WO2021129068A1 - 一种基于地球gnss和月球导航增强卫星的月球导航系统 - Google Patents

一种基于地球gnss和月球导航增强卫星的月球导航系统 Download PDF

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WO2021129068A1
WO2021129068A1 PCT/CN2020/121447 CN2020121447W WO2021129068A1 WO 2021129068 A1 WO2021129068 A1 WO 2021129068A1 CN 2020121447 W CN2020121447 W CN 2020121447W WO 2021129068 A1 WO2021129068 A1 WO 2021129068A1
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lunar
navigation
satellite
enhancement
gnss
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PCT/CN2020/121447
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English (en)
French (fr)
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蒙艳松
张中英
同钊
张蓬
王登峰
边朗
王延光
徐连军
雷文英
贾萌娜
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西安空间无线电技术研究所
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Priority to EP20906855.0A priority Critical patent/EP4080165A4/en
Publication of WO2021129068A1 publication Critical patent/WO2021129068A1/zh

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    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01C—MEASURING DISTANCES, LEVELS OR BEARINGS; SURVEYING; NAVIGATION; GYROSCOPIC INSTRUMENTS; PHOTOGRAMMETRY OR VIDEOGRAMMETRY
    • G01C21/00—Navigation; Navigational instruments not provided for in groups G01C1/00 - G01C19/00
    • G01C21/24—Navigation; Navigational instruments not provided for in groups G01C1/00 - G01C19/00 specially adapted for cosmonautical navigation
    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01C—MEASURING DISTANCES, LEVELS OR BEARINGS; SURVEYING; NAVIGATION; GYROSCOPIC INSTRUMENTS; PHOTOGRAMMETRY OR VIDEOGRAMMETRY
    • G01C21/00—Navigation; Navigational instruments not provided for in groups G01C1/00 - G01C19/00
    • G01C21/02—Navigation; Navigational instruments not provided for in groups G01C1/00 - G01C19/00 by astronomical means
    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01S—RADIO DIRECTION-FINDING; RADIO NAVIGATION; DETERMINING DISTANCE OR VELOCITY BY USE OF RADIO WAVES; LOCATING OR PRESENCE-DETECTING BY USE OF THE REFLECTION OR RERADIATION OF RADIO WAVES; ANALOGOUS ARRANGEMENTS USING OTHER WAVES
    • G01S13/00—Systems using the reflection or reradiation of radio waves, e.g. radar systems; Analogous systems using reflection or reradiation of waves whose nature or wavelength is irrelevant or unspecified
    • G01S13/74—Systems using reradiation of radio waves, e.g. secondary radar systems; Analogous systems
    • G01S13/76—Systems using reradiation of radio waves, e.g. secondary radar systems; Analogous systems wherein pulse-type signals are transmitted
    • G01S13/765—Systems using reradiation of radio waves, e.g. secondary radar systems; Analogous systems wherein pulse-type signals are transmitted with exchange of information between interrogator and responder
    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01S—RADIO DIRECTION-FINDING; RADIO NAVIGATION; DETERMINING DISTANCE OR VELOCITY BY USE OF RADIO WAVES; LOCATING OR PRESENCE-DETECTING BY USE OF THE REFLECTION OR RERADIATION OF RADIO WAVES; ANALOGOUS ARRANGEMENTS USING OTHER WAVES
    • G01S19/00—Satellite radio beacon positioning systems; Determining position, velocity or attitude using signals transmitted by such systems
    • G01S19/01—Satellite radio beacon positioning systems transmitting time-stamped messages, e.g. GPS [Global Positioning System], GLONASS [Global Orbiting Navigation Satellite System] or GALILEO
    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01S—RADIO DIRECTION-FINDING; RADIO NAVIGATION; DETERMINING DISTANCE OR VELOCITY BY USE OF RADIO WAVES; LOCATING OR PRESENCE-DETECTING BY USE OF THE REFLECTION OR RERADIATION OF RADIO WAVES; ANALOGOUS ARRANGEMENTS USING OTHER WAVES
    • G01S19/00—Satellite radio beacon positioning systems; Determining position, velocity or attitude using signals transmitted by such systems
    • G01S19/01—Satellite radio beacon positioning systems transmitting time-stamped messages, e.g. GPS [Global Positioning System], GLONASS [Global Orbiting Navigation Satellite System] or GALILEO
    • G01S19/03—Cooperating elements; Interaction or communication between different cooperating elements or between cooperating elements and receivers
    • G01S19/10—Cooperating elements; Interaction or communication between different cooperating elements or between cooperating elements and receivers providing dedicated supplementary positioning signals
    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01S—RADIO DIRECTION-FINDING; RADIO NAVIGATION; DETERMINING DISTANCE OR VELOCITY BY USE OF RADIO WAVES; LOCATING OR PRESENCE-DETECTING BY USE OF THE REFLECTION OR RERADIATION OF RADIO WAVES; ANALOGOUS ARRANGEMENTS USING OTHER WAVES
    • G01S19/00—Satellite radio beacon positioning systems; Determining position, velocity or attitude using signals transmitted by such systems
    • G01S19/01—Satellite radio beacon positioning systems transmitting time-stamped messages, e.g. GPS [Global Positioning System], GLONASS [Global Orbiting Navigation Satellite System] or GALILEO
    • G01S19/13—Receivers
    • G01S19/14—Receivers specially adapted for specific applications
    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01S—RADIO DIRECTION-FINDING; RADIO NAVIGATION; DETERMINING DISTANCE OR VELOCITY BY USE OF RADIO WAVES; LOCATING OR PRESENCE-DETECTING BY USE OF THE REFLECTION OR RERADIATION OF RADIO WAVES; ANALOGOUS ARRANGEMENTS USING OTHER WAVES
    • G01S19/00—Satellite radio beacon positioning systems; Determining position, velocity or attitude using signals transmitted by such systems
    • G01S19/38—Determining a navigation solution using signals transmitted by a satellite radio beacon positioning system
    • G01S19/39—Determining a navigation solution using signals transmitted by a satellite radio beacon positioning system the satellite radio beacon positioning system transmitting time-stamped messages, e.g. GPS [Global Positioning System], GLONASS [Global Orbiting Navigation Satellite System] or GALILEO
    • G01S19/42—Determining position
    • G01S19/45—Determining position by combining measurements of signals from the satellite radio beacon positioning system with a supplementary measurement
    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01S—RADIO DIRECTION-FINDING; RADIO NAVIGATION; DETERMINING DISTANCE OR VELOCITY BY USE OF RADIO WAVES; LOCATING OR PRESENCE-DETECTING BY USE OF THE REFLECTION OR RERADIATION OF RADIO WAVES; ANALOGOUS ARRANGEMENTS USING OTHER WAVES
    • G01S19/00—Satellite radio beacon positioning systems; Determining position, velocity or attitude using signals transmitted by such systems
    • G01S19/38—Determining a navigation solution using signals transmitted by a satellite radio beacon positioning system
    • G01S19/39—Determining a navigation solution using signals transmitted by a satellite radio beacon positioning system the satellite radio beacon positioning system transmitting time-stamped messages, e.g. GPS [Global Positioning System], GLONASS [Global Orbiting Navigation Satellite System] or GALILEO
    • G01S19/42—Determining position
    • G01S19/45—Determining position by combining measurements of signals from the satellite radio beacon positioning system with a supplementary measurement
    • G01S19/46—Determining position by combining measurements of signals from the satellite radio beacon positioning system with a supplementary measurement the supplementary measurement being of a radio-wave signal type

