A near-moon space wide-area monitoring system and an observation method based on the system

Abstract

The present invention discloses a near-lunar space wide-area surveillance system, comprising three observation satellites located in NRHO orbits at the Earth-Moon libration point L1, L2, and DRO orbits, respectively. The observation satellites carry a wide-field-of-view camera payload and a precision tracking camera payload. The wide-field-of-view camera payload is used for scanning, searching, and detecting wide-area airspace in near-lunar space, while the precision tracking camera payload is used for tracking and monitoring space targets. By leveraging the characteristics of the NRHO and DRO orbits, the system, using only three observation satellites, can achieve short-period, full-coverage detection of near-lunar space and tracking and monitoring of near-lunar space targets, while maintaining a low long-term presence cost.

Description

Technical Field

[0001] The present invention belongs to the field of satellite monitoring of space targets, and in particular relates to a near-moon space wide-area monitoring system and an observation method based on the system. Background Art

[0002] Near-lunar space, rich in strategic resources such as materials, locations, and environments, is another hotspot for human space exploration after near-Earth space. Wide-area surveillance of near-lunar space is a crucial method for providing information support for our cislunar space activities by detecting, cataloging, and tracking near-lunar space targets.

[0003] The Earth-Moon libration point is the gravitational equilibrium point of the Earth-Moon system. Its unique dynamic characteristics provide the necessary conditions for the long-term residence and low-energy transfer of spacecraft in Earth-Moon space. At the same time, the Earth-Moon libration point orbit is farther from the Moon than the near-moon orbit, giving it the strategic advantage of overlooking Earth-Moon space. Currently, the United States has proposed several Earth-Moon space situational awareness programs, including "Artemis," "XGEO Space Domain Awareness Architecture," and "Defense Deep Space Sentinel" (D2S2). Among them, the Artemis program is based on the NRHO orbit of the Earth-Moon libration point L2 to achieve detection and surveillance of parts of the Earth-Moon transfer space and near-moon space.

[0004] The existing wide-area surveillance system for near-lunar space can only monitor and observe a portion of the near-lunar space, and cannot achieve full coverage observation of the 4π near-lunar space. At the same time, the wide-area surveillance system for near-lunar space needs to overcome the energy consumption problem of long-term residence.

[0005] Therefore, in order to grasp the strategic locations in the near-moon space and form the ability to obtain information in the near-moon space, there is an urgent need for a near-moon space wide-area surveillance system with low residence cost and high coverage observation of the near-moon space. Summary of the Invention

[0006] The purpose of the present invention is to provide a near-moon space wide-area monitoring system and an observation method based on the system. The system is a three-star constellation system operating at the Earth-Moon libration point L1 / L2 point and the DRO orbit to solve the deficiency of the existing space monitoring system in lacking near-moon space monitoring means.

[0007] To solve the above technical problems, the present invention provides a near-moon space wide-area monitoring system, comprising three observation satellites located in the NRHO orbit at the L1 point, the NRHO orbit at the L2 point, and the DRO orbit at the Earth-Moon libration point;

[0008] The observation satellite is equipped with a wide-field-of-view camera payload and a precision tracking camera payload. The wide-field-of-view camera payload is used for scanning, searching, and detecting a wide area of near-moon space, and the precision tracking camera payload is used for tracking and monitoring space targets.

[0009] Furthermore, the wide-field-of-view camera payload has a field of view angle of 12.2°×12.2° and a detection capability of 18.8Mv.

[0010] Furthermore, the maximum amplitude of the L1 point NRHO orbit in the normal direction of the ecliptic plane is 84,000 kilometers, the maximum amplitude of the L2 point NRHO orbit in the normal direction of the ecliptic plane is 82,000 kilometers, and the maximum amplitude of the DRO orbit in the direction of the Moon-Earth line is 37,000 kilometers.

