CN112054838B - Design method of NGSO satellite bias scheme - Google Patents

Design method of NGSO satellite bias scheme Download PDF

Info

Publication number
CN112054838B
CN112054838B CN202010951218.0A CN202010951218A CN112054838B CN 112054838 B CN112054838 B CN 112054838B CN 202010951218 A CN202010951218 A CN 202010951218A CN 112054838 B CN112054838 B CN 112054838B
Authority
CN
China
Prior art keywords
satellite
angle
ngso
bias
latitude
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Active
Application number
CN202010951218.0A
Other languages
Chinese (zh)
Other versions
CN112054838A (en
Inventor
邹诚
李国通
姜泉江
姜兴龙
尚琳
夏师懿
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Shanghai Engineering Center for Microsatellites
Innovation Academy for Microsatellites of CAS
Original Assignee
Shanghai Engineering Center for Microsatellites
Innovation Academy for Microsatellites of CAS
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Shanghai Engineering Center for Microsatellites, Innovation Academy for Microsatellites of CAS filed Critical Shanghai Engineering Center for Microsatellites
Priority to CN202010951218.0A priority Critical patent/CN112054838B/en
Publication of CN112054838A publication Critical patent/CN112054838A/en
Application granted granted Critical
Publication of CN112054838B publication Critical patent/CN112054838B/en
Active legal-status Critical Current
Anticipated expiration legal-status Critical

Links

Images

Classifications

    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04B—TRANSMISSION
    • H04B7/00—Radio transmission systems, i.e. using radiation field
    • H04B7/14—Relay systems
    • H04B7/15—Active relay systems
    • H04B7/185—Space-based or airborne stations; Stations for satellite systems
    • H04B7/1851—Systems using a satellite or space-based relay
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04B—TRANSMISSION
    • H04B7/00—Radio transmission systems, i.e. using radiation field
    • H04B7/14—Relay systems
    • H04B7/15—Active relay systems
    • H04B7/185—Space-based or airborne stations; Stations for satellite systems
    • H04B7/1851—Systems using a satellite or space-based relay
    • H04B7/18513—Transmission in a satellite or space-based system
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04B—TRANSMISSION
    • H04B7/00—Radio transmission systems, i.e. using radiation field
    • H04B7/14—Relay systems
    • H04B7/15—Active relay systems
    • H04B7/185—Space-based or airborne stations; Stations for satellite systems
    • H04B7/1851—Systems using a satellite or space-based relay
    • H04B7/18519—Operations control, administration or maintenance
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04B—TRANSMISSION
    • H04B7/00—Radio transmission systems, i.e. using radiation field
    • H04B7/14—Relay systems
    • H04B7/15—Active relay systems
    • H04B7/185—Space-based or airborne stations; Stations for satellite systems
    • H04B7/18578—Satellite systems for providing broadband data service to individual earth stations
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04B—TRANSMISSION
    • H04B7/00—Radio transmission systems, i.e. using radiation field
    • H04B7/14—Relay systems
    • H04B7/15—Active relay systems
    • H04B7/185—Space-based or airborne stations; Stations for satellite systems
    • H04B7/18578—Satellite systems for providing broadband data service to individual earth stations
    • H04B7/18597—Arrangements for system physical machines management, i.e. for construction, operations control, administration, maintenance

Abstract

The invention discloses a design method of an NGSO satellite bias scheme, which comprises the steps of firstly calculating EPFD under the worst geometric condition according to parameters of an NGSO satellite and a GSO satellite, comparing the EPFD with a downlink EPFD limit value in ITU radio rule clause 22 to determine whether bias is required, further calculating values of a minimum interference angle and a minimum X-axis angle if the EPFD is required, respectively simulating according to the minimum X-axis angle and the minimum interference angle to obtain a starting latitude of the NGSO satellite and a bias angle when an under-satellite point latitude is 3.75 degrees under a scene of avoiding collinear interference and a scene of avoiding interference of an NGSO satellite coverage area, and finally respectively selecting a maximum starting latitude and a maximum bias angle in the two scenes to determine the bias schemes of the two scenes.