Definitions

  • the invention relates to a lunar navigation system based on earth GNSS and lunar navigation enhanced satellites, belonging to the technical field of navigation.
  • the follow-up mission of lunar exploration has changed from “focusing on science and engineering technology” to “focusing on scientific research and resource application”. This goal is for lunar users in application scenarios such as circumnavigation, lunar landing and ascent, lunar movement and walking.
  • the autonomy, real-time, and navigation accuracy of Chinese navigation put forward higher requirements.
  • the navigation technology for lunar exploration missions has major limitations in terms of autonomy, real-time performance and positioning accuracy.
  • the GNSS system uses ranging and timing to achieve space-based radio positioning, navigation and timing (PNT) functions, which can provide ground and low-orbit users with all-weather accurate three-dimensional position, three-dimensional speed and time information.
  • PNT radio positioning, navigation and timing
  • the GNSS system is mainly designed for ground or low-altitude users, it can realize real-time positioning and time synchronization of lunar users by receiving GNSS leakage signals.
  • domestic and foreign research institutions have carried out research on the application of GNSS to autonomous lunar navigation.
  • the difficulty of applying GNSS to lunar navigation lies in the fact that the space between the earth and the moon is long, the link attenuation is large, and lunar users mainly receive GNSS sidelobe signals, so the usable GNSS signal strength is extremely low; GNSS satellites are mainly concentrated on the moon users’ sky In the top area, the spatial distribution is extremely poor compared to the observation geometry of the lunar user, causing a large positioning error.
  • the technical problem solved by the present invention is to overcome the shortcomings of the prior art and provide a lunar navigation system based on earth GNSS and lunar navigation augmented satellites, which can be used in many applications such as circumnavigation, lunar landing and ascent, and lunar movement and walking.
  • the scene provides real-time positioning information for lunar users to meet the high autonomy, real-time and high-precision navigation requirements of lunar exploration follow-up missions. At the same time, it provides medium and low-speed two-way communication services for multiple lunar space users.
  • the technical solution of the present invention is: a lunar navigation system based on earth GNSS and lunar navigation enhancement satellites, including earth GNSS navigation constellations, ground deep space stations, lunar navigation enhancement satellites and lunar users;
  • the lunar navigation enhanced satellite is a satellite node with stable orbit and position and capable of transmitting measurement signals
  • the lunar users include lunar orbiters, lunar landers, lunar patrol vehicles, and lunar probes and astronauts that need to determine position coordinates;
  • the lunar navigation enhancement satellite is loaded with an orbit determination load for receiving the GNSS navigation signal of the earth GNSS navigation constellation, using pseudo code ranging to realize the pseudo-range measurement between the earth GNSS navigation constellation and the lunar navigation enhancement satellite, and realize the initial positioning and Timing; At the same time, it establishes a two-way measurement communication link with the ground deep space station or the inter-satellite link of the Earth GNSS navigation constellation, adopts two-way time comparison to realize the clock difference measurement between the Earth GNSS navigation constellation and the lunar navigation enhancement satellite, and receives the ground depth
  • the GNSS ephemeris injected by the space station is filtered according to the pseudo-range measurement, clock error measurement, GNSS ephemeris and the lunar navigation enhanced satellite orbit dynamics model to achieve orbit determination of the lunar navigation enhanced satellite; and generated by the loaded navigation signal generation module It also broadcasts and broadcasts lunar navigation signals with measurement functions, and modulates the ephemeris of the Earth GNSS navigation constellation and lunar navigation augmented satellites on the lunar navigation
  • the lunar user is equipped with a navigation terminal, which realizes absolute position determination by receiving GNSS navigation signals and lunar navigation signals.
  • the absolute position determination is achieved through the earth GNSS navigation constellation and the lunar navigation enhancement satellite
  • the specific method is: the moon user passively receives the navigation signal of no less than four satellites in the earth GNSS navigation constellation and the lunar navigation enhancement satellite through the navigation terminal, Obtain the pseudo-range measurement value with each navigation satellite, calculate the position coordinates of the moon user, and realize the four-satellite passive real-time positioning.
  • the absolute position determination is achieved through the earth GNSS navigation constellation and the lunar navigation enhancement satellite
  • the specific method is: the lunar user passively receives the GNSS navigation signal of the earth GNSS constellation through the navigation terminal, and conducts two-way measurement communication with the lunar navigation enhancement satellite.
  • the lunar radio beacon also includes a lunar radio beacon; the lunar radio beacon is located at a preset position on the lunar surface, and is loaded with a lunar beacon navigation signal generating module to generate and broadcast a lunar beacon with a measurement function Navigation signals, and time synchronization with the lunar navigation enhancement satellites, the lunar user simultaneously receives the lunar beacon, the earth GNSS navigation constellation and the lunar navigation enhancement satellite navigation signals of no less than three satellites to achieve the lunar preset location coverage area The navigation and positioning of lunar users have been enhanced.
  • the preset position is a position on the lunar surface that can meet the coverage of the arc segment of the lunar cycle, the rising phase of the lander's moon landing, and the area of the lunar surface activity demand.
  • the time synchronization between the lunar surface radio beacon and the lunar navigation augmented satellite is specific to: establishing a two-way measurement communication link between the lunar surface radio beacon and the lunar navigation augmented satellite, or establishing a two-way measurement with a lunar user
  • the communication link realizes the time synchronization between the lunar navigation enhancement satellite and the lunar user, and between the lunar user and the lunar radio beacon.
  • a two-way data transmission link is formed between the ground deep-space station or the earth GNSS navigation constellation and the lunar navigation enhanced satellite, and between the lunar navigation enhanced satellite and the lunar user, so as to realize the ground connection with the lunar navigation enhanced satellite as the relay.
  • the multiple access mode of the two-way data communication adopts a time division multiple access mode, and the time slot polling period is smaller than the relevant period of the direct sequence spread spectrum signal despreading used for measurement.
  • the lunar navigation enhancement satellite is provided with an atomic clock, which is used to keep the lunar navigation enhancement satellite timekeeping in the time interval of two two-way time comparisons, and to keep the time synchronization between the lunar navigation enhancement satellite and the earth GNSS navigation constellation .
  • the lunar navigation augmentation satellite is an orbiter that runs on the Earth-Moon Lagrangian point or a specific orbit of the moon, or a lander that lands on the lunar surface.
  • the present invention proposes a lunar navigation system based on the earth GNSS and lunar navigation enhancement satellites.
