Spacecraft orbit determination method and device based on one-way Doppler

Abstract

This application discloses a method and device for determining a spacecraft's orbit based on one-way Doppler, relating to the field of aerospace technology. The method comprises: establishing a first partial derivative model of the observation station's receiving frequency with respect to the target spacecraft's position based on a preset integration period and the one-way Doppler velocity equation, and establishing a second partial derivative model of the receiving frequency with respect to the target spacecraft's transmitting frequency based on the one-way Doppler velocity equation; solving the first and second partial derivative models to obtain the target spacecraft's position information and transmitting frequency; correcting the target spacecraft's position information and transmitting frequency based on random errors and systematic errors to obtain target position information and target transmitting frequency; and determining the target spacecraft's orbit based on the target position information and target transmitting frequency. This application solves the problem in related technologies of being unable to determine the orbit of distant spacecraft using two-way Doppler.

Description

Technical Field

[0001] The present application relates to the field of aerospace technology, and in particular to a method and device for determining a spacecraft orbit based on one-way Doppler. Background Art

[0002] The main types of deep-space radio measurements include velocity measurement, ranging, and Very Long Baseline Interferometry (VLBI). In deep-space exploration missions, velocity measurement is primarily achieved through Doppler velocity measurement, which uses the Doppler effect to measure the changes in the transmit and receive frequencies between a deep-space probe and an observatory to obtain the probe's line-of-sight velocity relative to the observatory. Doppler velocity measurement systems are generally categorized by measurement method: one-way, two-way, and three-way. Based on the integration method, they are further divided into instantaneous Doppler and integrated Doppler. The principle of instantaneous Doppler velocity measurement is the same as that of integrated Doppler, except that the integration period is shorter (e.g., 0.2 seconds). Two-way Doppler velocity measurement can be considered a special case of three-way Doppler velocity measurement. Two-way Doppler velocity measurement occurs when the uplink and downlink stations are the same. Currently, spacecraft orbit determination is often achieved through two-way Doppler velocities, where a station transmits an uplink signal to the spacecraft and receives a downlink signal back from the spacecraft. However, for long-distance measurements, two-way Doppler velocities cannot achieve two-way measurements due to time delays and the Earth's rotation. The uplink signal transmitted by the station cannot be received by the station after being forwarded by the spacecraft, resulting in a problem. One-way Doppler velocities are a cost-effective measurement method for deep space exploration. Their advantage is that they do not require an uplink, requiring only the station to receive the downlink signal transmitted by the satellite. This method saves resources and makes it easier to achieve long-distance deep space measurements.

[0003] Regarding the problem that two-way Doppler cannot be used to determine the orbit of a distant spacecraft in related technologies, no practical engineering solution has been proposed so far. Summary of the Invention

[0004] The main purpose of this application is to provide a method and device for determining a spacecraft orbit based on one-way Doppler, so as to solve the problem in the related art that the orbit of a long-distance spacecraft cannot be determined by two-way Doppler.

[0005] To achieve the above objectives, according to one aspect of the present application, a method for determining a spacecraft orbit based on one-way Doppler is provided. The method comprises: establishing a first partial derivative model of the observation station's receiving frequency with respect to the position of the target spacecraft based on a preset integration period and a one-way Doppler velocity equation, and establishing a second partial derivative model of the receiving frequency with respect to the transmitting frequency of the target spacecraft based on the one-way Doppler velocity equation; solving the first and second partial derivative models to obtain the position information and transmitting frequency of the target spacecraft; correcting the position information and transmitting frequency of the target spacecraft based on random errors and systematic errors to obtain target position information and target transmitting frequency; and determining the orbit of the target spacecraft based on the target position information and target transmitting frequency.

[0006] Furthermore, before establishing a first partial derivative model of the receiving frequency with respect to the position of the target spacecraft based on a preset integration period and a one-way Doppler velocity measurement equation, the method further includes: establishing the one-way Doppler velocity measurement equation based on the transmitting frequency of the target spacecraft and the receiving frequency of the observation station, wherein the one-way Doppler velocity measurement equation is in the form of: is the radial velocity of the target spacecraft relative to the observation station, f re is the receiving frequency, f s is the emission frequency, and c is the speed of light.

[0007] Furthermore, the first partial derivative model is:

[0008] Where r is the position information of the target spacecraft, ρ(t1) and ρ(t2) are the distances of the target spacecraft relative to the observation station at the integration start time and the integration end time, respectively, and ΔT is the integration period.

[0009] Furthermore, the second partial derivative model is: in, is the radial velocity of the target spacecraft relative to the observation station, f re is the receiving frequency, f s is the emission frequency, and c is the speed of light.

[0010] Furthermore, the random error includes at least a frequency deviation thermal noise error and a frequency source error. Before correcting the position information and the transmission frequency of the target spacecraft based on the random error and the system error to obtain the target position information and the target transmission frequency, the method further includes: calculating the frequency deviation thermal noise error based on the power spectral density of the downlink signal transmitted by the target spacecraft, the integration period and the receiving frequency; calculating the frequency source error based on the Allan variance of the oscillator of the target spacecraft; and calculating the system error based on the frequency error index value of the target spacecraft.

[0011] Furthermore, the frequency deviation thermal noise error is: in, is the power spectrum density of the downlink signal, B L is the unilateral loop bandwidth; the frequency source error is: Among them, C s The stability of the oscillator is expressed as Allan variance; the system error is: Wherein, Δfs is the frequency error index value.

