical field of equipment testing. Background Art

[0002] Radar performance testing runs through all stages of the radar's life cycle. Although the performance indicators of the radar, subsystems, and extensions have been tested in detail during the military inspection and acceptance before leaving the factory, various performance indicators may change during the radar's use. The decline of a single indicator will affect the radar's working status and combat effectiveness, and even cause radar failure. Therefore, it is very necessary to regularly measure radar performance parameters and conduct statistical analysis within a certain period of time to timely grasp the radar's technical status and take corresponding maintenance measures as appropriate.

[0003] The traditional in-situ measurement process of airborne radar signal parameters can be completed with the help of a combination of various general instruments. For example, for the measurement of signal peak power, the radiation method can be used to read the measurement results through a power meter; for the pulse signal waveform parameters, the signal can be connected to the detector and then connected to the oscilloscope, and the cursor can be operated to obtain data. Although the above measurement method is relatively classic and universal, it can meet the testing needs under general conditions (such as teaching practice in colleges and universities, and factory branch maintenance), but for the maintenance of military field aircraft, there are problems such as inconvenience in carrying and use, and cumbersome operation steps. In recent years, with the continuous development of instrument science and technology, more and more research tends to use computer software to control measuring instruments to complete radar system-related testing work, which to a certain extent solves the difficulties of low efficiency and poor accuracy of manual operation, but in the process of transforming radar testing from manual to automatic, there are still the following shortcomings:

[0004] (1) General-purpose instruments for field use: Software for automatic testing is still mostly developed for traditional general-purpose instruments. However, general-purpose instruments rely on external power supplies and are large in size and poor in portability, which is not conducive to efficient work in field conditions for troops.

[0005] (2) Streamlining the measurement process: Even though some high-performance instruments provide the option of measuring specific parameters, and some radar manufacturers have developed corresponding automatic test software, each test item still requires the adjustment of the instrument configuration in the software interface before it can be carried out. Therefore, the test process is not very coherent, and it does not have the ability to continuously, quickly, and streamline test multiple parameters. In addition, for some common complex signal forms such as repetition frequency difference, frequency agility, linear frequency modulation, etc., the existing automatic test technology still does not cover them sufficiently.

[0006] (3) BIT display: Currently, the BIT results of radar transmitter self-test are mostly displayed in the cockpit display in the form of codes, which makes it inconvenient for testers to grasp the health status of the equipment in a timely manner. Existing automatic test research is mostly focused on the measurement of external radiation parameters, ignoring the analysis and display of internal test results. Summary of the invention

[0007] In order to solve the three problems existing in the above-mentioned airborne radar transmitter detection, the present invention provides an airborne radar transmitter in-situ performance detection and status monitoring device, which has a compact and lightweight design, and also has the function of one-key process-based performance parameter rapid measurement, which can realize the combination of in-machine BIT data analysis and out-of-machine in-situ performance testing, so that testers can obtain the performance status of airborne radar transmitters more quickly and accurately, and provide strong support for subsequent maintenance and support work. In order to achieve the above-mentioned purpose, the technical solution of the present invention is:

[0008] An in-situ performance detection and status monitoring device for an airborne radar transmitter, characterized in that it comprises a hardware system and a software system;

[0009] The hardware system includes a spectrum analysis module 1, an embedded industrial computer 2, a power supply unit 3, and a touch screen 4 installed in the housing. The embedded industrial computer 2 communicates with the spectrum analysis module 1, the touch screen 4, and the radar transmitter 5. The power supply unit 3 supplies power to the spectrum analysis module 1, the touch screen 4, and the embedded industrial computer 2.