  • a small number (1 or more) satellites at the Earth-Moon Lagrangian point or the lunar orbit broadcasting navigation signals with measurement functions, and jointly Earth GNSS improves the observation geometry of lunar users;
  • two-way time synchronization links between ground deep-space stations or GNSS navigation constellations and lunar navigation enhancement satellites, and between lunar navigation enhancement satellites and lunar users are established to resolve user receiver clock errors and Radial distance errors cannot be decoupled, and GNSS navigation messages are forwarded to improve the real-time positioning accuracy of lunar users.
  • lunar radio beacons will be added to key areas of the moon to broadcast navigation signals with measurement functions to enhance regional navigation performance.
  • the ascender and the lunar orbiter can be located in real time with high precision, while the lunar navigation enhances the satellite orbit position to be high, and the visibility of the lunar aircraft is good, thereby providing both The rendezvous and docking provides ultra-long-range precise guidance;
  • the two-way link between the ground deep space station or the GNSS navigation constellation and the lunar navigation enhancement satellite, and between the lunar navigation enhancement satellite and the lunar user can be used for data transmission, so as to realize the function of two-way communication at medium and low speeds.
  • Figure 1 is a schematic diagram of the precise orbit determination scheme of the lunar navigation augmented satellite of the present invention
  • FIG. 2 is a schematic diagram of the lunar navigation system of the present invention.
  • FIG. 3 is a schematic diagram of the lunar navigation enhancement scheme of the present invention.
  • FIG. 4 is a schematic diagram of the lunar medium and low speed communication scheme of the present invention.
  • a lunar navigation system based on earth GNSS and lunar navigation augmented satellites adopts the "Earth GNSS + lunar navigation augmented satellite" joint real-time navigation and positioning technology solution, and lunar users simultaneously receive navigation broadcast by GNSS and lunar navigation augmented satellites.
  • Signal real-time four-star passive positioning or three-star active positioning.
  • the user observes the geometry to improve the accuracy of real-time positioning.
  • the lunar user uses the lunar navigation enhanced satellite as a relay to carry out medium and low-speed data communication between the lunar user and the ground and lunar users through the two-way data transmission link with the lunar navigation enhancement satellite.
  • the lunar navigation system based on the earth GNSS and the lunar navigation augmentation satellite includes the following parts:
  • Nodes that include orbiters, such as orbiters operating on the Earth-Moon Lagrangian points or specific orbits of the Moon, or landers landing on the lunar surface, with stable positions and the ability to transmit measurement signals.
  • orbiters such as orbiters operating on the Earth-Moon Lagrangian points or specific orbits of the Moon, or landers landing on the lunar surface, with stable positions and the ability to transmit measurement signals.
  • the lunar orbit is arranged on the lunar orbit, loaded with a precise orbit determination load, and receives earth GNSS navigation signals to realize initial positioning and timing.
  • the ground deep space station or the GNSS navigation constellation inter-satellite link is used to establish a two-way measurement communication link, and the distance and the clock error are decoupled through two-way high-precision measurement, and within the interval of two two-way comparison measurements, relying on miniaturization
  • the atomic clock performs short-term punctuality.
  • the time synchronization between the earth GNSS constellation and the lunar navigation enhancement satellite solves the coupling of the radial error and clock error of the navigation star positioning, and improves the accuracy of the output pseudorange and velocity observations.
  • the orbital dynamics model it can perform long-term (such as 24 hours) orbit filtering for orbit determination to improve orbit determination accuracy.
  • Lunar users including lunar orbiters, lunar landers, lunar patrol vehicles, and lunar probes and astronauts who need to determine position coordinates.
  • the lunar user is equipped with a navigation terminal, which realizes absolute position determination by receiving GNSS navigation signals and lunar navigation signals.
  • the lunar navigation augmented satellite loads navigation payloads, broadcasts and transmits navigation signals with measurement functions, and modulates the earth GNSS and the lunar navigation augmented satellite ephemeris on the signals; the lunar user loads the earth and the moon in real time
  • the navigation terminal simultaneously receives the navigation signals broadcast by the earth GNSS and lunar navigation enhancement satellites.
  • lunar users are equipped with high-sensitivity navigation receivers and support two positioning modes: 1) One-way measurement, that is, lunar users passively receive signals from the earth’s GNSS and lunar navigation enhancement satellites to achieve four-satellite passive real-time positioning; 2) two-way Measurement, the lunar user passively receives the earth GNSS navigation signal, and conducts active two-way measurement with the lunar navigation enhancement satellite, and the time synchronization between the real earth GNSS navigation constellation and the lunar navigation enhancement satellite, and between the lunar navigation enhancement satellite and the lunar user, The user directly realizes the clock error calculation, and no less than three satellites can realize real-time positioning, which reduces the number of satellite observations, further improves the observation PDOP, and improves the positioning accuracy;
  • a lunar radio beacon is laid in a key navigation area on the moon, and the beacon is equipped with an antenna, transceiver, and time-frequency generation unit to generate and broadcast radio beacon navigation signals, and Time synchronization with lunar navigation enhancement satellites.
  • the laying position of the beacon is required to meet the long-term coverage of the key areas, and the earth GNSS and lunar navigation enhancement satellites are combined to improve the navigation and positioning accuracy of the key areas on the moon.
  • the time synchronization with the lunar navigation enhanced satellite supports two time synchronization methods: 1) directly establish a two-way measurement link with the lunar navigation enhanced satellite; 2) establish a two-way measurement link with the lunar user to realize the lunar navigation enhanced satellite, Time synchronization between lunar users and lunar radio beacons.
  • Lunar radio beacons broadcast navigation signals with measurement functions, increase the number of pseudolites, and combine earth GNSS, lunar navigation enhancement satellites and lunar radio beacons to improve user observation geometry and further enhance navigation and positioning accuracy in key areas.
  • the lunar navigation enhancement satellite adopts a wide-beam antenna to cover the lunar surface and its adjacent space; the lunar user configures a multi-beam agile scanning antenna, and the lunar user establishes a two-way data link with the navigation enhancement satellite , To achieve two-way data communication between the ground and lunar users, and between lunar users with lunar navigation enhancement satellites as relays.
  • time division multiple access is used to support two-way measurement and communication between the lunar navigation enhancement satellite and multiple users.
  • Time division multiple access uses chip-level time slot widths to quickly rotate between different users.
  • the polling period 100ns ⁇ 10ms
  • the relevant period of the despreading of the navigation direct sequence spread spectrum signal is much smaller than the relevant period of the despreading of the navigation direct sequence spread spectrum signal. The user can realize continuous tracking measurement by simple processing, which can be equivalent to a continuous navigation signal.