Description

Design method of NGSO satellite bias scheme
Technical Field
The invention relates to the technical field of aerospace, in particular to a design method of an NGSO satellite bias scheme.
Background
The broadband communication Satellite system includes a GSO Geostationary Orbit Satellite broadband communication Satellite system and an NGSO (Non-Geostationary Satellite Orbit) Satellite system. Wherein the NGSO satellite system comprises a communication satellite constellation system operating in medium orbits (MEOs) 8000-20000 kilometers from the surface of the earth and Low Earth Orbits (LEOs) 2000-400 kilometers from the surface of the earth, which provides global Internet services and data interaction for global Internet of things. Compared with a GSO communication satellite system, the NGSO broadband communication satellite constellation system has the main advantages of global coverage, small influence by terrain, small signal delay, small transmission loss, convenience for miniaturization of a user terminal, low satellite launching and orbit entering cost, high frequency resource utilization rate and the like. In recent years, many enterprises with cross broadband low orbit systems at home and abroad have put forward huge low orbit satellite constellation plans of each enterprise, such as Starlink of SpaceX, constellation plan of OneWeb, and domestic swan and rainbow cloud constellation plans.
The existing NGSO satellite system generally adopts KU and KA frequency bands, so that the phenomenon of spectrum sharing with the GSO satellite system exists, and the problem of frequency collinear interference is a prominent problem. To ensure safe use of GSO satellite system frequencies, international union in radio regulations clause 22 limits the equivalent power flux density EPFD produced by the NGSO system in the KU and KA bands:
Figure BDA0002677003090000011
wherein N isaIs the number of transmitting stations, P, of the NGSO systemiFor the power of the input antenna of the ith transmitting station, Gt(θi) The off-axis angle of the transmitting antenna of the ith NGSO system is thetaiGain of diThe distance between the transmitting station of the NGSO system to the receiving station of the GSO system,
Figure BDA0002677003090000012
for the ith GSO system, the off-axis angle of the receiving antenna is
Figure BDA0002677003090000013
Gain of (a), and Gr,maxThe maximum gain of the station is accepted for the GSO system. The downlink EPFD of a single NGSO satellite to the GSO satellite system is
Figure BDA0002677003090000014
Figure BDA0002677003090000021
Considering the worst interference geometric scene, the downlink EPFD of the NGSO satellite is properly amplified, namely, the distance from the NGSO satellite to the ground station of the GSO system is unified into the orbital height of the NGSO satellite so as to ensure that a certain margin exists between the EPFD of the system and the EPFD limit value. Then, under the condition of the maximum EIRP (equivalent isotropic radiated power) of the NGSO satellite, the EPFD of the NGSO satellite downlink is mainly determined by the NGSO satellite antenna gain diagram and the GSO system ground station antenna pattern.
At present, the ITU also provides a spatial isolation method to reduce the interference of the NGSO system to the GSO system, and it can be seen from the EPFD formula that the downlink EPFD of the NGSO system of the system can be reduced by increasing the off-axis angle of the NGSO satellite transmitting antenna and the off-axis angle of the GSO satellite system ground station. The interference avoidance mode is closely related to the directional diagram of the antenna of the NGSO satellite. Therefore, the bias scheme of the NGSO satellite is reasonably designed, the downlink EPFD of the NGSO satellite is reduced, and the interference on the GSO system can be effectively avoided.
Disclosure of Invention
Aiming at the problem of coexistence of NGSO satellite system and GSO satellite system frequency spectrums, the invention provides a design method of an NGSO satellite bias scheme, which comprises the following steps:
calculating the EPFD in the worst case geometry based on the parameters of the NGSO satellite and the GSO satellite and comparing with the downlink EPFD limit in ITU radio rules clause 22;
if the EPFD under the worst geometrical situation is larger than the downlink EPFD limit value, calculating values of a minimum interference angle and a minimum X-axis angle;
respectively simulating according to the minimum X-axis angle and the minimum interference angle to obtain a bias angle when the polarization latitude of the NGSO satellite and the latitude of the subsatellite point are 3.75 degrees in a collineation interference avoiding scene and an NGSO satellite coverage area interference avoiding scene; and
and selecting a larger polarization latitude and a larger bias angle in the two scenes to determine a bias scheme.
Further, the biasing scheme includes linearly biasing between a 3.75 sub-satellite point latitude and a polarization latitude.
In the present invention, the X-axis angle is shown in fig. 1, in which an origin O is a coordinate of the NGSO satellite, a direction vector P is a vector between the NGSO satellite and the GSO ground station, and a cross section where a YOZ plane is coplanar with a long axis of a beam used by the NGSO satellite.
The design method of the NGSO satellite bias scheme provided by the invention respectively calculates the interference angle under the interference scene of the coverage area of the NGSO system and the X-axis angle under the collinear interference scene, further determines the polarization latitude and the bias angle under different scenes through the interference angle and the X-axis angle, selects the larger polarization latitude and the bias angle, and finally determines the bias scheme of the NGSO satellite so as to inhibit the downlink EPFD of the NGSO system and further avoid the interference on the GSO system.
Drawings
