CN109283587A - A kind of space debris detection system and method - Google Patents
A kind of space debris detection system and method Download PDFInfo
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- CN109283587A CN109283587A CN201811367005.2A CN201811367005A CN109283587A CN 109283587 A CN109283587 A CN 109283587A CN 201811367005 A CN201811367005 A CN 201811367005A CN 109283587 A CN109283587 A CN 109283587A
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Abstract
The present invention discloses a kind of space debris detection system and method, using geographically widely distributed, the ready-made broadcasting station FM as transmiting signal source, does not need additionally to build radar emission station, greatly reduces cost of building a station；Low-frequency radio telescope array is made of dual polarization dipole sub-antenna, and antenna can form the station, and several stations can form array, this convenient, flexible composite configuration is suitble to extensive strange land to dispose, each station can both work independently, and can also cooperate, and form interference array.Compared with traditional passive radar, system detection viewing field range of the invention is larger, high sensitivity, and the target that can be detected is bigger in visual direction range.
Description
Technical field
The present invention relates to space debris detection technical fields, and in particular to a kind of space debris detection system and method.
Background technique
Space junk refers to product of the mankind in space active procedure.It is main include the rocket rocket body for the task that is completed and
The collision between discards, space object during satellite body, rocket remains, execution space mission generates broken with weathering
Block etc., is the main pollution sources of space environment, therefore also known as space trash.These space junks are typically distributed across apart from the earth
On height about 100km to the track between 40,000km.As the continuous accumulation of space junk is cumulative, touching between space junk
The rate of colliding greatly increases, and the quantity of space junk is caused to sharply increase.More seriously, the space flight such as space junk and moving satellite
A possibility that colliding between device is consequently increased, involve great expense to these and with strategic importance assets cause it is great
Damage and threat.In order to reduce this risk of spacecraft, need to obtain these space junks detailed distribution situation (size,
Quality and orbit distribution etc.).Therefore, the detection of space junk has important and far-reaching meaning.
Currently, the main path of space exploration fragment has ground-based radar and optical telescope.Optical telescope is by connecing
The sun optical signal for receiving space junk reflection is detected, and the geostationary orbit that main detection height is about 35786km is contour
The space junk of track, this method are affected by sunlight.On the contrary, ground-based radar detection is not influenced by sunlight,
But it is limited by distance larger.So ground-based radar is more suitable for the sky of LEO (2000km height track-bound below)
Between fragment detection.Known according to the statistical analysis of customary space exploration task, optical telescope is broken to space on geostationary orbit
The detection limit of piece is about 30cm to 1m, and ground-based radar is about 5 to arrive to the detection limit of LEO space junk
10cm。
In addition, passive radar is also considered for space exploration fragment.Passive radar is really a kind of spy of bistatic radar
Different situation, this radar system do not have transmitter, are only detected by receiving the signal of other emission sources of target scattering.This
A little emission sources may be broadcasting station or the communication station etc..Since the signal of space junk scattering is fainter, and it is extraneous dry
Disturb that signal is strong and more, the detection result of passive radar acquisition is not highly desirable.Moreover, this method depends on large-scale ground battle array
Column, have just been able to enough sensitivity and resolution ratio receive more accurate space junk scattered signal.In recent years, although constantly
There is the proposition of similar detecting strategy or method, but be in theoretical research and test of heuristics stage, practicability is also far from enough.
Summary of the invention
To be solved by this invention is reception space fragment scattered signal in existing passive radar detection space junk technology
Ability is weak, and transmitting station's cost height and the undesirable problem of detection result provide a kind of space debris detection system and method.
To solve the above problems, the present invention is achieved by the following technical solutions:
A kind of space debris detection system, including the broadcasting station FM group and low-frequency radio telescope array data receive and processing
System；Transmitting terminal of the above-mentioned broadcasting station the FM group as system, is made of the L broadcasting station FM；Above-mentioned low-frequency radio telescope array
Data receiver and receiving end of the processing system as system, by low-frequency radio telescope array, beam synthesizer, receiver, phase
Close device and data processing module composition；Low-frequency radio telescope array is made of the M station, and each station is further by N number of
Dual polarization dipole sub-antenna composition, each dual polarization dipole sub-antenna receive the signal of two polarization directions of X and Y, and export X and
The signal of Y polarization direction；The quantity of beam synthesizer and the quantity of the station are identical, and as M；Each beam synthesizer includes 2
× N number of input terminal and 2 output ends, 2 × N number of input terminal are respectively connected to the polarization side X and Y of N number of dual polarization dipole sub-antenna
To signal, 2 output ends export the wave beam of X and Y polarization direction respectively；Receiver includes 2 × M input terminal and 2 × M
Output end, 2 × M input terminal are respectively connected to the wave beam of the X and Y polarization direction of M beam synthesizer output, and 2 × M defeated
Enter end and exports the road 2 × M complex signal respectively；Correlator has 2 × M input terminal and 1 output end, 2 × M input terminal point
Not Jie Ru receiver output complex signal, output end output observation data；The output end and data processing module of correlator
Input terminal connection；Wherein L, M and N are setting value.
In above scheme, each beam synthesizer by 2 × N number of low-noise amplifier, 2 × N number of bandpass filter, 2 × N
A switch time delay device, X-direction summer and Y-direction summer composition；Wherein N number of low-noise amplifier, N number of bandpass filter, N
A switch time delay device and X-direction summer constitute X-direction Beam synthesis unit；This N number of low-noise amplifier and N number of dual polarization are even
The signal output end of the X polarization direction of pole sub-antenna connects；The output end of each low-noise amplifier with 1 bandpass filter
Input terminal connection, the output end of each bandpass filter connect with the input terminal of 1 switch time delay device；This N number of switch prolongs
When device output end be connected with the input terminal of X-direction summer, X-direction summer export X polarization direction wave beam；In addition N number of
Low-noise amplifier, N number of bandpass filter, N number of switch time delay device and X-direction summer constitute Y-direction Beam synthesis unit；This
N number of low-noise amplifier is connect with the signal output end of the Y polarization direction of N number of dual polarization dipole sub-antenna；Each low noise is put
The output end of big device is connect with the input terminal of 1 bandpass filter, and the output end of each bandpass filter prolongs with 1 switch
When device input terminal connection；The output end of this N number of switch time delay device is connected with the input terminal of Y-direction summer, Y-direction summer
Export the wave beam of Y polarization direction.