[0012] To achieve the above-mentioned objectives, according to another aspect of the present application, a one-way Doppler-based spacecraft orbit determination device is provided. The device comprises: a first establishing unit, configured to establish a first partial derivative model of the observation station's receiving frequency with respect to the position of the target spacecraft based on a preset integration period and a one-way Doppler velocity equation, and to establish a second partial derivative model of the receiving frequency with respect to the transmitting frequency of the target spacecraft based on the one-way Doppler velocity equation; a solving unit, configured to solve the first partial derivative model and the second partial derivative model to obtain the position information and the transmitting frequency of the target spacecraft; a correction unit, configured to correct the position information and the transmitting frequency of the target spacecraft based on random errors and systematic errors to obtain target position information and target transmitting frequency; and a determining unit, configured to determine the orbit of the target spacecraft based on the target position information and the target transmitting frequency.

[0013] Furthermore, the apparatus further includes: a second establishing unit, configured to establish the one-way Doppler velocity measurement equation based on the transmitting frequency of the target spacecraft and the receiving frequency of the observation station before establishing the first partial derivative model of the receiving frequency with respect to the position of the target spacecraft based on a preset integration period and the one-way Doppler velocity measurement equation, wherein the one-way Doppler velocity measurement equation is in the form of: is the radial velocity of the target spacecraft relative to the observation station, f re is the receiving frequency, f s is the emission frequency, and c is the speed of light.

[0014] Furthermore, the first partial derivative model is:

[0015] Where r is the position information of the target spacecraft, ρ(t1) and ρ(t2) are the distances of the target spacecraft relative to the observation station at the integration start time and the integration end time, respectively, and ΔT is the integration period.

[0016] Furthermore, the second partial derivative model is: in, is the radial velocity of the target spacecraft relative to the observation station, f re is the receiving frequency, f s is the emission frequency, and c is the speed of light.

[0017] Furthermore, the random error includes at least a frequency deviation thermal noise error and a frequency source error, and the device also includes: a first calculation unit, used to calculate the frequency deviation thermal noise error based on the power spectral density of the downlink signal transmitted by the target spacecraft, the integration period and the receiving frequency before correcting the position information and the transmission frequency of the target spacecraft based on the random error and the systematic error to obtain the target position information and the target transmission frequency; a second calculation unit, used to calculate the frequency source error based on the Allan variance of the oscillator of the target spacecraft; and a third calculation unit, used to calculate the systematic error based on the frequency error index value of the target spacecraft.

[0018] Furthermore, the frequency deviation thermal noise error is: in, is the power spectrum density of the downlink signal, B L is the unilateral loop bandwidth; the frequency source error is: Among them, C s The stability of the oscillator is expressed as Allan variance; the system error is: Wherein, Δfs is the frequency error index value.

[0019] In order to achieve the above-mentioned object, according to one aspect of the present application, a processor is provided, which is used to run a program, wherein the program, when running, executes any one of the above-mentioned one-way Doppler-based spacecraft orbit determination methods.

[0020] In order to achieve the above-mentioned purpose, according to one aspect of the present application, an electronic device is provided, which includes one or more processors and a memory, and the memory is used to store the one or more processors to implement any one of the above-mentioned one-way Doppler-based spacecraft orbit determination methods.

[0021] Through the present application, the following steps are adopted: a first partial derivative model of the receiving frequency of the observation station with respect to the position of the target spacecraft is established based on a preset integration period and a one-way Doppler velocity measurement equation, and a second partial derivative model of the receiving frequency with respect to the transmitting frequency of the target spacecraft is established based on the one-way Doppler velocity measurement equation; the first partial derivative model and the second partial derivative model are solved to obtain the position information and transmitting frequency of the target spacecraft; the position information and transmitting frequency of the target spacecraft are corrected based on random errors and systematic errors to obtain target position information and target transmitting frequency; the orbit of the target spacecraft is determined based on the target position information and target transmitting frequency, thereby solving the problem in the related art that two-way Doppler cannot be used to determine the orbit of a distant spacecraft. Based on one-way Doppler, a first partial derivative model of the observation station's receiving frequency with respect to the target spacecraft position is constructed. Based on one-way Doppler, a second partial derivative model of the receiving frequency with respect to the target spacecraft's transmitting frequency is constructed. The target position information of the target spacecraft and the target transmitting frequency of the target spacecraft are solved by using the first partial derivative model and the second partial derivative model. Finally, the orbit of the target spacecraft is determined based on the target position information and the target transmitting frequency. Determining the orbit of the spacecraft based on one-way Doppler does not require an uplink. Instead, the observation station only needs to receive the downlink signal transmitted by the target spacecraft, which is not affected by time delay and the rotation of the earth, thereby achieving the effect of determining the orbit of a distant spacecraft. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] The accompanying drawings, which constitute part of this application, are intended to provide a further understanding of this application. The exemplary embodiments and descriptions of this application are intended to explain this application and do not constitute an improper limitation on this application. In the accompanying drawings:

[0023] Figure 1 is a flow chart of a method for determining a spacecraft orbit based on one-way Doppler according to an embodiment of the present application;

[0024] Figure 2 is a test residual graph of a spacecraft provided according to an embodiment of the present application;

[0025] Figure 3 is a schematic diagram of a spacecraft orbit determination device based on one-way Doppler according to an embodiment of the present application;

[0026] Figure 4 is a schematic diagram of an electronic device provided according to an embodiment of the present application. DETAILED DESCRIPTION

[0027] It should be noted that, in the absence of conflict, the embodiments and features of the embodiments in this application can be combined with each other. The present application will be described in detail below with reference to the accompanying drawings and in combination with the embodiments.