To further clarify the above and other advantages and features of embodiments of the present invention, a more particular description of embodiments of the present invention will be rendered by reference to the appended drawings. It is appreciated that these drawings depict only typical embodiments of the invention and are therefore not to be considered limiting of its scope. In the drawings, the same or corresponding parts will be denoted by the same or similar reference numerals for clarity.
FIG. 1 shows a schematic diagram of the X-axis angle of one embodiment of the present invention;
figure 2 shows a schematic diagram of beam footprint coverage employed by an NGSO satellite;
FIG. 3 is a schematic flow diagram illustrating a method for designing an NGSO satellite biasing scheme in accordance with one embodiment of the invention;
FIG. 4 illustrates a schematic diagram of a scenario of co-linear interference of an NGSO satellite with a GSO satellite;
FIG. 5 illustrates a schematic diagram of a scenario of NGSO system coverage area interference;
FIG. 6 is a diagram illustrating receive antenna gain at a ground station of the GSO system in accordance with an embodiment of the present invention;
FIG. 7a is a schematic diagram showing the variation of the minimum X-axis angle with the latitude of the sub-satellite point for different NGSO satellite pitch angles in one embodiment of the present invention;
FIG. 7b is a schematic representation of the minimum X-axis angle as a function of the NGSO satellite pitch angle at different sub-satellite latitudes in accordance with an embodiment of the present invention;
FIG. 8a is a schematic diagram showing the variation of the minimum interference angle with the latitude of the off-satellite point at different NGSO satellite pitch angles in one embodiment of the present invention;
FIG. 8b is a schematic diagram showing the variation of the minimum interference angle with the pitch angle of the NGSO satellite at different sub-satellite latitudes, in accordance with an embodiment of the present invention;
FIG. 9a is a schematic diagram illustrating the bias requirements of an NGSO system coverage area interference scenario in accordance with an embodiment of the present invention; and
FIG. 9b is a schematic diagram illustrating the bias requirements for a co-linear interference scenario, according to an embodiment of the present invention.
Detailed Description
In the following description, the present invention is described with reference to examples. One skilled in the relevant art will recognize, however, that the embodiments may be practiced without one or more of the specific details, or with other alternative and/or additional methods, materials, or components. In other instances, well-known structures, materials, or operations are not shown or described in detail to avoid obscuring aspects of the invention. Similarly, for purposes of explanation, specific numbers, materials and configurations are set forth in order to provide a thorough understanding of the embodiments of the invention. However, the invention is not limited to these specific details. Further, it should be understood that the embodiments shown in the figures are illustrative representations and are not necessarily drawn to scale.
Reference in the specification to "one embodiment" or "the embodiment" means that a particular feature, structure, or characteristic described in connection with the embodiment is included in at least one embodiment of the invention. The appearances of the phrase "in one embodiment" in various places in the specification are not necessarily all referring to the same embodiment.
It should be noted that the embodiment of the present invention describes the process steps in a specific order, however, this is only for illustrating the specific embodiment and is not meant to limit the sequence of the steps. Rather, in various embodiments of the present invention, the order of the steps may be adjusted according to process adjustments.
At present, strip beams shown in fig. 2 are adopted as service beams of an OneWeb broadband low-orbit satellite system, a coverage area of the strip beams on the ground is an oblong, a long axis direction of the oblong coverage area is an east-west direction, and a north-south direction corresponding to a short axis direction, and it can be seen that the attenuation of the strip beams in the north-south direction is rapid, and the attenuation in the east-west direction is slow. According to the characteristics of the strip wave beam, in order to avoid interference on a GSO system, the invention provides a design method of an NGSO satellite bias scheme, which comprises the steps of respectively calculating polarization latitudes and bias angles under different latitudes in different scenes, and then determining the bias scheme according to the larger polarization latitudes and bias angles. The solution of the invention is further described below with reference to the accompanying drawings of embodiments.
Fig. 3 is a flow chart illustrating a method for designing an NGSO satellite biasing scheme according to an embodiment of the present invention. As shown in fig. 3, a method for designing an NGSO satellite bias scheme includes:
first, at step 101, the EPFD in the worst case geometry is calculated. The worst geometry case, the maximum EPFD produced by a single beam of the NGSO satellite, is calculated according to the following equation:
Figure BDA0002677003090000041
where P is the power of the input antenna of the transmitting station,
Gt(theta) is the gain when the off-axis angle of the transmitting antenna of the NGSO system is theta,
d is the distance between the transmitting station of the NGSO system to the receiving station of the GSO system, which can be considered equal to the orbital altitude of the NGSO satellite,
Figure BDA0002677003090000051
off-axis for GSO system receiving antennaThe angle is
Figure BDA0002677003090000052
Gain of time, and
Gr,maxfor the maximum gain of the receiving station of the GSO system,
subjecting the EPFD tomaxCompare with the downlink EPFD limits of Table 22-1B in ITU radio rules clause 22, if EPFDmaxIf the value is greater than the downlink EPFD limit value, the step 102 is entered;
