阅读说明：本技术 深空x频段测距和干涉一体化信标装置、测量方法和系统 (Deep space X-frequency range finding and interference integrated beacon device, measuring method and system ) 是由 徐得珍 黄磊 陈少伍 于 2021-08-25 设计创作，主要内容包括：本发明属于航天器测控技术领域,特别涉及一种深空X频段测距和干涉一体化信标装置、测量方法和系统,主要适用于在深空探测的远距离、弱信号场景下地面站对深空航天器的X频段无线电双向测距和干涉测量,提高功率的综合利用效率,获取更高精度的地基测量数据。本发明利用了再生测距模式无转发噪声、残留遥控等无用损耗以及测量精度高的优势,复用伪码测距的单音信标辅助干涉测量的群时延解模糊,实现测距和干涉测量信标一体化。相比当前主用的经典信标,本发明的一体化信标的功率利用效率明显提高；双向测距精度显著提升,可改善双向测速精度、时延测量精度,提高可支持的遥测码速率。(The invention belongs to the technical field of spacecraft measurement and control, and particularly relates to a deep space X-frequency range distance measurement and interference integrated beacon device, a measurement method and a system, which are mainly suitable for the X-frequency range radio bidirectional distance measurement and interference measurement of a ground station on a deep space spacecraft in a deep space exploration long-distance and weak signal scene, so that the comprehensive utilization efficiency of power is improved, and higher-precision ground measurement data is obtained. The invention utilizes the advantages of no retransmission noise, useless loss of residual remote control and the like in a regenerative ranging mode and high measurement precision, reuses the group delay ambiguity resolution of the single-tone beacon auxiliary interferometry of pseudo code ranging, and realizes the integration of ranging and interferometry beacons. Compared with the current master classical beacon, the power utilization efficiency of the integrated beacon is obviously improved; the bidirectional distance measurement precision is obviously improved, the bidirectional speed measurement precision and the time delay measurement precision can be improved, and the supportable remote measurement code rate is improved.)

1. The deep space X-frequency range measurement and interference integrated beacon device is characterized by comprising a model module, wherein the model module comprises the following beacon models:

wherein s (t) is a downlink signal; p_TIs the downlink signal power; f. of_dIs a downlink carrier frequency; t is time; m is_PNThe modulation degree of the distance measurement; c. C_kFor ranging pseudo-code sequences, T_cFor ranging pseudo-code sequences c_kChip width of, said ranging pseudo code sequence c_kAnd its chip width T_cThe method comprises the steps of obtaining an uplink ranging pseudo code through capturing and synchronizing; m is_DORIs a DOR tone system; f. of_DORIs the frequency of the DOR tone; h (t-kT)_c) The time waveform of the baseband shaping filter has the following basic construction form h (t):

2. the integrated beacon device as claimed in claim 1, wherein the uplink ranging pseudocode is selected from T4B code or T2B code.

3. The integrated beacon device of claim 1, wherein the chip rate of the uplink ranging pseudocode is greater than the chip rate of the uplink ranging pseudocodeWherein l and k are constants; f. of_uIs the uplink carrier frequency.

4. An integrated beacon device as claimed in claim 1, in which the frequency f of the DOR tone is_DOR＝f_d/440, degree of distance measurement modulation m_PNAnd DOR tone system m_DORThe values of (A) are as follows:

0.4rad≤m_PN≤1.0rad

0.2rad≤m_DOR≤0.8rad。

5. a deep space X-frequency range measurement and interference integrated beacon measurement method is characterized by comprising the following steps:

s1: the ground station end and the deep space spacecraft end complete carrier bidirectional capture;

s2: modulating and sending the uplink ranging pseudo code by the ground station end;

s3: the deep space spacecraft end captures and regenerates the uplink ranging pseudo code to obtain a regenerated pseudo code, and the regenerated pseudo code and the DOR sound phase are modulated on a downlink carrier by using the integrated beacon device according to one of claims 1 to 4;

s4: acquiring a bidirectional ranging value after the ground station captures the regenerated pseudo code; meanwhile, the ground station terminal collects and records downlink carrier waves, pseudo code ranging and DOR sound signals;

s5: and the interference measurement data processing end uses the downlink carrier and the pseudo code ranging signal to assist in solving the ambiguity of the DOR sound, and obtains the high-precision time delay observed quantity.