In above scheme, each switch time delay device is arranged in a combination by 2 or more switch time delay lines.
In above scheme, receiver by 2 × M amplifier, 2 × M band limiting filter, 2 × M analog-digital converter, 2 ×
M multiphase filter group, 2 × M channel to channel adapter and 2 × M quantizer composition；The input terminal of each amplifier respectively accesses 1
The wave beam of the X or Y polarization direction of a beam synthesizer output；The input of the output end of each amplifier and 1 band limiting filter
End connection, the output end of each band limiting filter are connect with the input terminal of 1 analog-digital converter, the output of each analog-digital converter
End is connect with the input terminal of 1 multiphase filter group, the input of the output end and 1 channel to channel adapter of each multiphase filter group
End connection, the output end of each channel to channel adapter are connect with the input terminal of 1 quantizer；Each quantizer exports 1 road plural number letter
Number.
In above scheme, the broadcasting station FM, low-frequency radio telescope array and space junk must satisfy following formula:
In formula, S is the spectrum flux density that low frequency radio telescopic array receives, and r is the radius of space junk, RrFor space
The distance between fragment and low-frequency radio telescope array, RtFor the distance between space junk and the broadcasting station FM, PtIt is FM broadcast
The effective transmission power stood, G are gain of the broadcasting station the FM transmitting in space junk direction, and B is the band of the broadcasting station FM transmitting signal
Width, v are the centre frequencies of the broadcasting station FM transmitting signal.
A kind of space debris detection method, includes the following steps:
The signal that step 1, low-frequency radio telescope array in real time emit the broadcasting station FM is observed, to obtain space
Fragment observes data；In the process, the low-frequency radio telescope array signal that also timing issues radio source is observed,
To obtain calibration source observation data；
Step 2 carries out radio frequency (RF) interference removal to step 1 obtained calibration source observation data, while carrying out the time
Integral and frequency integrator obtain calibration source and remove interference integration data；
Step 3 goes interference integration data to carry out bad station label to calibration source, obtains calibration source and removes interference flag data；
Step 4, to calibration source go interference flag data in errors in visibility data carry out amplitude and phase correction, obtain pair
The complex gain solution with frequency variation at any time answered, and make the amplitude solution of this complex gain solution default less than amplitude solution
Value；
Step 5 goes the obtained complex gain solution of step 4 and step 3 obtained calibration source in interference flag data
Errors in visibility data be multiplied, obtain amplitude and phase correction after calibration source correction data；
Calibration source correction data is imaged in step 6, checks imaging results, when phase centre location occurs clearly
When calibration source and clearly point source many far from phase centre location appearance, then the observation data processing of calibration source is correct；Otherwise,
Check whether the parameter setting of step 1-5 is problematic, and repeats step 1-5, until the observation data processing of calibration source is correct, or
Person chooses the observation data for observing different calibration source on the same day, and repeats step 1-5, until calibration source observation data processing just
Really；
Step 7 carries out time integral and frequency integrator to the observation data of the obtained space junk of step 1, obtains sky
Between fragment band interfere integration data；
Step 8 carries out bad station label to space junk band interference integration data, obtains space junk band interference reference numerals
According to；
The obtained complex gain solution of step 4 and the obtained space junk band of step 8 are interfered flag data by step 9
In errors in visibility data be multiplied, obtain space junk band interference correction data；
Space junk band interference correction data are imaged in step 10, and the space junk for obtaining multiple times of integration is anti-
Penetrate image；
Step 11, for space junk reflected image, successively by its front and back 2, adjacent space junk reflected images are carried out
Subtract each other, obtains all reflection differences images under initial time integral；
Step 12 checks all reflection differences images under step 11 obtained initial time integral, when at least one
When segmental arc occurs in reflection differences image, that is, show that there may be space junks, at this time reduce initial integration time, and repeats to walk
Rapid 7-11 obtains all reflection differences images under new time integral；
Step 13 is checked all reflection differences images under the obtained new time integral of step 12, and is therefrom found
Continuously all there is the reflection differences image of segmental arc in multiple out；
Step 14, the position for calculating segmental arc in multiple reflection differences images for being found out of step 13, and by itself and same a period of time
The position for carving the space junk calculated according to TLE orbital tracking is compared, if the space junk that the position of segmental arc and TLE are calculated
Position right ascension and declination between difference be less than angle preset value when, then it is assumed that the segmental arc be by space junk reflection FM broadcast
Signal and generate, i.e., explanation detected the space junk.
In above-mentioned steps 1, the observation wave band of low-frequency radio telescope array need to cover all tranmitting frequencies in the broadcasting station FM.
In above-mentioned steps 7-12, it is also necessary to further following process:
When carrying out radio frequency (RF) interference removal to the observation data of the obtained space junk of step 1, and being carried out to it
Between integrate and frequency integrator, obtain space junk go interference integration data；
It goes interference integration data to carry out the bad station label space junk, obtains space junk and remove interference flag data；
The errors in visibility data in interference flag data is gone to be multiplied with space junk the obtained complex gain solution of step 4,
It obtains space junk and goes interference correction data；
It goes interference correction data to be imaged space junk, obtains the space junk radiation image of multiple times of integration；
For space junk radiation image, successively by its front and back, 2 adjacent space junk radiation images subtract each other
To radiation error image；
It checks radiation error image, and result, which authenticates, is checked to reflection differences image using radiation error image.