[0011] The present invention also provides an observation method based on the near-moon space wide-area monitoring system, the specific steps of which are as follows:

[0012] Step (1), the observation satellites on the L1 NRHO orbit and the L2 NRHO orbit of the Earth-Moon libration point adopt a circular scanning coverage observation mode to scan and detect the 2π space in the south and north of the near-moon space respectively, and jointly realize a 4π omnidirectional rapid traversal of the near-moon space;

[0013] Step (2), the observation satellite on the DRO orbit uses the lunar limb observation mode to scan and detect the near-moon space in the ecliptic plane;

[0014] In step (3), after the three observation satellites on the L1 NRHO orbit, L2 NRHO orbit and DRO orbit of the Earth-Moon libration point discover the space target through wide-area space scanning detection search, they can switch to the target tracking observation mode to monitor the space target.

[0015] Furthermore, the circumferential scanning coverage observation mode is specifically as follows: the L1 and L2 NRHO orbit satellite platforms rotate at a constant speed around the orbit in an inertial reference attitude toward the moon, and the wide-field-of-view camera's detection field of view rotates with the platform around the orbit; as the NRHO satellite orbits one circle in the conjunction system, the detection field of view completes a 360° scan around the moon in the near-moon space.

[0016] The present invention realizes wide-area search of near-lunar space and tracking and monitoring of near-lunar space targets by deploying three-star systems in NRHO orbits and DRO orbits at the L1 and L2 libration points. Full coverage detection of near-lunar space is achieved through the circumferential scanning coverage of NRHO orbit satellites and the observation mode of DRO orbit satellites cutting the lunar limb.

[0017] The coverage simulation results show that the system's instantaneous coverage period for the near-moon space is 8 days, and 100% coverage of the near-moon space can be achieved within 1.5 periods. The system can observe near-moon targets no less than 14 times in a single period, with an observation arc length of no less than 3.5 minutes.

[0018] The advantages of the present invention are as follows: by utilizing the characteristics of the NRHO orbit and the DRO orbit, the system can achieve short-period full-coverage detection of the near-moon space and tracking and monitoring of near-moon space targets using only three observation satellites, and has a low long-term residence maintenance cost. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 This is a schematic diagram of the distribution of satellite systems in the near-lunar space with a radius of 80,000 kilometers;

[0020] Figure 2 This is a schematic diagram of NRHO satellite circular scanning detection;

[0021] Figure 3 This is a schematic diagram of the DRO satellite observing the lunar limb;

[0022] Figure 4 This is a graph showing changes in the system's observation coverage of the near-moon space;

[0023] Figure 5 It is the observation arc diagram of the system for typical targets;

[0024] Figure 6 It is a distribution diagram of the system's available tracking arc segments for typical near-moon space targets within a year.

[0025] In the figure: 1 is L1, 2 is L2, 3 is L1 NRHO orbit, 4 is L2 NRHO orbit, 5 is DRO orbit, and 6 is the Moon. DETAILED DESCRIPTION

[0026] The following, combined with the accompanying drawings and specific embodiments, further details the near-lunar space wide-area monitoring system and observation mode proposed by the present invention. The advantages and features of the present invention will become more apparent from the following description and claims. It should be noted that the drawings are highly simplified and not to exact scale, and are intended solely to facilitate and clearly illustrate the embodiments of the present invention.

[0027] The embodiment of the present invention provides a near-moon space wide-area monitoring system, as shown in the attached Figure 1 As shown, the three satellites are respectively arranged at the Earth-Moon libration point L1 / L2 point NRHO orbit and DRO orbit observation satellites. NRHO orbit satellites adopt Figure 2 The wide-field camera payload rotates around the orbit with the satellite platform to scan 360°, and completes the circular scanning coverage observation of the 2π space in the south and north of the near-moon space with the orbital periodic motion. Figure 3The lunar limb observation method shown here completes a sweeping observation of the lunar near-lunar space within the ecliptic plane as the orbital period progresses. The wide-field camera payload has a field of view of 12.2° × 12.2° and a detection capability of 18.8 Mv, sufficient for searching and detecting lunar targets larger than 30 cm.

