CN104267265A - Evaluating system and method based on radio astronomical instrument device electromagnetic radiation - Google Patents

Abstract

The invention relates to an evaluating system and method based on radio astronomical instrument device electromagnetic radiation. The evaluating system comprises a microwave switch, a receiving antenna, a reference noise source, a signal source and an emitting antenna, wherein two normally-open contacts are arranged at one end of the microwave switch, the other end of the microwave switch is connected to a spectrometer through a pre-amplifier, the spectrometer is connected with a computer, the receiving antenna is connected to one normally-open contact of the microwave switch, the standard noise source is connected to the other normally-open contact of the microwave switch, the signal source is connected to the computer through the network, and the emitting antenna is connected to the output end of the signal source through a radio frequency cable. According to the system and method, by means of the technical index and observation requirements of a radio astronomical observation system, radio astronomical instrument device radiated emission is tested and evaluated, the influence of radio astronomical instrument device radiated emission on a radio telescope is analyzed, so that reference is provided for compatibility design, shielding design and site radio management of the radio astronomical observation system, and the engineering significance is high.

Description

A kind of evaluating system based on the electromagnetic radiation of radio astronomy instrument and equipment and method

Technical field

The present invention relates to the Electromagnetic Interference Test in electromagnetic compatibility technology, assessment technology, particularly relate to a kind of evaluating system based on the electromagnetic radiation of radio astronomy instrument and equipment and method.

Background technology

Specify in China national military standard GJB72-85, Electro Magnetic Compatibility refers to the ability that electronics, electrical equipment or system normally work by designing requirement in the electromagnetic environment of expection, its reflection be that equipment or system can normally work when bearing electromagnetic disturbance, do not produce again the ability of the electromagnetic disturbance exceeding prescribed limits simultaneously.Electro Magnetic Compatibility is the important performance indexes of equipment or system, is also the task performance of safeguards system and the key factor of raising system reliability.

Heavy caliber single antenna radio telescope has high system sensitivity, and in system, between system and platform location inner electronic equipment from many.Along with development and the application of High-Frenquency Electronic Technology, high-speed figure treatment technology, the construction of digital receiver, digital terminal, business machine, electrical equipment and platform location optical observation equipment, makes platform location electromagnetic environment become particularly complicated.Radio telescope completes reception and the data processing of data by antenna, feed, receiver, transmission system, data processing terminal etc., wherein antenna, feed, transmission system are the weak link of system, are vulnerable to the impact of extraneous electronic equipment radiation-emitting signal; In addition, coexisted in radio telescope system antenna driving system, change feedback system, data processing terminal, control and supervisory system and other electrical equipments etc., the electromagnetic radiation of these equipment easily enters receiving system by antenna sidelobe, thus reduces system signal noise ratio.

The intensity of Radio frequency interference (RFI) (radio frequency interference, RFI) and spectral density can make observed result deeply consequently lose use value by the impact of Radio frequency interference (RFI).Especially, the observation (continuous spectrum or spectrum) utilizing single antenna radio telescope to carry out is vulnerable to the impact disturbed most, its reason is: the increase of integral time improves the sensitivity of telescope to astronomical signal, but also improves to equal extent the sensitivity of its radio frequency undesired signal.

As can be seen here, radio astronomy recording geometry has high sensitivity, and the performance that recording geometry is interior or between system, electromagnetic compatibility problem can affect this system, reduction system signal noise ratio, electronic equipment radiation-emitting simultaneously, namely Radio frequency interference (RFI) not only can affect the quality of some observation or specific observation type, but also the overall efficiency of radio astronomy system can be limited, increase the complicacy of observation time and process data.Therefore, for radio observatory location instrument and equipment radiation-emitting, rapid evaluation is carried out on the impact of radio astronomical sight, thus for the design of radio telescope system EMC, shielding design, the radio control of platform location provides important evidence, has important engineering significance.

In the prior art, judge astronomical instrument radiation of equipment launches whether meet standard, needs to carry out Electromagnetic Interference Test; The most frequently used experimental technique of current Electromagnetic Interference Test uses anechoic chamber.But although anechoic chamber, can isolate extraneous bad electromagnetic environment, the test of simulation open area test site, its cost is high, and test result can not be directly used in assessment testing apparatus radiation-emitting to the impact of radio astronomical sight system.

And, due to other field electromagnetic compatibility test, standard noise source is not used to calibrate test macro, and usually adopt test and theoretical calculation system-gain, that is, whether test result exceeds standard according to relevant criterion valuator device, which adds the uncertainty of test, therefore, the above-mentioned index for other field electromagnetic compatibility test system and reliability all poor.

Domestic development for radio astronomy RFI measuring technology comes from FAST engineering (Five-hundred-meter Aperture Spherical radio telescope peoject, 500 meters of bore spherical radio telescope engineerings) promotion of project, early stage FSAT project predevelopment phase, the Guizhou radio council has carried out measurement of electromagnetic environment for FSAT platform location, pass through international exchange, Guizhou learns SKA addressing RFI without committee technician from SKA expert group and tests and data processing method, as namely document " radio astronomy station electromagnetic environment measuring method and analysis " testing and analyzing method comes from SKA (the Square kilometer array that R.Ambrosini in 2003 etc. write, square kilometer array) addressing RFI test protocol, this agreement gives the requirement of RFI Design of Test System for scientific goal and technical need, test pattern and data processing method, this method of testing carries out testing and data processing for radio observatory location wave environments.But this method of testing is only for wave environments test, and does not provide relevant appraisal procedure for the transmitting of radio observatory location single instrument radio radiation to the impact evaluation of radio astronomy service.

In addition, FCC FCC15-109Class A & Class B standard and CCIR's CISPR11 & CISPR22 standard give the maximum radiated power limit that the radiation devices such as consumer electronics allow.These standards are used more extensive, tested equipment be given to the radiation-emitting electric field intensity limit value of set a distance in standard, radiation test is tested usually in microwave dark room, these standards do not provide radio astronomy recording geometry feed aperture interference level limit value, therefore, foundation cannot be provided for the impact of assessment radio astronomy instrument and equipment radiation-emitting on radio astronomical sight.

And International Telecommunications Union (ITU) (International Telecommunication Union, ITU) for the sensitivity of radio astronomy instrument and equipment and different observation mode requirement, formulate ITU-R RA.769 recommendation, the spectral bandwidth that this recommendation distributes according to radio astronomy, integral time is 2000s, give radio astronomy recording geometry feed aperture place continuum spectra observations higher than 13MHz by calculating, spectral line observation is higher than the armful traffic density maximum of 327MHz; But this recommendation is only for general radio telescope, and the tasks of science of different bore radio telescope and technical indicator different, therefore it is more meaningful to calculate feed aperture place interference level limit value for different radio telescope technical indicator and scientific requirement.

In sum, for the transformation of radio telescope Electro Magnetic Compatibility and system EMC design, there is important directive significance owing to assessing radio astronomy instrument and equipment radiation characteristic scientifically and rationally, therefore, need a kind of appraisal procedure based on the electromagnetic radiation of radio astronomy instrument and equipment of exploitation and system at present badly, to ensure the task performance of radio astronomy recording geometry and to improve system reliability.

Summary of the invention

In order to solve above-mentioned prior art Problems existing, the present invention aims to provide a kind of evaluating system based on the electromagnetic radiation of radio astronomy instrument and equipment and method, to test fast for the instrument and equipment radiation-emitting of different radio observatory location, analyze and to assess, thus obtain instrument and equipment radiation-emitting to the influence degree of radio astronomical sight system, and provide shielding demand for the instrument and equipment had an impact for radio astronomy recording geometry, and then ensure the task performance of radio astronomy recording geometry and improve system reliability.