A kind of space debris detection method, characterized in that include the following steps:
The signal that step 1, low-frequency radio telescope array in real time emit the broadcasting station FM is observed, to obtain space
Fragment observes data；In the process, the low-frequency radio telescope array signal that also timing issues radio source is observed,
To obtain calibration source observation data；
Step 2 carries out radio frequency (RF) interference removal to step 1 obtained calibration source observation data, while carrying out the time
Integral and frequency integrator obtain calibration source and remove interference integration data；
Step 3 goes interference integration data to carry out bad station label to calibration source, obtains calibration source and removes interference flag data；
Step 4, to calibration source go interference flag data in errors in visibility data carry out amplitude and phase correction, obtain pair
The complex gain solution with frequency variation at any time answered, and make the amplitude solution of this complex gain solution default less than amplitude solution
Value；
Step 5 goes the obtained complex gain solution of step 4 and step 3 obtained calibration source in interference flag data
Errors in visibility data be multiplied, obtain amplitude and phase correction after calibration source correction data；
Calibration source correction data is imaged in step 6, checks imaging results, when phase centre location occurs clearly
When calibration source and clearly point source many far from phase centre location appearance, then the observation data processing of calibration source is correct；Otherwise,
Check whether the parameter setting of step 1-5 is problematic, and repeats step 1-5, until the observation data processing of calibration source is correct, or
Person chooses the observation data for observing different calibration source on the same day, and repeats step 1-5, until calibration source observation data processing just
Really；
Step 7 carries out time integral and frequency integrator to the observation data of the obtained space junk of step 1, obtains sky
Between fragment band interfere integration data；
Step 8 carries out bad station label to space junk band interference integration data, obtains space junk band interference reference numerals
According to；
The obtained complex gain solution of step 4 and the obtained space junk band of step 8 are interfered flag data by step 9
In errors in visibility data be multiplied, obtain space junk band interference correction data；
Space junk band interference correction data are imaged in step 10, and the space junk for obtaining multiple times of integration is anti-
Penetrate image；
Step 11, for space junk reflected image, successively by its front and back 2, adjacent space junk reflected images are carried out
Subtract each other, obtains reflection differences image；
Step 12 searches software using radio source, carries out source search to reflection differences image, exports island size and flow
Density information, and maximum angular is selected more than angle preset value and number of pixels is more than the island of pixel preset value, as time
Select source；
The candidate source that step 12 obtains is compared by step 13 with brighter radio source in known star catalogue: if
Candidate source is Chong Die with some source space position in star catalogue, then the candidate source is not space junk, will be excluded；Otherwise, retain
The candidate source；
Step 14, the candidate source for being retained step 13 are compared with corresponding reflected image, if certain in reflected image
A radio reflection event is consistent over time and space, then it is assumed that the candidate source is to be reflected FM broadcast singal by space junk and produced
Raw, i.e., explanation has detected the space junk.
In above-mentioned steps 1, the observation wave band of low-frequency radio telescope array need to cover all tranmitting frequencies in the broadcasting station FM.
Compared with prior art, the present invention has a characteristic that
1, using the broadcasting station FM widely distributed on the earth as transmiting signal source, passive radar principle, Observable are based on
Near-Earth object reflects the signal of FM, but does not need additionally to build radar emission station.
2, the construction cost of low frequency dipole antenna is low, cloth station simple and flexible, is suitble to large scale deployment.
3, compared with traditional ground higher-frequency radar detection system, the visual field of low-frequency radio telescope array detection is larger,
It is suitable to observe the terrestrial space fragment quickly moved；Sensitivity is higher, can detect farther target.
4, compared with drift scanning optical telescope, detection system of the invention is not limited by weather and meteorological condition, can
With all weather operations, therefore the segmental arc of space exploration fragment is longer.
5, two kinds of data processing methods are provided, space junk can either be found manually, it can also be fast in mass data
The fast more space junk candidate bodies of Automatic-searching, can simultaneously serve as the identification of other side's result.
Detailed description of the invention
Fig. 1 is the block diagram of space debris detection system.
Fig. 2 is the broadcasting station FM location distribution schematic diagram.
Fig. 3 is the position distribution schematic diagram of the station.
Fig. 4 is X polarization direction Beam synthesis flow chart.
Fig. 5 is receiver flow chart.
Fig. 6 is cube satellite (DUCHIFAT 1) detection result example.
Specific embodiment
To make the objectives, technical solutions, and advantages of the present invention clearer, below in conjunction with specific example, and referring to attached
Figure, the present invention is described in more detail.
In order to strengthen passive radar detection space junk technology, the present invention proposes one kind by low-frequency radio telescope array
(working principle is similar to passive radar) and the sky formed with it apart from farther away FM fm broadcasting station (as signal emitting-source)
Between fragment detection system, and provide corresponding detection method.
A kind of space debris detection system, as shown in Figure 1, its mainly by low-frequency radio telescope array data receive with
Reason system and the broadcasting station FM group's composition.
The above-mentioned broadcasting station FM group is by the broadcasting station FM apart from low-frequency radio telescope array (distance is greater than 100 kilometers) farther out
Composition, as transmitting station of the invention.In the present embodiment, the location distribution figure in the broadcasting station FM is as shown in Fig. 2, five in figure
What angle asterisk was known is the geographical location of low-frequency radio telescope array, remaining circle identifies the geographical location in the broadcasting station FM.This
The a little broadcasting station FM operating frequency ranges are 87.5-108MHz, their transmission power range is differed at several watts to hundreds of kilowatts.
Above-mentioned low-frequency radio telescope array data receives and receiving end of the processing system as system, is hoped by low frequency radio
Remote lens array, beam synthesizer, receiver, correlator and data processing module composition.Low-frequency radio telescope array is by M platform
It stands composition, each station is further made of N number of dual polarization dipole sub-antenna, and each dual polarization dipole sub-antenna receives X and Y
The signal of two polarization directions, and export the signal of X and Y polarization direction.The quantity of beam synthesizer and the quantity of the station are identical,
As M；Each beam synthesizer includes 2 × N number of input terminal and 2 output ends, and 2 × N number of input terminal is respectively connected to N number of double
The signal of the X and Y polarization direction of polarized dipole and electrical sub-antenna, 2 output ends export the wave beam of X and Y polarization direction respectively.It receives
Device include 2 × M input terminal and 2 × M output end, 2 × M input terminal be respectively connected to M beam synthesizer export X with
The wave beam of Y polarization direction, 2 × M input terminal export the road 2 × M complex signal respectively.Correlator have 2 × M input terminal with
1 output end, 2 × M input terminal are respectively connected to the complex signal of receiver output, output end output observation data.Phase
The input terminal of the output end and data processing module that close device connects.Wherein L, M and N are setting value.