[0028] In order to enable those skilled in the art to better understand the present invention, the following will clearly and completely describe the technical solutions in the embodiments of the present invention in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments in the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts should fall within the scope of protection of this application.

[0029] It should be noted that the terms "first", "second", etc. in the specification and claims of the present application and the above-mentioned drawings are used to distinguish similar objects and are not necessarily used to describe a specific order or sequential order. It should be understood that the data used in this way can be interchanged where appropriate, so that the embodiments of the present application described here. In addition, the terms "including" and "having" and any of their variations are intended to cover non-exclusive inclusions. For example, a process, method, system, product or device that includes a series of steps or units is not necessarily limited to those steps or units clearly listed, but may include other steps or units that are not clearly listed or inherent to these processes, methods, products or devices.

[0030] The present invention will be described below in conjunction with preferred implementation steps. Figure 1 is a flow chart of a method for determining a spacecraft orbit based on one-way Doppler according to an embodiment of the present application, such as Figure 1 As shown, the method includes the following steps:

[0031] Step S101: Establish a first partial derivative model of the receiving frequency of the observation station with respect to the position of the target spacecraft based on a preset integration period and a one-way Doppler velocity measurement equation, and establish a second partial derivative model of the receiving frequency with respect to the transmitting frequency of the target spacecraft based on the one-way Doppler velocity measurement equation.

[0032] Step S102: Solve the first partial derivative model and the second partial derivative model to obtain the position information and launch frequency of the target spacecraft.

[0033] Step S103 , correcting the position information and transmission frequency of the target spacecraft according to the random error and the systematic error to obtain the target position information and the target transmission frequency.

[0034] Step S104: Determine the orbit of the target spacecraft based on the target position information and the target transmission frequency.

[0035] Specifically, the present application proposes a method for determining a spacecraft orbit based on one-way Doppler. One-way Doppler velocity measurement is an economical and effective measurement method in deep space exploration. Its advantage is that it does not require an uplink, and only requires the measurement station to receive the downlink signal transmitted by the satellite. This measurement method saves resource consumption and is easier to achieve deep space measurement at a long distance. First, when measuring velocity through integration, the integration period will be set, which can generally be set to 1s, 10s or 60s. According to the set integration period and the one-way Doppler velocity measurement equation, a first partial derivative model of the receiving frequency of the observation station to the position of the target spacecraft is constructed, and a second partial derivative model of the receiving frequency to the transmitting frequency of the target spacecraft is established through the one-way Doppler velocity measurement equation. Then, the first partial derivative model and the second partial derivative model are solved to obtain the position information and transmitting frequency of the target spacecraft.

[0036] In the specific implementation process, for deep space exploration, the short stable value of 1×10 -12 The ultra-stable oscillator (USO) with a speed of 10 / s provides navigation services that can meet the 1.5km ephemeris reconstruction requirements. To achieve the best Doppler navigation performance, the USO short-term stability must be better than 1×10 -13 / s, therefore, the error of one-way Doppler must be considered. The error terms of one-way Doppler mainly include random error and systematic error.

[0037] Based on the above error factors, the position information and transmission frequency of the target spacecraft are corrected by random error and systematic error to obtain the target position information and target transmission frequency. Finally, the orbit of the target spacecraft is determined based on the target position information and target transmission frequency.

[0038] In summary, a first partial derivative model of the observation station's receiving frequency with respect to the target spacecraft position is constructed based on one-way Doppler, and a second partial derivative model of the receiving frequency with respect to the target spacecraft's transmitting frequency is constructed based on one-way Doppler. The target position information of the target spacecraft and the target transmitting frequency of the target spacecraft are solved by using the first partial derivative model and the second partial derivative model. Finally, the orbit of the target spacecraft is determined based on the target position information and the target transmitting frequency. Determining the orbit of the spacecraft based on one-way Doppler does not require an uplink, and only requires the observation station to receive the downlink signal transmitted by the target spacecraft, thereby improving the computational efficiency of determining the spacecraft orbit.

[0039] In the one-way Doppler-based spacecraft orbit determination method provided in an embodiment of the present application, before establishing a first partial derivative model of the receiving frequency with respect to the target spacecraft position based on a preset integration period and a one-way Doppler velocity measurement equation, the method further includes: establishing a one-way Doppler velocity measurement equation based on the transmitting frequency of the target spacecraft and the receiving frequency of the observation station, wherein the one-way Doppler velocity measurement equation is in the form of: is the radial velocity of the target spacecraft relative to the observation station, f re is the receiving frequency, f s is the emission frequency and c is the speed of light.

[0040] The first partial derivative model is: Among them, r is the position information of the target spacecraft, ρ(t1) and ρ(t2) are the distances of the target spacecraft relative to the observation station at the start and end of the integration, respectively, and ΔT is the integration period.

[0041] The second partial derivative model is: in, is the radial velocity of the target spacecraft relative to the observation station, f re is the receiving frequency, f s is the emission frequency and c is the speed of light.

[0042] The frequency offset thermal noise error is calculated based on the power spectrum density, integration period, and receiving frequency of the downlink signal transmitted by the target spacecraft. The frequency source error is calculated based on the Allan variance of the target spacecraft's oscillator. The system error is calculated based on the frequency error index value of the target spacecraft. The frequency offset thermal noise error is: in, is the power spectrum density of the downlink signal, B L is the unilateral loop bandwidth; the frequency source error is: Among them, C s Indicates the stability of the oscillator, expressed as Allan variance; the system error is: Among them, Δfs is the frequency error index value.

