Satellite system for observing a GEO target in cooperation with a low orbit and method for observing a GEO target in cooperation with a low orbit

Abstract

The application provides a satellite system for observing GEO targets from low orbit and an observation method thereof. The satellite system is composed of a plurality of sun-synchronous orbit satellites, and the orbit altitudes of the plurality of sun-synchronous orbit satellites are distributed in the 300-1500 km orbit altitude. The plurality of sun-synchronous orbit satellites all adopt a north polar staring observation method, that is, the satellites work 20-30 minutes before and after passing the north polar region, the satellite reference attitude is a geodetic attitude, based on the VVLH coordinate system, the camera is fixed along the satellite Y axis, the satellite adjusts the longitude direction pointing around the Z axis of the VVLH coordinate system to ensure the light avoidance requirement of the load, the satellite adjusts the latitude direction around the X axis of the VVLH coordinate system to point to the latitude region between-15° and 15° corresponding to the GEO band, and the pointing of the latitude band of each satellite at different times within one year is calculated and distributed according to a planning scheme. The miniaturized satellite system can realize high-time-efficiency observation of GEO targets.

Description

TECHNICAL FIELD

[0001] The present application belongs to the field of satellite monitoring of space targets, and in particular relates to a satellite system for cooperative observation of GEO targets from low earth orbit and an observation method thereof. BACKGROUND

[0002] There are a large number of satellites with high strategic value in high orbit space, especially in geosynchronous orbit space, and their functions cover many fields such as communication, navigation, remote sensing, military reconnaissance, etc., which are the strategic highlands of space utilization at present. Therefore, it is of great strategic value to monitor, track and maintain the catalog of high orbit space targets.

[0003] Among the current monitoring means for high orbit targets, space-based systems have wider detection range, higher observation accuracy and are not limited by weather conditions compared with ground-based systems. They can complement each other and are valued by major spacefaring nations.

[0004] There is currently a lack of satellite constellations with wide-area survey capability for high-orbit satellites in the prior art, and corresponding capabilities need to be arranged. In addition, in order to realize traversal of GEO band targets, the field of view of the load required by the existing satellite system is often large, and a turntable also needs to be set up for more complex observation modes, or high-frequency large-scale adjustment of the satellite attitude is realized, which makes the size and power consumption of the satellite large, so a small satellite constellation is needed to realize rapid traversal of high-orbit targets. SUMMARY

[0005] To solve the problems in the prior art, the present application provides a satellite system for cooperative observation of GEO targets from low earth orbit and an observation method thereof. The small satellite system can realize high-time-efficiency observation of GEO targets.

[0006] The technical scheme of the present application is: a satellite system for cooperative observation of GEO targets from low earth orbit, the satellite system is composed of a plurality of sun-synchronous orbit satellites, and the orbit altitudes of the plurality of sun-synchronous orbit satellites are distributed in the range of 300-1500 km orbit altitude.

[0007] Further, the number of sun-synchronous orbit satellites is 2-10.

[0008] Further, the number of sun-synchronous orbit satellites is 3-5.

[0009] Further, the field of view of the sun-synchronous orbit satellite system is 2°x2°-5°x5°.

[0010] The application also provides a satellite observation method for observing GEO targets from a low orbit, which is realized by the satellite system for observing GEO targets from a low orbit according to the method.

[0011] Further, the planning scheme step is as follows:

[0012] (1) Obtain the distribution rule of GEO satellites, divide the latitude range of -15°-15° into several regions according to 1°-5°, and analyze according to the existing GEO target library;

[0013] (2) According to the latitude distribution rule of GEO targets in the four solstices of spring equinox, summer solstice, autumnal equinox and winter solstice, set four observation modes of spring equinox, summer solstice, autumnal equinox and winter solstice; adopt the four observation modes of spring equinox, summer solstice, autumnal equinox and winter solstice respectively during February 21-April 21, April 21-August 21, August 21-October 21 and October 21-February 21; in the observation mode of the four seasons, the latitude direction of the satellite is planned according to the number of satellites and the field of view, so that it can cover all the latitude bands where GEO satellites are concentrated within 1-3 days.