Low-frequency radio telescope array must be built in quiet radio region, it is ensured that surrounding radio frequency (RF) interference to the greatest extent may be used
Can be few, the especially interference (cannot have the broadcasting station FM in 100 kilometers) of FM broadcasting band signal.Observing frequency range must be included
All frequencies of the transmitting signal in the broadcasting station FM.Low-frequency radio telescope array can acquire about 2000 square metres of region letters
Number, field range about 200-2500 square degree square grade, (the farthest spacing between resolution ratio and the station has about 3 jiaos points of highest angular resolution
It closes).In the present embodiment, it is 26.703 degree of south latitude that low-frequency radio telescope array, which is built in center, the position that 116.671 degree of east longitude
It sets, which is located in quiet radio region, and the interference of surrounding radio frequency (RF) is less, does not have the broadcasting station FM nearby (in 100 kilometers).It should
Low-frequency radio telescope array can acquire about 2000 square metres of regional signals, field range about 200-2500 square degree square grade, most
About 3 jiaos points of fine angular resolution (the farthest spacing between resolution ratio and the station is related).One typical low-frequency radio telescope array
Be made of (M is generally higher than 100, and specific number can be adjusted according to actual deployment) the M station, most of Station distribution diameter about
To guarantee sufficiently high sensitivity in 1.5 kilometers of nucleus, a small number of Station distributions are at about 3 kilometers of peripheral diameter to improve
The resolution ratio of entire array.Each station is further made of N number of dual polarization dipole sub-antenna unit, and each antenna element connects
Receive the signal of two polarization directions of X and Y.All antenna elements of each station are distributed in 5 × 5 square metres of plane domain
It is interior, form 4 × 4 grid that a spacing is 1.1 meters.The operating frequency range of each antenna element is 80-300MHz.At this
In embodiment, low-frequency radio telescope array is made of 128 stations, as shown in figure 3, being the location map of all stations.
Most of Station distribution is in about 1.5 kilometers of diameter of nucleus in figure, and a small number of Station distributions are at about 3 kilometers of diameter.Often
A station is made of 16 dual polarization dipole sub-antenna units again.All antenna elements of each station are distributed in 5 × 5 squares
In the plane domain of rice, 4 × 4 grid that a spacing is 1.1 meters is formed.The operating frequency range of each antenna element is
80-300MHz.Each station enters beam synthesizer progress Beam synthesis after receiving signal.
Each beam synthesizer by 2 × N number of low-noise amplifier, 2 × N number of bandpass filter, 2 × N number of switch time delay
Device, X-direction summer and Y-direction summer composition.N number of low-noise amplifier, N number of bandpass filter, N number of switch time delay device and
X-direction summer constitutes X-direction Beam synthesis unit；This N number of low-noise amplifier and N number of dual polarization dipole sub-antenna unit
The signal output end of X polarization direction connects；The output end of each low-noise amplifier connects with the input terminal of 1 bandpass filter
It connects, the output end of each bandpass filter is connect with the input terminal of 1 switch time delay device；The output of this N number of switch time delay device
End is connected with the input terminal of X-direction summer, and the output end of X-direction summer forms beam synthesizer output X polarization direction
Wave beam.N number of low-noise amplifier, N number of bandpass filter, N number of switch time delay device and X-direction summer constitute Y-direction wave beam and close
At unit；This N number of low-noise amplifier is connect with the signal output end of the Y polarization direction of N number of dual polarization dipole sub-antenna unit；
The output end of each low-noise amplifier is connect with the input terminal of 1 bandpass filter, the output end of each bandpass filter
It is connect with the input terminal of 1 switch time delay device；The input terminal phase of the output end of this N number of switch time delay device and Y-direction summer
Even, the output end of Y-direction summer forms the wave beam of beam synthesizer output Y polarization direction.Referring to fig. 4.In the present embodiment,
Beam synthesizer includes 32 input interfaces, is respectively connected to the signal of the X and Y polarization direction of 16 antenna elements.Each access
Signal can connect 1 low-noise amplifier (LNA), carry out signal amplification.The signal of each LNA output is using 60-
600MHz bandpass filter is filtered, and removes the interference of high-frequency signal.The signal of each bandpass filter output enters 5 and opens
It closes delay line and carries out signal compensation of delay.Delay line (if budget is enough, can also use accuracy using analog circuit realization
Higher digital circuit).By permutation and combination method, every delay line has on and off two ways, and 5 delay lines just have 32 kinds of groups
It closes.I.e. 0-31 is numbered using Arabic numerals in 32 kinds of combinations, and compensation of delay range is in 17ns between 30ns.16
After antenna element accesses signal, after the delay by selecting different numbers, 16 X polarization directions and 16 Y polarization directions are prolonged
When signal sum respectively, synthesize dual polarization wave beam.Wherein, beam position is compiled by changing the delay of 16 antenna elements
Number combining form control, to be directed toward range be 15 degree to 50 degree.Finally, dual polarization Beam synthesis result passes through coaxial cable
It is transmitted to receiver.