[0010] The software system includes a performance detection module 6, a status monitoring module 7, a BIT monitoring module 8, and a system setting module 9, which are arranged in the embedded industrial computer 2; the radar signal parameters measured by the performance detection module 6 will serve as the data source for the status monitoring module 7 to view the historical performance trend; the environmental parameters and aircraft model set in the system setting module 9 will determine the measurement items, processes, and conversion results of the performance detection module 6;

[0011] The performance detection module 6 is used to realize data interaction by controlling the spectrum analysis module, and complete one-key automatic measurement and storage of radar transmitter performance parameters such as phase noise, pulse waveform, peak power, etc.;

[0012] The state monitoring module 7 performs statistical comparison on various performance parameters of the transmitter based on the performance parameter measurement data of the radar transmitter 5 such as signal power, phase noise, pulse width, pulse repetition period, etc. provided by the performance detection module 6, and facilitates subsequent performance evaluation and state prediction through graphical display and historical data curve trend analysis, and provides reference suggestions for the maintenance and guarantee of the radar transmitter 5;

[0013] The BIT monitoring module 8 is used to read the BIT data of the airborne radar transmitter through the RS232 serial port to quickly discover and locate faults; since the BIT information is transmitted in hexadecimal serial data, the BIT monitoring module 8 distinguishes the health status of the internal units of the radar transmitter 5 with different colors and prompts the current fault status of the radar transmitter 5;

[0014] The system setting module 9 is used to set multiple environmental parameters during the measurement process, such as cable loss, antenna spacing, antenna gain, etc. for transmitter performance parameter conversion; different aircraft models can be selected to quickly load environmental parameters and signal patterns; and the self-test status, connection status and battery usage of the device can be displayed in real time.

[0015] Furthermore, the shell is composed of multiple panels, on which mounting columns and fans are provided. The interior of the shell adopts a layered design, so that the internal functional modules are distributed more compactly, and the overall size of the device can be controlled within a smaller range, which is convenient for carrying and field use. In addition, heat dissipation holes are opened on the two side panels, which are used in conjunction with fans to facilitate heat dissipation of the equipment.

[0016] Furthermore, the spectrum analysis module 1 can perform time domain and frequency domain analysis and measurement on the received radar signal according to the measurement requirements set by the software platform, and send the measurement results to the software platform; the spectrum analysis module 1 is composed of a superheterodyne receiver RF front end and an FPGA digital processing back end, and can work in four states: "frequency scanning", "power detection", "IQ analysis", and "real-time spectrum".

[0017] Furthermore, the embedded industrial computer 2 carries multiple IO interfaces, including: 2 USB3.0 interfaces connected to the spectrum analysis module to realize data interaction; serial port COM1 is connected to the radar transmitter 5 through a dedicated cable to receive BIT data; serial port COM2 receives real-time battery power information sent by the power supply unit 3; HDMI interface is connected to the touch display screen 4;

[0018] Furthermore, the power supply unit 3 includes a battery and a power adapter board. The battery provides electric energy to the power adapter board. The power supply voltage is 14.8V. The adapter board converts the battery voltage into multiple specific voltages to meet the power requirements of various devices in the hardware system. The power adapter board can read the battery information and transmit it to the embedded industrial computer 2 through serial communication for human-machine interface display.

[0019] Furthermore, the touch display screen 4 has a screen size of 8 inches, a display resolution of 800*600, and supports a maximum input signal parameter of 1920*1080p@75fps.

[0020] Furthermore, the automatic measurement of multiple key parameters of the radar signal frequency domain is completed by the performance detection module 6, and the specific steps include:

[0021] S11. The performance detection module 6 places the spectrum analysis module 1 in the "real-time spectrum" mode to obtain continuous and uninterrupted real-time spectrum data;

[0022] S12. Set the sweep width SPAN range to be sufficient to cover the main lobe of the target spectrum, and set the resolution bandwidth RBW to automatic; find the frequency point corresponding to the power peak according to the spectrum sequence, and record it as F; then set the center frequency CF of the spectrum analysis module 1 to F, set SPAN to be slightly larger than 5 times the current RBW, and then adjust RBW<=SPAN / 200, read the maximum power again, and you can get a more accurate carrier frequency measurement result F′;

[0023] S13. Set RBW to satisfy RBW≤0.3*Δf, and read the power value P at the carrier frequency F′ in the spectrum sequence. c , and the frequency power value P near the frequency offset Δf from F′ Δf , then the calculation formula of phase noise L(Δf) is:

[0024]

[0025] Furthermore, if the radar signal under test contains agile frequency, the steps are as follows:

[0026] S21. The performance detection module 6 makes the spectrum analysis module 1 work in the "maximum hold" state, sets the SPAN to cover all agile frequency points, sets the RBW to automatic, and waits for the trace to remain basically unchanged;

