Background technology
At present, along with the continuous development of China's meteorological cause, weather radar of new generation has obtained widespread use, and it has brought into play vital role closing on of significant weather in Short-term Forecast.Since first Doppler radar of China in 2000 succeeded in developing; Various Doppler radar is arranged net in the whole nation and service operation has reached the tuber of stemona; Whether radar running status and performance index are normal; How radar fault is searched and is got rid of, and becomes the great difficult problem that the radar flight crew faces.Native system has been dissolved this difficult problem with a kind of brand-new frame mode; Make the flight crew come quick diagnosis radar running status with simple setting through close friend's man-machine interface; The fault location source; Even also can simply overhaul fault according to the radar electric handbook that provides, to reach fast, to test flexibly, efficiently and the fault detect purpose.
The technical scheme of prior art; As shown in Figure 1, because domestic New Generation Doppler Weather Radar of arranging net comes from different producers, interface and function are not quite similar; Differentiation neither one unified method for radar state; The mode of demarcating in outer Meter Test of employing machine and the machine mostly, complex operation is to having relatively high expectations of operating personnel.
The radar performance test is divided into transmitter performance test and receiver performance test two parts.The transmitter performance index test adopts the outer instrument and meter of machine directly to test, through microwave power meter test output power, through wave detector and oscillograph combined test output envelope waveform, through spectrum analyzer test spectrum distribution and improvement factor; The receiver performance index comprises sensitivity, noise figure and dynamic range etc.; Inject the radiofrequency signal of known power to low noise amplifier (LNA) by the outer radio-frequency signal source of machine; Test with frequency spectrograph at medium frequency output end; Calculate receiver sensitivity and dynamic range values, inject the broadband white noise to LNA, read receiver noise factor and gain with the noise figure table at medium frequency output end with solid-state noise source.
The shortcoming of prior art:
1, total man worker's operation is had relatively high expectations to the technician;
2, need a plurality of instrument supports, cost is high, complex structure;
3, can not directly generate report, test result needs manual calculation;
4, can not the guiding operation personnel be overhauled by the system failure.
The utility model content
The purpose of the utility model is: to the weak point of above-mentioned prior art; A kind of weather radar test and failure detector are provided; Its made up one automatically, detection system efficiently, it is auxiliary to need not other instruments, greatly reduces hardware cost and personnel's technical ability demand; The automatic reporting printing that provides, fault restoration guidance technology have enriched detections of radar and maintenance means especially, can effectively solve the problem that above-mentioned prior art exists.
To achieve these goals; The technical scheme that the utility model technical solution problem adopts is: a kind of weather radar test and failure detector are provided; It comprises transmitter, receiver, directional coupler, the existing signal processing system of radar system, tunable radio frequency test source, capture card A, capture card B, data processing card and VPX bus (VPX is a SDXC); The output terminal of transmitter links to each other with the input end of directional coupler; The output terminal of directional coupler links to each other with the input end of capture card A; The output terminal of capture card A links to each other with the input end of VPX bus, and the output terminal of VPX bus links to each other with the input end of tunable radio frequency test source, and the output terminal of tunable radio frequency test source links to each other with the input end of receiver; The output terminal of receiver links to each other with the input end of capture card B, and the output terminal of capture card B links to each other with the input end of VPX bus; The output terminal of the existing signal processing system of radar system links to each other with the input end of data processing card.
As a kind of optimal way, wherein: the output terminal of tunable radio frequency test source links to each other with the coupled end of low noise amplifier in the receiver.
As a kind of optimal way, wherein: tunable radio frequency test source, capture card A, capture card B and data processing card are integrated in the portable cabinet of VPX bus based on the VPX bus.
Further, also be integrated with the power supply of 220V in the portable cabinet of VPX bus.
Further, the reference frequency output of tunable radio frequency test source is that 10MHz~6GHz, maximum output swing are 1dB stepping numerical-control attenuator maximum attenuation amount 96dB, the attenuated error 0.2dB that 15dBm, plate carry.