Receiver is by 2 × M amplifier, 2 × M band limiting filter, 2 × M analog-digital converter, 2 × M multiphase filtering
Device group, 2 × M channel to channel adapter and 2 × M quantizer composition.The input terminal of each amplifier respectively accesses 1 beam synthesizer
The wave beam of the X or Y polarization direction of output；The output end of each amplifier is connect with the input terminal of 1 band limiting filter, each band
The output end of limit filter is connect with the input terminal of 1 analog-digital converter, and the output end of each analog-digital converter and 1 multiphase are filtered
The input terminal of wave device group connects, and the output end of each multiphase filter group is connect with the input terminal of 1 channel to channel adapter, Mei Getong
The output end of track selector is connect with the input terminal of 1 quantizer；Each quantizer exports complex signal.Referring to Fig. 5.In this reality
It applies in example, each receiver includes 16 identical process flows, handles the Beam synthesis signal that 8 stations transmit.Place
Reason process be successively amplifier, band limiting filter, analog-digital converter (ADC), multiphase filter group (PFB), channel to channel adapter and
Quantization.Each receiver includes 16 amplifiers, 16 band limiting filters, 16 ADC and 16 PFB.Each Beam synthesis letter
It number is introduced into 1 amplifier and carries out signal amplification, the signal of amplification enters 1 band limiting filter and is filtered.Band limiting filter
3dB frequency range be 80-300MHz, stopband attenuation frequency is 327.68MHz.Input in filtered signal access ADC
Interface carries out analog-to-digital conversion, and the sample frequency of ADC is 655.36MHz (2 times of input signal highest frequency), sampling resolution 8
Position.Data after sampling carry out channel division into multiphase filter group, and multiphase filter group carries out data using 4096 channels
Sampling exports 256 narrow band signals, and each narrow band signal includes the complex signal of 16 real parts and 16 imaginary parts, and width is
1.28MHz.Signal after channel divides enters channel to channel adapter, here can be 24 channels of arbitrary continuation in 256 channels
As a wave band, the bandwidth of each wave band is 30.72MHz.The data of 24 continuous passages chosen are quantified, defeated
It out include the complex signal of 5 real parts and 5 imaginary parts.Finally, the signal of output is transmitted to correlator using optical fiber.
Correlator carries out Fourier transformation to the signal that receiver exports, and frequency domain is converted the signal into, then according to difference
The station carry out multiplication cross, obtain errors in visibility data simultaneously be stored as fits file format.
Processing module carries out data processing to the errors in visibility data transmission that correlator is sent into.
Space junk height to be measured is in 200km-3000km, minimum dimension 10cm.Space debris detection system of the invention
The broadcasting station FM, low-frequency radio telescope array and space junk must satisfy following formula in system:
In formula, S is the spectrum flux density (unit Jansky) that low-frequency radio telescope array received arrives, and r is space junk
Radius, RrFor the distance between space junk and low-frequency radio telescope array, RtBetween space junk and the broadcasting station FM
Distance, PtIt is the effective transmission power (unit kW) in the broadcasting station FM, G is gain of the broadcasting station the FM transmitting in space junk direction, B
It is the bandwidth (unit MHz) of the broadcasting station FM transmitting signal, v is the centre frequency (unit MHz) of the broadcasting station FM transmitting signal.
A kind of space debris detection method, specifically includes that steps are as follows:
When step 1, the observation of low-frequency radio telescope array, all antennas are directed toward zenith, and (azimuth is 0 degree, and pitch angle is
90 degree), the observation wave band used must cover all tranmitting frequencies in the broadcasting station FM.The temporal resolution of observation is 0.5 second to 2
Between second, determined by the specific space junk observed, observing frequency 40kHz.Furthermore, it is necessary to which time sight one stronger is penetrated
Power supply calibrates space junk data as calibration source.The data of correlator output include data and the school of space junk
The data in quasi- source.
Step 2 carries out radio frequency (RF) interference (RFI) removal to the observation data of calibration source, while carrying out T seconds time integrals
With F kHz frequency integrator.Wherein T should be the integral multiple of temporal resolution, and is observed and divides exactly total time；F is frequency resolution
Integral multiple.Data after being integrated in output RFI removal, time and frequency.
Step 3, the abnormal station that do not work or work provided according to observation report, the data that step 2 is exported
In describe in station information mark value set 1 (0 for do not mark), complete the label of the bad station, thus export RFI removal, when
Between and frequency on integrated and carried out data after the label of the bad station.
Step 4, in step 3 output data errors in visibility data carry out amplitude and phase amendment and export it is corresponding with
The complex gain solution file of time and frequency variation.By checking this complex gain solution result: if amplitude is respectively less than 2,
Illustrate that calibration is correct.If amplitude is larger, illustrate that the data processing of calibration source is incorrect, it can be by checking above-mentioned steps 1-4
Parameter setting it is whether correct, reprocessing, until calibration result is correct；Or different calibration sources was observed by the selection same day
Data duplication step 1 is observed to 4 until calibration result is correct.
Errors in visibility data progress in step 5, the solution file for exporting step 4 in complex gain and step 3 output data
It is multiplied, the data after obtaining amplitude and phase correction.
The data after correcting obtained in step 5 are imaged in step 6, check imaging results: if phase center position
Set appearance clearly calibration source and the separate many clearly point sources of phase centre location appearance, then the observation data processing of calibration source
Correctly；If incorrect, check whether the parameter setting of step 1-5 problematic, repeat step 1-5, until processing result just
Really；Or the observation Data duplication step 1-5 of the different calibration source of same day observation is chosen, until processing result is correct.
Step 7 only carries out T to the observation data of space junk1Second integral and 40kHz frequency integrator obtain retaining RFI's
Data norfi_data.RFI removal is carried out to the observation data of space junk, while carrying out T1Second time integral and 40kHz frequency
Rate integral, obtains the data rfi_data of removal RFI.
Treated that data carry out bad station label for step 8, step 7, obtains new rfi_data and norfi_data.
Step 9, the complex gain solution in applying step 4 is obtained to rfi_data and norfi_data in step 8 respectively
New rfi_data and norfi_data.
Step 10 is respectively imaged rfi_data obtained in step 9 and norfi_data, the time of integration of imaging
It is disposed as T1Second, respectively obtain Q radiation image and Q reflected image.Wherein Q=observation time is divided by T1。
Step 11, by the space junk radiation image of the Q obtained time of integration of rfi_data in step 10, former and later two
Adjacent integral image is subtracted each other to obtain radiation error image.By the Q obtained time of integration of norfi_data in step 9
Space junk penetrates image, former and later two images are subtracted each other to obtain reflection differences image.