[0027] S22. Record each point P(x, y) of the spectrum trace in the current state into the array dlist, where x is the frequency and y is the power; traverse dlist, for the element dlist[i] with index number i, search for all the inflection points in dlist according to formula (2) and store them in turlist;

[0028]

[0029] S23. Sort the elements of turlist from large to small. According to the principle that the power value at each agile frequency point of the frequency agile radar signal is consistent, the power values ​​of two adjacent elements are subtracted to obtain the absolute value Δu. If Δu is less than the set threshold u (which can be set to 0.5dB), turlist[i].x is considered to be an agile frequency point, and turlist[i] is stored in the array peaklist. When Δu>u appears for the first time, the search is completed, and the rough value array peaklist of each agile frequency point is obtained.

[0030] S24. Take each element in the peaklist as the center frequency of the spectrum analysis module in turn, and refer to the method described in S12 to correct each frequency point value in the peaklist one by one to obtain an accurate agile frequency array peaklist'.

[0031] Furthermore, the performance detection module 6 can complete the automatic measurement of several key parameters in the time domain of radar signals. The specific steps include:

[0032] S31. The performance detection module 6 places the spectrum analysis module 1 in the "IQ analysis" mode, sets CF = F', sets the length of the analysis period (hereinafter referred to as one frame) to be L, and obtains the I and Q time-domain sequences ilist and qlist. Both of them contain information in two dimensions (x, y), where x represents the sampling time and y represents the signal power value corresponding to the x time;

[0033] S32. Traverse the I and Q sequences. For the element with index i in the sequence, calculate:

[0034]

[0035] Then tlist is the current signal time-domain waveform sequence;

[0036] S33. Compare the power difference |ΔP| between two adjacent sampling points in tlist. If |ΔP| < u, where u is a threshold and u = 0.5dB, it is determined that the pulse top has arrived. Reduce the power of the current sampling point by 3dB to obtain the half-power point and record its power value as P 3dB , search for all points in tlist with a power value of P 3dB and add them to the array tlist 3dB in, then tlist 3dB contains the arrival and end times of all pulses in the current frame;

[0037] S34. If the power difference between two adjacent white noises also just satisfies the condition |ΔP| < u, at this time the algorithm will also misjudge it as the pulse top. However, for noise, its occurrence has random characteristics, and the probability of continuous high level existence is extremely low. And the pulse width of a general airborne pulse Doppler radar is higher than 1μs. Therefore, only by adding the constraint that tlist 3dB [i] - dlist 3dB [i - 1] ≥ 1μs can the interference of noise be excluded;

[0038] S35. Suppose the number of elements in tlist 3dB is n (n ≥ 4 to ensure at least one complete repetition period). Mark each element in dlist 3dB with the index i and traverse it. If i is odd, then the average pulse repetition period in the current frame

[0039]

[0040] If i is an even number, then subtract adjacent elements and sum them to obtain the average value of the in-frame pulse width.

[0041]

[0042] S36. When analyzing the current frame, if a pulse happens to appear incompletely at the frame head, i.e., tlist 3dB [0].x = 0, then this pulse should be discarded; if it appears incompletely at the frame tail, it can be automatically filtered according to step S33. Therefore, the basis for judging the existence of a pulse is:

[0043]

[0044] S37. According to step S33, record the voltage value U (V) at the pulse duration moment; assume the impedance of the spectrum analysis module 1 is R (Ω), and use formula (7) to complete the power P (dBm) conversion:

[0045] P = 10·lg(1000*U 2 / R) (7)

[0046] Furthermore, for the case where the measured signal contains multiple groups of repetition periods (PRF), the specific steps include:

[0047] S41. Combining the conditions in formula (6), calculate the in-frame repetition period values in sequence according to formula (4). If the difference |ΔT r | between two adjacent repetition periods exceeds 1 μs, it is considered that the pulse PRF just completes the switching during the measurement period, and the data of this frame should be discarded;

[0048] S42. If the analysis period length L is greater than the PRF switching time (CPI), then |ΔT r | > 1 μs is always satisfied within the frame, and no result can be measured after being restricted according to step S41; at this time, only need to gradually reduce the number of analysis points while keeping Δt unchanged until L < CPI; therefore, the additional constraint condition that needs to be added on the basis of formula (6) when the measured signal contains multiple groups of repetition periods is

[0049]

[0050] Furthermore, while the above one-key process automated measurement is in progress, the BIT monitoring module 8 of the device software platform can simultaneously complete the parsing and display of the BIT data sent by the transmitter, that is, the combination of in-board BIT and out-of-board in-situ detection is realized.

