CN104764466A - Dynamic pulsar signal simulating device with multiple physical properties - Google Patents

Abstract

The invention discloses a dynamic pulsar signal simulating device with multiple physical properties, and mainly aims at solving the problem that an existing device cannot simulate a pulsar signal with physical properties. The dynamic pulsar signal simulating device comprises an outline data generation unit, a signal output unit, an electric control linear light source, an optical attenuator, a photomultiplier, an electronics readout unit and a system validation unit, wherein the outline data generation unit is used for generating pulse outline data with multiple physical properties, and converting the pulse outline data into a voltage signal through the signal output unit; the electric control linear light source is controlled to generate an optical signal of which the radiation intensity is proportional to an outline voltage signal, and attenuate the optical signal into single photon stream through the optical attenuator; and the photomultiplier is used for converting the signal photon stream into an electric pulse signal and outputting to the electronics readout unit, carrying out time marking, and outputting photon arrival time data to the system validation unit. According to the dynamic pulsar signal simulating device, high-reliability simulation of the pulsar signal with multiple physical properties is realized; and the dynamic pulsar signal simulating device can be used for providing data support for pulsar navigation ground validation system.

Description

There is the dynamic pulse star signal imitation device of many physical characteristicss

Technical field

The invention belongs to signal processing technology field, particularly relate to a kind of dynamic pulse star signal imitation device with many physical characteristicss, can be used for the X-ray pulsar photon sequence that virtual space detector receives, for the research of pulsar navigation correlation theory provides Data support and the important component part as pulsar navigation ground validation system.

Background technology

X-ray pulsar independent navigation XNAV is a kind of emerging, complete autonomous navigation method of having much development prospect, has important engineer applied and is worth and strategic research meaning, enjoy international concern.From 1999, each spacefaring nation in the world started the work such as the research of X-ray pulsar navigation correlation theory, flight experiment checking one after another.U.S. Department of Defense in 2004 proposes X-ray pulsar navigation XNAV demonstration plan, has completed feasibility study at present and ground experiment is verified, is about to carry out space flight experiment.In addition, European Space Agency, Russia and Japan and other countries and organizing has carried out the work such as a large amount of principle prototype checkings and flight experiment equally.Domesticly carry out X-ray pulsar navigation correlative study work equally, especially in theoretical and ground validation systematic research, achieve great successes.

But, due to the pulsar distance earth generally at hundreds of to hundreds of thousands light-year, so X-ray pulsar signal attenuation is very serious, the signal arriving detector is very faint, makes X-ray pulsar signal observe comparatively difficult; The disappearance of measured data constrains X-ray pulsar navigational system, especially the research of theoretical frame.Therefore, the ground simulation system of high precision, high confidence level reproduction space environment just seems particularly important.

According to published patented claim, in recent years, domestic ground simulation system mainly contains following several:

(1) " a kind of ground simulation method for X-ray pulsar navigation and device (Authorization Notice No.: CN101782390B) ", (2) " a kind of pulsar signal simulator (Authorization Notice No.: CN101603831B) ", (3) " have the X-ray pulsar photon signal ground simulation system (application publication number: CN102778236A) of high time-frequency stability ".The each tool advantage of this several device, but there are some shortcomings being difficult to overcome simultaneously:

1. the first simulation system employs x-ray source and tests, in X-ray detector technical research, have advantage, but due to the introducing of physical construction, the simulation precision that result in pulsar cyclophysis is lower, can not meet the demand of theoretical research.

2. the second simulation system adopts pure electrical way analog pulse star signal, but pulsar signal is produced by computer program, is software simulation in essence, with a low credibility.

3. the third simulation system remains the physical process of simulation, simulate with a high credibility, and there is very high time-frequency stability and precision, but the shortcoming existed is: cannot simulate the pulsar signal with many physical characteristicss, comprise the Doppler effect of pulsar rotation characteristic, Pulsar timing noisiness and generation of being moved by spacecraft.