A kind of evaluating system based on the electromagnetic radiation of radio astronomy instrument and equipment that one of the present invention is described, it comprises:

One microwave switch, its one end is two normally opened contacts, and its other end is connected to a frequency spectrograph by a prime amplifier;

Described frequency spectrograph is connected with a computing machine;

One receiving antenna being connected to a described normally opened contact of described microwave switch;

One be connected to described microwave switch another described in the standard noise source of normally opened contact;

One is connected to the signal source of described computing machine by network; And

One is connected to the emitting antenna of described signal source output terminal by RF cable;

Wherein, described computing machine comprises:

System calibration module, after it is connected with described prime amplifier and described frequency spectrograph respectively for the two ends at described standard noise source, controls described frequency spectrograph frequency sweep, and adopts Y factor method to calculate acquisition system noise and system-gain;

Electromagnetic Interference Test module, it is for be connected with described prime amplifier at described receiving antenna and after arranging contiguous peripheral instrument and equipment to be assessed, control described frequency spectrograph frequency sweep to obtain the radiation-emitting frequency spectrum of described instrument and equipment to be assessed, and data calibration is carried out to obtain test antenna actinal surface place radiation power to this radiation-emitting frequency spectrum;

Interference level limit value computing module, it is for according to given antenna noise temperature, the resolution bandwidth of described system noise and default described frequency spectrograph and integral time, calculate and obtain feed telescope actinal surface interference level limit value, and according to the given radio telescope angle of pitch, described equipment to be assessed is to the horizontal range of feed telescope aperture centre and floor projection and described equipment to be assessed to the vertical range of feed telescope aperture centre, calculate and obtain radio telescope side lobe gain, again according to described feed telescope actinal surface interference level limit value and described radio telescope side lobe gain, calculate and obtain the interference level limit value that described instrument and equipment to be assessed arrives feed telescope actinal surface,

Path attenuation measurement module, it is for arranging contiguous described instrument and equipment to be assessed at described emitting antenna, and after described receiving antenna arranges contiguous peripheral feed telescope actinal surface, control described signal source outputting standard signal to receive for described receiving antenna, and control described frequency spectrograph frequency sweep, obtain to calculate the electromagnetic wave path attenuation that described standard signal arrives feed telescope actinal surface place;

Radiation-emitting evaluation module, it is for arriving interference level limit value and the electromagnetic wave path attenuation of feed telescope actinal surface according to described instrument and equipment to be assessed, calculate and obtain instrument and equipment radiated transmission power limit value, and compare the size of this instrument and equipment radiated transmission power limit value and described test antenna actinal surface place radiation power, if described test antenna actinal surface place radiation power is less than described instrument and equipment radiated transmission power limit value, the radiation-emitting being then evaluated as described instrument and equipment to be assessed does not affect radio astronomical sight, otherwise, the radiation-emitting being then evaluated as described instrument and equipment to be assessed has an impact to radio astronomical sight, and export corresponding instrument and equipment shielding demand.

In the above-mentioned evaluating system based on the electromagnetic radiation of radio astronomy instrument and equipment, described microwave switch is connected by the input end of RF cable with described prime amplifier.

In the above-mentioned evaluating system based on the electromagnetic radiation of radio astronomy instrument and equipment, described frequency spectrograph is connected with described computing machine by general purpose interface bus card.

In the above-mentioned evaluating system based on the electromagnetic radiation of radio astronomy instrument and equipment, described computing machine also comprises a database, and it is for the interference level limit value storing described system noise, system-gain, radiation-emitting frequency spectrum, test antenna actinal surface place radiation power, instrument and equipment to be assessed arrive feed telescope actinal surface, electromagnetic wave path attenuation and described shielding demand.

In the above-mentioned evaluating system based on the electromagnetic radiation of radio astronomy instrument and equipment, described computing machine also comprise one with the data management module of described DataBase combining, its for show, search and/delete data in described database.

A kind of appraisal procedure based on the electromagnetic radiation of radio astronomy instrument and equipment described in two of the present invention, it comprises the following steps:

Preparation process, provides as the evaluating system based on the electromagnetic radiation of radio astronomy instrument and equipment in claim 1-5 as described in any one;

System calibration step, switch described microwave switch the two ends of described standard noise source are connected with described prime amplifier and described frequency spectrograph respectively, control described frequency spectrograph frequency sweep by described system calibration module, and adopt Y factor method to calculate acquisition system noise and system-gain;

Radiation emission test step, switch described microwave switch described receiving antenna is connected with described prime amplifier, and described receiving antenna is arranged contiguous peripheral instrument and equipment to be assessed, control described frequency spectrograph frequency sweep to obtain the radiation-emitting frequency spectrum of described instrument and equipment to be assessed by described Electromagnetic Interference Test module, and data calibration is carried out to obtain test antenna actinal surface place radiation power to this radiation-emitting frequency spectrum;

Instrument and equipment to be assessed arrives the interference level limit value calculation procedure of feed telescope actinal surface, described interference level limit value computing module is according to given antenna noise temperature, the resolution bandwidth of described system noise and default frequency spectrograph and integral time, calculate and obtain feed telescope actinal surface interference level limit value, and according to the given radio telescope angle of pitch, described equipment to be assessed is to the horizontal range of feed telescope aperture centre and floor projection and described equipment to be assessed to the vertical range of feed telescope aperture centre, calculate and obtain radio telescope side lobe gain, again according to described feed telescope actinal surface interference level limit value and described radio telescope side lobe gain, calculate and obtain the interference level limit value that described instrument and equipment to be assessed arrives feed telescope actinal surface,

Electromagnetic wave path attenuation testing procedure, described emitting antenna is arranged contiguous described instrument and equipment to be assessed, and described receiving antenna is arranged contiguous feed telescope actinal surface, control described signal source outputting standard signal by described path attenuation measurement module to receive for described receiving antenna, and control described frequency spectrograph frequency sweep, obtain to calculate the electromagnetic wave path attenuation that described standard signal arrives feed telescope actinal surface place;

Instrument and equipment radiation-emitting appraisal procedure, described radiation-emitting evaluation module arrives interference level limit value and the electromagnetic wave path attenuation of feed telescope actinal surface according to described instrument and equipment to be assessed, calculate and obtain instrument and equipment radiated transmission power limit value, and compare the size of this instrument and equipment radiated transmission power limit value and described test antenna actinal surface place radiation power, if described test antenna actinal surface place radiation power is less than described instrument and equipment radiated transmission power limit value, the radiation-emitting being then evaluated as described instrument and equipment to be assessed does not affect radio astronomical sight, otherwise, the radiation-emitting being then evaluated as described instrument and equipment to be assessed has an impact to radio astronomical sight, and export corresponding instrument and equipment shielding demand.

In the above-mentioned appraisal procedure based on the electromagnetic radiation of radio astronomy instrument and equipment, described system calibration step comprises:

Calibration initial frequency, the calibration sweeping steps of described frequency spectrograph are set according to the calibration testing bandwidth preset and calibration resolution bandwidth, and mark the test frequency point of described frequency spectrograph;

Controlled the on off state of described standard noise source by described system calibration module, and control under described frequency spectrograph is captured in the open and close state of described standard noise source respectively, the performance number P corresponding to test frequency point of mark _onand P _off;

Described system calibration module obtains described system noise T according to following formulae discovery _rwith system-gain G _s, and by this system noise T _rwith system-gain G _sstored in described database:

Y＝P _on/P _off (1)，

NF＝ENR-10log ₁₀(Y-1)+10log ₁₀(T ₀/T _off) (2)，

T _R＝T ₀(NF-1) (3)，

T _on＝T ₀ENR+T _off (4)，

G _S＝P _on-10log ₁₀(T _on+T _R)-10log ₁₀(B)-10log ₁₀(K)-30 (5)，

Wherein, NF is system noise factor, and ENR is the excess noise ratio of the described standard noise source prestored in the database, T ₀for standard temperature, T _offfor closing temperature during described standard noise source, T _onfor opening temperature during described standard noise source, B is described calibration resolution bandwidth, and K is Boltzmann constant.