Compared with prior art; The beneficial effect that the utility model brings is: this utility model weather radar test and failure detector adopt the integral type casing structure based on the VPX bus; Made up one automatically, detection system efficiently, it is auxiliary to need not other instruments, greatly reduces hardware cost and personnel's technical ability demand; The automatic reporting printing that provides, fault restoration guidance technology have enriched detections of radar and maintenance means especially, have effectively improved work efficiency.
Embodiment
Technique scheme of the utility model and advantage thereof are not difficult from the detailed description and accompanying drawing of following selected embodiment, to obtain to understand in depth.
Like Fig. 2, shown in Figure 3; Embodiment; This weather radar test and failure detector comprise that transmitter, receiver and radar system have signal processing system, tunable radio frequency test source, capture card, data processing card and terminal software unit now, and the output terminal of transmitter links to each other with the input end of directional coupler, and the output terminal of directional coupler links to each other with the input end of capture card A; The output terminal of capture card A links to each other with the input end of VPX bus; The output terminal of VPX bus links to each other with the input end of tunable radio frequency test source, and the output terminal of tunable radio frequency test source links to each other with the coupled end of low noise amplifier in the receiver, and the output terminal of receiver links to each other with the input end of capture card B; The output terminal of capture card B links to each other with the input end of VPX bus, and the VPX bus links to each other with the terminal software unit; The output terminal of the existing signal processing system of radar system links to each other with the input end of data processing card, and the output terminal of data processing card links to each other with the expansion interface of terminal software unit.
Can draw its signal flow according to said structure is: when test Radar Transmitter Performance index; Transmitter power is exported through directional coupler forward coupled end; Be connected to native system data collecting plate card A through the low radio-frequency cable that decreases; The latter obtains direct current signal after to its envelope detection and sends into the ADC real-time sampling, and carries out data analysis by the high performance parallel processor that plate carries, and draws the transmitter envelope trait; This processor also calculates transmitter instantaneous peak value power according to envelope amplitude simultaneously, is committed to the terminal through the VPX bus; When the test receiver performance index; Terminal software control tunable radio frequency test source output radio frequency continuous wave signal is injected receiver low noise amplifier coupled end; The output of receiver intermediate frequency is connected to data collecting card B; Stepping decay radio frequency source output signal power is to investigate receiver linear dynamic range and sensitivity; Data processing card is sent to radar terminal with native system result of calculation through expansion interface in order to connect the existing signal processing system of radar system, makes radar terminal also can obtain test result, improves the native system using value.
As shown in Figure 3: the power supply of tunable radio frequency test source, capture card A, capture card B, 220V and data processing card are integrated in the portable cabinet of VPX bus based on the VPX bus.
The principle of work of test of the utility model weather radar and failure detector is:
Radio frequency source is in order to produce radio frequency continuous wave test signal; Its reference frequency output is 10MHz~6GHz; Maximum output swing is 15dBm, the 1dB stepping numerical-control attenuator maximum attenuation amount 96dB that plate carries, attenuated error 0.2dB; The test signal that output is successively decreased continuously under the control of terminal software is with the linear dynamic range and the sensitivity of test receiver.
Data collecting card A is used for the test receiver performance index; The envelope detector that plate carries is converted into direct current signal with RF pulse envelope; 10 bit parallel ADC chip AD7813 are quantified as digital signal with this direct current signal; Calculate each item characteristic of this envelope in real time by extensive field programmable gate array (FPGA) EP2S30, comprise that pulse width, pulse height, pulse top fall, rising edge time, negative edge time etc., adopt the compensation and the algorithm computation of tabling look-up to go out transmitter instantaneous peak value power simultaneously; And carrying out multiple averaging by demanding terminal, the result is sent to terminal software through the VPX bus the most at last.