Summary of the invention

The object of the invention is to for above-mentioned the deficiencies in the prior art, a kind of dynamic pulse star signal imitation device with many physical characteristicss is proposed, make simulating signal can reflect real physical characteristics, comprise the Doppler effect of pulsar rotation characteristic, Pulsar timing noisiness and generation of being moved by spacecraft, realize the high precision to X-ray pulsar radiation signal, the simulation of high confidence level.

The present invention has the dynamic pulse star signal imitation device of many physical characteristicss, comprises outline data generation unit, signal output unit, automatically controlled linear light sorurce, optical attenuator, photomultiplier, electronics sensing element and system verification unit;

It is characterized in that:

Described outline data generation unit, comprising:

Initialization module, emulating the parameter such as initial time, the configuration sampling time interval for determining, inputting trajectory files, JPL planet moon ephemeris file, pulsar ephemeris file, pulsar rotation phase model, timing noise model and nominal contour simultaneously;

Time scale modular converter, Doppler effect for spacecraft motion being produced is carried in pulse profile, according to the trajectory files inputted, JPL planet moon ephemeris file and pulsar ephemeris file, signal propagation delays on computer sim-ulation moment spacecraft place and pulsar direction, solar system barycenter SSB place, result of calculation was added with the emulation moment, exports phase calculation module to;

Phase calculation module, for pulsar rotation characteristic, Pulsar timing noisiness are carried in pulse profile, according to the pulsar ephemeris file of input, the pulsar rotation phase model at SSB place and timing noise model, calculate the phase place in the emulation moment after elapsed time spatial scaling, export nominal contour to and search module;

Nominal contour searches module, for searching the amplitude of phase calculation result respective pulses nominal contour, exports result to data outputting module;

Data outputting module, for exporting the outline data of input to signal output unit;

The emulation moment increases progressively module, for the emulation moment is added the configuration sampling time interval, feeds back to time scale modular converter, realizes the continuity of emulation;

Described signal output unit, comprises FPGA circuit, D/A circuit, clock shaping circuit and atomic clock; Atomic clock is the clock signal of FPGA circuit with stable by clock shaping circuit, FPGA circuit receives outline data that outline data generation unit produces and drives D/A circuit outline data to be converted to voltage signal and exports automatically controlled linear light sorurce to, and D/A circuit produces trigger pip simultaneously and exports electronics sensing element to.

The present invention, compared with existing pulsar analogue means, has the following advantages:

1. present invention employs special outline data generation unit, make the different pulsar of system dynamic real-time simulation, comprise the signal of different physical characteristics, add the dirigibility of emulation.

2. multiple physical characteristics has been loaded on pulse profile by the present invention, and the pulsar signal that system simulation is obtained, more close to measured data, specifically reflects following physical characteristics: a) pulsar rotation characteristic; B) Pulsar timing noisiness; C) moved by spacecraft and the Doppler effect produced.

3. the present invention adopts the communication process of physical process simulations pulsar signal in universe, simulates with a high credibility.

Below in conjunction with accompanying drawing, the invention will be further described:

Accompanying drawing explanation

Fig. 1 is the structural representation of apparatus of the present invention;

Fig. 2 is outline data generation unit structured flowchart in the present invention;

Fig. 3 is signal output unit structured flowchart in the present invention.