In the above-mentioned appraisal procedure based on the electromagnetic radiation of radio astronomy instrument and equipment, described radiation emission test step comprises:

Initial frequency, the sweeping steps of described frequency spectrograph are set according to the test bandwidth preset, integral time, resolution bandwidth;

In test environment by described Electromagnetic Interference Test module all electronic equipments around closing, control the on off state of described instrument and equipment to be assessed, and control described radiation-emitting frequency spectrum P when described frequency spectrograph gathers environment frequency spectrum when cutting out described instrument and equipment to be assessed respectively and opens described instrument and equipment to be assessed _a, and by this radiation-emitting frequency spectrum P _astored in described database;

By contrasting described environment frequency spectrum and described radiation-emitting frequency spectrum, to obtain radiation-emitting spectral characteristic;

By described Electromagnetic Interference Test module according to the receiving antenna gain G of described default resolution bandwidth to the described receiving antenna prestored in the database _a, described system-gain G _scarry out linear interpolation, and based on this receiving antenna gain G _aand system-gain G _sto described radiation-emitting frequency spectrum P _acarry out data calibration, thus obtain described test antenna actinal surface place radiation power P according to following formula, and by this test antenna actinal surface place radiation power P stored in described database:

P＝P _A-G _S-G _A (6)。

In the above-mentioned appraisal procedure based on the electromagnetic radiation of radio astronomy instrument and equipment, the interference level limit value calculation procedure that described instrument and equipment to be assessed arrives feed telescope actinal surface comprises:

Described interference level limit value computing module is according to given described antenna noise temperature T _a, described system noise T _rand preset described frequency spectrograph resolution bandwidth B and integral time τ, obtain described feed telescope actinal surface interference level limit value L according to following formulae discovery _t1:

$L_{T1}=0.1\×K\×B\×(T_A+T_R)/\sqrt{\mathrm{B\τ}}---\left(7\right),$

Wherein, K is Boltzmann constant;

Described interference level limit value computing module is according to the given radio telescope angle of pitch described equipment to be assessed is to the horizontal range L of feed telescope aperture centre and floor projection _dand described equipment to be assessed is to the vertical range H of feed telescope aperture centre, obtain radio telescope side lobe gain G (Φ) according to following formulae discovery:

$G\left(\mathrm{\Φ}\right)=\left\{\begin{array}{cc}32-25\log \left(\mathrm{\Φ}\right)& 1\≤\mathrm{\Φ}\≤48\\ -10& 48\≤\mathrm{\Φ}\≤80\\ -5& 80\≤\mathrm{\Φ}\≤120\\ -10& 120\≤\mathrm{\Φ}\≤180\end{array}\right.---\left(9\right),$

Wherein, Φ is the angle that instrument and equipment to be assessed departs from radio telescope main beam axis;

Described interference level limit value computing module is according to described feed telescope actinal surface interference level limit value L _t1and described radio telescope side lobe gain G (Φ), obtain according to following formulae discovery the interference level limit value L that described instrument and equipment to be assessed arrives feed telescope actinal surface _t:

L _T＝L _T1-G(Φ) (10)；

Described interference level limit value computing module arrives the interference level limit value L of feed telescope actinal surface to described instrument and equipment to be assessed according to the described resolution bandwidth in described radiation emission test step _tcarry out linear interpolation, and this instrument and equipment to be assessed is arrived the interference level limit value L of feed telescope actinal surface _tstored in described database.

In the above-mentioned appraisal procedure based on the electromagnetic radiation of radio astronomy instrument and equipment, described electromagnetic wave path attenuation testing procedure comprises:

Signal frequency and the signal amplitude of the described standard signal that described signal source exports are set by described path attenuation measurement module;

Arrange according to the test bandwidth preset, sweep time, resolution bandwidth and mark the scanning frequency of described frequency spectrograph, and this scanning frequency mates with the signal frequency of described standard signal;

Control described signal source by described path attenuation measurement module and export described standard signal, the signal receiving this emitting antenna to make described receiving antenna and send, and the performance number P corresponding to scanning frequency controlling described frequency spectrograph collection mark _r;

Described path attenuation measurement module is electromagnetic wave path attenuation S according to following formulae discovery _p:

S _P＝P _R-G _S-G _A-P _T+C _A-G _AT (11)，

Wherein, G _sfor described system-gain, G _afor the receiving antenna gain of the described receiving antenna in the database that prestores, P _tfor the signal amplitude of described standard signal, C _afor the Insertion Loss of the described signal source prestored in the database and the RF cable be connected between emitting antenna, G _aTfor the gain of the described emitting antenna in the database that prestores;

Described path attenuation measurement module according to the described resolution bandwidth in described radiation emission test step to described electromagnetic wave path attenuation S _pcarry out linear interpolation, and by this electromagnetic wave path attenuation S _pstored in described database.

In the above-mentioned appraisal procedure based on the electromagnetic radiation of radio astronomy instrument and equipment, described electromagnetic wave path attenuation testing procedure also comprises:

After the scanning frequency of the signal frequency and signal amplitude and described frequency spectrograph that are provided with described standard signal, described signal source and described frequency spectrograph is connected by RF cable, and the difference of signal that the standard signal that exports of signal source described in comparison and described frequency spectrograph receive, if this difference is within ± 1dB, then proceed described electromagnetic wave path attenuation testing procedure, otherwise, if do not meet, reset the signal frequency of described standard signal and/or the scanning frequency of signal amplitude and/or described frequency spectrograph.

In the above-mentioned appraisal procedure based on the electromagnetic radiation of radio astronomy instrument and equipment, described instrument and equipment radiation-emitting appraisal procedure comprises:

Described radiation-emitting evaluation module obtains described instrument and equipment radiated transmission power limit value L according to following formulae discovery:

L＝L _T-S _P-3dB (12)；

Wherein, L _tfor described instrument and equipment to be assessed arrives the interference level limit value of feed telescope actinal surface, S _pfor described electromagnetic wave path attenuation, 3dB is uncertainty of measurement;

Described radiation-emitting evaluation module exports described instrument and equipment shielding demand SE according to following formula, and by this instrument and equipment shielding demand SE stored in described database:

SE＝P-L (13)。

Owing to have employed above-mentioned technical solution, first the present invention, uses standard noise source to calibrate test macro based on Y factor method, computing system noise and system-gain; Secondly, use electromagnetic interference measurement, EMI measurement technology, the electromagnetic wave launched by receiving antenna receiving instrument radiation of equipment, and data processing is carried out to instrument and equipment radiation-emitting frequency spectrum, to obtain test antenna actinal surface place radiation power; Then, the interference level limit value of feed telescope actinal surface is calculated according to radio telescope technical indicator and observation mode (as antenna noise temperature, system noise, resolution bandwidth and integral time etc.); Then, control signal source outputs signal, and transmitted to feed telescope direction by emitting antenna, and at feed telescope actinal surface place, highly sensitive receiving antenna etc. is installed, to calculate the electromagnetic wave path attenuation that standard signal arrives feed aperture place; Finally, based on above-mentioned interference level limit value and path attenuation computing equipment radiation of equipment emissive power limit value, and based on this instrument and equipment radiated transmission power limit value and test antenna actinal surface place radiation power (namely, instrument and equipment radiation-emitting frequency spectrum after calibration), assessment instrument and equipment radiation-emitting on radio telescope observation impact, and provides corresponding instrument and equipment shielding demand.To sum up, the present invention is in conjunction with radio astronomy recording geometry technical indicator and observation requirements, test by launching radio astronomical instrument radiation of equipment and assess, analysis Instrument equipment radiation-emitting is on the impact of radio telescope, thus for radio astronomy recording geometry electromagnetic Compatibility Design, shielding design, the radio control of platform location provides reference frame, has important engineering significance.