In order to screen to the space junk found, the present invention can be realized by following 2 schemes:
Scheme one:
Step 12 checks all reflection differences images that step 11 obtains, and shows that point source is that equipment or air agitation are former
Thus fail the background radio radiation source completely eliminated；Be shown as segmental arc is then space junk, this can be with radiation image and spoke
It penetrates error image comparison and carries out further identification；At this point, repeating step 7 to step 11, but the time of integration is changed to T2Second.
Step 13 checks T2The reflection differences image of second integral is found in multiple continuous (being more than or equal to 4) images and is all occurred
The error image of segmental arc.
Step 14, the position for calculating multiple error image segmental arcs in step 13, respectively with synchronization North America air defense department
The right ascension for the space junk that TLE (the two row orbital trackings) orbital tracking for enabling portion provide calculates and declination position are compared, if
Difference between the right ascension and declination of the position that the position of segmental arc and TLE are calculated is when within 2 degree, then it is assumed that the segmental arc is by this
Space junk reflects FM broadcast singal and generates, and illustrates to have detected the space junk.
Time of integration T in above-mentioned steps1And T2Need to be determined according to the height of space junk, the higher setting of height when
Between it is longer；In addition, T1And T2It should be the integral multiple of temporal resolution, and be observed and divide exactly total time；T2< T1 T2It is T14 times
More than.
Scheme two,
Step 12 searches software using radio source, carries out source search to reflection differences image, exports " island " size and stream
Metric density information, picks out that maximum angular is more than 5 degree and number of pixels is more than 10 " island ", arranges as space junk candidate source
Table.
Brighter radio source (being greater than 10Jy) carries out in step 13, the candidate source that step 12 is obtained and known star catalogue
Compare.If candidate source is Chong Die with some source space position in star catalogue, this candidate source is not space junk, will be arranged
It removes.
Step 14, the candidate source screened by step 13, then compared with corresponding reflected image, if reflected image
In some radio reflection event be consistent over time and space, we will be considered that it be likely to be space junk transmitting FM it is wide
Caused by broadcasting signal, and determine that the candidate source is space junk.
Relative to scheme one, scheme two being capable of more rapidly and more search space fragment
For detecting DUCHIFAT-1 satellite, observation initial time is that 40 minutes 14 points of on December 14th, 2014 is whole, total
Observation time is 232 seconds.All stations are directed toward zenith, and the delay line of each station antenna element selects number 0.The phase of observation
Position center is 59.7 degree of right ascension, and declination -26.7 is spent, and observing frequency selects the wave band centered on the 69th channel, and frequency range is
72.96-102.4MHz.The temporal resolution of observation is 2 seconds, frequency resolution 40KHz.Use FM all in Fig. 2 wide
Station is broadcast as transmitting station.The observation time of calibration source is 20 o'clock sharps on the same day, and phase center is 139.9 degree of right ascension, declination -26.6
Degree, remaining observation time are identical with the observation of satellite.Using above-mentioned data processing method, obtain as shown in FIG. 6
Satellite trajectory figure.Here the T in data processing step 1 is set as 8 seconds；F is set as 40KHz.T in step1And T2Respectively 8
Second and 2 seconds, the N in step 9 are equal to 29.This time processing result, finds that there are segmental arcs (to defend for continuous 4 reflection differences images altogether
Star trails), the hollow white circle in Fig. 6 is the calculated satellite position of TLE orbital tracking by North American Air Defense Command.It elongates
White segmental arc is the DUCHIFAT-1 satellite position obtained using detection system of the invention.The position versus of 4 figures, angular distance
Within the scope of 2 degree, illustrate that detection result of the present invention is correct.The change in location of continuous 4 images shows that the satellite exists
Its aerial motion profile.
Main advantage of the invention is: using geographically widely distributed, the ready-made broadcasting station FM as transmitting signal
Source does not need additionally to build radar emission station, greatly reduces cost of building a station；Low-frequency radio telescope array is by dual polarization dipole
Antenna composition, antenna can form the station, and several stations can form array, and this convenient, flexible composite configuration is suitble to big rule
The deployment of mould strange land, each station can both work independently, can also cooperate, and form interference array.With traditional passive thunder
Up to comparing, system detection viewing field range of the invention is larger, high sensitivity, and the target that can be detected is bigger in visual direction range.
It should be noted that although the above embodiment of the present invention be it is illustrative, this be not be to the present invention
Limitation, therefore the invention is not limited in above-mentioned specific embodiment.Without departing from the principles of the present invention, all
The other embodiment that those skilled in the art obtain under the inspiration of the present invention is accordingly to be regarded as within protection of the invention.
Claims (10)
1. a kind of space debris detection system, characterized in that connect including the broadcasting station FM group and low-frequency radio telescope array data
Receipts and processing system；
Transmitting terminal of the above-mentioned broadcasting station the FM group as system, is made of the L broadcasting station FM；
Above-mentioned low-frequency radio telescope array data receives and receiving end of the processing system as system, by low-frequency radio telescope
Array, beam synthesizer, receiver, correlator and data processing module composition；
Low-frequency radio telescope array is made of the M station, and each station is further by N number of dual polarization dipole sub-antenna group
At each dual polarization dipole sub-antenna receives the signal of two polarization directions of X and Y, and exports the signal of X and Y polarization direction；
The quantity of beam synthesizer and the quantity of the station are identical, and as M；Each beam synthesizer include 2 × N number of input terminal and
2 output ends, 2 × N number of input terminal are respectively connected to the signal of the X and Y polarization direction of N number of dual polarization dipole sub-antenna, and 2
Output end exports the wave beam of X and Y polarization direction respectively；
Receiver includes 2 × M input terminal and 2 × M output end, and 2 × M input terminal is respectively connected to M beam synthesizer
The wave beam of the X and Y polarization direction of output, 2 × M input terminal export the road 2 × M complex signal respectively；
Correlator has 2 × M input terminal and 1 output end, and 2 × M input terminal is respectively connected to the plural number of receiver output
Signal, output end output observation data；
The output end of correlator and the input terminal of data processing module connect；
Wherein L, M and N are setting value.