[0043] Specifically, 1. Establish the first partial derivative model of the receiving frequency of the observation station with respect to the position of the target spacecraft.

[0044] The expression of the one-way Doppler velocity measurement equation is shown in formula (1):

[0045]

[0046] in, is the apparent velocity of the spacecraft relative to the observation station, f re is the receiving frequency, f s is the emission frequency and c is the speed of light.

[0047] For integrated Doppler,

[0048] Where ρ(t1) and ρ(t2) are the distances of the spacecraft relative to the observation station at the start and end of the integration, respectively, and ΔT is the preset integration period. Therefore, the first partial derivative model of the receiving frequency with respect to the target spacecraft position is shown in formula (3):

[0049]

[0050] Among them, r is the position information of the target spacecraft.

[0051] It should be noted that when solving the position information of the target spacecraft, the following steps can be used to solve ρ(t1) and ρ(t2). Specifically:

[0052] The calculation of ρ needs to take into account the light travel time iteration. Assuming that the data time stamp is the time when the signal is received, then:

[0053] ρ=|r(t S )-R(t R )| (4)

[0054] R(t R )、r(t S ) represent the station position at the time of signal reception and the detector interpolated ephemeris at the corresponding time of transmission, respectively, where,

[0055]

[0056] When RLT is relativistic light travel, it can be calculated using the following formula:

[0057]

[0058] Where: i represents a celestial body in the solar system, r s / c i represents the distance from the detector to the center of mass of celestial body i, r R i Indicates the distance from the station to the center of mass of celestial body i, μ i is the gravitational constant of celestial body i. In the Mars mission, the influence of the sun is mainly considered. γ is the post-Newtonian parameter, which can generally be set to 1.

[0059] 2. Establish the second partial derivative model of the receiving frequency to the transmitting frequency

[0060] According to formula (1), the second partial derivative model of the receiving frequency to the transmitting frequency can be calculated as:

[0061]

[0062] In summary, by solving the first partial derivative model and the second partial derivative model, the position information and launch frequency of the target spacecraft can be obtained.

[0063] In the specific implementation process, for deep space exploration, the use of an ultra-stable oscillator (USO) with a short stability of 1×10-12 / s to provide navigation services can meet the 1.5km ephemeris reconstruction requirements. To achieve the best Doppler navigation performance, the USO short stability must be better than 1×10-13 / s. Therefore, the one-way Doppler error must be considered. The one-way Doppler error terms mainly include random error and systematic error.

[0064] 1. Random error analysis

[0065] (1) Receiver thermal noise at the observation station

[0066] The carrier phase of the speed measurement signal is affected by the thermal noise of the receiver at the observation station, resulting in random errors. For the second-order phase-locked loop, the frequency deviation thermal noise error It can be expressed as

[0067]

[0068] in, is the power spectrum density of the downlink signal, B L is the bandwidth of the single-sided loop.

[0069] In an optional embodiment, a spacecraft (TW01) uses different modulation schemes for its tracking and control (TT&C) and data transmission modes. In the T&C mode, vestigial sideband modulation is primarily used, while in the data transmission mode, suppressed carrier modulation is primarily used. Different onboard antennas are also used in the different modes. In the T&C mode, high-gain antennas are primarily used for ground communication, while medium-gain antennas are primarily used in the data transmission mode. Furthermore, factors such as modulation index and signal transmission rate cause significant variations in the signal-to-noise ratio (SNR) of the downlink signal. The TW01 unidirectional Doppler signals analyzed by this method are mostly acquired in the T&C mode. Therefore, the velocity measurement error caused by the corresponding receiver thermal noise is approximately ±0.02 mm / s.

[0070] (2) Error introduced by frequency source stability

[0071] For one-way velocity measurement, this error mainly includes the frequency stability of the frequency source on board and the frequency standard source of the ground receiver. Since the ground receiver uses rubidium atomic clocks or hydrogen atomic clocks with high frequency stability, the introduced error is relatively small. Here, the error caused by the frequency stability of the onboard frequency source on the velocity measurement is mainly considered. VF The calculation formula for (that is, the frequency source error mentioned above) is approximately

[0072]

[0073] C s Indicates the stability of the oscillator, expressed as Allan variance.

[0074] In an optional embodiment, due to limitations in volume, mass, and power consumption, the TW01 transmitter uses a high-stable constant-temperature crystal oscillator with a short-term frequency stability of 1×10 -12 / s, and the long-term stability is 1×10 -10 / day. It can be estimated that the velocity measurement error caused by the stability of the onboard frequency source is approximately ±0.3 mm / s.

[0075] 2. System error analysis

[0076] The main difference between one-way Doppler and two-way Doppler is the systematic error caused by frequency accuracy. Since the frequency is directly transmitted by the on-board frequency source, according to formula (7), the frequency offset will cause a systematic error in the Doppler velocity measurement. This systematic error is a nonlinear constant and is proportional to the line-of-sight velocity of the observation station. The corresponding systematic error solution formula is as follows:

[0077]

[0078] In an optional embodiment, due to the poor accuracy of the TW01 satellite-borne signal frequency source, the frequency error index value is ±5×10 -6 The corresponding maximum transmission frequency error is ±42MHz, the maximum speed measurement error is ±150m / s, and the actual measured error is about ±20m / s.

[0079] The position information and transmission frequency of the spacecraft are corrected by the above-mentioned random errors and systematic errors, thereby improving the accuracy of the position information and transmission frequency of the spacecraft.