Accompanying drawing explanation

Fig. 1 is the structured flowchart of the evaluating system based on the electromagnetic radiation of radio astronomy instrument and equipment of one of the present invention;

Fig. 2 is the inner structure block diagram of one of the present invention Computer;

Fig. 3 is the structured flowchart of one of the present invention when carrying out system calibration;

Fig. 4 is the process flow diagram of the appraisal procedure based on the electromagnetic radiation of radio astronomy instrument and equipment of the present invention two;

Fig. 5 is the schematic diagram that instrument and equipment to be assessed departs from the angle of radio telescope main beam axis.

Embodiment

Below in conjunction with accompanying drawing, provide preferred embodiment of the present invention, and be described in detail.

As shown in Figure 1, one of the present invention, that is, based on an evaluating system for radio astronomy instrument and equipment electromagnetic radiation, comprising: receiving antenna 1, microwave switch 2, prime amplifier 3, frequency spectrograph 4, standard noise source 5, computing machine 6, emitting antenna 8 and signal source 9.

Microwave switch 2 is two-way change-over switch, that is, one end of microwave switch 2 is two normally opened contacts; Receiving antenna 1 is connected with a normally opened contact of microwave switch 2, standard noise source 5 is connected with another normally opened contact of microwave switch 2, the other end of microwave switch 2 is connected by the input end of RF cable with prime amplifier 3 (being low noise amplifier in the present embodiment), the output terminal of prime amplifier 3 is connected with the 28V direct current supply interface of frequency spectrograph 4, frequency spectrograph 4 is connected with computing machine 6 by general purpose interface bus card 7 (General-Purpose Interface Bus, hereinafter referred to as GPIB card); Signal source 9 is by netting twine access to LAN 10 (LAN) 11, and communicated to connect with computing machine 6 by this LAN (Local Area Network) 10, thus control this signal source 9 outputting standard signal by this computing machine 6, to make the emitting antenna 8 emission standard signal being connected to this signal source 9 output terminal by RF cable, receive for receiving antenna 1.

In above-mentioned evaluating system, when the position of the switch of microwave switch 2 switch to make to form path between receiving antenna 1 and prime amplifier 3 time, this receiving antenna 1, microwave switch 2, prime amplifier 3, frequency spectrograph 4, GPIB card 7 and computing machine 6 composition is used for the Electromagnetic Interference Test subsystem carrying out instrument and equipment radiation emission test (that is, Electromagnetic Interference Test); When the position of the switch of microwave switch 2 switch to make to form path between standard noise source 5 and prime amplifier 3 time, realize the calibration to above-mentioned Electromagnetic Interference Test subsystem.As can be seen here, can realize by the switching of the position of the switch to microwave switch 2 automatic switchover that instrument and equipment radiation emission test and Electromagnetic Interference Test subsystem calibrate.

As shown in Figure 2, computing machine 6 inside specifically comprises: system calibration module 61, Electromagnetic Interference Test module 62, interference level limit value computing module 63, path attenuation measurement module 64, radiation-emitting evaluation module 65, database 66 and data management module 67; The concrete function of these modules 61 will elaborate hereinafter.

Below in conjunction with the principle of work of Fig. 4 to above-mentioned evaluating system, that is, the appraisal procedure based on the electromagnetic radiation of radio astronomy instrument and equipment of the present invention two, describes in detail.

Appraisal procedure of the present invention comprises the following steps:

The first step, system calibration, specifically comprises:

First, by switching microwave switch 2, standard noise source 5 is replaced receiving antenna 1 connecting system, and the 28V direct current supply interface (as shown in Figure 3) of the other end of this standard noise source 5 access frequency spectrograph 4;

Then, calibration initial frequency, the calibration sweeping steps of frequency spectrograph 4 are set according to the calibration testing bandwidth preset and calibration sampled point interval width (i.e. calibration resolution bandwidth), such as, can directly select to arrange on frequency spectrograph 4: calibration resolution bandwidth: 3MHz; Video resolution bandwidth: 10MHz; Calibration testing bandwidth: 1KHz; Sweep time: 200 milliseconds (above-mentioned parameter arranges and all can effectively improve system calibration precision); According to the parameter of above-mentioned setting, the test frequency point of markings frequency spectrum instrument 4;

Then, the on off state of the system calibration module 61 control criterion noise source 5 in computing machine 6, and according to state modulator frequency spectrograph 4 frequency sweep of above-mentioned setting, with under the open and close state being captured in standard noise source 5 respectively, the performance number (frequency spectrum) corresponding to test frequency point of mark, that is, the reading opening standard noise source 5 time-frequency spectrometer 4 is P _on(unit is dBm), the reading of standard of closure noise source 5 time-frequency spectrometer 4 is P _off(unit is dBm); And by above-mentioned data stored in database 66;

Finally, system calibration module 61 adopts Y factor method, and (this Y factor method is method as known in the art, as microwave device noise-factor measurement (individual devices), penetrate the astronomical observation signal calibration in sky etc. and all adopt the method, the method is simple to operate, is easy to calculate), and based on the excess noise ratio ENR of the standard noise source 5 be pre-stored in database 66, calculate system noise and system-gain, meanwhile, the data that this is calculated stored in database 66, specifically:

System calibration module 61 is first according to following formulae discovery system noise factor NF (unit is dB):

Y＝P _on/P _off (1)，

NF＝ENR-10log ₁₀(Y-1)+10log ₁₀(T ₀/T _off) (2)，

Wherein, T ₀for standard temperature (this temperature is fixed temperature value 290k), T _offfor temperature (test environment temperature during standard of closure noise source 5, the measuring accuracy of this temperature is less demanding, general thermometer can be adopted to carry out actual measurement, and very little on test result impact, the measuring error of environment temperature can be ignored the impact of test error);

Then, according to following formulae discovery system noise T _r:

T _R＝T ₀(NF-1) (3)，

Finally, according to following formulae discovery system-gain G _s:

T _on＝T ₀ENR+T _off (4)，

G _S＝P _on-10log ₁₀(T _on+T _R)-10log ₁₀(B)-10log ₁₀(K)-30 (5)，

Wherein, T _onfor opening temperature during standard noise source 5, B is the calibration resolution bandwidth (as mentioned above, this parameter is by artificial setting) of frequency spectrograph 4, and K is Boltzmann constant.

Above-mentioned formula (1)-(5) are formula as known in the art, the system noise T obtained by above-mentioned formulae discovery _rwhether be normally mainly used for verification system sensitivity index, such as, if prime amplifier 3, RF cable etc. go wrong, then find that whether system sensitivity is normal by above-mentioned quick test and data processing, thus improve the reliability of follow-up test data; And said system gain G _sradiation-emitting frequency spectrum then for obtaining in subsequent radiative emission test frequency spectrograph 4 is calibrated, to obtain the radiation power (specific works principle will describe in detail hereinafter) of test antenna actinal surface.