[0014] Further, the satellite system can select the latitude band with more targets for multiple coverage to improve the cataloging success rate of the targets on the basis of meeting the coverage requirement.

[0015] The application has the following advantages:

[0016] (1) The observation task planning is carried out according to the distribution rule of GEO targets, which improves the effective utilization rate of the camera field of view.

[0017] (2) The satellite can work with a small camera (2°x2°-5°x5° field of view), the satellite scale is small (2-5 satellites can meet the high-time-efficiency traversal), and the satellite is arranged in a low orbit, so the launch and manufacturing costs are low. BRIEF DESCRIPTION OF DRAWINGS

[0018] Figure 1 It is a satellite system observation mode schematic diagram;

[0019] Figure 2 It is the declination distribution of GEO satellites in four seasons;

[0020] Figure 3 A schematic diagram of a regional gaze latitude planning scheme. DETAILED DESCRIPTION

[0021] As shown in the accompanying Figure 1 The satellite system is composed of several sun-synchronous orbit satellites. The orbit altitudes of the several satellites are distributed in the 300-1500 km orbit altitudes, and the observation method of north polar gaze is adopted, that is, the satellite works 20-30 min before and after passing the north polar region, the satellite reference attitude is the earth-oriented attitude (VVLH coordinate system), the camera is fixed to point along the Y axis of the satellite, the satellite adjusts the pointing direction in the longitude direction by rotating around the Y axis of the VVLH to ensure the light avoidance requirement of the load, and the satellite adjusts the pointing direction in the latitude direction by rotating around the X axis of the VVLH to point to the latitude region corresponding to the GEO zone (-15°-15°), and the pointing direction of the latitude zone of each satellite in different time within one year is calculated and distributed according to the planning scheme. The planning scheme steps are as follows:

[0022] (1) Obtain the GEO satellite distribution rule, divide the -15°-15° latitude range into several regions according to 1°-5°, and analyze according to the existing GEO target library to obtain the latitude distribution rule of the GEO target in the four solstices and equinoxes. As shown in the accompanying Figure 2 .

[0023] (2) According to the latitude distribution rule of the GEO target in the four solstices and equinoxes, four observation modes of spring equinox, summer solstice, autumn equinox and winter solstice are set. In January-March, April-June, July-September, and October-December, the four observation modes of spring equinox, summer solstice, autumn equinox and winter solstice are adopted respectively. In the observation mode of the four seasons, the latitude pointing direction is planned according to the number of satellites and the field of view, so that it can cover all the GEO satellite concentrated distribution latitude zones within 1-3 days.

[0024] The number of satellite systems can be selected to be 2-10, preferably 3-5. The satellite field of view is 2°x2°-5°x5°. The number of satellites and the field of view can be combined to realize high-time-efficiency traversal of the GEO zone target within 1-3 days. On the basis of meeting the coverage requirement, the satellite system can adopt redundant field of view to multiple cover the latitude zone with more targets to improve the cataloging success rate of the target.

[0025] The application will be further described in conjunction with the specific embodiments:

[0026] Through the analysis of the GEO target distribution characteristics, it can be obtained that most of the GEO targets are "drawn eight characters" in the ±15-degree latitude zone, and the period is 1 day. And from the perspective of all GEO target distribution, it is found that the GEO targets in the ±15-degree latitude zone are not uniformly distributed throughout the year, but are concentrated in different regions at different time periods throughout the year.

[0027] Dividing the area into 2° latitude zones, the simulation results preliminarily yielded the latitudinal distribution of the GEO target throughout the year, as follows: Figure 2 As shown.

[0028] A three-satellite constellation is adopted. The satellites use the Arctic staring observation method, that is, the satellites work for 20-30 minutes before and after passing through the Arctic region. The satellite's reference attitude is the Earth-oriented attitude (VVLH coordinate system). The camera is fixed along the satellite's Y-axis. The satellite adjusts its longitude direction around the Y-axis of the VVLH to ensure the payload's light-avoidance requirements. The satellite adjusts its latitude direction around the X-axis of the VVLH to point to the latitude region corresponding to the GEO zone (between -15° and 15°). The satellite constellation settings are shown in Table 1.