at step 102, a minimum interference angle and a minimum X-axis angle are calculated. In an interference scene of an NGSO system and a GSO system, a main shaft of an antenna of a ground station of the GSO satellite system always points to a GSO satellite, so that the value of downlink EPFD of the system is reduced by increasing the off-axis angle of the ground station of the GSO satellite system in a satellite coverage area; when the ground stations of the GSO satellite, the NGSO satellite and the GSO satellite system are collinear, the downlink EPFD of the NGSO system is restrained by increasing the off-axis angle of the transmitting antenna of the NGSO satellite. Therefore, for the NGSO system coverage area interference scenario and the collinear interference scenario, the offset scheme is determined by the interference angle and the X-axis angle, respectively:
the collinear interference scene is shown in fig. 4, in which L is an NGSO satellite, H and G points are both located on a GSO satellite orbit, where the G point and the NGSO satellite have the same longitude, the relative longitude difference between the H point and the NGSO satellite is δ, and the latitude of the NGSO satellite is ψ; point D is the position of the GSO ground station, which is on the same line as the NGSO satellite and the GSO satellite; B. c, E are also located on the earth surface, and B, C, E are all α relative to the pitching angle of the NGSO satellite, α corresponds to the pitching angle corresponding to the long axis of the highest beam in the NGSO satellite latitude; meanwhile, the azimuth angle of the NGSO satellite corresponding to the point C is 0 degree, and the B, E points are respectively located at the east and west ends of the beam. The pitch angle decreases progressively along the direction of ascent of the NGSO satellite and is in the north-south direction, it can be seen that C, O, G, L lie in the same plane. Establishing a beam rectangular coordinate system based on a beam at the highest latitude side of the NGSO satellite in the figure 4, wherein the origin of the beam rectangular coordinate system is the NGSO satellite coordinate, the X axis is vertical to the BLE beam section, and the positive direction is the satellite orbit-raising direction; the Z-axis direction is a straight line LC and the positive direction points to a point C; and the Y axis is perpendicular to the plane OCLG, the positive direction of which is the direction of delta increase. In a collinear interference scenario, an off-axis angle of a receiving antenna of a ground station of a GSO satellite system is 0 degree, and therefore, an X-axis angle between a straight line GD and a planar BCE can be increased by increasing a bias angle of an NGSO satellite, so as to reduce a downlink EPFD of the NGSO satellite, in an embodiment of the present invention, the calculation of the X-axis angle includes:
firstly, establishing an earth rectangular coordinate system, wherein a Z axis of the earth rectangular coordinate system is vertical to an equatorial plane and the positive direction of the earth rectangular coordinate system is the ascending direction of an NGSO satellite; the Y axis is a straight line OG and the positive direction is that the point O points to the point G; and the X axis is the outward direction of the vertical plane OLH, then according to the latitude and relative longitude difference of the NGSO satellite, the coordinates of the NGSO satellite and the GSO satellite under a ground rectangular coordinate system can be obtained:
Figure BDA0002677003090000067
wherein R isnIs the radius of the earth, RgIs the orbital radius of the NGSO satellite;
next, it can be calculated
Figure BDA0002677003090000061
Direction of vector P:
Figure BDA0002677003090000062
next, the direction vector P is transformed into a beam rectangular coordinate system by a transformation matrix R as follows:
Figure BDA0002677003090000063
and
finally, in a beam rectangular coordinate system, solving an X-axis angle mu according to the direction vector P:
Figure BDA0002677003090000064
wherein, x, y and z are coordinate values of the direction vector P in the beam rectangular coordinate system;
and
an interference scene of an NGSO system coverage area is shown in fig. 5, in which L is an NGSO satellite, G and H points are points on a GSO satellite orbit, H point is a position of the GSO satellite, longitude of G point is the same as longitude of L point, relative longitude difference between G point and H point is δ, and a direction from point G to point H is a positive west direction. Located on the surface of the earth
Figure BDA0002677003090000066
Points on the arc represent points on the earth surface corresponding to the pitch angle alpha of the NGSO satellite in the coverage area of the NGSO satellite, the azimuth angle theta of the NGSO satellite corresponding to the point C, and the corresponding interference angle beta. The place with the strongest interference in the NGSO satellite coverage area can be approximated to the place with the smallest interference angle in the NGSO satellite coverage area, and in this scenario, the EPFD in the NGSO satellite coverage area is reduced mainly by increasing the interference angle in the coverage area in order to avoid the interference to the GSO system. In an embodiment of the present invention, the interference angle is calculated by a trigonometric function relationship of a triangular LCH:
Figure BDA0002677003090000065
wherein, the first and the second end of the pipe are connected with each other,
cl is obtained by trigonometric relation of triangle OLC:
cl2+ol2-oc2＝2cl×olcos∠CLO，
wherein oc is the earth radius, ol is the sum of the earth radius and the NGSO satellite height, and ═ CLO ═ arccos (cos (θ) cos (α)), since cl is less than ol, a unique solution for cl can be obtained;
constructing a right triangle KLH by introducing a point K, which is the intersection point of the perpendicular line of the OG passing through the L point and the OG, and obtaining the value of lh by the Pythagorean theorem:
