The active calibration facility of a kind of frequency memory relay type shipborne radarTechnical field
Patent of the present invention belongs to a kind of Radar Calibration equipment, the particularly active calibration facility of a kind of frequency memory relay type shipborne radar, the demarcation that can solve carrier-borne primary radar detection range and bearing accuracy.
Background technology
The demarcation of shipborne radar is the important measures that ensure radar range and bearing accuracy, and demarcating is exactly that the position true value data of the measured value to target and target by radar are calculated, and draws the process of distance and bearing error.Present stage carries out timing signal at the detection range to shipborne radar and bearing accuracy and conventionally adopts passive calibration facility to carry out, and passive calibration facility must be built in the area of shipborne radar acquisition environment relative clean, corner reflector is equipped with to increase radar area in its top.Timing signal, also will be docked in naval vessels the fixed quay of appointed place, and requiring must be unobstructed between radar and school marking device.Therefore there is comparatively difficulty of passive calibration facility addressing, build drop into and follow-up maintenance, upkeep cost very expensive, and the problem such as signal characteristic is not obvious.
Domestic having begun one's study utilized the demarcation of target simulator technology for shipborne radar at present, but these equipment mostly are specialized equipment, adopt the technical scheme such as direct relay type, time delay relay type, these modes have very large limitation, are only applicable to the demarcation to specific radar.
Summary of the invention
The present invention is directed to the deficiency of existing equipment and technology, provide that a kind of signal characteristic is obvious, frequency coverage is wide, function is complete, and the active calibration facility of shipborne radar easy to carry, maintainability is strong.
The present invention is based on radio frequency and store retransmission technique, invented the active calibration facility of a kind of frequency memory relay type shipborne radar, shipborne radar is carried out to active demarcation.This equipment can store the radiofrequency signal by mark shipborne radar receiving, sorting, by the selection to signal spatial domain, frequency domain, time domain, after producing radio-frequency response signal, complete being replied by mark radar, control the technology such as the having or not of orientation width, signal amplitude of answer signal, additional Doppler frequency by employing, in a large amount of clutters, make answer signal very easily be distinguished, on shipborne radar, answer signal is measured, obtained the measured value data of target; Adopt True Data measuring equipment to measure by the position true value data between mark radar and calibration facility, realize the demarcation of shipborne radar detection range and bearing accuracy by calculating the measured value data of radar and target true value data.
Technical scheme of the present invention:
The active calibration facility of a kind of frequency memory relay type shipborne radar, comprises frequency memory relay type e-mail marking machine, dual-mode antenna, True Data measuring equipment three parts, and composition as shown in Figure 1.
Dual-mode antenna comprises antenna and transmit-receive switch.Transmit-receive switch control antenna receives by the radio-frequency response signal of the radiofrequency signal of mark radar and the generation of electron emission Radio Beacon.
True Data measuring equipment comprises movement station one, movement station two and base station totally 3 Big Dipper receiving terminal machines.The Big Dipper receiving terminal machine that is placed on frequency memory relay type e-mail marking machine place is movement station one, for measuring the position true value of e-mail marking machine; Being placed on by the Big Dipper receiving terminal machine at mark radar place is movement station two, for measuring by the position true value of mark radar; Being placed on away from what marked radar and e-mail marking machine is base station, and the data of measurement are reference data.The data that the data of respectively movement station one and movement station two being measured and base station are measured are carried out Difference Calculation, obtain being marked the position True Data between radar and e-mail marking machine.
Frequency memory relay type e-mail marking machine comprises receiving element, high intermediate frequency lower frequency changer circuit, digital frequency memory circuit, high intermediate frequency up-converter circuit, transmitter unit, frequency synthesizer unit, mark frequency circuit, Doppler modulation circuit, signal processing circuit and display control terminal, and its annexation as shown in Figure 2, the receiving element of frequency memory relay type e-mail marking machine is sent to high intermediate frequency lower frequency changer circuit by antenna reception by mark radar electromagnetic wave signal, high intermediate frequency lower frequency changer circuit carries out sending to digital frequency memory circuit to store after down coversion, sorting, numeral frequency memory circuit passes through signal spatial domain, frequency domain, the answer signal that the selection of time domain produces time delay sends to high intermediate frequency up-converter circuit, high up-converter circuit again and again up-converts the signals to radio-frequency power and sends to transmitter unit, transmitter unit is gone out by antenna transmission, marked the answer signal that can measure simulation on radar, for being marked radar.Frequency synthesizer unit is connected to receiving element and transmitter unit provides required local oscillation signal for it provides Up/Down Conversion network, mark frequency circuit rate of connections compositor unit, digital frequency memory circuit, signal processing circuit, high intermediate frequency lower frequency changer circuit, Doppler modulation circuit respectively, Doppler modulation circuit is connected to signal processing circuit and high intermediate frequency up-converter circuit, and signal processing circuit receives the parameter of display control terminal transmission, the duty of control figure frequency memory circuit.