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  • Engineering & Computer Science (AREA)
  • Radar, Positioning & Navigation (AREA)
  • Remote Sensing (AREA)
  • Physics & Mathematics (AREA)
  • General Physics & Mathematics (AREA)
  • Computer Networks & Wireless Communication (AREA)
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  • Automation & Control Theory (AREA)
  • Position Fixing By Use Of Radio Waves (AREA)

Abstract

一种基于地球GNSS和月球导航增强卫星的月球导航系统，属于导航技术领域。通过在地月拉格朗日点或月球轨道增加少量(1颗或多颗)卫星，播发具有测量功能的导航信号，联合地球GNSS改善月球用户的观测几何；同时建立地面深空站或者GNSS导航星座与月球导航增强卫星之间、月球导航增强卫星与月球用户之间的双向时间同步链路，解决用户接收机钟差和径向距离误差无法解耦的问题，提升月球用户实时定位精度。同时在月球重点区域增加月面无线电信标，播发具有测量功能的导航信号，进行区域导航性能增强。在增加少量月球导航资源的基础上，能够大幅度提升月球用户导航定位的实时性与精度，并提供地面与月球用户、月球用户之间的中低速双向通信。

Description

一种基于地球GNSS和月球导航增强卫星的月球导航系统
本申请要求于2019年12月26日提交中国专利局、申请号为201911368874.1、发明名称为“一种基于地球GNSS和月球导航星的月球导航系统”的中国专利申请的优先权，其全部内容通过引用结合在本申请中。
技术领域
本发明涉及一种基于地球GNSS和月球导航增强卫星的月球导航系统，属于导航技术领域。
背景技术
月球探测后续任务已经从“以科学与工程技术为重点”转变为“以科学研究与资源应用为重点”，该目标对月球用户在环月、月球着陆及上升、月面移动及行走等应用场景中导航的自主性、实时性、导航精度提出了更高的要求。目前月球探测任务的导航技术手段在自主性、实时性及定位精度方面存在较大局限。
GNSS系统利用测距和计时实现天基无线电定位、导航和授时(PNT)功能，能够为地面及低轨用户提供全天候的精确三维位置、三维速度和时间信息。虽然GNSS系统主要针对地面或低空用户设计，但可以通过接收GNSS漏信号实现对月球用户实时定位和时间同步，目前国内外研究机构已经开展了GNSS应用于月球自主导航的研究。
将GNSS应用于月球导航的难点在于：地月空间距离远、链路衰减大，且月球用户主要接收GNSS旁瓣信号，因此可使用的GNSS信号强度极低；GNSS卫星主要集中于月球用户的天顶区域，空间分布相对于月球用户的观测几何极差，造成较大的定位误差。
发明内容
本发明解决的技术问题是：克服现有技术的不足，提供了一种基于地球GNSS和月球导航增强卫星的月球导航系统，可以在环月、月球着陆及上升、月面移动行走等多个应用场景中为月球用户提供实时定位信息，满足月球探测后续任务的高自主性、实时性及高精度导航需求，同时为月球空间多用户提供中低速双向通信服务。
本发明的技术解决方案是：一种基于地球GNSS和月球导航增强卫星的月球导航系统，包括地球GNSS导航星座、地面深空站、月球导航增强卫星和月球用户；
所述月球导航增强卫星为轨道和位置稳定且具备发射测量信号功能的卫星节点；
所述月球用户包括环月轨道器、月面着陆器、月面巡视车和需要确定位置坐标的月球探测器及宇航员；
所述月球导航增强卫星上装载定轨载荷，用于接收地球GNSS导航星座的GNSS导航信号，利用伪码测距实现地球GNSS导航星座与月球导航增强卫星之间的伪距测量，实现初始定位和授时；同时与地面深空站或地球GNSS导航星座星间链路建立双向测量通信链路，采用双向时间比对实现地球GNSS导航星座与月球导航增强卫星之间的钟差测量，并接收地面深空站注入的GNSS星历，根据伪距测量、钟差测量和GNSS星历以及月球导航增强卫星轨道动力学模型进行轨道滤波实现月球导航增强卫星定轨；并通过装载的导航信号生成模块，生成并播发与具有测量功能的月球导航信号，并在所述月球导航信号上调制地球GNSS导航星座与月球导航增强卫星的星历，用于月球用户导航定位解算；