Figure BDA0002677003090000071
wherein, because the orbit that NGSO satellite belongs to is the polar orbit, LEO satellite's orbital plane and equatorial plane are perpendicular, therefore straight line LK is perpendicular to equatorial plane, have:
lk＝ol×sinψ，
ok ═ ol × cos ψ, and
Figure BDA0002677003090000072
and
the ch value is calculated by the trigonometric function relation of the triangular OCH:
Figure BDA0002677003090000073
the calculation of the angle COH is complicated, the value of the angle COH depends on the pitch angle, the azimuth angle and the relative longitude difference of the wave beam, and the angle CKL only depends on the pitch angle and the azimuth angle of the wave beam, so that the solution of the ch can be conveniently transited through the solution of the angle CKL. The solving process of the angle & lt CKL is as follows:
making a perpendicular line of the plane OLG through a point C and crossing at a point E, where ═ ELO is a beam pitch angle corresponding to the point C, and ═ ELO is α, then:
ce＝cl×sinθ，
le ═ cl × cos θ, and
Figure BDA0002677003090000074
the angle EOL can be expressed as:
Figure BDA0002677003090000075
then it can be further obtained that:
Figure BDA0002677003090000076
wherein the angle EOG is equal to angle LOG plus angle EOL, and the angle LOG is the latitude of the NGSO satellite. If the longitude reference angle is zero, the ≈ LCG is an interference angle:
Figure BDA0002677003090000081
wherein the content of the first and second substances,
Figure BDA0002677003090000082
when the longitude reference angle delta is not zero, the value of & lt CKL can be obtained according to the trigonometric function relation of the triangle COK:
Figure BDA0002677003090000083
wherein the content of the first and second substances,
Figure BDA0002677003090000084
Figure BDA0002677003090000085
with reference to the above process, the solution of ≈ COH is simplified by introducing a point P on a straight line OH, wherein the PCLK four points are coplanar, i.e. the projections of the straight line PK and the LC straight line on the equatorial plane coincide, and an included angle θ' between the KP straight line and the OH straight line is as follows:
Figure BDA0002677003090000086
then the process of the first step is carried out,
Figure BDA0002677003090000087
wherein:
when the longitude reference angle delta is greater than 0,point P is on line segment OH, at which time angle COH is equal to COP, angle OKP is equal to θ', angle OPK is equal to pi- δ - θ,
Figure BDA0002677003090000088
comprises the following steps:
Figure BDA0002677003090000089
Figure BDA00026770030900000810
and
Figure BDA00026770030900000811
when the longitude reference angle δ is less than 0 and | δ | - θ' >0, the point P and the point H are located on both sides of the point O, where ═ COH ═ pi-COP, there are:
Figure BDA00026770030900000812
Figure BDA00026770030900000813
and
Figure BDA00026770030900000814
when the longitude reference angle delta is less than 0, and delta theta'<At 0, point P and point H are located on the same side of point O, and angle COH is ═ COP, and angle OPK and θ' are complementary,
Figure BDA0002677003090000091
comprises the following steps:
Figure BDA0002677003090000092
Figure BDA0002677003090000093
and
Figure BDA0002677003090000094
and
when the longitude reference angle delta is equal to 0, approximating the delta to 0 to obtain a value of < COH;
next, in step 103, the polarization latitude and the polarization angle are determined. Respectively simulating according to the minimum X-axis angle and the minimum interference angle obtained by calculation in the step 102 to obtain a bias angle when the polarization latitude and the satellite-to-satellite point latitude of the NGSO satellite are 3.75 degrees in the scene of avoiding collinear interference and the scene of avoiding the interference of the NGSO satellite coverage area; and
finally, in step 104, a biasing scheme is determined. And respectively selecting a larger polarization latitude and a larger bias angle in the two scenes to determine a bias scheme. In one embodiment of the invention, the bias scheme includes linearly biasing between 3.75 ° of the substellar point latitude and a bias latitude such that the bias angle decreases linearly from a maximum bias angle to zero degrees; when the latitude of the substellar point is larger than the bias latitude, no bias is made; and when the sub-satellite latitude decreases from 3.75 ° to zero degrees, the NGSO satellite turns off all beams and starts reverse biasing such that the bias angle is 0 ° at a sub-satellite latitude of 0 °.
In order to better describe the technical effect of the embodiment of the invention, the simulation of the X-axis angle in the collinear interference scene and the simulation result of the interference angle in the interference scene avoiding the NGSO satellite coverage area are given below, wherein the relative longitude difference in the simulation ranges from-40 degrees to 40 degrees.
The coverage area of the strip wave beam adopted by a certain NGSO satellite is in a strip shape, and the difference between the EIRP of the strip area and the maximum EIRP of the NGSO satellite is not more than 3 dB. The wave beam width of the NGSO satellite in the minor axis direction is 3 degrees, the wave beam width in the major axis direction is 50 degrees, the azimuth angle corresponding to the satellite is-25 degrees to 25 degrees, the maximum EIRP is 1.5dBW, the reference bandwidth is 40kHz, and meanwhile, the NGSO satellite has the advantages thatThe orbit is a circular orbit, the height of the orbit is 1200 kilometers, the inclination angle of the orbit is 90 degrees, each orbit surface has 48 stars, and the phase difference between adjacent satellites on the same orbit surface is 7.5 degrees. Meanwhile, the GSO ground station antenna model is a recommendation model of reference ITU-RS.1428-1, the antenna radius is 1 meter, and the gain is shown in FIG. 6. Then the single beam of the NGSO satellite produces a maximum EPFD of-131.1 dBW/m in the worst geometry case, according to the downlink EPFD expression2Down EPFD limit of-164 dBW/m, corresponding to radio rules 22-1B2With a difference of 32.9 dB. The corresponding GSO ground interference angle is 5.2 degrees. Then, the antenna attenuation performance is assumed here to be 32.9dB for the X-axis 10 degree outer attenuation of the NGSO satellite four-beam synthesized antenna gain outer beam.