6. A deep space X-frequency range measurement and interference integrated beacon measurement system is characterized by comprising a deep space spacecraft end, a ground station end and an interference measurement data processing end; the ground station end comprises ground measurement and control equipment and ground interference measurement equipment;

the deep space spacecraft end comprising a carrier capture module, a pseudo code capture and regeneration module and the integrated beacon device according to one of claims 1 to 4; the carrier capture module is used for capturing and forwarding the uplink carrier transmitted by the ground measurement and control equipment; the pseudo code capturing and regenerating module is used for capturing an uplink ranging pseudo code sent by the ground measurement and control equipment and synchronously generating a regenerated pseudo code; the integrated beacon device is used for modulating the regenerated pseudo code and the DOR sound phase on a downlink carrier and sending the downlink carrier to the ground station end;

the ground measurement and control equipment is used for sending an uplink carrier to the deep space spacecraft end, capturing a downlink carrier sent by the deep space spacecraft end, capturing a regeneration pseudo code sent by the deep space spacecraft end and acquiring a two-way ranging value; the ground interference measurement equipment is used for collecting and recording downlink carrier waves, pseudo code ranging and DOR (direction of arrival) sound signals sent by the deep space spacecraft end;

and the interferometric measurement data processing end is used for solving the ambiguity of the DOR sound by using the downlink carrier wave and the pseudo code ranging signal in an auxiliary manner to obtain the high-precision time delay observed quantity.

Technical Field

The invention belongs to the technical field of spacecraft measurement and control, and particularly relates to a deep space X-frequency range distance measurement and interference integrated beacon device, a measuring method and a system, which are mainly suitable for X-frequency range radio bidirectional distance measurement and interference measurement of a ground station to a deep space spacecraft in a deep space exploration long-distance and weak signal scene.

Background

At present, in China, the X-band orbit measurement of lunar and mars detection adopts forward ranging based on 500kHz sidetone and interferometric measurement based on 2 pairs of DOR (Differential One-way ranging) tones to respectively obtain ranging and time delay observed quantities, and further is used for spacecraft navigation. The typical distance measurement precision of the X frequency band is better than 1m, the time delay measurement precision is better than 1ns, and the successful detection tasks of the moon and the mars in the past are effectively supported.

With the gradual progress of subsequent manned landing, lunar exploration in the fourth period, interplanetary and solar system marginal detection, the measurement and control system needs to realize high-precision orbit measurement under the measurement conditions of shorter arc sections, more targets and weaker signals, which provides new challenges for the existing measurement precision and mode. Therefore, in addition to improving the transceiving performance of spacecraft and ground measurement and control, a measurement system with higher precision is further considered, the measurement beacon is integrally designed, the power utilization potential is exploited, and the effective improvement of the measurement precision is realized.

Disclosure of Invention

Aiming at the problems and combining the technical characteristics of the regenerated pseudo code ranging and delta DOR measurement proposed by CCSDS, the invention provides a deep space X-band high-precision radio ranging and interference measurement integrated beacon device, a measuring method and a system, which are mainly suitable for radio two-way ranging and interference measurement of a ground station to a deep space spacecraft in a deep space exploration long-distance and weak signal scene, improve the comprehensive utilization efficiency of power and acquire higher-precision ground measurement data. The invention utilizes the advantages of no retransmission noise, no useless loss such as residual remote control and the like in a regenerative ranging mode and high measurement precision, reuses the group delay ambiguity resolution of the single-tone beacon auxiliary interferometry of pseudo code ranging, and realizes the integration of ranging and interferometry beacons.