所述月球用户上装载有导航终端，通过接收GNSS导航信号和月球导航信号实现绝对位置确定。
进一步地，通过地球GNSS导航星座和月球导航增强卫星实现绝对位置确 定，具体的方法为：月球用户通过导航终端无源接收地球GNSS导航星座和月球导航增强卫星中不小于四颗卫星的导航信号，获得与各颗导航卫星的伪距测量值，解算出月球用户的位置坐标，实现四星无源实时定位。
进一步地，通过地球GNSS导航星座和月球导航增强卫星实现绝对位置确定，具体的方法为：月球用户通过导航终端无源接收地球GNSS星座的GNSS导航信号，并与月球导航增强卫星进行双向测量通信，获得与地球GNSS星座和月球导航增强卫星中不小于三颗卫星的伪距测量值，并通过地球GNSS导航星座与月球导航增强卫星之间，以及月球导航增强卫星与月球用户之间的时间同步，实现月球用户的钟差解算，完成月球用户实时定位。
进一步地，还包括月面无线电信标；所述月面无线电信标位于月球表面预设位置处，其上装载有月面信标导航信号生成模块，生成并播发具有测量功能的月面信标导航信号，并与月球导航增强卫星之间进行时间同步，月球用户同时接收月面信标、地球GNSS导航星座和月球导航增强卫星中不小于三颗卫星的导航信号，实现月球预设位置覆盖区域的月球用户的导航定位增强。
进一步地，所述预设位置为能够满足对环月需求弧段、着陆器落月上升阶段及月面活动需求区域的覆盖的月面位置。
进一步地，所述月面无线电信标与月球导航增强卫星之间进行时间同步，其具体方法为：月面无线电信标与月球导航增强卫星建立双向测量通信链路，或与月球用户建立双向测量通信链路，实现月球导航增强卫星与月球用户之间、月球用户与月面无线电信标之间的时间同步。
进一步地，所述地面深空站或地球GNSS导航星座与月球导航增强卫星之间、月球导航增强卫星与月球用户之间构成双向数据传输链路，实现以月球导航增强卫星为中继的地面与月球用户之间以及月球用户与月球用户之间的中低速双向数据通信。
进一步地，所述双向数据通信的多址方式采用时分多址方式，时隙轮询周期小于用于测量的直接序列扩频信号解扩的相关周期。
进一步地，所述月球导航增强卫星上设有原子钟，用于两次双向时间比对的时间间隔中对月球导航增强卫星进行守时，保持月球导航增强卫星与地球GNSS导航星座之间的时间同步。
进一步地，所述月球导航增强卫星为运行在地月拉格朗日点或月球特定轨道上的环绕器或着陆于月面的着陆器。
本发明与现有技术相比的优点在于：
本发明提出一种基于地球GNSS和月球导航增强卫星的月球导航系统，通过在地月拉格朗日点或月球轨道增加少量(1颗或多颗)卫星，播发具有测量功能的导航信号，联合地球GNSS改善月球用户的观测几何；同时建立地面深空站或者GNSS导航星座与月球导航增强卫星之间、月球导航增强卫星与月球用户之间的双向时间同步链路，解决用户接收机钟差和径向距离误差无法解耦的问题，并转发GNSS导航电文，提升月球用户实时定位精度。同时在月球重点区域增加月面无线电信标，播发具有测量功能的导航信号，进行区域导航性能增强。在增加少量月球导航资源的基础上，能够大幅度提升月球用户导航定位的实时性与精度，为绕月飞行、定点着陆返回、月面巡视提供实时的高精度导航服务，支持紧急情况下的随时机动，并提供地面与月球用户、月球用户之间的中低速双向通信功能。具体如下：
1)实现了环月阶段月球用户的高精度实时定位，为紧急情况下的变轨、应急处置提供有力支撑；
2)在月球着陆阶段，可以为着陆器提供高精度导航定位服务，为月球后续“定点落月”任务提供保障；
3)在月面上升及快速自主交会阶段，可以实时对上升器和环月轨道器进行高精度实时定位，同时月球导航增强卫星轨道位置高，对环月飞行器可视性好，从而为两者的交会对接提供超远程精确引导；
4)能够为巡视车及宇航员月面移动行走提供实时高精度位置信息，为月球原位科学研究、资源勘察和应用验证等任务提供支撑；
5)可利用地面深空站或者GNSS导航星座与月球导航增强卫星之间、月球导航增强卫星与月球用户之间的双向链路进行数据传输，实现中低速双向通信功能。
附图说明
图1是本发明的月球导航增强卫星精密定轨方案示意图；
图2是本发明的月球导航系统方案示意图；
图3是本发明的月球导航增强方案示意图；
图4是本发明的月球中低速通信方案示意图。
具体实施方式
为了更好的理解上述技术方案，下面通过附图以及具体实施例对本申请技术方案做详细的说明，应当理解本申请实施例以及实施例中的具体特征是对本申请技术方案的详细的说明，而不是对本申请技术方案的限定，在不冲突的情况下，本申请实施例以及实施例中的技术特征可以相互组合。