Under the collinear interference scene, the pitching angle of the NGSO satellite is-22.5 degrees, and the pitching angle of the beam center with the highest latitude corresponds to the pitching angle under the condition that the NGSO satellite has no offset. From fig. 7a, it can be known that the curve of the NGSO satellite with the pitch angle of-22.5 ° intersects with the straight line with the X-axis angle of 10 ° (27,10), and in order to ensure that the X-axis angle is greater than 10 °, the beam of the NGSO satellite needs to be biased to a low latitude area. In fig. 7b, the minimum X-axis angle varies with the NGSO satellite pitch angle as shown by the black curve when the NGSO satellite infrasatellite point is 3.75 °. In order to make the minimum X-axis angle greater than 10 ° intersect with the line (5.5,10) having the minimum X-axis angle of 10 ° according to the black curve, the pitch angle of the NGSO satellite corresponding to the latitudinal highest beam center at the time of the offset maximum angle is 5.5 °, and the offset angle at this time is 28 °. It is thus possible to obtain NGSO satellites with a polarization latitude of 27 ° and a maximum bias angle of 28 °.
The biasing scheme in the co-linear interference scenario is shown in fig. 9 b: the latitude of the satellite subsatellite point is 3.75 degrees to 27 degrees, and the offset angle is reduced from 28 degrees to 0 degree; when the latitude is greater than 27 °, the low-orbit satellite does not take any bias; when the low earth satellite intersatellite point latitude decreases from 3.75 ° to 0 °, the low earth satellite turns off all beams and starts reverse biasing and just biases the angle to 0 ° at 0 ° intersatellite point latitude.
Under the interference scene of the NGSO satellite coverage area, the pitching angle of the NGSO satellite is 24 degrees, and the corresponding pitching angle of the outermost edge of the wave beam with the highest latitude under the non-bias situation of the NGSO satellite is achieved. From fig. 8a, it can be known that a curve with a low-orbit satellite pitch angle of 24 ° intersects with a straight line with a minimum interference angle of 5.2 ° (24.5,5.2), and in order to ensure that the minimum interference angle is greater than 5.2 °, the beams of the NGSO satellite need to be biased to a low-latitude area. In fig. 8b, when the low earth orbit satellite is 3.75 °, the minimum interference angle is shown as a black curve as the NGSO satellite pitch angle changes. . In order to make the most interference angle greater than 5.2 ° intersect with the line with the least interference angle of 5.2 ° according to the black curve (1.32,5.2), the pitch angle of the NGSO satellite corresponding to the outer edge of the latitudinal highest beam at the time of the maximum offset angle is 1.32 °, and the offset angle at this time is 25.32 °. From the above two figures, it can be seen that the NGSO satellite has a declination of 24.5 ° and a maximum bias angle of 25.32 °.
Then, the bias scheme in the NGSO satellite footprint interference scenario is shown in fig. 9 a: the latitude of the satellite subsatellite point is 3.75 degrees to 24.5 degrees, and the offset angle is reduced from 25.32 degrees to 0 degree; when the latitude is greater than 24.5 degrees, the low-orbit satellite does not adopt any bias; as the low orbit satellite substellar point latitude decreases from 3.75 ° to 0 °, the low orbit satellite turns off all beams and begins reverse biasing and is biased at 0 ° to just 0 ° at the substellar point latitude.
Under the condition that the two schemes respectively adopt respective linear bias, the minimum interference angle and the minimum X-axis angle both meet the requirement. The offset angle required to avoid co-linear interference is larger than that of the NGSO satellite coverage area, and the more severe offset is required to avoid co-linear interference, which is mainly caused by the slower attenuation of the strip beam in the north-south direction, and the larger offset angle is required to reach the same downlink EPFD.
The collinear interference scene can achieve the purpose of reducing the offset by improving the sidelobe attenuation of the antenna. The NGSO satellite bias angle is greater than or equal to the bias of the NGSO satellite coverage area even if the satellite beam is attenuated very rapidly. Biasing of the NGSO satellite coverage area is a hard requirement that cannot reduce the bias angle of the NGSO satellite coverage area by speeding up sidelobe fading of the NGSO satellite.
In order for the EPFD of the above two scenarios to meet ITU radio rules clause 22, the polarization latitude and the maximum polarization angle are the maximum of the two scenarios. The bias method ensures that the downlink interference of a single NGSO satellite to the geostationary orbit satellite is lower than an EPFD limit value in ITU related documents, and the bias requirement determining scheme can provide certain suggestions for the formulation of an interference avoidance strategy of an NGSO satellite constellation and the design of an on-satellite payload.
While various embodiments of the present invention have been described above, it should be understood that they have been presented by way of example only, and not limitation. It will be apparent to persons skilled in the relevant art that various combinations, modifications, and changes can be made thereto without departing from the spirit and scope of the invention. Thus, the breadth and scope of the present invention disclosed herein should not be limited by any of the above-described exemplary embodiments, but should be defined only in accordance with the following claims and their equivalents.