[0080] The orbit determination method for spacecraft provided in this application has been successfully applied for the first time in deep space exploration missions. The orbit determination was performed using one-way Doppler data from 2021-06-04 to 2021-06-12 for a spacecraft. The orbit determination residual results are as follows: Figure 2 As shown in Figure 1, orbit determination is performed using one-way Doppler data from three deep space stations in Jiamusi, Kashgar, and Argentina. Table 1 shows the orbit determination strategy:

[0081] Table 1 Parameters related to orbit determination calculation

[0082]

[0083] The orbit determination results are statistically analyzed. Table 2 shows the calculated system error, the comparison results with the reference orbit, and the orbit accuracy of the overlapping arc segment. The results show that the orbit determination method of this application can achieve a position accuracy better than 1 km.

[0084] Table 2 One-way Doppler orbit determination results

[0085]

[0086] The embodiment of the present application provides a method for determining a spacecraft orbit based on one-way Doppler, which establishes a first partial derivative model of the receiving frequency of the observation station with respect to the position of the target spacecraft based on a preset integration period and the one-way Doppler velocity measurement equation, and establishes a second partial derivative model of the receiving frequency with respect to the transmitting frequency of the target spacecraft based on the one-way Doppler velocity measurement equation; solves the first partial derivative model and the second partial derivative model to obtain the position information and transmitting frequency of the target spacecraft; corrects the position information and transmitting frequency of the target spacecraft based on random errors and systematic errors to obtain target position information and target transmitting frequency; and determines the orbit of the target spacecraft based on the target position information and target transmitting frequency, thereby solving the problem in related technologies that two-way Doppler cannot be used to determine the orbit of a distant spacecraft. Based on one-way Doppler, a first partial derivative model of the observation station's receiving frequency with respect to the target spacecraft position is constructed. Based on one-way Doppler, a second partial derivative model of the receiving frequency with respect to the target spacecraft's transmitting frequency is constructed. The target position information of the target spacecraft and the target transmitting frequency of the target spacecraft are solved by using the first partial derivative model and the second partial derivative model. Finally, the orbit of the target spacecraft is determined based on the target position information and the target transmitting frequency. Determining the orbit of the spacecraft based on one-way Doppler does not require an uplink. Instead, the observation station only needs to receive the downlink signal transmitted by the target spacecraft, which will not be affected by time delay and the rotation of the earth, thereby achieving the effect of determining the orbit of a distant spacecraft.

[0087] It should be noted that the steps shown in the flowcharts of the accompanying drawings can be executed in a computer system such as a set of computer-executable instructions, and that, although a logical order is shown in the flowcharts, in some cases, the steps shown or described can be executed in an order different from that shown here.

[0088] The present application also provides a one-way Doppler-based spacecraft orbit determination device. It should be noted that the one-way Doppler-based spacecraft orbit determination device of the present application can be used to execute the one-way Doppler-based spacecraft orbit determination method provided in the present application. The following describes the one-way Doppler-based spacecraft orbit determination device provided in the present application.

[0089] Figure 3 Schematic diagram of a spacecraft orbit determination device based on one-way Doppler according to an embodiment of the present application. Figure 3 As shown, the device includes: a first establishing unit 301 , a solving unit 302 , a correcting unit 303 and a determining unit 304 .

[0090] A first establishing unit 301 is configured to establish a first partial derivative model of the receiving frequency of the observation station with respect to the position of the target spacecraft based on a preset integration period and a one-way Doppler velocity measurement equation, and to establish a second partial derivative model of the receiving frequency with respect to the transmitting frequency of the target spacecraft based on the one-way Doppler velocity measurement equation;

[0091] A solving unit 302 is configured to solve the first partial derivative model and the second partial derivative model to obtain the position information of the target spacecraft and the transmission frequency;

[0092] A correction unit 303 is configured to correct the position information of the target spacecraft and the transmission frequency according to random errors and systematic errors to obtain target position information and target transmission frequency;

[0093] The determination unit 304 is configured to determine the orbit of the target spacecraft based on the target position information and the target transmission frequency.

[0094] The one-way Doppler-based spacecraft orbit determination device provided in an embodiment of the present application establishes a first partial derivative model of the observation station's receiving frequency with respect to the target spacecraft position based on a preset integration period and a one-way Doppler velocity measurement equation through a first establishing unit 301, and establishes a second partial derivative model of the receiving frequency with respect to the transmitting frequency of the target spacecraft based on the one-way Doppler velocity measurement equation; a solving unit 302 solves the first partial derivative model and the second partial derivative model to obtain the position information and the transmitting frequency of the target spacecraft; a correction unit 303 corrects the position information and the transmitting frequency of the target spacecraft based on random errors and systematic errors to obtain target position information and target transmitting frequency; a determination unit 304 determines the orbit of the target spacecraft based on the target position information and the target transmitting frequency, thereby solving the problem in the related art that two-way Doppler cannot realize orbit determination of distant spacecraft. Based on one-way Doppler, a first partial derivative model of the observation station's receiving frequency with respect to the target spacecraft position is constructed. Based on one-way Doppler, a second partial derivative model of the receiving frequency with respect to the target spacecraft's transmitting frequency is constructed. The target position information of the target spacecraft and the target transmitting frequency of the target spacecraft are solved by using the first partial derivative model and the second partial derivative model. Finally, the orbit of the target spacecraft is determined based on the target position information and the target transmitting frequency. Determining the orbit of the spacecraft based on one-way Doppler does not require an uplink. Instead, the observation station only needs to receive the downlink signal transmitted by the target spacecraft, which will not be affected by time delay and the rotation of the earth, thereby achieving the effect of determining the orbit of a distant spacecraft.