Second step, radiation emission test (that is, Electromagnetic Interference Test), specifically comprises:

First, by switching microwave switch 2 by receiving antenna 1 connecting system, thus form Electromagnetic Interference Test subsystem as above, and receiving antenna 1 is arranged on instrument and equipment (not shown) 1 meter that distance is used for testing or 3 meters of (concrete distance is determined by the size of instrument and equipment, and setting principle is the requirement that the beam angle meeting receiving antenna 1 covers instrument and equipment);

Then, according to the detecting information such as test bandwidth, integral time, resolution bandwidth (i.e. sampled point interval width) preset, (detecting information also comprises such as testing apparatus title, test duration, tester's information etc., these detecting informations are all stored in database 66) initial frequency, sweeping steps etc. of frequency spectrograph 4 are set, such as, can directly select to arrange on frequency spectrograph 4: test bandwidth: 380MHz-3GHz, resolution bandwidth: 30KHz (suitably can change according to testing requirement); Video resolution bandwidth: 300KHz; And set frequency spectrograph 4 and gather that to count be 10000 at every turn, because each resolution bandwidth gathers a point, thus make test subband wide to be 10000 × 30KHz=300MHz, automatically to enter next sub-bandwidth test after the wide test of subband completes, until complete whole bandwidth test; The scan mode arranging frequency spectrograph 4 is that the mode that sampling combines with linear averaging (adopts the scan mode of linear averaging can improve the sensitivity of test subsystems, reduction burst and glitch are on the impact of test result, and adopt the method for linear averaging to reduce system noise because radio astronomy observation is same, so just can match with the data processing method of radio astronomy observed terminals), wherein, the subband wide single sweep operation time is 0.5 second, linear averaging number of times is 20 times, and the wide total scanning time of subband is then 0.5 second × 20 times=10 seconds;

Then, in the test environment of all electronic equipments around closing of the Electromagnetic Interference Test module 62 in computing machine 6, the on off state of control instrument equipment, and according to state modulator frequency spectrograph 4 frequency sweep of above-mentioned setting, the instrument and equipment duty radiation-emitting frequency spectrum P with the environment frequency spectrum obtained respectively when closing instrument and equipment and when opening instrument and equipment _a(unit is dBm) (hereinafter referred to as radiation-emitting frequency spectrum); And by above-mentioned test data stored in database 66; By the environment recorded frequency spectrum and radiation-emitting frequency spectrum are compared, radiation-emitting spectral characteristic can be found out easily, especially on the impact of neighbourhood noise, such as, data processing terminal significantly can improve neighbourhood noise, intuitively can arrive the impact of instrument and equipment radiation-emitting on neighbourhood noise by comparison;

Finally, Electromagnetic Interference Test module 62 according to the sampled point interval (namely carrying out the sweeping steps of the frequency spectrograph 4 of setting during radiation emission test) of above-mentioned setting, to the receiving antenna gain G of the receiving antenna 1 be pre-stored in database 66 _a(antenna gain is gain data subsidiary when buying antenna, is the antenna gain data through calibration when antenna dispatches from the factory), the system-gain G obtained by the above-mentioned first step _scarry out linear interpolation, and based on this receiving antenna gain G _aand system-gain G _sto above-mentioned radiation-emitting frequency spectrum P _acarry out data calibration, thus obtain test antenna actinal surface place radiation power (frequency spectrum) P (as Suo Shi following formula (6)):

P＝P _A-G _S-G _A (6)；

This test antenna actinal surface place radiation power P is stored in database 66, and is shown as figure by Electromagnetic Interference Test module 62.

3rd step, calculates the interference level limit value that instrument and equipment to be assessed arrives feed telescope actinal surface, specifically comprises:

First, interference level limit value computing module 63 in computing machine 6 according to alliance of International Telecommunication Association for system sensitivity computing method in radio astronomy service recommendation ITU-R RA.769.2 and radio telescope technical indicator and observation requirements, that is, according to the antenna noise temperature T of given radio telescope typical case frequency _a, system noise T _r, resolution bandwidth B, integral time τ (consider that low-frequency range mainly carries out continuous spectrum and observations of pulsar, in this enforcement, integral time, τ was set to 10 seconds) values such as (all determine according to actual radio telescope technical indicator and observation requirements) above-mentioned resolution bandwidth, integral time, and calculate feed telescope actinal surface interference level limit value L according to following formula (7) _t1:

$L_{T1}=0.1\×K\×B\×(T_A+T_R)/\sqrt{\mathrm{B\τ}}---\left(7\right),$

Wherein, K is Boltzmann constant;

Then, consider that radio telescope main beam is extremely narrow, the radiation of surface instrumentation installation electromagnetical enters receiving system by antenna sidelobe, and the feed telescope actinal surface interference level limit value L of above-mentioned calculating _t1for the interference level limit value that radio telescope side lobe gain is 0dBi, therefore, in the present invention, interference level limit value computing module 63 needs first according to the given radio telescope angle of pitch be pre-stored in database 66 equipment to be assessed is to the horizontal range L of feed telescope aperture centre and floor projection _dand equipment to be assessed to feed telescope aperture centre vertical range H (as shown in Figure 5, in figure, A point represents instrument and equipment to be assessed, B point represents feed telescope aperture centre, C represents radio telescope parabola), and obtain radio telescope side lobe gain G (Φ) according to following formulae discovery, unit is that (ITU-RSA.509-3 recommendation gives the general sidelobe gain model of the large-scale parabola antenna being applicable to D/ λ>=100 to dBi, wherein D is antenna diameter, and λ is operation wavelength):

$G\left(\mathrm{\Φ}\right)=\left\{\begin{array}{cc}32-25\log \left(\mathrm{\Φ}\right)& 1\≤\mathrm{\Φ}\≤48\\ -10& 48\≤\mathrm{\Φ}\≤80\\ -5& 80\≤\mathrm{\Φ}\≤120\\ -10& 120\≤\mathrm{\Φ}\≤180\end{array}\right.---\left(9\right),$

Wherein, Φ is the angle (assess this instrument and equipment and only consider extremely bad situation to during the affecting of radio telescope, namely the projection of radio telescope main beam axis overlaps with instrument and equipment to be assessed) that instrument and equipment to be assessed departs from radio telescope main beam axis; Then, interference level limit value computing module 63 is according to feed telescope actinal surface interference level limit value L _t1and radio telescope side lobe gain G (Φ), obtain according to following formulae discovery the interference level limit value L that instrument and equipment to be assessed arrives feed telescope actinal surface _t:

L _T＝L _T1-G(Φ) (10)；

Finally, interference level limit value computing module 63, based on the sampled point interval width in second step, arrives the interference level limit value L of feed telescope actinal surface to above-mentioned instrument and equipment to be assessed _tcarry out linear interpolation, with corresponding with the frequency of the radiation-emitting frequency spectrum in second step; Finally, this instrument and equipment to be assessed arrives the interference level limit value L of feed telescope actinal surface _tbe stored in database 66, and be shown as figure by interference level limit value computing module 63.