Claims (4)

1. A design method of an NGSO satellite bias scheme is characterized by comprising the following steps:
calculating the EPFD in the worst case geometry based on the parameters of the NGSO satellite and the GSO satellite and comparing with the downlink EPFD limit in ITU radio rules clause 22;
if the EPFD under the worst geometrical situation is larger than the downlink EPFD limit value, calculating values of a minimum interference angle and a minimum X-axis angle;
respectively simulating according to the minimum X-axis angle mu and the minimum interference angle beta to obtain a bias angle when the polarization latitude and the under-satellite point latitude of the NGSO satellite are 3.75 degrees under a collineation interference avoiding scene and an NGSO satellite coverage area interference avoiding scene; and
respectively selecting the maximum polarization latitude and the maximum bias angle in the two scenes, and determining bias schemes of the two scenes, wherein the bias schemes comprise:
linearly biasing between the latitude of the subsatellite point of 3.75 degrees and the polarization latitude, so that the bias angle is linearly reduced to zero degrees from the maximum bias angle;
when the latitude of the substellar point is larger than the bias latitude, no bias is made; and
when the sub-satellite latitude decreases from 3.75 ° to zero degrees, the NGSO satellite turns off all beams and starts reverse biasing such that the bias angle is 0 ° at a sub-satellite latitude of 0 °.
2. The design method of claim 1, wherein the EPFD in the worst case geometry is calculated as follows:
Figure FDA0003527342380000011
wherein the content of the first and second substances,
p is the power of the input antenna of the transmitting station,
Gt(theta) is the gain when the off-axis angle of the NGSO satellite transmitting antenna is theta,
d is the distance between the transmitting station of the NGSO satellite and the receiving station of the GSO satellite, is equal to the orbital altitude of the NGSO satellite,
Figure FDA0003527342380000012
for GSO satellite receiving antenna off-axis angle of
Figure FDA0003527342380000013
Gain of time, and
Gr,maxis the maximum gain of the GSO satellite receiving station.
3. The design method of claim 1, wherein the calculation of the minimum X-axis angle μ comprises:
Figure FDA0003527342380000021
and x, y and z are coordinate values of a direction vector of the NGSO satellite pointing to the GSO satellite ground station in a beam rectangular coordinate system.
4. The design method of claim 1, wherein the minimum interference angle β is calculated by trigonometric function of a triangular LCH, where L is the NGSO satellite coordinates, C is the earth surface point corresponding to the NGSO satellite azimuth angle θ and H is a point on the GSO satellite orbit, and the relative longitude difference between the H point and the GSO satellite is δ:
Figure FDA0003527342380000022
CN202010951218.0A 2020-09-11 2020-09-11 Design method of NGSO satellite bias scheme Active CN112054838B (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
CN202010951218.0A CN112054838B (en) 2020-09-11 2020-09-11 Design method of NGSO satellite bias scheme