[0051] The in-situ performance detection and status monitoring device of an airborne radar transmitter of the present invention can be powered by a built-in battery, is light and portable, and is suitable for field use; in terms of function, it can realize the combination of in-machine BIT data analysis and out-machine in-situ performance testing, and the testing process adopts a one-button automatic mode to complete radar transmitter status inspection, performance detection and fault location; in addition, it can also display radar health status and fault information in a graphical manner, and can record, manage and analyze multi-source test data to realize radar transmitter status monitoring. The present invention effectively simplifies the cumbersome operation and function setting of the instrument by military test personnel, reduces the requirements for test personnel's knowledge reserves such as test principles and professional theories, reduces field work time and human resource allocation, and improves the efficiency of equipment maintenance and support. BRIEF DESCRIPTION OF THE DRAWINGS

[0052] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0053] Figure 1 It is a schematic diagram of the hardware system composition of the present invention;

[0054] Figure 2 It is a diagram of the internal structure of the hardware system of the present invention;

[0055] Figure 3 It is a software platform architecture diagram of the present invention;

[0056] Figure 4 It is a functional module diagram of the software platform of the present invention;

[0057] Figure 5 This is a flow chart of automatic measurement of conventional pulse and repetition frequency staggered signal of the present invention;

[0058] Figure 6 It is the automatic measurement interface of conventional pulse and repetition frequency difference signal of the present invention;

[0059] Figure 7 It is the linear frequency modulation signal automatic measurement interface of the present invention;

[0060] Figure 8 It is the frequency agile signal automatic measurement interface of the present invention;

[0061] Fig. 9 It is a schematic diagram of the test scenario of the present invention. DETAILED DESCRIPTION

[0062] The present invention will be further described in detail below in conjunction with the accompanying drawings and embodiments. It will be appreciated that the specific embodiments described herein are only used to explain the relevant inventions and are not intended to limit the invention. It should also be noted that, for ease of description, only portions related to the relevant inventions are shown in the accompanying drawings. It should be noted that, in the absence of conflict, the embodiments in this application and the features in the embodiments may be combined with each other. The present application will be described in detail below with reference to the accompanying drawings and in conjunction with the embodiments.

[0063] Embodiment 1:

[0064] Attached Figure 1 A schematic diagram of the hardware system composition of an airborne radar transmitter in-situ performance detection and status monitoring device provided in Example 1 of the present invention, with Figure 2 The internal structure diagram of the hardware system of an in-situ performance detection and status monitoring device for an airborne radar transmitter provided in Example 1 of the present invention; in combination with the above diagram, the specific working principle of the present invention is: after the high-power radar RF signal is received by the receiving antenna, the signal power is first attenuated by the attenuator to avoid damaging the spectrum analysis module connected thereto; after the spectrum analysis module 1 receives the signal, it is processed by the superheterodyne receiving front end and the FPGA back end, and the measurement data is transmitted to the embedded industrial computer 2; the performance detection module 6 in the software platform running on the embedded industrial computer 2 executes the corresponding algorithm based on the measurement data and the aircraft model, completes the automatic measurement of multiple performance parameters, and displays the measurement results on the human-machine interface; at the same time, the monitoring port of the radar transmitter 5 is connected to the embedded industrial computer 2 through a dedicated cable, the embedded industrial computer 2 obtains the BIT data and the BIT monitoring module 8 completes the analysis, and finally presents it on the touch display screen 4; the circuit unit in the host can provide power guarantee for the embedded industrial computer 2, the spectrum analysis module 1, and the touch display screen 4 respectively.