4th step, electromagnetic wave path attenuation is tested, and specifically comprises:

First, emitting antenna 8 is placed on position residing for receiving antenna in second step 1 (namely, distance is for the instrument and equipment 1 meter tested or 3 meters of), and receiving antenna 1 is arranged on the position near feed telescope actinal surface, the signal source 9 be connected with emitting antenna 8 is by netting twine access to LAN 10;

Secondly, the standard signal bandwidth exported by the path attenuation measurement module 64 signalization source 9 in computing machine 6, intensity are (namely, signal frequency and amplitude), wherein, the Frequency point that the frequency of standard signal provides according to GB12190 sets, other radio traffics of interference are tested to prevent radio wave attenuation, the amplitude of standard signal then carries out suitable setting according to receiving antenna and test antenna distance, if measuring distance is far away, signal amplitude is larger, then need to carry out security protection, to prevent electromagnetic wave harm tester; Such as, arranging this standard signal is single frequency point signal, and signal bandwidth is as far as possible narrow;

Then, the scanning frequency (this frequency is identical with the above-mentioned Frequency point arranged signal source 9) etc. of frequency spectrograph 4 is set according to the detecting information such as test bandwidth, sweep time, resolution bandwidth preset, such as, can directly select to arrange on frequency spectrograph 4: resolution bandwidth: 30KHz; Video resolution bandwidth: 3MHz; Test bandwidth: 1KHz; Sweep time: 200 milliseconds; According to the parameter of above-mentioned setting, the scanning frequency of markings frequency spectrum instrument 4;

Then, path attenuation measurement module 64 control signal source 9 outputting standard signal, the signal receiving this emitting antenna 8 to make receiving antenna 1 and send, and control frequency spectrograph 4 frequency sweep, with performance number (frequency spectrum) P corresponding to the scanning frequency gathering mark _r; And by above-mentioned data stored in database 66;

Finally, path attenuation measurement module 64 is according to following formulae discovery electromagnetic wave path attenuation S _p:

S _P＝P _R-G _S-G _A-P _T+C _A-G _AT (11)，

Wherein, G _sfor the system-gain obtained in second step, G _afor receiving antenna gain, P _tfor the signal amplitude of the standard signal that signal source 9 exports, C _afor being pre-stored in the Insertion Loss of the signal source 9 in database 66 and the RF cable be connected between emitting antenna 8, G _aTfor being pre-stored in transmitter antenna gain (dBi) (its G the same as receiving antenna gain in database 66 _a, be the antenna gain data through calibration when line dispatches from the factory); Path attenuation measurement module 64 also based on the sampled point interval width (that is, all carrying out difference with the sampled point interval width set in electromagnetism Electromagnetic Interference Test step) in above-mentioned second step, to above-mentioned electromagnetic wave path attenuation S _pcarry out linear interpolation, with corresponding with the frequency spectrum frequency that frequency spectrograph 4 tests out; Finally, this electromagnetic wave path attenuation S _pbe stored in database 66, and be shown as figure by path attenuation measurement module 64.

In addition, in the 4th step, after the scanning frequency of the signal frequency and signal amplitude and frequency spectrograph 4 that are provided with standard signal, first can pass through RF cable connecting signal source 9 and frequency spectrograph 4, thus the difference of comparison typical case frequency signal source output signal and frequency spectrograph Received signal strength, if difference is within ± 1dB, carry out path attenuation test again, if do not meet, need check that signal source and frequency spectrograph are arranged, to improve measuring accuracy.

5th step, instrument and equipment radiation-emitting is assessed, and specifically comprises:

Test antenna actinal surface place radiation power P (being obtained by second step) in radiation-emitting evaluation module 65 calling data storehouse 66 in computing machine 6, instrument and equipment to be assessed arrive the interference level limit value L of feed telescope actinal surface _t(being obtained by the 3rd step) and electromagnetic wave path attenuation S _p(being obtained by the 4th step), whether the shielding demand (shield effectiveness) of computing equipment equipment, that is, assess instrument and equipment radiation-emitting and have an impact to radio astronomical sight system, specifically:

First, consider test uncertainty, radiation-emitting evaluation module 65 is according to the instrument and equipment radiated transmission power limit value L at following formulae discovery instrument and equipment place:

L＝L _T-S _P-3dB (12)；

Wherein, 3dB is uncertainty of measurement;

Then, whether radiation-emitting evaluation module 65 compare test Antenna aperture place radiation power P exceedes instrument and equipment radiated transmission power limit value L, and provides instrument and equipment shielding demand (i.e. shield effectiveness SE) according to following formula:

SE＝P-L (13)；

If P-L<0, that is, test antenna actinal surface place radiation power P does not exceed instrument and equipment radiated transmission power limit value L, and shield effectiveness SE is negative, then illustrate that instrument and equipment radiation-emitting does not affect radio astronomical sight; If P-L >=0, namely, test antenna actinal surface place radiation power P exceedes instrument and equipment radiated transmission power limit value L, shield effectiveness SE is just, then illustrate that instrument and equipment radiation-emitting produces interference to radio astronomical sight, need to take shielding protection measure to suppress instrument and equipment radiation-emitting, such as, by shielding and filtering, shielding protection is carried out to instrument and equipment; Above-mentioned shield effectiveness data are stored in database 66.

In addition, in the present invention, each detecting information is (as test bandwidth, testing apparatus title, test duration, tester, the radio telescope angle of pitch etc.) all stored in database 66, and show these data by data management module 67, thus be convenient to staff by selecting detecting information on data management module 67, and obtain database 66 Instrumental radiation of equipment transmitting assessment data source path to find corresponding data source file according to this detecting information, and then be convenient in data management module 67 to before test data carry out quick mapping display or deletion.In the present invention, above-mentioned data source file comprises: system performance document presss from both sides, for stored in system noise and system-gain; Tested device file folder, for stored in testing apparatus title, test duration and Electromagnetic Interference Test data (i.e. the radiation-emitting frequency spectrum of instrument and equipment), test antenna actinal surface place radiation power data, shield effectiveness data etc.; Interference level limit value file, for arriving the interference level limit value data file of different telescope actinal surface stored in instrument and equipment to be assessed; Path attenuation file, for stored in electric wave path attenuation data; Microwave device file, for stored in the microwave device self performance parameters such as antenna gain, noise source ENR, RF cable Insertion Loss data (through producer calibration).

In the present embodiment, receiving antenna 1 adopts model to be the Realization of Product of Aaronia HyperLog3080; Prime amplifier 3 adopts model to be the Realization of Product of Aaronia UBBV2; Frequency spectrograph 4 adopts model to be the Realization of Product of R & S FSW26; Standard noise source 5 adopts model to be the Realization of Product of Agilent 346C; General purpose interface bus card 7 adopts model to be the Realization of Product of Agilent 82357B; Emitting antenna 8 adopts model to be the Realization of Product of Aaronia HyperLog3080; Signal source 9 adopts model to be the Realization of Product of R & SSMA100A.

In sum, the present invention has the following advantages:

1, the present invention is by before testing instrument and equipment radiation-emitting, first the dependence test device of Electromagnetic Interference Test subsystem in native system is calibrated, to obtain the system-gain of this test subsystems, thus the uncertainty of radiation of equipment transmission test can be reduced, namely, (the test uncertainty as frequency spectrograph is 0.4dB can to remove the uncertainty of the microwave devices such as RF cable, prime amplifier, microwave switch, the uncertainty 0.4dB of standard noise source, total test uncertainty is 0.8dB), and then improve measuring accuracy.In addition, the present invention is calibrated with the noise temperature obtaining this test subsystems above-mentioned test subsystems by standard noise source, and by after this system calibration or noise temperature designed rear fixed standard noise temperature with native system and compared, to analyze the stability of noise temperature, if device (as prime amplifier) goes wrong in test subsystems, so system sensitivity (system noise) will decline to a great extent, if test subsystems is now tested again, test data will be caused unreliable, therefore, can determine that whether test subsystems is normal by above-mentioned analysis, if analysis result shows that system performance is abnormal, then staff can check microwave device, RF cable, whether joints etc. have problem, and need when dealing with problems to change microwave device, to make test subsystems, there is good sensitivity, thus improve the reliability of test subsystems and test result.

2, the present invention can calculate its feed aperture interference level limit value for different radio telescope technical indicators and scientific requirement (as antenna noise temperature, resolution bandwidth and integral time etc.), its foundation radio astronomical sight affected as assessment radio astronomy instrument and equipment radiation-emitting, the unreasonable radio telescope system that causes of interference level limit value can be effectively prevented to owe design or cross design, for system EMC design, shielding protection, the radio control of platform location provide foundation, has larger meaning.