Embodiment

With reference to Fig. 1, the present invention has the dynamic pulse star signal imitation device of many physical characteristicss, comprising: outline data generation unit 1, signal output unit 2, automatically controlled linear light sorurce 3, optical attenuator 4, photomultiplier 5, optics shielding chamber 6, electronics sensing element 7 and system verification unit 8; It is characterized in that:

Outline data generation unit 1, adopts but is not limited to C# language and writes, by but be not limited to PCIE interface and be connected with signal output unit 2;

Between signal output unit 2 and automatically controlled linear light sorurce 3, between photomultiplier 5 and electronics sensing element 7, and between signal output unit 2 and electronics sensing element 7, all connected by concentric cable;

Automatically controlled linear light sorurce 3, optical attenuator 4 and photomultiplier 5 seal successively and are arranged in optics shielding chamber 6, and do optical encapsulant process;

Photomultiplier 5, select but be not limited to PMTH-S1-R1527P type side window type photoelectric tube, the spectral response range of this model photomultiplier is between 185-680nm, and peak response wavelength is 400nm, and typical dark counting is 30/second;

System verification unit 8, adopts but is not limited to C# language and writes, by but be not limited to USB data line and be connected with electronics sensing element 7;

Pulsar rotation characteristic, Pulsar timing noisiness and the Doppler effect by spacecraft motion generation are loaded on pulse profile by outline data generation unit 1, dynamic generation has the pulse profile data of many physical characteristicss, exports signal output unit 2 to; Outline data is converted to voltage signal and exports automatically controlled linear light sorurce 3 to by signal output unit 2, meanwhile, produces trigger pip and exports electronics sensing element 7 to, for initialization electronics sensing element 7, and the time synchronized of both realizations; Automatically controlled linear light sorurce 3 produces the light signal that radiation intensity is directly proportional to profile voltage signal, decays to monochromatic light subflow by optical attenuator 4; Photomultiplier 5 pairs of single photon streams detect, and are converted to electric impulse signal and export electronics sensing element 7 to; Electronics sensing element 7 pairs of electric impulse signals carry out time mark, export photon TOA time of arrival data to system verification unit 8 simultaneously.

With reference to Fig. 2, described outline data generation unit 1, comprises initialization module 11, time scale modular converter 12, phase calculation module 13, nominal contour searches module 14, data outputting module 15 and emulation moment and increase progressively module 16, wherein:

Initialization module 11, emulating initial time t, configuration sampling time interval Δ t for determining, inputting trajectory files, JPL planet moon ephemeris file, pulsar ephemeris file, pulsar rotation phase model, timing noise model and nominal contour simultaneously;

Time scale modular converter 12, Doppler effect for spacecraft motion being produced is carried in pulse profile, according to the trajectory files inputted, JPL planet moon ephemeris file and pulsar ephemeris file, the computer sim-ulation moment t spacecraft place and pulsar direction, solar system barycenter SSB place on signal propagation delays δ t, and result of calculation δ t is added with emulation moment t, export phase calculation module to, the computing formula of this propagation delay δ t is:

$\mathrm{\δt}=\frac{1}{c^2}{r}_{\mathrm{SC}/E}\·v_E+P+\frac{n\·r_A}{c}+\frac{{2\mathrm{GM}}_s}{c^3}\ln (1+\cos \mathrm{th});$

In formula, r _sC/Erepresent the position vector of spacecraft relative to the earth, v _erepresent ball speed vector, P represents the correction term between proper time and coordinate time, and c represents the light velocity, n indicating impulse star direction vector, r _arepresent that spacecraft is relative to SSB position vector, G is universal gravitational constant, M _srepresent the quality of the sun, the cosine value of angle between the costh indicating impulse star-sun-spacecraft;

Emulation moment after elapsed time spatial scaling: t '=t+ δ t;

Phase calculation module 13, for pulsar rotation characteristic, Pulsar timing noisiness are carried in pulse profile, according to the pulsar ephemeris file of input, the pulsar rotation phase model at SSB place and timing noise model, calculate the phase of the emulation moment t ' correspondence after elapsed time spatial scaling _{t '}, export nominal contour to and search module 14, this phase _{t '}calculation procedure as follows:

A) pulsar rotation phase model φ and timing noise model δ is set up _t:

$\left\{\begin{array}{c}\mathrm{\φ}=\mathrm{\φ}\left(T_0\right)+f(t^{\′}-T_0)+\frac{1}{2}\stackrel{\·}{f}{(t^{\′}-T_0)}^2+\frac{1}{6}\stackrel{\·\·}{f}{(t^{\′}-T_0)}^3\\ {\mathrm{\δ}}_t~N(0,C_2{f}^{\mathrm{\α}}{\left|\stackrel{\·}{f}\right|}^{\mathrm{\β}}{T}^{\mathrm{\γ}})\end{array}\right.;$

Wherein, T ₀the indicating impulse star timing reference time, f, with indicating impulse star is at reference time T respectively ₀time rotation frequency, frequency first order derivative and frequency second derivative, timing noise δ _tobedience average is 0, variance is gaussian distribution, wherein C ₂, α, β and γ be the parameter that long-term observation data fitting obtains, and is respectively lnC ₂=1.6 ± 0.4, α=-1.4 ± 0.1, β=1.1 ± 0.1, γ=2.0 ± 0.2, T is observation time yardstick;

B) by timing noise δ _tsubstitute in rotation phase model φ, obtain phase _{t '}:

${\mathrm{\φ}}_{t^{\′}}=\mathrm{\φ}\left(T_0\right)+f(t^{\′}+{\mathrm{\δ}}_t-T_0)+\frac{1}{2}\stackrel{\·}{f}{(t^{\′}+{\mathrm{\δ}}_t-T_0)}^2+\frac{1}{6}\stackrel{\·\·}{f}{(t^{\′}+{\mathrm{\δ}}_t-T_0)}^3;$

Nominal contour searches module 14, for searching phase calculation result φ _{t '}the amplitude of respective pulses nominal contour, i.e. outline data, and export data outputting module 15 to;

Data outputting module 15, by but be not limited to PCIE communication interface and export outline data to signal output unit 2;

The emulation moment increases progressively module 16, for adding the configuration sampling time interval in the emulation moment, i.e. t=t+ Δ t, formed and emulate the moment next time, and this emulation moment is fed back to time scale modular converter 12, realize time scale modular converter 12, periodic duty that phase calculation module 13, nominal contour search module 14 and data outputting module 15, to export continuous print, there are the pulse profile data of many physical characteristicss

With reference to Fig. 3, described signal output unit 2, comprises FPGA circuit 21, D/A circuit 22, clock shaping circuit 23 and atomic clock 24.Atomic clock 24 by clock shaping circuit 23 for FPGA circuit 21 provides stable clock signal, FPGA circuit 21 receives outline data that outline data generation unit 1 produces and drives D/A circuit 22 outline data to be converted to voltage signal and exports automatically controlled linear light sorurce 3, D/A circuit 22 to and produce trigger pip simultaneously and export electronics sensing element 7 to.

Described FPGA circuit 21, comprises communication interface modules 211, First Input First Output 212, D/A driver module 213 and clock multiplier module 214, wherein:

Communication interface modules 211, for receiving the outline data that outline data generation unit 1 produces, exports First Input First Output 212 to;

First Input First Output 212, its input end connects communication interface modules 211, and output terminal connects D/A driver module 213, for the outline data that Cache Communication interface module 211 receives, ensures that data exported with the configuration sampling time interval determined by initialization module 11;

D/A driver module 213, its input end connects First Input First Output 212, and output terminal connects D/A circuit 22, for generation of the clock signal of D/A circuit 22 need of work;

Clock multiplier module 214, carries out frequency multiplication for the clock signal exported clock shaping circuit 23, for other module of FPGA circuit 21 provides high-speed clock signal, exports communication interface modules 211, First Input First Output 212 and D/A driver module 213 respectively to.

Above embodiment is only with reference to explanation to of the present invention; do not form any restriction to content of the present invention; obviously for those skilled in the art; after having understood content of the present invention and principle; all may when not deviating from the principle of the invention, structure; carry out the various correction in form and details and change, but these corrections based on inventive concept and change are still within claims of the present invention.