In order to achieve the above object, the present invention provides a deep space X-band ranging and interference integrated beacon device, which includes a model module, where the model module includes the following beacon models:

wherein s (t) is a downlink signal; p_TIs the downlink signal power; f. of_dIs a downlink carrier frequency; t is time; m is_PNThe modulation degree of the distance measurement; c. C_kFor ranging pseudo-code sequences, T_cFor ranging pseudo-code sequences c_kChip width of, said ranging pseudo code sequence c_kAnd itChip width T_cThe method comprises the steps of obtaining an uplink ranging pseudo code through capturing and synchronizing; m is_DORIs a DOR tone system; f. of_DORIs the frequency of the DOR tone; h (t-kT)_c) The time waveform of the baseband shaping filter has the following basic construction form h (t):

further, the uplink ranging pseudo code selects a T4B code or a T2B code.

Further, the chip rate of the uplink ranging pseudo codeWherein l and k are constants; f. of_uIs the uplink carrier frequency.

Further, the frequency f of the DOR tone_DOR＝f_d/440, degree of distance measurement modulation m_PNAnd DOR tone system m_DORThe values of (A) are as follows:

0.4rad≤m_PN≤1.0rad

0.2rad≤m_DOR≤0.8rad。

the invention also provides a deep space X frequency range ranging and interference integrated beacon measuring method, which comprises the following steps:

s1: the ground station end and the deep space spacecraft end complete carrier bidirectional capture;

s2: modulating and sending the uplink ranging pseudo code by the ground station end;

s3: the deep space spacecraft end captures and regenerates the uplink ranging pseudo code to obtain a regenerated pseudo code, and the regenerated pseudo code and the DOR sound phase are modulated on a downlink carrier by the integrated beacon device;

s4: acquiring a bidirectional ranging value after the ground station captures the regenerated pseudo code; meanwhile, the ground station terminal collects and records downlink carrier waves, pseudo code ranging and DOR sound signals;

s5: and the interference measurement data processing end uses the downlink carrier and the pseudo code ranging signal to assist in solving the ambiguity of the DOR sound, and obtains the high-precision time delay observed quantity.

The invention further provides a deep space X frequency range distance measurement and interference integrated beacon measurement system, which comprises a deep space spacecraft end, a ground station end and an interference measurement data processing end; the ground station end comprises ground measurement and control equipment and ground interference measurement equipment;

the deep space spacecraft end comprises a carrier capturing module, a pseudo code capturing and regenerating module and the integrated beacon device; the carrier capture module is used for capturing and forwarding the uplink carrier transmitted by the ground measurement and control equipment; the pseudo code capturing and regenerating module is used for capturing an uplink ranging pseudo code sent by the ground measurement and control equipment and synchronously generating a regenerated pseudo code; the integrated beacon device is used for modulating the regenerated pseudo code and the DOR sound phase on a downlink carrier and sending the downlink carrier to the ground station end;

the ground measurement and control equipment is used for sending an uplink carrier to the deep space spacecraft end, capturing a downlink carrier sent by the deep space spacecraft end, capturing a regeneration pseudo code sent by the deep space spacecraft end and acquiring a two-way ranging value; the ground interference measurement equipment is used for collecting and recording downlink carrier waves, pseudo code ranging and DOR (direction of arrival) sound signals sent by the deep space spacecraft end;

and the interferometric measurement data processing end is used for solving the ambiguity of the DOR sound by using the downlink carrier wave and the pseudo code ranging signal in an auxiliary manner to obtain the high-precision time delay observed quantity.