[0065] Attached Figure 3 A software platform architecture diagram of an airborne radar transmitter in-situ performance detection and status monitoring device provided in Example 1 of the present invention; Figure 4 A functional module diagram of a software platform for an in-situ performance detection and status monitoring device for an airborne radar transmitter provided in Example 1 of the present invention; in combination with the above diagram, the workflow of the software platform of the present invention is as follows: the system setting module 9 informs the performance detection module 6 in advance of the automatic measurement items, processes and conversion parameters to be executed according to the aircraft model and environmental parameters set by the user; after the user starts the measurement task, the performance detection module 6 realizes one-click automatic measurement of the transmitter performance parameters according to the pre-set settings, and the measurement results confirmed and saved by the user will be used as the data source for the status monitoring module 7 to evaluate the historical trend of transmitter performance and compare and display; during the execution of the above process, the BIT monitoring module 8 can synchronously obtain and parse the BIT information sent by the transmitter, and display it in a graphical manner.

[0066] Embodiment 2:

[0067] Table 1 shows the parameters and measurement results of an in-situ performance detection and status monitoring device for an airborne radar transmitter provided in Example 2 of the present invention when a microwave signal source is used to simulate conventional pulse and repetition frequency-varied radar signals under laboratory conditions. Figure 5 For automated measurement flow chart, Figure 6 This is the software interface for each stage of the measurement process; combined with the above chart, the specific measurement process is:

[0068] Table 1: Parameters for simulating conventional pulse and repetition frequency-varied radar signals

[0069]

[0070] S21. Set SPAN = 0.1GHz, RBW to automatic; find the frequency point F = 10.122GHz corresponding to the power peak according to the spectrum sequence; then set the spectrum analysis module CF to 10.122GHz, SPAN = 10MHz, and then adjust RBW = 2kHz, read the maximum power again, and you can get a more accurate carrier frequency measurement result F′ = 10.1234GHz;

[0071] S22. When measuring phase noise, set Δf = 2kHz, RBW = 100Hz, and follow the formula (1) Complete the measurement;

[0072] S23. The performance detection module 6 controls the spectrum analysis module to work in the "IQ analysis" state, according to formula (6) The conditions listed, combined with formula (4) (5) (7)P=10·lg(1000*U 2 / R), complete the pulse width, pulse repetition period, peak power measurement, the test results are displayed in the display bar at the bottom of the software interface, such as Figure 6 As shown in (a), the measurement results can be saved and used as the data source of the status monitoring module 7, or the measurement can be performed again;

[0073] S24. For the repetition frequency staggered signal, the overall measurement process is consistent with the conventional pulse. The additional conditions that need to be added are listed in formula (8). Finally, multiple groups of repetition period values ​​can be measured, as shown in the attached Figure 6 (b) as shown.

[0074] Embodiment 3:

[0075] Table 2 shows the parameters and measurement results of an in-situ performance detection and status monitoring device for an airborne radar transmitter provided in Example 3 of the present invention when simulating a linear frequency modulation radar signal under laboratory conditions. Figure 7 This is the test process software interface; combined with the above chart, the measurement process is as follows:

[0076] S31. After starting the automatic measurement, the software platform controls the spectrum analysis module to be placed in the "maximum hold" state based on the characteristics of the measured signal;

[0077] S32. Set RPAN = 0.1 GHz, RBW = 2 MHz, and obtain the power value at the highest point of the trace. After considering the attenuation conversion, it is P p =-3.3dBm, the error is small.

[0078] Table 2: Parameters for simulating linear frequency modulation radar signals

[0079]

[0080] Example 4

[0081] Table 3 is a device for in-situ performance detection and status monitoring of an airborne radar transmitter provided in Example 4 of the present invention, and the parameters and measurement results set when simulating frequency agile radar signals under laboratory conditions, with the number of agile frequency points being 8; Figure 8 This is the test process software interface; combined with the above chart, the measurement process is as follows:

[0082] S41. Performance detection module 6 makes the spectrum analysis module work in the "maximum hold" state, sets RPAN = 1GHz, RBW is set to automatic, and the measurement time is 5s, which is sufficient to capture the power peak of all agile frequency points;

[0083] S42. Record each point P(x,y) of the spectrum trace in the current state into the array dlist, where x is the frequency and y is the power; traverse dlist, and for the element dlist[i] with index number i, according to formula (2) Find all inflection points in dlist and store them in turlist;