[0095] Optionally, in the one-way Doppler-based spacecraft orbit determination device provided in an embodiment of the present application, the device further includes: a second establishment unit, configured to establish the one-way Doppler velocity measurement equation based on the transmitting frequency of the target spacecraft and the receiving frequency of the observation station before establishing the first partial derivative model of the receiving frequency with respect to the position of the target spacecraft based on a preset integration period and the one-way Doppler velocity measurement equation, wherein the one-way Doppler velocity measurement equation is in the form of: is the radial velocity of the target spacecraft relative to the observation station, f re is the receiving frequency, f s is the emission frequency, and c is the speed of light.

[0096] Optionally, in the one-way Doppler-based spacecraft orbit determination device provided in an embodiment of the present application, the first partial derivative model is: Where r is the position information of the target spacecraft, ρ(t1) and ρ(t2) are the distances of the target spacecraft relative to the observation station at the integration start time and the integration end time, respectively, and ΔT is the integration period.

[0097] Optionally, in the one-way Doppler-based spacecraft orbit determination device provided in an embodiment of the present application, the second partial derivative model is: in, is the radial velocity of the target spacecraft relative to the observation station, f re is the receiving frequency, f s is the emission frequency, and c is the speed of light.

[0098] Optionally, in the one-way Doppler-based spacecraft orbit determination device provided in an embodiment of the present application, the random error includes at least a frequency deviation thermal noise error and a frequency source error, and the device further includes: a first calculation unit, used to correct the position information and the transmission frequency of the target spacecraft based on the random error and the system error to obtain the target position information and the target transmission frequency, and calculate the frequency deviation thermal noise error based on the power spectral density of the downlink signal transmitted by the target spacecraft, the integration period and the receiving frequency; a second calculation unit, used to calculate the frequency source error based on the Allan variance of the oscillator of the target spacecraft; and a third calculation unit, used to calculate the system error based on the frequency error index value of the target spacecraft.

[0099] Optionally, in the spacecraft orbit determination device based on one-way Doppler provided in an embodiment of the present application, the frequency deviation thermal noise error is: in, is the power spectrum density of the downlink signal, B Lis the unilateral loop bandwidth; the frequency source error is: Among them, C s The stability of the oscillator is expressed as Allan variance; the system error is: Wherein, Δfs is the frequency error index value.

[0100] The one-way Doppler-based spacecraft orbit determination device includes a processor and a memory. The first establishing unit 301, the solving unit 302, the correcting unit 303, and the determining unit 304 are all stored as program units in the memory. The processor executes the program units stored in the memory to implement corresponding functions.

[0101] The processor contains a kernel, which retrieves the corresponding program unit from the memory. There can be one or more kernels, and the spacecraft's orbit can be confirmed by adjusting the kernel parameters.

[0102] The memory may include non-permanent memory in a computer-readable medium, random access memory (RAM) and / or non-volatile memory, such as read-only memory (ROM) or flash RAM, and the memory includes at least one memory chip.

[0103] An embodiment of the present invention provides a processor, which is used to run a program, wherein the program executes the one-way Doppler-based spacecraft orbit determination method when running.

[0104] like Figure 4 As shown, an embodiment of the present invention provides an electronic device, which includes a processor, a memory, and a program stored in the memory and executable on the processor. When the processor executes the program, the following steps are implemented: a first partial derivative model of the receiving frequency of the observation station with respect to the position of the target spacecraft is established based on a preset integration period and a one-way Doppler velocity measurement equation, and a second partial derivative model of the receiving frequency with respect to the transmitting frequency of the target spacecraft is established based on the one-way Doppler velocity measurement equation; the first partial derivative model and the second partial derivative model are solved to obtain the position information and the transmitting frequency of the target spacecraft; the position information and the transmitting frequency of the target spacecraft are corrected based on random errors and systematic errors to obtain target position information and target transmitting frequency; and the orbit of the target spacecraft is determined based on the target position information and the target transmitting frequency.

[0105] Optionally, before establishing a first partial derivative model of the receiving frequency with respect to the position of the target spacecraft based on a preset integration period and a one-way Doppler velocity measurement equation, the method further includes: establishing the one-way Doppler velocity measurement equation based on the transmitting frequency of the target spacecraft and the receiving frequency of the observation station, wherein the one-way Doppler velocity measurement equation is in the form of: is the radial velocity of the target spacecraft relative to the observation station, f re is the receiving frequency, f s is the emission frequency, and c is the speed of light.

[0106] Optionally, the first partial derivative model is:

[0107] Where r is the position information of the target spacecraft, ρ(t1) and ρ(t2) are the distances of the target spacecraft relative to the observation station at the integration start time and the integration end time, respectively, and ΔT is the integration period.

[0108] Optionally, the second partial derivative model is: in, is the radial velocity of the target spacecraft relative to the observation station, f re is the receiving frequency, f s is the emission frequency, and c is the speed of light.

[0109] Optionally, the random error includes at least a frequency deviation thermal noise error and a frequency source error. Before correcting the position information and the transmission frequency of the target spacecraft based on the random error and the system error to obtain the target position information and the target transmission frequency, the method further includes: calculating the frequency deviation thermal noise error based on the power spectral density of the downlink signal transmitted by the target spacecraft, the integration period and the receiving frequency; calculating the frequency source error based on the Allan variance of the oscillator of the target spacecraft; and calculating the system error based on the frequency error index value of the target spacecraft.

[0110] Optionally, the frequency offset thermal noise error is: in, is the power spectrum density of the downlink signal, B L is the unilateral loop bandwidth; the frequency source error is: Among them, C s The stability of the oscillator is expressed as Allan variance; the system error is: Wherein, Δfs is the frequency error index value.