The invention has the beneficial effects that:

1) compared with the current master classical beacon, the integrated beacon has the following advantages:

the power distribution is concentrated, and the intermodulation harmonic component is less;

useless losses such as forwarding noise, residual remote control and the like are avoided, and the utilization efficiency of downlink power is improved;

only one pair of special DOR tones is added and modulated, pseudo code ranging signals are adopted to assist group delay in resolving ambiguity, and the utilization efficiency of downlink power is further improved through beacon multiplexing;

the regenerated pseudo code is adopted for ranging, so that the ranging precision is obviously improved;

the utilization efficiency of downlink power is improved, the downlink carrier power under the same condition is stronger, the speed measurement and interference measurement precision is improved, and the supportable remote measurement code rate is improved;

2) the integrated beacon has a good support foundation for spacecraft and ground measurement and control equipment, and is compatible with international interaction support requirements; under the development trend that digital answering machines are gradually and widely applied to lunar and deep space exploration tasks, the integrated beacon can be realized without consuming extra core cost.

Drawings

Figure 1 is the combination logic of the periodic component codes proposed by the CCSDS and their constituent ranging pseudo codes;

FIG. 2 is an example of a power spectrum of a deep space X-band ranging and interference integrated beacon and a current lunar and deep space exploration classical beacon according to an embodiment of the present invention;

fig. 3 is an estimate of Δ dor (delta dor) measurement accuracy in the integrated beacon and classical beacon modes of an embodiment of the invention.

Detailed Description

The invention adopts the regenerative pseudo code ranging to replace the traditional transmitting sidetone ranging to improve the precision of the deep space radio ranging, wherein, because the frequency spectrum of the pseudo code signal has similarity with the DOR beacon, the DOR beacon can be replaced or partially replaced, thereby realizing the high-efficiency utilization of the power.

The invention is further described below with reference to the accompanying drawings and examples, it being understood that the examples described below are intended to facilitate the understanding of the invention, and are not intended to limit it in any way.

The following embodiments are based on typical X-band space and ground measurement and control technical states of Chinese lunar exploration tasks. Uplink carrier frequency f_u: 7218.00 MHz; downlink carrier frequency f_d: 8480.43 MHz; the ground distance: 40 kilometers; gain of a receiving antenna of the deep space spacecraft: -7 dBi; the deep space spacecraft receives the G/T value: -35 dBi/K; downlink EIRP value of deep space spacecraft: 0.0 dBW; surface uplink EIRP value: 104.0 dBW; receiving a G/T value on the ground: 49.0 dBi/K; uplink ranging modulation degree: 0.95 rad; uplink remote control modulation degree: 0.95 rad; downlink telemetry modulation degree: 0.80 rad.

Example 1

The embodiment provides a deep space X-band ranging and interferometry integrated beacon device, which comprises a model module, wherein the model module comprises the following beacon models:

wherein s (t) is a downlink signal; p_TThe power of the downlink signal is determined by the transmitting power of the deep space spacecraft (non-design parameters); downlink carrier frequency f_dAnd the uplink carrier frequency f_uCoherence (as shown above, the forward ratio f_d/f_u880/749); t is time; m is_PNThe modulation degree of the distance measurement; c. C_kFor ranging pseudo code sequence, take value of + -1, T_cFor ranging pseudo-code sequences c_kChip width of (d); m is_DORIs a DOR tone system; f. of_DORIs the frequency of the DOR tone; h (t-kT)_c) The time waveform of the baseband shaping filter has the following basic construction form h (t):

ranging pseudo code sequence c in beacon model_kAnd its chip width T_cAnd acquiring the uplink ranging pseudo code sent by the ground station end through the deep space spacecraft end by capturing and synchronizing. The uplink ranging pseudo code sequence selects T4B code c suggested by CCSDS (coherent Committee for Space Data systems)_T4BOr T2B code c_T2B：

c_T4B＝sign(4C1+C2-C3-C4+C5-C6)

c_T2B＝sign(2C1+C2-C3-C4+C5-C6)

Wherein, T4B code c_T4BWeighted equalization Tausworhe code with weight 4, T2B code c_T2BA weighted equalization Tausworthe code with a weight of 2; sign represents a sign operation, and C1-C6 are six periodic component codes, and the specific forms of the component codes and the ways of forming ranging pseudo codes are shown in FIG. 1. In this embodiment, the uplink ranging pseudo codeSelecting the code c of T4B_T4B. Chip rate F of uplink ranging pseudo code_chip Wherein, l is 4, k is 6, l is 8, and k is 6. In this embodiment, l is 8, k is 6, and the chip rate F of the uplink ranging pseudo code is taken_chipAbout 2.08 Mchip/s.