2. a kind of space debris detection system according to claim 1, characterized in that each beam synthesizer is by 2 × N
A low-noise amplifier, 2 × N number of bandpass filter, 2 × N number of switch time delay device, X-direction summer and Y-direction summer group
At；
Wherein N number of low-noise amplifier, N number of bandpass filter, N number of switch time delay device and X-direction summer constitute X-direction wave beam
Synthesis unit；This N number of low-noise amplifier is connect with the signal output end of the X polarization direction of N number of dual polarization dipole sub-antenna；Often
The output end of a low-noise amplifier is connect with the input terminal of 1 bandpass filter, and the output end of each bandpass filter is equal
It is connect with the input terminal of 1 switch time delay device；The output end of this N number of switch time delay device is connected with the input terminal of X-direction summer,
The wave beam of X-direction summer output X polarization direction；
In addition N number of low-noise amplifier, N number of bandpass filter, N number of switch time delay device and X-direction summer constitute Y-direction wave beam
Synthesis unit；This N number of low-noise amplifier is connect with the signal output end of the Y polarization direction of N number of dual polarization dipole sub-antenna；Often
The output end of a low-noise amplifier is connect with the input terminal of 1 bandpass filter, and the output end of each bandpass filter is equal
It is connect with the input terminal of 1 switch time delay device；The output end of this N number of switch time delay device is connected with the input terminal of Y-direction summer,
The wave beam of Y-direction summer output Y polarization direction.
3. a kind of space debris detection system according to claim 2, characterized in that each switch time delay device by 2 with
On switch time delay line be arranged in a combination.
4. a kind of space debris detection system according to claim 1, characterized in that receiver is by 2 × M amplifier, 2
× M band limiting filter, 2 × M analog-digital converter, 2 × M multiphase filter group, 2 × M channel to channel adapter and 2 × M
Quantizer composition；
The input terminal of each amplifier respectively accesses the wave beam of the X or Y polarization direction of 1 beam synthesizer output；Each amplifier
Output end connect with the input terminal of 1 band limiting filter, the output end of each band limiting filter is defeated with 1 analog-digital converter
Enter end connection, the output end of each analog-digital converter is connect with the input terminal of 1 multiphase filter group, each multiphase filter group
Output end connect with the input terminal of 1 channel to channel adapter, the input terminal of the output end of each channel to channel adapter and 1 quantizer
Connection；Each quantizer exports 1 road complex signal.
5. a kind of space debris detection system according to claim 1, characterized in that the broadcasting station FM, low frequency radio are looked in the distance
Lens array and space junk must satisfy following formula:
In formula, S is the spectrum flux density that low frequency radio telescopic array receives, and r is the radius of space junk, RrFor space junk
The distance between low-frequency radio telescope array, RtFor the distance between space junk and the broadcasting station FM, PtIt is the broadcasting station FM
Effective transmission power, G are gain of the broadcasting station the FM transmitting in space junk direction, and B is the bandwidth of the broadcasting station FM transmitting signal, v
It is the centre frequency of the broadcasting station FM transmitting signal.
6. a kind of space debris detection method, characterized in that include the following steps:
The signal that step 1, low-frequency radio telescope array in real time emit the broadcasting station FM is observed, to obtain space junk
Observe data；In the process, the low-frequency radio telescope array signal that also timing issues radio source is observed, to obtain
It obtains calibration source and observes data；
Step 2 carries out radio frequency (RF) interference removal to step 1 obtained calibration source observation data, while carrying out time integral
And frequency integrator, it obtains calibration source and removes interference integration data；
Step 3 goes interference integration data to carry out bad station label to calibration source, obtains calibration source and removes interference flag data；
Step 4 goes the errors in visibility data in interference flag data to carry out the correction of amplitude and phase to calibration source, obtains corresponding
The complex gain solution changed at any time with frequency, and the amplitude solution of this complex gain solution is made to be less than amplitude solution preset value；
Step 5, the obtained complex gain solution of step 4 and the obtained calibration source of step 3 are gone in interference flag data can
See calibration source correction data of the degree according to being multiplied, after obtaining amplitude and phase correction；
Calibration source correction data is imaged in step 6, checks imaging results, when phase centre location appearance is clearly calibrated
When source and clearly point source many far from phase centre location appearance, then the observation data processing of calibration source is correct；Otherwise, it checks
Whether the parameter setting of step 1-5 is problematic, and repeats step 1-5, until the observation data processing of calibration source is correct, Huo Zhexuan
It took the same day to observe the observation data of different calibration sources, and repeats step 1-5, until the observation data processing of calibration source is correct；
Step 7 carries out time integral and frequency integrator to the observation data of the obtained space junk of step 1, and it is broken to obtain space
Piece band interferes integration data；
Step 8 carries out bad station label to space junk band interference integration data, obtains space junk band interference flag data；
Step 9 interferes step 4 obtained complex gain solution in flag data with the obtained space junk band of step 8
Errors in visibility data is multiplied, and obtains space junk band interference correction data；
Space junk band interference correction data are imaged in step 10, obtain the space junk reflectogram of multiple times of integration
Picture；
Step 11, for space junk reflected image, successively by its front and back 2, adjacent space junk reflected images carry out phases
Subtract, obtains all reflection differences images under initial time integral；
Step 12 checks the lower all reflection differences images of step 11 obtained initial time integral, when at least one reflection
When segmental arc occurs in error image, that is, show that there may be space junks, at this time reduce initial integration time, and repeats step 7-
11, obtain all reflection differences images under new time integral；
Step 13 checks all reflection differences images under the obtained new time integral of step 12, and the therefrom company of searching out
Continue multiple and the reflection differences image of segmental arc all occurs；
Step 14, the position for calculating segmental arc in multiple reflection differences images for being found out of step 13, and by itself and synchronization root
The position of the space junk calculated according to TLE orbital tracking is compared, if the position for the space junk that the position of segmental arc and TLE are calculated
When difference between the right ascension set and declination is less than angle preset value, then it is assumed that the segmental arc is to reflect FM broadcast singal by space junk
And generate, i.e., explanation has detected the space junk.