[0111] The devices in this article can be servers, PCs, PADs, mobile phones, etc.

[0112] The present application also provides a computer program product, which, when executed on a data processing device, is suitable for executing an initialized program having the following method steps: establishing a first partial derivative model of the observation station's receiving frequency with respect to the position of the target spacecraft based on a preset integration period and a one-way Doppler velocity measurement equation, and establishing a second partial derivative model of the receiving frequency with respect to the transmitting frequency of the target spacecraft based on the one-way Doppler velocity measurement equation; solving the first partial derivative model and the second partial derivative model to obtain the position information and the transmitting frequency of the target spacecraft; correcting the position information and the transmitting frequency of the target spacecraft based on random errors and systematic errors to obtain target position information and target transmitting frequency; and determining the orbit of the target spacecraft based on the target position information and the target transmitting frequency.

[0113] Optionally, before establishing a first partial derivative model of the receiving frequency with respect to the position of the target spacecraft based on a preset integration period and a one-way Doppler velocity measurement equation, the method further includes: establishing the one-way Doppler velocity measurement equation based on the transmitting frequency of the target spacecraft and the receiving frequency of the observation station, wherein the one-way Doppler velocity measurement equation is in the form of: is the radial velocity of the target spacecraft relative to the observation station, f re is the receiving frequency, f s is the emission frequency, and c is the speed of light.

[0114] Optionally, the first partial derivative model is:

[0115] Where r is the position information of the target spacecraft, ρ(t1) and ρ(t2) are the distances of the target spacecraft relative to the observation station at the integration start time and the integration end time, respectively, and ΔT is the integration period.

[0116] Optionally, the second partial derivative model is: in, is the radial velocity of the target spacecraft relative to the observation station, f re is the receiving frequency, f s is the emission frequency, and c is the speed of light.

[0117] Optionally, the random error includes at least a frequency deviation thermal noise error and a frequency source error. Before correcting the position information and the transmission frequency of the target spacecraft based on the random error and the system error to obtain the target position information and the target transmission frequency, the method further includes: calculating the frequency deviation thermal noise error based on the power spectral density of the downlink signal transmitted by the target spacecraft, the integration period and the receiving frequency; calculating the frequency source error based on the Allan variance of the oscillator of the target spacecraft; and calculating the system error based on the frequency error index value of the target spacecraft.

[0118] Optionally, the frequency offset thermal noise error is: in, is the power spectrum density of the downlink signal, B L is the unilateral loop bandwidth; the frequency source error is: Among them, C s The stability of the oscillator is expressed as Allan variance; the system error is: Wherein, Δfs is the frequency error index value.

[0119] Those skilled in the art will appreciate that the embodiments of the present application can be provided as methods, systems, or computer program products. Therefore, the present application can adopt the form of a complete hardware embodiment, a complete software embodiment, or an embodiment in combination with software and hardware. Moreover, the present application can adopt the form of a computer program product implemented on one or more computer-usable storage media (including but not limited to magnetic disk storage, CD-ROM, optical storage, etc.) that contain computer-usable program code.

[0120] The present application is described with reference to the flowcharts and / or block diagrams of the methods, devices (systems), and computer program products according to the embodiments of the present application. It should be understood that each process and / or box in the flowchart and / or block diagram, as well as the combination of the processes and / or boxes in the flowchart and / or block diagram, can be implemented by computer program instructions. These computer program instructions can be provided to a processor of a general-purpose computer, a special-purpose computer, an embedded processor, or other programmable data processing device to produce a machine, so that the instructions executed by the processor of the computer or other programmable data processing device generate instructions for implementing the steps in the process. Figure 1 a process or multiple processes and / or boxes Figure 1 A device that provides the functions specified in a block or multiple blocks.

[0121] These computer program instructions may also be stored in a computer readable memory that can direct a computer or other programmable data processing device to work in a specific manner, so that the instructions stored in the computer readable memory produce an article of manufacture comprising an instruction device, which implements the process Figure 1 a process or multiple processes and / or boxes Figure 1 The function specified in one or more boxes.

[0122] These computer program instructions can also be loaded onto a computer or other programmable data processing device so that a series of operational steps are executed on the computer or other programmable device to produce a computer-implemented process, thereby providing the instructions executed on the computer or other programmable device for implementing the process. Figure 1 a process or multiple processes and / or boxes Figure 1 A step that specifies a function in one or more boxes.

[0123] In a typical configuration, a computing device includes one or more processors (CPUs), input / output interfaces, network interfaces, and memory.

[0124] The memory may include non-permanent memory in a computer-readable medium, random access memory (RAM) and / or non-volatile memory in the form of read-only memory (ROM) or flash RAM. The memory is an example of a computer-readable medium.

[0125] Computer-readable media includes permanent and non-permanent, removable and non-removable media that can be implemented by any method or technology to store information. The information can be computer-readable instructions, data structures, program modules or other data. Examples of computer storage media include, but are not limited to, phase change memory (PRAM), static random access memory (SRAM), dynamic random access memory (DRAM), other types of random access memory (RAM), read-only memory (ROM), electrically erasable programmable read-only memory (EEPROM), flash memory or other memory technology, compact disc read-only memory (CD-ROM), digital versatile disc (DVD) or other optical storage, magnetic cassettes, magnetic disk storage or other magnetic storage devices or any other non-transmission media that can be used to store information that can be accessed by a computing device. As defined herein, computer-readable media does not include transitory computer-readable media (transitory media), such as modulated data signals and carrier waves.