[0084] S43. Based on the principle that the power values ​​of each agile frequency point of the frequency agile radar signal are consistent, starting from the first element of turlist, the power values ​​of two adjacent elements are subtracted in turn, that is, the absolute value Δu. If Δu<0.5dB, turlist[i].x is considered to be an agile frequency point, and turlist[i] will be stored in the array peaklist; until Δu>0.5dB appears for the first time, the search ends, and the rough value array peaklist of each agile frequency point is obtained;

[0085] S44. Traverse peaklist, for the element with index number i, set the center frequency of the spectrum analysis module to peaklist(i), SPAN=6.25MHz, RBW=2kHz, obtain the frequency corresponding to the maximum power to correct peaklist(i), and finally obtain the accurate agile frequency array peaklist′;

[0086] S45. Taking any element in peaklist′ as the center frequency of the spectrum analysis module, the performance detection module 6 makes the spectrum analysis module work in the "IQ analysis" mode. When the frequency of the agile signal is the same as the center frequency, a time domain detection sequence is obtained. According to formula (5) The conditions listed, combined with formula (3) (4) (6) It can complete the measurement of pulse width, pulse repetition period and peak power. Figure 8 As shown, except for a small error in power, other measurement results are completely consistent with the set values.

[0087] Table 3: Parameters set when simulating frequency agile radar signals

[0088]

[0089] Example 5

[0090] Attached Fig. 9 A schematic diagram of a test scenario for an airborne radar transmitter in-situ performance detection and status monitoring device provided in Example 5 of the invention, specifically: a test antenna is placed at a certain distance in front of the nose, radar radiation signals are received through the test antenna and connected to a detection device, so as to complete automatic measurement of multiple performance parameters of multi-type signals; at the same time, the detection device is connected to the radar transmitter monitoring interface via a cable to complete the acquisition and display of BIT monitoring information.

[0091] In this embodiment, the environmental parameters are specifically as follows: the distance between the airborne radar and the test antenna is 5m, the airborne radar antenna gain is 30dB, the test antenna gain is 15dB, the cable attenuation is 12dB, the attenuation of the attenuator is 20dB, and after the model is selected, the radar works in the RWS mode, and the corresponding signal form is repetition frequency variation; then, using the method described in Example 4, the measured signal power is 10.1dBm. After the environmental parameters are converted, the actual radar transmit power is 63.55dBm, which is less than 2dB different from the standard value, so the measurement result of the present invention is valid.

[0092] The beneficial effects of the embodiments of the present invention include:

[0093] (1) Supports field in-situ performance testing, powered by a built-in battery, lightweight and portable, suitable for field use;

[0094] (2) Support adaptive measurement items and processes for multi-type radar signals;

[0095] (3) It can realize process-based automatic measurement of key performance parameters of the transmitter;

[0096] (4) Test results are automatically recorded and saved to support subsequent data statistical analysis;

[0097] (5) The combination of BIT fault location inside the machine and in-situ performance testing outside the machine is realized.

[0098] The above is a specific description of the preferred implementation of the present invention, but the invention is not limited to the embodiments. Those skilled in the art may make equivalent modifications or substitutions without violating the spirit of the present invention. These equivalent modifications and substitutions are all included in the scope defined by the claims of this application.

Claims

1. An in-situ performance detection and status monitoring device for an airborne radar transmitter, characterized in that: It includes a hardware system and a software system. The hardware system includes a spectrum analysis module, an embedded industrial computer, a power supply unit, and a touch screen installed in the shell. The embedded industrial computer communicates with the spectrum analysis module, the touch screen, and the radar transmitter. The power supply unit supplies power to the spectrum analysis module, the embedded industrial computer, and the touch screen. The software system includes a performance detection module, a status monitoring module, a BIT monitoring module, and a system setting module in the embedded industrial computer. The radar signal parameters measured by the performance detection module will serve as the data source for the status monitoring module to view historical performance trends. The environmental parameters and aircraft models set in the system setting module will determine the measurement items, processes, and conversion results of the performance detection module. The performance detection module is used to realize data interaction by controlling the spectrum analysis module, and complete one-key automatic measurement and storage of radar transmitter performance parameters such as phase noise, pulse waveform, peak power, etc.; The status monitoring module performs statistical comparison on various performance parameters of the transmitter based on the performance parameter measurement data of the radar transmitter such as signal power, phase noise, pulse width, pulse repetition period, etc. provided by the performance detection module, and facilitates subsequent performance evaluation and status prediction through graphical display and historical data curve trend analysis, and provides reference suggestions for radar transmitter maintenance and guarantee; The BIT monitoring module is used to read the BIT data of the airborne radar transmitter through the RS232 serial port to quickly discover and locate faults; since the BIT information is transmitted in hexadecimal serial data, the BIT monitoring module distinguishes the health status of the internal units of the radar transmitter with different colors and prompts the current fault status of the radar transmitter; The system setting module is used to set multiple environmental parameters during the measurement process, such as cable loss, antenna spacing, and antenna gain for transmitter performance parameter conversion; different aircraft models can be selected to quickly load environmental parameters and signal patterns; It can display the device's self-test status, connection status and battery usage in real time.