Claims (6)

1. one kind has the dynamic pulse star signal imitation device of many physical characteristicss, comprise: outline data generation unit (1), number output unit (2), automatically controlled linear light sorurce (3), optical attenuator (4), photomultiplier (5), electronics sensing element (7) and system verification unit (8), is characterized in that:

Described outline data generation unit (1), comprising:

Initialization module (11), emulating the parameter such as initial time, the configuration sampling time interval for determining, inputting trajectory files, JPL planet moon ephemeris file, pulsar ephemeris file, pulsar rotation phase model, timing noise model and nominal contour simultaneously;

Time scale modular converter (12), Doppler effect for spacecraft motion being produced is loaded into pulse profile, according to the trajectory files inputted, JPL planet moon ephemeris file and pulsar ephemeris file, signal propagation delays on computer sim-ulation moment spacecraft place and pulsar direction, solar system barycenter SSB place, result of calculation was added with the emulation moment, exports phase calculation module (13) to;

Phase calculation module (13), for pulsar rotation characteristic, Pulsar timing noisiness are carried in pulse profile, according to the pulsar ephemeris file of input, the pulsar rotation phase model at SSB place and timing noise model, calculate the phase place in the emulation moment after elapsed time spatial scaling, export nominal contour to and search module (14);

Nominal contour searches module (14), for searching the amplitude of phase calculation result respective pulses nominal contour, result is exported to data outputting module (15);

Data outputting module (15), for exporting the outline data of input to signal output unit (2);

The emulation moment increases progressively module (16), for the emulation moment is added the configuration sampling time interval, feeds back to time scale modular converter (12), realizes the continuity of emulation;

Described signal output unit (2), comprises FPGA circuit (21), D/A circuit (22), clock shaping circuit (23) and atomic clock (24); Atomic clock (24) by clock shaping circuit (23) for FPGA circuit (21) provides stable clock signal, FPGA circuit (21) receives outline data generation unit (1) outline data that produces and drives D/A circuit (22) outline data to be converted to voltage signal and exports automatically controlled linear light sorurce (3) to, and D/A circuit (22) produces trigger pip simultaneously and exports electronics sensing element (7) to.

2. device according to claim 1, it is characterized in that time scale modular converter (12), phase calculation module (13), nominal contour search module (14), data outputting module (15) and emulation the moment increase progressively module (16) periodic duty, dynamically to generate continuous print, there are the pulse profile data of many physical characteristicss.

3. device according to claim 1, is characterized in that FPGA circuit (21), comprising:

Communication interface modules (211), for receiving the outline data that outline data generation unit (1) produces, exports First Input First Output (212) to;

First Input First Output (212), its input end connects communication interface modules (211), output terminal connects D/A driver module (213), for the outline data that Cache Communication interface module (211) receives, ensure that data exported with the configuration sampling time interval determined by initialization module (11);

D/A driver module (213), its input end connects First Input First Output (212), and output terminal connects D/A circuit (22), for generation of the clock signal of D/A circuit (22) need of work;

Clock multiplier module (214), clock signal for exporting clock shaping circuit (23) carries out frequency multiplication, for FPGA circuit (21) other module provides high-speed clock signal, export communication interface modules (211), First Input First Output (212) and D/A driver module (213) respectively to.

4. device according to claim 1, is characterized in that automatically controlled linear light sorurce (3), and optical attenuator (4) and photomultiplier (5) seal successively and be arranged in optics shielding chamber (6).

5. device according to claim 1, it is characterized in that between signal output unit (2) and automatically controlled linear light sorurce (3), between photomultiplier (5) and electronics sensing element (7), and between signal output unit (2) and electronics sensing element (7), all connected by concentric cable.

6. device according to claim 1, is characterized in that the trigger pip that electronics sensing element (7) is exported by signal output unit (2) carries out time synchronized.