以下结合说明书附图对本申请实施例所提供的一种基于地球GNSS和月球导航增强卫星的月球导航系统做进一步详细的说明。
如图1～4，一种基于地球GNSS和月球导航增强卫星的月球导航系统，采用“地球GNSS+月球导航增强卫星”联合实时导航定位技术方案，月球用户同时接收GNSS与月球导航增强卫星播发的导航信号，进行实时四星无源定位或三星有源定位。同时建立地面深空站或者地球GNSS导航星座与月球导航增强卫星之间、月球导航增强卫星与月球用户之间的时间同步链路，并在重点区域采用月面无线电信标导航增强方法，进一步改善用户观测几何，提高实时定位的精度。月球用户通过与月球导航增强卫星之间的双向数据传输链路，以月球导航增强卫星为中继进行月球用户与地面、月球用户之间的中低速数据通信。
在本申请实施例提供的技术方案中，基于地球GNSS和月球导航增强卫星的月球导航系统包括以下部分：
月球导航增强卫星：包括运行在地月拉格朗日点或月球特定轨道上的环绕 器或着陆于月面的着陆器等轨道、位置稳定且具备发射测量信号功能的节点。
进一步，布置在月球轨道上，装载有精密定轨载荷，接收地球GNSS导航信号，实现初始定位和授时。同时利用地面深空站或者GNSS导航星座星间链路建立双向测量通信链路，通过双向高精度测量将距离与钟差进行解耦，并在两次双向比对测量的间隔内，依靠小型化原子钟进行短期守时。地球GNSS星座与月球导航增强卫星的时间同步，解决了导航星定位径向误差与钟差的耦合，提升了输出伪距、速度观测量的精度。并结合轨道动力学模型，进行长时间(如24小时)的轨道滤波定轨，提升定轨精度。
月球用户：包括环月轨道器、月面着陆器、月面巡视车和需要确定位置坐标的月球探测器及宇航员。
进一步，月球用户上装载有导航终端，通过接收GNSS导航信号和月球导航信号实现绝对位置确定。
具体的，在一种可能实现的方式中，月球导航增强卫星装载导航载荷，播发与具有测量功能的导航信号，并在信号上调制地球GNSS与月球导航增强卫星星历；月球用户装载地月实时导航终端，同时接收地球GNSS与月球导航增强卫星播发的导航信号。
进一步，月球用户装载高灵敏度导航接收机，并支持两种定位模式：1)单向测量，即月球用户无源接收地球GNSS和月球导航增强卫星信号，实现四星无源实时定位；2)双向测量，月球用户无源接收地球GNSS导航信号，并与月球导航增强卫星进行有源双向测量，实地球GNSS导航星座与月球导航增强卫星之间、月球导航增强卫星与月球用户之间的时间同步，用户直接实现钟差解算，不少于三颗卫星即可实现实时定位，降低卫星观测数目需求，进一步改善观测PDOP，提升定位精度；
具体的，在一种可能实现的方式中，在月球重点导航区域铺设月面无线电信标，信标配置天线、收发信机和时频生成单元，用于生成和播发无线电信标导航信号，并与月球导航增强卫星之间进行时间同步。信标铺设位置要求满足 重点区域的长时间覆盖，联合地球GNSS、月球导航增强卫星提升月球重点区域的导航定位精度。
进一步，与月球导航增强卫星之间的时间同步支持两种时间同步方式：1)直接与月球导航增强卫星建立双向测量链路；2)与月球用户建立双向测量链路，实现月球导航增强卫星、月球用户、月面无线电信标三者之间的时间同步。月面无线电信标播发具有测量功能的导航信号，增加伪卫星数目，联合地球GNSS、月球导航增强卫星和月面无线电信标，改善用户观测几何，进一步提升重点区域的导航定位精度。
利用地面深空站或者GNSS导航星座、月球导航增强卫星与月球用户之间的双向链路，双向链路具备测量及低速率数据通信功能，以月球导航增强卫星为中继，提供地球与月球用户之间及月球空间多用户之间超远程超视距的数据通信，支撑航天器指控、远程交会对接等任务。
具体的，在一种可能实现的方式中，月球导航增强卫星采用宽波束天线，覆盖月球表面及其邻近空间；月球用户配置多波束捷变扫描天线，月球用户与导航增强卫星建立双向数据链路，实现以月球导航增强卫星为中继的地面与月球用户之间、月球用户之间的双向数据通信。
具体的，在一种可能实现的方式中，采用时分多址方式支持月球导航增强卫星与多用户之间的双向测量及通信，时分多址采用码片级时隙宽度，在不同用户间快速轮询切换，用户间轮询周期(100ns～10ms)远小于导航直接序列扩频信号解扩的相关周期，用户简单处理即可实现连续跟踪测量，可以等效为连续导航信号。
显然，本领域的技术人员可以对本申请进行各种改动和变型而不脱离本申请的精神和范围。这样，倘若本申请的这些修改和变型属于本申请权利要求及其等同技术的范围之内，则本申请也意图包含这些改动和变型在内。
本发明说明书中未作详细描述的内容属本领域技术人员的公知技术。