2. The in-situ performance detection and status monitoring device for an airborne radar transmitter as claimed in claim 1, characterized in that: The shell is composed of a plurality of panels, on which mounting columns and fans are arranged. The interior of the shell adopts a layered design, and heat dissipation holes are opened on the panels on both sides.

3. The in-situ performance detection and status monitoring device for an airborne radar transmitter according to claim 1, characterized in that: The spectrum analysis module can perform time domain and frequency domain analysis and measurement on the received radar signal according to the measurement requirements set by the software platform, and send the measurement results to the software platform; the spectrum analysis module consists of two parts: a superheterodyne receiver RF front end and an FPGA digital processing back end, and can work in four states: "frequency scanning", "power detection", "IQ analysis", and "real-time spectrum".

4. The in-situ performance detection and status monitoring device for an airborne radar transmitter as claimed in claim 1, characterized in that: The embedded industrial computer carries multiple I / O interfaces, including: a USB3.0 interface connected to a spectrum analysis module to realize data interaction; a serial port COM1 connected to a radar transmitter via a dedicated cable to receive BIT data; a serial port COM2 receives real-time battery power information sent by a power supply unit; and a HDMI interface connected to a touch display screen.

5. The in-situ performance detection and status monitoring device for an airborne radar transmitter according to claim 1, characterized in that: The power supply unit includes a battery and a power adapter board. The battery provides electrical energy to the power adapter board. The supply voltage is 14.8V. The adapter board converts the battery voltage into multiple specific voltages to meet the power requirements of various devices in the hardware system. The power adapter board can read the battery information and transmit it to the embedded industrial computer through serial communication for human-machine interface display.

6. The in-situ performance detection and status monitoring device for an airborne radar transmitter according to claim 1, characterized in that: The touch display screen has a screen size of 8 inches, a display resolution of 800*600, and supports a maximum input signal parameter of 1920*1080p@75fps; the airborne radar 5 is an airborne pulse Doppler radar.

7. The airborne radar transmitter in-situ performance detection and status monitoring device according to claim 1, characterized in that: The performance detection module automatically measures multiple key parameters of the radar signal in the frequency domain, and the specific steps include: S11 performance detection module will be placed in the spectrum analysis module "real-time spectrum" mode, to obtain continuous and uninterrupted real-time spectrum data; S12. Set the sweep width SPAN range to cover the main lobe of the target spectrum, and set the resolution bandwidth RBW to automatic; find the frequency point corresponding to the power peak according to the spectrum sequence, record it as F; then set the center frequency CF of the spectrum analysis module to F, set SPAN to slightly larger than 5 times the current RBW, and then adjust RBW<=SPAN / 200, read the maximum power again, and you can get a more accurate carrier frequency measurement result F′; S13. Set RMW to satisfy RBW≤0.3*Δf, and read the power value P at the carrier frequency F′ in the spectrum sequence. c , and the frequency power value P near the frequency offset Δf from F′ Δf , then the phase noise l(Δf) calculation formula is:

8. The airborne radar transmitter in-situ performance detection and status monitoring device according to claim 7, characterized in that: When the radar signal contains agile frequency, the steps are as follows: S21. The performance detection module makes the spectrum analysis module work in the "maximum hold" state, sets the SPAN to cover all agile frequency points, sets the RBW to automatic, and waits for the trace to remain basically unchanged; S22. Record each point P(x, y) of the spectrum trace in the current state into the array dlist, where x is the frequency and y is the power; traverse dlist, for the element dlist[i] with index number i, search for all the inflection points in dlist according to formula (2) and store them in turlist; S23. Sort the elements of turlist from large to small. Based on the principle that the power values ​​at each agile frequency point of the frequency agile radar signal are consistent, the power values ​​of two adjacent elements are subtracted in turn to obtain the absolute value Δu. If Δu is less than the set threshold u, turlist[i].x is considered to be an agile frequency point, and turlist[i] is stored in the array peaklist. The search ends when Δu>u appears for the first time, and the rough value array peaklist of each agile frequency point is obtained. S24. Taking each element in peaklist as the center frequency of the spectrum analysis module in turn, referring to the method described in S12, correct each frequency point value in peaklist one by one to obtain an accurate agile frequency array peaklist′.

9. The airborne radar transmitter in-situ performance detection and status monitoring device according to claim 7, characterized in that: The performance detection module can automatically measure multiple key parameters of radar signals in the time domain, and the specific steps include: S31. The performance detection module places the spectrum analysis module in the "IQ analysis" mode, sets CF = F', sets the analysis period length to L, obtains the I and Q time domain sequences ilist and qlist, both of which contain information of two dimensions (x, y), where x represents the sampling time and y represents the signal power value corresponding to the time x; S32. Traverse the I and Q sequences, and for the element with index number i in the sequence, calculate: Then tlist is the current signal time domain waveform sequence; S33. Compare the power difference |ΔP| between two adjacent sampling points in tlist. If |ΔP| < u, where u is the threshold and u = 0.5 dB, it is determined that the pulse top has arrived. Reduce the power of the current sampling point by 3 dB to obtain the half-power point and record its power value as P 3dB , search for all points in tlist with a power value of P 3dB , and add them to the array tlist 3dB . Then tlist 3dB contains the arrival and end times of all pulses in the current frame; S34. If the power difference between two adjacent white noises also just meets the condition of |ΔP| < u, the algorithm will misjudge it as the top of the pulse at this time. However, for noise, its occurrence has random characteristics, and the probability of continuous high level is extremely low. And the pulse width of general airborne pulse Doppler radars is higher than 1 μs. Therefore, only by adding the constraint that tlist 3dB [i] - tlist 3dB [i - 1] ≥ 1 μs can the interference of noise be excluded; S35. Set tlist 3dB The number of elements in tlist is n, n ≥ 4 to ensure that there is at least one complete repetition cycle. 3dB Each element in is marked with index number i and traversed. If i is an odd number, the average value of the pulse repetition period in the current frame is If i is an even number, the average pulse width in the frame can be obtained by subtracting adjacent elements and then summing them. S36. When analyzing the current frame, if the pulse happens to appear incompletely at the frame header, that is, tlist 3dB [0].x=0, ​​the pulse should be discarded; if it appears incompletely at the end of the frame, it can be automatically filtered out according to step S33. Therefore, the basis for judging the existence of the pulse is: S37. According to step S33, record the level value U (V) at the time when the pulse persists; assume that the impedance of the spectrum analysis module is R (Ω), and use formula (7) to complete the power P (dBm) conversion: P=10·lg(1000*U 2 / R) (7).

10. The airborne radar transmitter in-situ performance detection and status monitoring device according to claim 9, characterized in that: The automatic measurement of multiple key parameters in the time domain, when the measured signal includes multiple groups of repetitive cycles, specifically comprises the following steps: S41. Combined with the conditions in formula (6), calculate the repetition period values ​​in the frame in turn according to formula (4). If the difference between two adjacent repetition periods |ΔT r | If it exceeds 1μs, it is considered that the pulse repetition frequency is switched just during the measurement period, and the frame data is discarded; S42. If the analysis period length L is greater than the pulse repetition frequency switching time CPI, then within the frame, it always satisfies |ΔT r | > 1 μs, and no result can be measured after the constraint according to step S41; at this time, only need to gradually reduce the number of analysis points under the condition of keeping Δt unchanged until L < CPI; therefore, when the measured signal contains multiple groups of repeated periods, the additional constraint condition to be added based on Equation (6) is

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