Frequency f of DOR tone in beacon model_DORThe value of (A) is as follows: f. of_DOR＝f_dThe/440 is approximately equal to 20 MHz; modulation m for distance measurement_PNAnd DOR tone system m_DORThe value ranges are as follows: m is less than or equal to 0.4rad_PN≤1.0rad，0.2rad≤m_DORLess than or equal to 0.8 rad. The embodiment selects the modulation degree m of the distance measurement_PNAnd DOR tone system m_DOR0.70rad and 0.40rad respectively.

Example 2

The embodiment provides a deep space X-frequency range measurement and interference integrated beacon measurement method, which comprises the following steps:

s1: the ground station end and the deep space spacecraft end complete carrier bidirectional capture;

s2: the ground station end follows the chip rate F in embodiment 1_chipSum pattern modulation and transmission of T4B code c_T4B；

S3: the deep space spacecraft end finishes capturing and regenerating the uplink ranging pseudo code to obtain a regenerated pseudo code, and the regenerated pseudo code and the DOR sound phase are modulated on a downlink carrier by using the integrated beacon device in the embodiment 1;

s4: acquiring a bidirectional ranging value after the ground station captures the regenerated pseudo code; meanwhile, the ground station end collects and records signals such as downlink carrier waves, pseudo code ranging and DOR (direction of arrival) tones and the like;

s5: and the interference measurement data processing end uses downlink carrier waves, pseudo code ranging signals and the like to assist in solving the ambiguity of the DOR sound, and obtains high-precision time delay observed quantity.

Example 3

The embodiment provides a deep space X-frequency range measurement and interference integrated beacon measurement system, which comprises a deep space spacecraft end, a ground station end and an interference measurement data processing end; the ground station end comprises ground measurement and control equipment and ground interference measurement equipment;

the deep space spacecraft end comprises a capturing module, a pseudo code capturing and regenerating module and the integrated beacon device according to the embodiment 1; the carrier capture module is used for capturing and forwarding the uplink carrier transmitted by the ground measurement and control equipment; the pseudo code capturing and regenerating module is used for capturing an uplink ranging pseudo code sent by the ground measurement and control equipment and synchronously generating a regenerated pseudo code; the integrated beacon device is used for modulating the regenerated pseudo code and the DOR sound phase on a downlink carrier and sending the downlink carrier to the ground station end;

the ground measurement and control equipment is used for sending an uplink carrier to the deep space spacecraft end, capturing a downlink carrier sent by the deep space spacecraft end, capturing a regeneration pseudo code sent by the deep space spacecraft end and acquiring a two-way ranging value; the ground interference measurement equipment is used for collecting and recording signals such as downlink carrier waves, pseudo code ranging and DOR (direction of arrival) sounds and the like sent by the deep space spacecraft end;

and the interferometric measurement data processing end is used for solving the ambiguity of the DOR sound by utilizing signals such as downlink carrier waves, pseudo code ranging and the like in an auxiliary manner to obtain high-precision time delay observed quantity.

Example 4

In this embodiment, link estimation is performed on the integrated beacon model (hereinafter referred to as an integrated beacon) established in embodiment 1 and the current master classical beacon model (hereinafter referred to as a classical beacon) respectively, and errors of distance measurement, speed measurement and time delay measurement are analyzed, so as to compare and illustrate the effectiveness and the advancement of the integrated beacon of the present invention.

Fig. 2 is an upper graph of a power spectrum example corresponding to a deep space X-band radio high-precision ranging and interferometry integrated beacon obtained according to the integrated beacon and parameters in embodiment 1, and a lower graph of a power spectrum example of a current lunar and deep space exploration X-band classical downlink signal. According to the typical X-frequency band space and ground measurement and control technical state of the lunar exploration task in China, link estimation is respectively carried out on the integrated beacon and the classical beacon. The main node parameters and the level estimation of the measurement beacon are of major interest and the results are given in table 1 below.