[0029] Table 1

[0030]

[0031]

[0032] Based on the annual latitudinal distribution patterns of GEO targets, and considering the satellite constellation and field of view, the proposed plans for the spring equinox, summer solstice, autumn equinox, and winter solstice are attached. Figure 3 As shown in Table 2, the scheme outlines the latitude zones oriented by the center of the line of sight of the three satellites during the four solar terms. Specifically, satellite 01 uses a 2°×2° field of view, while satellites 01 and 03 both use a 5°×5° field of view.

[0033] Table 2

[0034]

[0035] After optimization calculations, the applicable time ranges for the four solar term schemes are shown in Table 3.

[0036] Table 3

[0037] Scheme name Coverage Coverage duration Vernal equinox scheme 2021 / 02 / 21-2021 / 04 / 21 2 months Summer solstice scheme 2021 / 04 / 21-2021 / 08 / 21 4 months Autumnal equinox scheme 2021 / 08 / 21-2021 / 10 / 21 2 months Winter solstice scheme 2021 / 10 / 21-2022 / 02 / 21 4 months

[0038] A uniform selection of 1265 GEO satellites was used for coverage simulation verification, and the coverage changes of different schemes are shown in Tables 4 and 5.

[0039] Table 4

[0040]

[0041]

[0042] Table 5

[0043]

[0044] The above is a three-satellite planning scheme determined by adjusting the three-satellite staring latitude zone in a selected working mode (north polar region staring), which can meet the requirement of achieving more than 90% coverage in two days in a year by selecting four different schemes in a year. In actual conditions, the coverage rate and timeliness can be further improved by selecting different numbers of satellites and different fields of view, using different working modes, and optimizing the three-satellite staring latitude.

[0045] The above only describes the preferred embodiments of the present application, and it should be noted that those skilled in the art can make several improvements and refinements without departing from the principles of the present application, and these improvements and refinements should also be considered within the protection scope of the present application.

Claims

1. A satellite observation method for co-observing GEO targets from low Earth orbit, characterized in that: This is achieved based on a satellite system for collaborative observation of GEO targets from low Earth orbit, the satellite system consisting of several sun-synchronous orbit satellites with orbital altitudes ranging from 300 to 1500 km. All of the aforementioned sun-synchronous orbit satellites employ the Arctic staring observation method, meaning that the satellites operate for 20-30 minutes before and after passing through the Arctic region. The satellite's reference attitude is an Earth-oriented attitude, based on the VVLH coordinate system. The camera is fixed along the satellite's Y-axis. The satellite adjusts its longitude direction around the Z-axis of the VVLH coordinate system to ensure the payload's light-avoidance requirements. The satellite adjusts its latitude direction around the X-axis of the VVLH coordinate system to point to the latitude region between -15° and 15° corresponding to the GEO zone. The pointing of each satellite's latitude zone at different times of the year is calculated and allocated according to the planning scheme. The planning steps are as follows: (1) Obtain the distribution pattern of GEO satellites, divide the latitude range of -15° to 15° into several regions of 1° to 5°, and analyze them based on the existing GEO target database; (2) Based on the latitudinal distribution pattern of GEO targets during the four solar terms of spring equinox, summer solstice, autumn equinox, and winter solstice, four observation modes are set up for spring equinox, summer solstice, autumn equinox, and winter solstice. The four observation modes are adopted during the periods of February 21-April 21, April 21-August 21, August 21-October 21, and October 21-February 21, respectively. In the observation modes of the four seasons, the latitudinal direction is planned according to the number of satellites and the field of view, so that it can cover the latitudinal zone where all GEO satellites are concentrated within 1 to 3 days. (3) A three-satellite constellation is adopted, with satellite 01 using a 2°×2° field of view, and satellites 02 and 03 both using a 5°×5° field of view; the staring latitude zone schemes adopted by each satellite in different solar terms are shown in the table below:

2. The satellite observation method for co-observing GEO targets from low Earth orbit according to claim 1, characterized in that, In addition to meeting coverage requirements, the satellite system can select latitude zones with a large number of targets for multiple coverage to improve the success rate of target cataloging.

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