[0028] The system's coverage efficiency of the near-moon space was simulated by simulation software. The instantaneous coverage rate of the system in the near-moon space within one month was as follows: Figure 4 As shown, the system's instantaneous coverage of the near-moon space is 8 days, and 100% coverage of the near-moon space can be achieved within 1.5 cycles. The system's tracking and monitoring performance simulation of near-moon space targets shows that the system can observe near-moon targets no less than 14 times in a single cycle, with an observation arc length of no less than 3.5 minutes. The system's coverage and monitoring arc for a typical near-moon space in a single cycle is shown below. Figure 5 As shown, the arc segments are evenly distributed. The available tracking arc segments for a typical near-moon space target in one year are distributed as follows: Figure 6 As shown, there are 28 arc segments available for precise tracking and orbit determination, with the longest arc length being 6.4 days, the shortest arc length being 0.84 days, and the average arc length being 2.92 days, which can meet the requirements for cataloging and orbit determination of near-moon targets and Earth-Moon transfer targets.

[0029] In summary, the above embodiments provide detailed descriptions of various configurations of a near-lunar space wide-area monitoring system and observation methods based on such a system. The present invention includes, but is not limited to, the configurations described in the above embodiments. Any variations based on the configurations provided in the above embodiments fall within the scope of protection of the present invention. Those skilled in the art can draw inferences based on the above embodiments.

[0030] The various embodiments in this specification are described in a progressive manner, with each embodiment focusing on the differences from other embodiments. Reference can be made to the common and similar parts between the various embodiments. For the systems disclosed in the embodiments, since they correspond to the methods disclosed in the embodiments, the description is relatively simple, and the relevant parts can be referred to the method description.

[0031] The above description is only a description of the preferred embodiments of the present invention and does not limit the scope of the present invention. Any changes and modifications made by ordinary technicians in the field of the present invention based on the above disclosure shall fall within the scope of protection of the claims.

Claims

1. A near-lunar space wide-area surveillance system, characterized by: It includes three observation satellites located in the NRHO orbit at L1, NRHO orbit at L2 and DRO orbit respectively. The observation satellite is equipped with a wide-field-of-view camera payload and a precision tracking camera payload. The wide-field-of-view camera payload is used for scanning, searching, and detecting a wide area of near-moon space, and the precision tracking camera payload is used for tracking and monitoring space targets. The maximum amplitude of the L1 point NRHO orbit in the normal direction of the ecliptic plane is 84,000 kilometers, the maximum amplitude of the L2 point NRHO orbit in the normal direction of the ecliptic plane is 82,000 kilometers, and the maximum amplitude of the DRO orbit in the direction of the moon-earth line is 37,000 kilometers.

2. The near-lunar space wide-area surveillance system according to claim 1, characterized in that: The wide-field-of-view camera payload has a field of view angle of 12.2°×12.2° and a detection capability of 18.8Mv.

3. An observation method based on the near-moon space wide-area monitoring system according to claim 1 or 2, characterized in that: The specific steps are as follows: Step (1), the observation satellites on the L1 NRHO orbit and the L2 NRHO orbit of the Earth-Moon libration point adopt a circular scanning coverage observation mode to scan and detect the 2π space in the south and north of the near-moon space respectively, and jointly realize a 4π omnidirectional rapid traversal of the near-moon space; The circular scanning coverage observation mode is as follows: the NRHO orbit satellite platform at L1 and L2 points rotates at a constant speed around the orbit in an inertial reference attitude to the moon, and the wide-field-of-view camera detects the field of view as the platform rotates around the orbit; as the NRHO satellite orbits one circle in the conjunction system, the detection field of view completes a 360-degree scan around the moon in the near-moon space; Step (2), the observation satellite on the DRO orbit uses the lunar limb observation mode to scan and detect the near-moon space in the ecliptic plane; In step (3), after the three observation satellites on the L1 NRHO orbit, L2 NRHO orbit and DRO orbit of the Earth-Moon libration point discover the space target through wide-area space scanning detection search, they can switch to the target tracking observation mode to monitor the space target.

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