TABLE 1 Link estimation scenarios for Integrated beacons and classical beacons

From table 1, compared with the classical beacon, the integrated beacon of the present invention has no residual ineffective losses such as remote control, forwarding noise, etc., and 1 pair of DOR tones is omitted; although the modulation degree of the downlink ranging is slightly improved (0.56rad to 0.70rad), the residual carrier wave, the telemetering, the DOR sound and the like are 1.1dB higher than those of the classical signal, and the ranging tone is 1.2dB higher than that of the classical signal, which means that the integrated beacon has higher measurement accuracy and supports about 30% improvement of the telemetry code rate. The power utilization efficiency of the integrated beacon and the power utilization efficiency of the classical beacon are respectively 90.0% and 73.3% through calculation. Thus, the power utilization efficiency of the integrated beacon of the present invention is improved by about 23% compared to the classical beacon.

For distance measurement and speed measurement, the thermal noise error is absolutely dominant in the total error, and the embodiment only calculates the thermal noise error. During calculation, the typical value of the ground ranging (single-side) loop bandwidth is 1Hz, and the typical value of the spacecraft regenerative pseudo code ranging (single-side) loop bandwidth is 2 Hz; the range (1 st order) signal to noise spectral density ratio values are given in table 1. The pseudo code ranging bidirectional random error is related to both uplink and downlink random errors, and according to the worst condition: RSS (root Sum square) in two terms. Calculating to obtain a sidetone ranging bidirectional random error (1 sigma) of 0.80 m; the random errors (1 sigma) of the pseudo code ranging in the uplink and the downlink are respectively 0.01m and 0.17m, and the random error (1 sigma) in the two directions is 0.17 m. The integration time of speed measurement is 1s, the bandwidth of carrier (bilateral) loop is 500Hz, and the value of residual carrier-to-noise ratio is shown in Table 1. The random errors (1 sigma) of the bidirectional velocity measurement are respectively 0.31mm/s and 0.27mm/s under the classical beacon and the integrated beacon obtained by calculation.

The time delay measurement error has more factors, and can be divided into radio source thermal noise, spacecraft thermal noise, clock instability, phase dispersion, site error, earth orientation error, troposphere time delay jitter, ionosphere time delay error, ionosphere time delay jitter, solar plasma, radio source coordinates and the like. The error estimation is carried out by combining the actual situation of VLBI observation in China, and the result is shown in FIG. 3, wherein New represents the integrated beacon of the invention, and Now represents the classical beacon. As seen from the figure, in the classical beacon and the integrated beacon modes, the delay measurement accuracy (1 σ) is about 0.12 ns. In fact, the signal strength of the DOR tone in the integrated beacon mode of the invention is slightly improved, the error caused by the thermal noise of the spacecraft is smaller (0.006ns is improved to 0.005ns), but the total measurement accuracy is basically the same because other error sources are dominant.

The following table 2 summarizes the above calculations, and it can be seen that: the distance measurement precision of the integrated beacon is improved most obviously and reaches 79%; because energy losses such as residual remote control, forwarding noise and the like are avoided, and 1 pair of DOR tones are cancelled, the utilization efficiency of the downlink signal power of the integrated beacon is improved to 90.0% from 73.3%, the residual carrier-to-noise ratio is improved by 1.1dB, and the supported telemetry code rate is improved by about 30%. The time delay measurement error caused by the thermal noise of the spacecraft is reduced, but the contribution to the total time delay measurement precision is weak.

TABLE 2 comparison of the Effect of the Integrated Beacon of the present invention and the classical Beacon

It will be apparent to those skilled in the art that various modifications and improvements can be made to the embodiments of the present invention without departing from the inventive concept thereof, and these modifications and improvements are intended to be within the scope of the invention.