Data collecting card B is used for the test receiver performance index; Its need with the radio frequency source collaborative work; The terminal software radio frequency continuous wave signal of certain damping capacity of control radio frequency source output earlier injects receiver low noise amplifier coupled end; This signal is received the machine amplification and is mixed to intermediate frequency, behind bandpass filtering, inserts this capture card.Integrated High Speed High Precision ADC on the capture card; Directly the intermediate frequency signal in real time is sampled; Based on obtaining the baseband I Q signal after the Digital Down Convert of FPGA and the Filtering Processing, terminal software obtains behind this signal through multiple averaging and FFT conversion through the VPX bus, calculates the information such as performance number, spectrum distribution of this signal; Adjust the radio frequency source output amplitude once more, so repeatedly up to EOT.
Data processing card is mainly used in radar system and docks as the expansion board clamping of native system, exports test result to radar terminal through expansion interface.Data processing card at first obtains the result of calculation of terminal software from the VPX bus, and it is cached in plate carries in the storer.Dock with radar system in order to satisfy, interface level and interface protocol all need satisfy the radar system requirement, consider the stability and the anti-interference of transmission, and interface level adopts the RS422 standard, and interface protocol adopts standard UART, per minute transmission primaries result of calculation.
Native system adopts alternating current 220V/50Hz power supply, and power module carries out EMI filtering with the alternating current of input earlier, carries out the AC-DC conversion then; Obtain the 12V direct supply as system's primary power; Also need on each integrated circuit board this power supply is carried out transient state suppressing and Filtering Processing, and do the DC-DC step-down by specific requirement and handle, power supply needs to realize step-down by LDO (LT1963 series power supply chip) for the ADC among data acquisition board A and the B; To reduce power supply noise, improve performance.
The native system terminal software is based on embedded system platform; With the virtual instrument LABVIEW of NI company is the hommization function software of basis establishment; Open parameter interface is provided, can have adjusted parameters such as radio frequency source output amplitude, data collecting card sampling rate, pulse threshold threshold flexibly; This software has also designed automatic test, automatic multinomial human nature service such as reporting printing, interpretation of result automatically, fault restoration guidance, make things convenient for the user also can fast detecting under the situation of not being proficient in radar arrangement, safeguard radar system.
Can realize that the key technical indexes is following:
1, radio frequency source output frequency: 10MHz~6GHz, the maximum 15dBm of output power;
2, pulse width detects error :≤100ns;
3, instantaneous peak value power detection error :≤10KW;
4, dynamic range detects error :≤2dB;
5, sensitivity detects error :≤2dB.
Therefore, test of the utility model weather radar and failure detector possess following beneficial effect:
1, based on the integral type casing structure of VPX bus.Integrated tunable radio frequency test source, transmitter performance test integrated circuit board (both capture card A), receiver performance test integrated circuit board (both capture card B) and data processing card are realized data sharing through the VPX bus, coordinate control by terminal software;
2, be the software architecture of platform with NI company ripe embedded system and LABVIEW;
3, need not full-automatic detections of radar by other supplementary instruments, only need to click the terminal software testing button, the latter controls the test signal that corresponding amplitude and frequency are exported in the radio frequency testing source automatically, and starts related data collection and analysis module, the generation test result;
4, automatic reporting printing, open-and-shut interpretation of result;
5, fault restoration instructs, and brand-new service mode need not operating personnel and grasps a large amount of professional skills.Terminal software is analyzed test result; Automatically judge nonconformance; In conjunction with a large amount of Radar Design, maintainer's experience, provide the fault restoration guiding opinion, thereby exempt the user can't locate and overhaul radar system fast because of relevant speciality technical ability shortcoming worry.
As being familiar with this, technological personnel understood; The preferred embodiment of the above the utility model only is used to help to understand the enforcement of the utility model; The utility model is not limited to above-mentioned embodiment; Those of ordinary skills made to any conspicuous improvement of above-mentioned embodiment or change, can not exceed the design of the utility model and the protection domain of accompanying claims.