Receiving element is shipborne radar frequency of operation 2～18GHz by receiving antenna receive frequency, and the down conversion module of receiving element adopts two modules to realize, and is respectively two frequency ranges of 2GHz～6GHz and 6GHz～18GHz.The radiofrequency signal of radar emission, amplification frequency-conversion processing becomes the high intermediate-freuqncy signal of centre frequency 3.5GHz.High intermediate frequency lower frequency changer circuit is mainly used in the radiofrequency signal of the 3.5GHz of reception & disposal unit output to change to the intermediate-freuqncy signal of 250MHz, outputs to digital frequency memory circuit.
Numeral frequency memory circuit receives 250MHz intermediate-freuqncy signal, through sample quantization, storage, time delay control, then reverts to 250MHz intermediate-freuqncy signal, outputs to high intermediate frequency up-converter circuit.
High intermediate frequency up-converter circuit is that the contrary of high intermediate frequency lower frequency changer circuit processed, and its function is the intermediate-freuqncy signal of the 250MHz of digital frequency memory output to be faded to the high intermediate-freuqncy signal of 3.5GHz, and keeps relatively constant power level, exports to transmitter unit.
Transmitter unit is that the contrary of receiving element processed, for signal being processed and the output signal of interface circuit, the high intermediate-freuqncy signal forming after distance and Doppler modulation are reduced to radiofrequency signal.The 3.5GHz target echo signal of high ifd module output is returned in the radar radio frequency signal frequency of 2～6GHz, 6～18GHz.
Frequency synthesizer unit major function provides Up/Down Conversion network required local oscillation signal for receiving element and transmitter unit.
Mark frequency circuit adopts crystal oscillator as benchmark, after frequency division, frequency multiplication, for frequency synthesizer unit provides reference signal, for digital frequency memory circuit, signal processing circuit provide clock signal, for high intermediate frequency lower frequency changer circuit, Doppler modulation circuit etc. provide fixing local oscillation signal.
Doppler modulation circuit is subject to the control of signal processing circuit, the Doppler frequency modulation signal of signal processing circuit output is converted into 1.5GHz centre frequency and gets on, as the local oscillation signal of high intermediate frequency up-converter module.
Signal processing circuit receives working method, the control parameter that display control terminal sends, the duty of control figure frequency memory circuit by serial ports.According to display control terminal input by mark radar pulsewidth parameter, the triggering reference signal of high intermediate frequency lower frequency changer circuit output is carried out to matched filtering, the undesired signal in filtering complex environment.
Display control terminal is used for inputting by information such as mark radar pulsewidth parameter, e-mail marking machine parameter and simulated target parameters.
The invention has the beneficial effects as follows:
The active calibration facility of frequency memory relay type shipborne radar of the present invention adopts digital frequency memory relay type e-mail marking machine design, have the advantages that frequency memory band is wide, export spuious little, full coherent guinea pig target echo, adaptation arteries and veins internal modulation form is many, flexible working mode.
1, set up simply, e-mail marking machine is arranged on to distance and is arrived ten thousand metres place by 600 meters of mark radars, after True Data measuring equipment is placed, get final product work;
2, easy and simple to handle, the radio frequency analog signal feature of generation is obvious, be easy to be received and measure by radar, and the radio-frequency response signal of simulation any distance, calibration cost is low.
3. broadband system design, frequency memory relay type e-mail marking machine operational frequency bandwidth of the present invention is 2～18GHz, reach 9 octaves, the operating frequency range of frequency coverage all shipborne radars of present stage, can realize the precision calibration to all shipborne radar distance and bearings.
Brief description of the drawings
Fig. 1 is the active calibration facility composition of frequency memory relay type shipborne radar of the present invention schematic diagram.
Fig. 2 is frequency memory relay type electronic beacon machine composition schematic diagram of the present invention.
Fig. 3 is digital frequency memory the electric circuit constitute schematic diagram of the present invention.
In figure:
1 receiving element; 2 high intermediate frequency lower frequency changer circuits; 3 digital frequency memory circuit; 4 high intermediate frequency up-converter circuits;
5 transmitter units; 6 frequency synthesizer unit; 7 mark frequency circuits; 8 Doppler modulation circuit;
9 signal processing circuits; 10 display control terminals.
Embodiment
As Fig. 1 describes, the concrete signal flow of frequency memory relay type electronic beacon machine is as follows: when (1) accepting state, transmit-receive switch is connected antenna and receiving element, by antenna reception by mark the transmitting of radar, after receiving element frequency-selecting, amplification, amplitude regulation and control, be converted to high intermediate frequency (centre frequency 1.25GHz); High intermediate-frequency circuit carries out being converted to 250MHz intermediate frequency after signal amplitude adjustment, and keeps spiking output amplitude substantially constant, as the input signal of digital frequency memory; (2) digital frequency memory module receives 250MHz intermediate-freuqncy signal, through sample quantization, storage, time delay control, then reverts to 250MHz intermediate-freuqncy signal, the distance modulated of settling signal.(3) the Doppler modulation letter that signal processing circuit produces, through Doppler modulation circuit, in the local oscillator of the high intermediate frequency up-converter module that is added to, then passes through up-converter module, is added in radio frequency output signal, and the Doppler modulation of settling signal.(4) signal processing circuit module receives the instruction of display control terminal, the duty of control figure frequency memory module, generation Doppler modulation signal; Signal processing circuit also produces control signal, analogue echo output amplitude control signal and other control signals of receiving element frequency-selecting filter control signal, frequency synthesizer according to the instruction of display control terminal, coordinate the duty of complete machine.