3, because electromagnetic wave space propagation has too many uncertain factor, therefore, the method for performance test of the present invention is to obtain the electric wave path decay that instrument and equipment radiation-emitting more accurately arrives feed telescope actinal surface place.

4, the present invention can carry out rapid evaluation for instrument and equipment radiation-emitting in radio observatory location, and provides shielding demand, thus for system EMC design, shielding protection, the radio control of platform location provide foundation.

Above-described, be only preferred embodiment of the present invention, and be not used to limit scope of the present invention, the above embodiment of the present invention can also make a variety of changes.Namely every claims according to the present patent application and description are done simple, equivalence change and modify, and all fall into the claims of patent of the present invention.The not detailed description of the present invention be routine techniques content.

Claims (12)

1. based on an evaluating system for radio astronomy instrument and equipment electromagnetic radiation, it is characterized in that, described evaluating system comprises:

One microwave switch, its one end is two normally opened contacts, and its other end is connected to a frequency spectrograph by a prime amplifier;

Described frequency spectrograph is connected with a computing machine;

One receiving antenna being connected to a described normally opened contact of described microwave switch;

One be connected to described microwave switch another described in the standard noise source of normally opened contact;

One is connected to the signal source of described computing machine by network; And

One is connected to the emitting antenna of described signal source output terminal by RF cable;

Wherein, described computing machine comprises:

System calibration module, after it is connected with described prime amplifier and described frequency spectrograph respectively for the two ends at described standard noise source, controls described frequency spectrograph frequency sweep, and adopts Y factor method to calculate acquisition system noise and system-gain;

Electromagnetic Interference Test module, it is for be connected with described prime amplifier at described receiving antenna and after arranging contiguous peripheral instrument and equipment to be assessed, control described frequency spectrograph frequency sweep to obtain the radiation-emitting frequency spectrum of described instrument and equipment to be assessed, and data calibration is carried out to obtain test antenna actinal surface place radiation power to this radiation-emitting frequency spectrum;

Interference level limit value computing module, it is for according to given antenna noise temperature, the resolution bandwidth of described system noise and default described frequency spectrograph and integral time, calculate and obtain feed telescope actinal surface interference level limit value, and according to the given radio telescope angle of pitch, described equipment to be assessed is to the horizontal range of feed telescope aperture centre and floor projection and described equipment to be assessed to the vertical range of feed telescope aperture centre, calculate and obtain radio telescope side lobe gain, again according to described feed telescope actinal surface interference level limit value and described radio telescope side lobe gain, calculate and obtain the interference level limit value that described instrument and equipment to be assessed arrives feed telescope actinal surface,

Path attenuation measurement module, it is for arranging contiguous described instrument and equipment to be assessed at described emitting antenna, and after described receiving antenna arranges contiguous peripheral feed telescope actinal surface, control described signal source outputting standard signal to receive for described receiving antenna, and control described frequency spectrograph frequency sweep, obtain to calculate the electromagnetic wave path attenuation that described standard signal arrives feed telescope actinal surface place;

Radiation-emitting evaluation module, it is for arriving interference level limit value and the electromagnetic wave path attenuation of feed telescope actinal surface according to described instrument and equipment to be assessed, calculate and obtain instrument and equipment radiated transmission power limit value, and compare the size of this instrument and equipment radiated transmission power limit value and described test antenna actinal surface place radiation power, if described test antenna actinal surface place radiation power is less than described instrument and equipment radiated transmission power limit value, the radiation-emitting being then evaluated as described instrument and equipment to be assessed does not affect radio astronomical sight, otherwise, the radiation-emitting being then evaluated as described instrument and equipment to be assessed has an impact to radio astronomical sight, and export corresponding instrument and equipment shielding demand.

2. the evaluating system based on the electromagnetic radiation of radio astronomy instrument and equipment according to claim 1, is characterized in that, described microwave switch is connected by the input end of RF cable with described prime amplifier.

3. the evaluating system based on the electromagnetic radiation of radio astronomy instrument and equipment according to claim 1, is characterized in that, described frequency spectrograph is connected with described computing machine by general purpose interface bus card.

4. the evaluating system based on the electromagnetic radiation of radio astronomy instrument and equipment according to claim 1, it is characterized in that, described computing machine also comprises a database, and it is for the interference level limit value storing described system noise, system-gain, radiation-emitting frequency spectrum, test antenna actinal surface place radiation power, instrument and equipment to be assessed arrive feed telescope actinal surface, electromagnetic wave path attenuation and described shielding demand.

5. the evaluating system based on the electromagnetic radiation of radio astronomy instrument and equipment according to claim 4, it is characterized in that, described computing machine also comprise one with the data management module of described DataBase combining, its for show, search and/delete data in described database.

6. based on an appraisal procedure for radio astronomy instrument and equipment electromagnetic radiation, it is characterized in that, said method comprising the steps of:

Preparation process, provides as the evaluating system based on the electromagnetic radiation of radio astronomy instrument and equipment in claim 1-5 as described in any one;

System calibration step, switch described microwave switch the two ends of described standard noise source are connected with described prime amplifier and described frequency spectrograph respectively, control described frequency spectrograph frequency sweep by described system calibration module, and adopt Y factor method to calculate acquisition system noise and system-gain;

Radiation emission test step, switch described microwave switch described receiving antenna is connected with described prime amplifier, and described receiving antenna is arranged contiguous peripheral instrument and equipment to be assessed, control described frequency spectrograph frequency sweep to obtain the radiation-emitting frequency spectrum of described instrument and equipment to be assessed by described Electromagnetic Interference Test module, and data calibration is carried out to obtain test antenna actinal surface place radiation power to this radiation-emitting frequency spectrum;

Instrument and equipment to be assessed arrives the interference level limit value calculation procedure of feed telescope actinal surface, described interference level limit value computing module is according to given antenna noise temperature, the resolution bandwidth of described system noise and default frequency spectrograph and integral time, calculate and obtain feed telescope actinal surface interference level limit value, and according to the given radio telescope angle of pitch, described equipment to be assessed is to the horizontal range of feed telescope aperture centre and floor projection and described equipment to be assessed to the vertical range of feed telescope aperture centre, calculate and obtain radio telescope side lobe gain, again according to described feed telescope actinal surface interference level limit value and described radio telescope side lobe gain, calculate and obtain the interference level limit value that described instrument and equipment to be assessed arrives feed telescope actinal surface,

Electromagnetic wave path attenuation testing procedure, described emitting antenna is arranged contiguous described instrument and equipment to be assessed, and described receiving antenna is arranged contiguous feed telescope actinal surface, control described signal source outputting standard signal by described path attenuation measurement module to receive for described receiving antenna, and control described frequency spectrograph frequency sweep, obtain to calculate the electromagnetic wave path attenuation that described standard signal arrives feed telescope actinal surface place;

Instrument and equipment radiation-emitting appraisal procedure, described radiation-emitting evaluation module arrives interference level limit value and the electromagnetic wave path attenuation of feed telescope actinal surface according to described instrument and equipment to be assessed, calculate and obtain instrument and equipment radiated transmission power limit value, and compare the size of this instrument and equipment radiated transmission power limit value and described test antenna actinal surface place radiation power, if described test antenna actinal surface place radiation power is less than described instrument and equipment radiated transmission power limit value, the radiation-emitting being then evaluated as described instrument and equipment to be assessed does not affect radio astronomical sight, otherwise, the radiation-emitting being then evaluated as described instrument and equipment to be assessed has an impact to radio astronomical sight, and export corresponding instrument and equipment shielding demand.