Claims (10)

  1. 一种基于地球GNSS和月球导航增强卫星的月球导航系统，其特征在于：包括地球GNSS导航星座、地面深空站、月球导航增强卫星和月球用户；
    所述月球导航增强卫星为轨道和位置稳定且具备发射测量信号功能的卫星节点；
    所述月球用户包括环月轨道器、月面着陆器、月面巡视车和需要确定位置坐标的月球探测器及宇航员；
    所述月球导航增强卫星上装载定轨载荷，用于接收地球GNSS导航星座的GNSS导航信号，利用伪码测距实现地球GNSS导航星座与月球导航增强卫星之间的伪距测量，实现初始定位和授时；同时与地面深空站或地球GNSS导航星座星间链路建立双向测量通信链路，采用双向时间比对实现地球GNSS导航星座与月球导航增强卫星之间的钟差测量，并接收地面深空站注入的GNSS星历，根据伪距测量、钟差测量和GNSS星历以及月球导航增强卫星轨道动力学模型进行轨道滤波实现月球导航增强卫星定轨；并通过装载的导航信号生成模块，生成并播发与具有测量功能的月球导航信号，并在所述月球导航信号上调制地球GNSS导航星座与月球导航增强卫星的星历，用于月球用户导航定位解算；
    所述月球用户上装载有导航终端，通过接收GNSS导航信号和月球导航信号实现绝对位置确定。
  2. 根据权利要求1所述的一种基于地球GNSS和月球导航增强卫星的月球导航系统，其特征在于：通过地球GNSS导航星座和月球导航增强卫星实现绝对位置确定，具体的方法为：月球用户通过导航终端无源接收地球GNSS导航星座和月球导航增强卫星中不小于四颗卫星的导航信号，获得与各颗导航卫星的伪距测量值，解算出月球用户的位置坐标，实现四星无源实时定位。
  3. 根据权利要求1所述的一种基于地球GNSS和月球导航增强卫星的月球导航系统，其特征在于：通过地球GNSS导航星座和月球导航增强卫星实现 绝对位置确定，具体的方法为：月球用户通过导航终端无源接收地球GNSS星座的GNSS导航信号，并与月球导航增强卫星进行双向测量通信，获得与地球GNSS星座和月球导航增强卫星中不小于三颗卫星的伪距测量值，并通过地球GNSS导航星座与月球导航增强卫星之间，以及月球导航增强卫星与月球用户之间的时间同步，实现月球用户的钟差解算，完成月球用户实时定位。
  4. 根据权利要求1所述的一种基于地球GNSS和月球导航增强卫星的月球导航系统，其特征在于：还包括月面无线电信标；所述月面无线电信标位于月球表面预设位置处，其上装载有月面信标导航信号生成模块，生成并播发具有测量功能的月面信标导航信号，并与月球导航增强卫星之间进行时间同步，月球用户同时接收月面信标、地球GNSS导航星座和月球导航增强卫星中不小于三颗卫星的导航信号，实现月球预设位置覆盖区域的月球用户的导航定位增强。
  5. 根据权利要求4所述的一种基于地球GNSS和月球导航增强卫星的月球导航系统，其特征在于：所述预设位置为能够满足对环月需求弧段、着陆器落月上升阶段及月面活动需求区域的覆盖的月面位置。
  6. 根据权利要求4所述的一种基于地球GNSS和月球导航增强卫星的月球导航系统，其特征在于：所述月面无线电信标与月球导航增强卫星之间进行时间同步，其具体方法为：月面无线电信标与月球导航增强卫星建立双向测量通信链路，或与月球用户建立双向测量通信链路，实现月球导航增强卫星与月球用户之间、月球用户与月面无线电信标之间的时间同步。
  7. 根据权利要求1所述的一种基于地球GNSS和月球导航增强卫星的月球导航系统，其特征在于：所述地面深空站或地球GNSS导航星座与月球导航增强卫星之间、月球导航增强卫星与月球用户之间构成双向数据传输链路，实现以月球导航增强卫星为中继的地面与月球用户之间以及月球用户与月球用户之间的中低速双向数据通信。
  8. 根据权利要求7所述的一种基于地球GNSS和月球导航增强卫星的月 球导航系统，其特征在于：所述双向数据通信的多址方式采用时分多址方式，时隙轮询周期小于用于测量的直接序列扩频信号解扩的相关周期。
  9. 根据权利要求1所述的一种基于地球GNSS和月球导航增强卫星的月球导航系统，其特征在于：所述月球导航增强卫星上设有原子钟，用于两次双向时间比对的时间间隔中对月球导航增强卫星进行守时，保持月球导航增强卫星与地球GNSS导航星座之间的时间同步。
  10. 根据权利要求1所述的一种基于地球GNSS和月球导航增强卫星的月球导航系统，其特征在于：所述月球导航增强卫星为运行在地月拉格朗日点或月球特定轨道上的环绕器或着陆于月面的着陆器。
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Cited By (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN113687394A (zh) * 2021-07-21 2021-11-23 西安空间无线电技术研究所 一种高轨卫星厘米级定轨系统与方法
CN115378490A (zh) * 2022-08-11 2022-11-22 中国科学院国家天文台 一种基于地面站的多级中继卫星星座行星际导航的方法
CN115396008A (zh) * 2022-08-11 2022-11-25 中国科学院国家天文台 一种多级中继卫星星座行星际导航的方法、系统及设备
CN117885915A (zh) * 2024-03-15 2024-04-16 中国科学院地质与地球物理研究所 一种月球极低轨道双星探测方法