Frequency memory relay type e-mail marking machine adopts based on digital frequency memory technique and Doppler modulating technology, has realized the simulation of the full coherent target echo of radar, adopts the indexs such as the coherent of this technical modelling target echo to be ensured preferably.
1, the realization of digital frequency memory circuit:
Frequency memory relay type e-mail marking machine adopts digital memory circuit, realizes being transmitted and carry out frequency memory forwarding by mark shipborne radar, and simulation produces radio-frequency response signal.
The composition of numeral frequency memory circuit comprises analog to digital converter, string modular converter, Double Port Random Memory, digital frequency memory controller, parallel serial conversion module, digital to analog converter composition, and composition as shown in Figure 3.Adopt the signal processing method such as digital upper and lower frequency conversion and the extraction of signal reduction of speed to realize high-speed sampling, storage, the late replicating to radar mean frequency baseband signal.The intermediate frequency baseband signal of input is quantized into digital signal by analog to digital converter, by string modular converter, digital signal is at a high speed carried out to reduction of speed processing, deliver in Double Port Random Memory and store, the storage of numeral frequency memory controller control Double Port Random Memory and calling, and produce corresponding reading, writing address; Data after time delay convert high-speed digital signal in parallel serial conversion module, then revert to required analog intermediate frequency signal by digital to analog converter.Implementation is as follows:
Numeral frequency memory module receives 250MHz intermediate-freuqncy signal, through sample quantization, storage, time delay control, then reverts to 250MHz intermediate-freuqncy signal.
Numeral frequency memory module adopts single channel, 1GHz sampling rate, 10bit amplitude quantizing scheme.Base band radio-frequency input signals is quantized into four tunnels high speeds, 10Bit differential digital signal through high-speed AD converter, pass through again level switch module, change into fiduciary level, then through string modular converter, high speed, 10Bit data-switching are become to low speed, 80Bit data, under the control of the writing pulse signal being generated by digital frequency memory controller, transponder pulse sample is slided to window formula and store in the memory block of digital frequency memory module.Parallel serial conversion module, low speed, 80Bit data-switching Cheng Si road high speed, 10Bit, standard high-speed digital signal, is given high-speed A/D converter, and digital signal is reverted to baseband rf signal.
Numeral frequency memory controller, according to the target range of setting, calculates the time delay value of target echo with respect to trigger pulse, generates the time delay control word reading in digital frequency memory controller.In turn corresponding intermediate frequency transmitting sample is read by time delay value in each radar period, through parallel serial conversion module low speed, 80Bit data-switching Cheng Si road high speed, 10Bit, standard high-speed digital signal, give high-speed A/D converter, digital signal is reverted to 250MHz, the intermediate frequency baseband signal of instant bandwidth ± 150MHz.Like this, radar signal produces target echo simulating signal through the storage of digital frequency memory circuit and the time delay control of control circuit, thus the time delay of the coherent target echoes such as analog pulse compression and frequency agile radar.
(2) generation of delay time signal
Frequency memory relay type e-mail marking machine is the transponder pulse signal from tested radar by antenna reception, frequency conversion network carries out frequency conversion to received signal, baseband signal after frequency conversion is sent into and postponed and Doppler modulation unit, carry out the modulation of target echo signal, guinea pig echoed signal, for radar calibration.
In display control terminal, the simulated target position setting according to demarcation, calculate the distance of target with respect to radar, determine the time delay value of target echo signal with respect to radar transmitted pulse, under radar emission signal demodulator pulse synchronous, technology generator in distance-Doppler modulating unit reads the corresponding intermediate frequency transponder pulse of digital radiofrequency memory storage by these time delay value orders, and accurately simulation is corresponding to each target echo of different delay value.
(3) target Doppler simulation
In order to simulate the Doppler shift of coherent target echo, in digital frequency memory circuit, the medium-frequency pulse signal of being read by digital radiofrequency memory is by a frequency converter, and the reference signal of this frequency converter is that Doppler signal generation module produces.The target echo Doppler shift being calculated according to the radial motion speed of the relative radar of target by indicative control unit, and control the frequency of Doppler signal, in medium-frequency pulse signal, add the Doppler shift value of this target.
Intermediate frequency transponder pulse signal through time delay and Doppler shift modulation carries out up-conversion in output frequency changer circuit, can produce the radiofrequency signal identical with radar transmitted pulse frequency.This target echo signal analog form can be simulated the coherent and the non-coherent target echo signal that comprise pulse compression, frequency agility and pulse Doppler radar realistically.