7. the appraisal procedure based on the electromagnetic radiation of radio astronomy instrument and equipment according to claim 6, is characterized in that, described system calibration step comprises:

Calibration initial frequency, the calibration sweeping steps of described frequency spectrograph are set according to the calibration testing bandwidth preset and calibration resolution bandwidth, and mark the test frequency point of described frequency spectrograph;

Controlled the on off state of described standard noise source by described system calibration module, and control under described frequency spectrograph is captured in the open and close state of described standard noise source respectively, the performance number P corresponding to test frequency point of mark _onand P _off;

Described system calibration module obtains described system noise T according to following formulae discovery _rwith system-gain G _s, and by this system noise T _rwith system-gain G _sstored in described database:

Y＝P _on/P _off (1)，

NF＝ENR-10log ₁₀(Y-1)+10log ₁₀(T ₀/T _off) (2)，

T _R＝T ₀(NF-1) (3)，

T _on＝T ₀ENR+T _off (4)，

G _S＝P _on-10log ₁₀(T _on+T _R)-10log ₁₀(B)-10log ₁₀(K)-30 (5)，

Wherein, NF is system noise factor, and ENR is the excess noise ratio of the described standard noise source prestored in the database, T ₀for standard temperature, T _offfor closing temperature during described standard noise source, T _onfor opening temperature during described standard noise source, B is described calibration resolution bandwidth, and K is Boltzmann constant.

8. the appraisal procedure based on the electromagnetic radiation of radio astronomy instrument and equipment according to claim 6, is characterized in that, described radiation emission test step comprises:

Initial frequency, the sweeping steps of described frequency spectrograph are set according to the test bandwidth preset, integral time, resolution bandwidth;

In test environment by described Electromagnetic Interference Test module all electronic equipments around closing, control the on off state of described instrument and equipment to be assessed, and control described radiation-emitting frequency spectrum P when described frequency spectrograph gathers environment frequency spectrum when cutting out described instrument and equipment to be assessed respectively and opens described instrument and equipment to be assessed _a, and by this radiation-emitting frequency spectrum P _astored in described database;

By contrasting described environment frequency spectrum and described radiation-emitting frequency spectrum, to obtain radiation-emitting spectral characteristic;

By described Electromagnetic Interference Test module according to the receiving antenna gain G of described default resolution bandwidth to the described receiving antenna prestored in the database _a, described system-gain G _scarry out linear interpolation, and based on this receiving antenna gain G _aand system-gain G _sto described radiation-emitting frequency spectrum P _acarry out data calibration, thus obtain described test antenna actinal surface place radiation power P according to following formula, and by this test antenna actinal surface place radiation power P stored in described database:

P＝P _A-G _S-G _A(6)。

9. the appraisal procedure based on the electromagnetic radiation of radio astronomy instrument and equipment according to claim 8, is characterized in that, the interference level limit value calculation procedure that described instrument and equipment to be assessed arrives feed telescope actinal surface comprises:

Described interference level limit value computing module is according to given described antenna noise temperature T _a, described system noise T _rand preset described frequency spectrograph resolution bandwidth B and integral time τ, obtain described feed telescope actinal surface interference level limit value L according to following formulae discovery _t1:

$L_{T1}=0.1\&times;K\&times;B\&times;(T_A+T_R)/\sqrt{\mathrm{B\&tau;}}---\left(7\right),$

Wherein, K is Boltzmann constant;

Described interference level limit value computing module is according to the given radio telescope angle of pitch described equipment to be assessed is to the horizontal range L of feed telescope aperture centre and floor projection _dand described equipment to be assessed is to the vertical range H of feed telescope aperture centre, obtain radio telescope side lobe gain G (Φ) according to following formulae discovery:

$G\left(\mathrm{\&Phi;}\right)\left\{\begin{array}{cc}32-25\log \left(\mathrm{\&Phi;}\right)& 1\&le;\mathrm{\&Phi;}\&le;48\\ -10& 48\&le;\mathrm{\&Phi;}\&le;80\\ -5& 80\&le;\mathrm{\&Phi;}\&le;120\\ -10& 120\&le;\mathrm{\&Phi;}\&le;180\end{array}\right.---\left(9\right),$

Wherein, Φ is the angle that instrument and equipment to be assessed departs from radio telescope main beam axis;

Described interference level limit value computing module is according to described feed telescope actinal surface interference level limit value L _t1and described radio telescope side lobe gain G (Φ), obtain according to following formulae discovery the interference level limit value L that described instrument and equipment to be assessed arrives feed telescope actinal surface _t:

L _T＝L _T1-G(Φ) (10)；

Described interference level limit value computing module arrives the interference level limit value L of feed telescope actinal surface to described instrument and equipment to be assessed according to the described resolution bandwidth in described radiation emission test step _tcarry out linear interpolation, and this instrument and equipment to be assessed is arrived the interference level limit value L of feed telescope actinal surface _tstored in described database.

10. the appraisal procedure based on the electromagnetic radiation of radio astronomy instrument and equipment according to claim 8, is characterized in that, described electromagnetic wave path attenuation testing procedure comprises:

Signal frequency and the signal amplitude of the described standard signal that described signal source exports are set by described path attenuation measurement module;

Arrange according to the test bandwidth preset, sweep time, resolution bandwidth and mark the scanning frequency of described frequency spectrograph, and this scanning frequency mates with the signal frequency of described standard signal;

Control described signal source by described path attenuation measurement module and export described standard signal, the signal receiving this emitting antenna to make described receiving antenna and send, and the performance number P corresponding to scanning frequency controlling described frequency spectrograph collection mark _r;

Described path attenuation measurement module is electromagnetic wave path attenuation S according to following formulae discovery _p:

S _P＝P _R-G _S-G _A-P _T+C _A-G _AT (11)，

Wherein, G _sfor described system-gain, G _afor the receiving antenna gain of the described receiving antenna in the database that prestores, P _tfor the signal amplitude of described standard signal, C _afor the Insertion Loss of the described signal source prestored in the database and the RF cable be connected between emitting antenna, G _aTfor the gain of the described emitting antenna in the database that prestores;

Described path attenuation measurement module according to the described resolution bandwidth in described radiation emission test step to described electromagnetic wave path attenuation S _pcarry out linear interpolation, and by this electromagnetic wave path attenuation S _pstored in described database.

11. appraisal procedures based on the electromagnetic radiation of radio astronomy instrument and equipment according to claim 10, is characterized in that, described electromagnetic wave path attenuation testing procedure also comprises:

After the scanning frequency of the signal frequency and signal amplitude and described frequency spectrograph that are provided with described standard signal, described signal source and described frequency spectrograph is connected by RF cable, and the difference of signal that the standard signal that exports of signal source described in comparison and described frequency spectrograph receive, if this difference is within ± 1dB, then proceed described electromagnetic wave path attenuation testing procedure, otherwise, if do not meet, reset the signal frequency of described standard signal and/or the scanning frequency of signal amplitude and/or described frequency spectrograph.

12. appraisal procedures based on the electromagnetic radiation of radio astronomy instrument and equipment according to claim 6, is characterized in that, described instrument and equipment radiation-emitting appraisal procedure comprises:

Described radiation-emitting evaluation module obtains described instrument and equipment radiated transmission power limit value L according to following formulae discovery:

L＝L _T-S _P-3dB (12)；

Wherein, L _tfor described instrument and equipment to be assessed arrives the interference level limit value of feed telescope actinal surface, S _pfor described electromagnetic wave path attenuation, 3dB is uncertainty of measurement;

Described radiation-emitting evaluation module exports described instrument and equipment shielding demand SE according to following formula, and by this instrument and equipment shielding demand SE stored in described database:

SE＝P-L (13)。