Families Citing this family (9)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN110986964B (zh) * 2019-12-26 2021-10-01 西安空间无线电技术研究所 一种基于地球gnss和月球导航星的月球导航系统
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WO2023032822A1 (ja) * 2021-08-30 2023-03-09 三菱電機株式会社 測位方法、月測位システム、および、測位衛星
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CN116626386B (zh) * 2023-05-11 2023-12-15 中国科学院国家空间科学中心 一种基于地月锥时空剖分的频谱信息表征方法及系统

Citations (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN103148849A (zh) * 2013-03-12 2013-06-12 北京控制工程研究所 基于地月卫星联合测距和紫外敏感器的组合导航方法
CN103941263A (zh) * 2014-04-28 2014-07-23 北京控制工程研究所 一种基于星上量子光源和反射镜的星间测距方法
US20150077288A1 (en) * 2013-09-17 2015-03-19 Accord Software & Systems Pvt Ltd Time To First Fix Optimization In A Satellite Navigation Receiver
CN105158781A (zh) * 2015-07-29 2015-12-16 北京航空航天大学 一种地球gnss卫星实现外层空间用户定位的方法
CN107402391A (zh) * 2017-07-10 2017-11-28 中国人民解放军装备学院 一种导航卫星星座兼容与互操作分析方法
CN110986964A (zh) * 2019-12-26 2020-04-10 西安空间无线电技术研究所 一种基于地球gnss和月球导航星的月球导航系统

Family Cites Families (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN102736091B (zh) * 2012-06-29 2014-01-08 上海微小卫星工程中心 星球表面广域探测的卫星导航方法及系统
CN102998687B (zh) * 2012-11-30 2014-10-08 北京控制工程研究所 一种基于地球卫星和月球卫星联合测距的自主导航方法
CN105486314A (zh) * 2015-11-24 2016-04-13 南京航空航天大学 对月球空间无缝覆盖的拉格朗日导航星座及其构建方法
CN108827323B (zh) * 2018-08-16 2021-02-09 西安空间无线电技术研究所 一种地月空间航天器单向自主导航方法
CN109917431B (zh) * 2019-04-02 2021-03-23 中国科学院空间应用工程与技术中心 一种利用dro轨道和星间测量实现gnss卫星自主导航的方法

Patent Citations (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN103148849A (zh) * 2013-03-12 2013-06-12 北京控制工程研究所 基于地月卫星联合测距和紫外敏感器的组合导航方法
US20150077288A1 (en) * 2013-09-17 2015-03-19 Accord Software & Systems Pvt Ltd Time To First Fix Optimization In A Satellite Navigation Receiver
CN103941263A (zh) * 2014-04-28 2014-07-23 北京控制工程研究所 一种基于星上量子光源和反射镜的星间测距方法
CN105158781A (zh) * 2015-07-29 2015-12-16 北京航空航天大学 一种地球gnss卫星实现外层空间用户定位的方法
CN107402391A (zh) * 2017-07-10 2017-11-28 中国人民解放军装备学院 一种导航卫星星座兼容与互操作分析方法
CN110986964A (zh) * 2019-12-26 2020-04-10 西安空间无线电技术研究所 一种基于地球gnss和月球导航星的月球导航系统

Non-Patent Citations (1)

* Cited by examiner, † Cited by third party
Title
See also references of EP4080165A4

Cited By (8)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN113687394A (zh) * 2021-07-21 2021-11-23 西安空间无线电技术研究所 一种高轨卫星厘米级定轨系统与方法
CN113687394B (zh) * 2021-07-21 2023-12-29 西安空间无线电技术研究所 一种高轨卫星厘米级定轨系统与方法
CN115378490A (zh) * 2022-08-11 2022-11-22 中国科学院国家天文台 一种基于地面站的多级中继卫星星座行星际导航的方法
CN115396008A (zh) * 2022-08-11 2022-11-25 中国科学院国家天文台 一种多级中继卫星星座行星际导航的方法、系统及设备
CN115378490B (zh) * 2022-08-11 2023-06-20 中国科学院国家天文台 一种基于地面站的多级中继卫星星座行星际导航的方法
CN115396008B (zh) * 2022-08-11 2023-06-23 中国科学院国家天文台 一种多级中继卫星星座行星际导航的方法、系统及设备
CN117885915A (zh) * 2024-03-15 2024-04-16 中国科学院地质与地球物理研究所 一种月球极低轨道双星探测方法
CN117885915B (zh) * 2024-03-15 2024-06-07 中国科学院地质与地球物理研究所 一种月球极低轨道双星探测方法

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