[0126] It should also be noted that the terms "comprises," "includes," or any other variations thereof are intended to encompass non-exclusive inclusion, such that a process, method, commodity, or apparatus that includes a series of elements includes not only those elements but also other elements not explicitly listed, or includes elements inherent to such process, method, commodity, or apparatus. In the absence of further limitations, an element defined by the phrase "comprises a ..." does not exclude the presence of other identical elements in the process, method, commodity, or apparatus that includes the element.

[0127] Those skilled in the art will appreciate that the embodiments of the present application may be provided as methods, systems, or computer program products. Therefore, the present application may take the form of a complete hardware embodiment, a complete software embodiment, or an embodiment combining software and hardware. Furthermore, the present application may take the form of a computer program product implemented on one or more computer-usable storage media (including but not limited to magnetic disk storage, CD-ROM, optical storage, etc.) containing computer-usable program code.

[0128] The above are merely embodiments of the present application and are not intended to limit the present application. For those skilled in the art, the present application may have various changes and variations. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principles of the present application should all be included within the scope of the claims of the present application.

Claims

1. A method for determining a spacecraft orbit based on one-way Doppler, characterized in that: include: Establishing a first partial derivative model of the receiving frequency of the observation station with respect to the position of the target spacecraft based on a preset integration period and a one-way Doppler velocity measurement equation, and establishing a second partial derivative model of the receiving frequency with respect to the transmitting frequency of the target spacecraft based on the one-way Doppler velocity measurement equation; Among them, the first partial derivative model is: Among them, r is the position information of the target spacecraft, f re is the receiving frequency of the observation station, f s is the launch frequency of the target spacecraft, c is the speed of light, ρ(t1) and ρ(t2) are the distances of the target spacecraft relative to the observation station at the start and end times of integration, respectively. ΔT is the integration period. The distance of the target spacecraft relative to the observation station is calculated using the light travel time iteration algorithm. Solving the first partial derivative model and the second partial derivative model to obtain the position information of the target spacecraft and the launch frequency; Correcting the position information of the target spacecraft and the transmission frequency according to random errors and systematic errors to obtain target position information and target transmission frequency, wherein the random errors include at least frequency offset thermal noise errors and frequency source errors; The orbit of the target spacecraft is determined based on the target position information and the target transmission frequency.

2. The method according to claim 1, characterized in that Before establishing a first partial derivative model of the receiving frequency with respect to the position of the target spacecraft according to a preset integration period and a one-way Doppler velocity measurement equation, the method further includes: The one-way Doppler velocity measurement equation is established based on the transmitting frequency of the target spacecraft and the receiving frequency of the observation station, wherein the one-way Doppler velocity measurement equation is in the form of: is the radial velocity of the target spacecraft relative to the observation station, f re is the receiving frequency, f s is the emission frequency, and c is the speed of light.

3. The method according to claim 1, characterized in that The second partial derivative model is: in, is the radial velocity of the target spacecraft relative to the observation station, f re is the receiving frequency, f s is the emission frequency, and c is the speed of light.

4. The method according to claim 1, wherein Before correcting the position information of the target spacecraft and the transmission frequency based on the random error and the systematic error to obtain the target position information and the target transmission frequency, the method further includes: Calculating the frequency offset thermal noise error based on the power spectral density of the downlink signal transmitted by the target spacecraft, the integration period, and the receiving frequency; Calculating the frequency source error according to the Allan variance of the oscillator of the target spacecraft; The system error is calculated based on the frequency error index value of the target spacecraft.

5. The method according to claim 4, characterized in that The frequency deviation thermal noise error is: in, is the power spectrum density of the downlink signal, B L is the bandwidth of the single-sided loop; The frequency source error is: Among them, C s The stability of the oscillator is expressed in terms of the Allan variance; The systematic error is: Where Δf s is the frequency error index value.

6. A spacecraft orbit determination device based on one-way Doppler, characterized in that: include: a first establishing unit, configured to establish a first partial derivative model of a receiving frequency of the observation station with respect to a target spacecraft position according to a preset integration period and a one-way Doppler velocity measurement equation, and to establish a second partial derivative model of the receiving frequency with respect to a transmitting frequency of the target spacecraft according to the one-way Doppler velocity measurement equation; Among them, the first partial derivative model is: Among them, r is the position information of the target spacecraft, f re is the receiving frequency of the observation station, f s is the launch frequency of the target spacecraft, c is the speed of light, ρ(t1) and ρ(t2) are the distances of the target spacecraft relative to the observation station at the start and end times of integration, respectively. ΔT is the integration period. The distance of the target spacecraft relative to the observation station is calculated using the light travel time iteration algorithm. a solving unit, configured to solve the first partial derivative model and the second partial derivative model to obtain the position information of the target spacecraft and the launch frequency; a correction unit, configured to correct the position information of the target spacecraft and the transmission frequency according to random errors and systematic errors to obtain target position information and target transmission frequency, wherein the random errors include at least frequency offset thermal noise errors and frequency source errors; A determination unit is used to determine the orbit of the target spacecraft based on the target position information and the target transmission frequency.

7. A processor, characterized in that: The processor is configured to run a program, wherein the program, when running, executes the spacecraft orbit determination method based on one-way Doppler according to any one of claims 1 to 5.

8. An electronic device, characterized in that: The method comprises one or more processors and a memory, wherein the memory is used to store one or more programs, wherein when the one or more programs are executed by the one or more processors, the one or more processors implement the one-way Doppler-based spacecraft orbit determination method according to any one of claims 1 to 5.

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