7. a kind of space debris detection method according to claim 6, characterized in that in step 1, low frequency radio is looked in the distance
The observation wave band of lens array need to cover all tranmitting frequencies in the broadcasting station FM.
8. a kind of space debris detection method according to claim 6, characterized in that in step 7-12, it is also necessary into
The following process of one step:
Radio frequency (RF) interference removal is carried out to the observation data of the obtained space junk of step 1, and carries out time product to it
Point and frequency integrator, obtain space junk go interference integration data；
It goes interference integration data to carry out the bad station label space junk, obtains space junk and remove interference flag data；
It goes the errors in visibility data in interference flag data to be multiplied with space junk the obtained complex gain solution of step 4, obtains
Space junk goes interference correction data；
It goes interference correction data to be imaged space junk, obtains the space junk radiation image of multiple times of integration；
For space junk radiation image, successively by its front and back, 2 adjacent space junk radiation images are subtracted each other to obtain spoke
Penetrate error image；
It checks radiation error image, and result, which authenticates, is checked to reflection differences image using radiation error image.
9. a kind of space debris detection method, characterized in that include the following steps:
The signal that step 1, low-frequency radio telescope array in real time emit the broadcasting station FM is observed, to obtain space junk
Observe data；In the process, the low-frequency radio telescope array signal that also timing issues radio source is observed, to obtain
It obtains calibration source and observes data；
Step 2 carries out radio frequency (RF) interference removal to step 1 obtained calibration source observation data, while carrying out time integral
And frequency integrator, it obtains calibration source and removes interference integration data；
Step 3 goes interference integration data to carry out bad station label to calibration source, obtains calibration source and removes interference flag data；
Step 4 goes the errors in visibility data in interference flag data to carry out the correction of amplitude and phase to calibration source, obtains corresponding
The complex gain solution changed at any time with frequency, and the amplitude solution of this complex gain solution is made to be less than amplitude solution preset value；
Step 5, the obtained complex gain solution of step 4 and the obtained calibration source of step 3 are gone in interference flag data can
See calibration source correction data of the degree according to being multiplied, after obtaining amplitude and phase correction；
Calibration source correction data is imaged in step 6, checks imaging results, when phase centre location appearance is clearly calibrated
When source and clearly point source many far from phase centre location appearance, then the observation data processing of calibration source is correct；Otherwise, it checks
Whether the parameter setting of step 1-5 is problematic, and repeats step 1-5, until the observation data processing of calibration source is correct, Huo Zhexuan
It took the same day to observe the observation data of different calibration sources, and repeats step 1-5, until the observation data processing of calibration source is correct；
Step 7 carries out time integral and frequency integrator to the observation data of the obtained space junk of step 1, and it is broken to obtain space
Piece band interferes integration data；
Step 8 carries out bad station label to space junk band interference integration data, obtains space junk band interference flag data；
Step 9 interferes step 4 obtained complex gain solution in flag data with the obtained space junk band of step 8
Errors in visibility data is multiplied, and obtains space junk band interference correction data；
Space junk band interference correction data are imaged in step 10, obtain the space junk reflectogram of multiple times of integration
Picture；
Step 11, for space junk reflected image, successively by its front and back 2, adjacent space junk reflected images carry out phases
Subtract, obtains reflection differences image；
Step 12 searches software using radio source, carries out source search to reflection differences image, exports island size and flux density
Information, and maximum angular is selected more than angle preset value and number of pixels is more than the island of pixel preset value, as candidate source；
The candidate source that step 12 obtains is compared by step 13 with brighter radio source in known star catalogue: if candidate
Source is Chong Die with some source space position in star catalogue, then the candidate source is not space junk, will be excluded；Otherwise, retain the time
Select source；
Step 14, the candidate source for being retained step 13 are compared with corresponding reflected image, if some in reflected image is penetrated
Galvanic reflex event is consistent over time and space, then it is assumed that and the candidate source is to be reflected FM broadcast singal by space junk and generated,
I.e. explanation has detected the space junk.
10. a kind of space debris detection method according to claim 9, characterized in that in step 1, low frequency radio is hoped
The observation wave band of remote lens array need to cover all tranmitting frequencies in the broadcasting station FM.
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Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN109856464A (en) * | 2019-04-01 | 2019-06-07 | 国家卫星气象中心(国家空间天气监测预警中心) | It is a kind of for spaceborne very low frequency solar radio radiation observation system |
| CN111193112A (en) * | 2020-02-17 | 2020-05-22 | 中国科学院国家天文台 | In-orbit satellite interference pre-evaluation method for radio telescope |
Citations (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN101980048A (en) * | 2010-09-29 | 2011-02-23 | 中国科学院国家天文台 | Antenna array forming technology-based ground-based radar system for space debris |
-
2018
- 2018-11-16 CN CN201811367005.2A patent/CN109283587A/en active Pending
Patent Citations (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN101980048A (en) * | 2010-09-29 | 2011-02-23 | 中国科学院国家天文台 | Antenna array forming technology-based ground-based radar system for space debris |
Non-Patent Citations (2)
| Title |
|---|
| S.J.TINGAY 等: "The Murchison Widefield Array: The Square Kilometre Array Precursor at Low Radio Frequencies", 《PUBLICATIONS OF THE ASTRONOMICAL SOCIETY OF AUSTRALIA (PASA)》 * |
| 张翔 等: "基于调频广播信号的空间碎片探测方法", 《天文学报》 * |
Cited By (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN109856464A (en) * | 2019-04-01 | 2019-06-07 | 国家卫星气象中心(国家空间天气监测预警中心) | It is a kind of for spaceborne very low frequency solar radio radiation observation system |
| CN109856464B (en) * | 2019-04-01 | 2023-09-19 | 国家卫星气象中心(国家空间天气监测预警中心) | Very low frequency solar radio observation system for spaceborne |
| CN111193112A (en) * | 2020-02-17 | 2020-05-22 | 中国科学院国家天文台 | In-orbit satellite interference pre-evaluation method for radio telescope |
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