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
CN202010951218.0A CN112054838B (en) 2020-09-11 2020-09-11 Design method of NGSO satellite bias scheme

Publications (2)

Publication Number Publication Date
CN112054838A CN112054838A (en) 2020-12-08
CN112054838B true CN112054838B (en) 2022-05-17

Family

ID=73611200

Family Applications (1)

Application Number Title Priority Date Filing Date
CN202010951218.0A Active CN112054838B (en) 2020-09-11 2020-09-11 Design method of NGSO satellite bias scheme

Country Status (1)

Country Link
CN (1) CN112054838B (en)

Families Citing this family (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN113433571B (en) * 2021-05-21 2022-09-23 航天科工空间工程发展有限公司 Method for quickly estimating worst interference of downlink
CN114598380B (en) * 2022-03-07 2023-10-20 国家无线电监测中心 Method and device for determining downlink worst geometric shape of NGSO satellite constellation system
CN115276862A (en) * 2022-07-28 2022-11-01 银河航天(北京)网络技术有限公司 Method and device for simulating coverage of non-stationary orbit satellite

Citations (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN102681547A (en) * 2012-04-25 2012-09-19 中国人民解放军装备学院 Method for maintaining and controlling longitude of IGSO (inclined geo stationary earth orbit) sub-satellite point orbit intersection
CN102927983A (en) * 2012-10-31 2013-02-13 北京控制工程研究所 Method for protecting earth sensor probe under GEO (Geosynchronous Orbit) satellite pitch offset
CN107408979A (en) * 2015-04-03 2017-11-28 高通股份有限公司 For the method and apparatus for the interference limitation for avoiding exceeding native to this world stationary satellite system
CN108712202A (en) * 2018-05-16 2018-10-26 清华大学 Evade the method and satellite communication system of co-channel interference by deflecting antenna direction
US10277308B1 (en) * 2016-09-22 2019-04-30 Viasat, Inc. Methods and systems of adaptive antenna pointing for mitigating interference with a nearby satellite
CN110417460A (en) * 2019-08-16 2019-11-05 国家无线电监测中心 A kind of analysis method that non-geo satellite interferes satellite
CN110518965A (en) * 2019-10-09 2019-11-29 北京中科晶上科技股份有限公司 A kind of Non GEO satellite is to geosynchronous satellite uplink interference bypassing method

Family Cites Families (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN110958047A (en) * 2019-10-12 2020-04-03 中国空间技术研究院 Low-orbit constellation GEO frequency interference avoidance method based on multiple coverage

Patent Citations (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN102681547A (en) * 2012-04-25 2012-09-19 中国人民解放军装备学院 Method for maintaining and controlling longitude of IGSO (inclined geo stationary earth orbit) sub-satellite point orbit intersection
CN102927983A (en) * 2012-10-31 2013-02-13 北京控制工程研究所 Method for protecting earth sensor probe under GEO (Geosynchronous Orbit) satellite pitch offset
CN107408979A (en) * 2015-04-03 2017-11-28 高通股份有限公司 For the method and apparatus for the interference limitation for avoiding exceeding native to this world stationary satellite system
US10277308B1 (en) * 2016-09-22 2019-04-30 Viasat, Inc. Methods and systems of adaptive antenna pointing for mitigating interference with a nearby satellite
CN108712202A (en) * 2018-05-16 2018-10-26 清华大学 Evade the method and satellite communication system of co-channel interference by deflecting antenna direction
CN110417460A (en) * 2019-08-16 2019-11-05 国家无线电监测中心 A kind of analysis method that non-geo satellite interferes satellite
CN110518965A (en) * 2019-10-09 2019-11-29 北京中科晶上科技股份有限公司 A kind of Non GEO satellite is to geosynchronous satellite uplink interference bypassing method

Non-Patent Citations (4)

* Cited by examiner, † Cited by third party
Title
Corrections to "Beam Coverage Comparison of LEO Satellite Systems Based on User Diversification";Shiyi Xia 等;《IEEE Access》;20200716;第8卷;全文 *
RFI Estimation from Non-GSO Satellites Based on Two Line Element Assisted Equivalent Power Flux Density Calculations;Tom Hartman 等;《2018 International Symposium on Electromagnetic Compatibility》;20181008;全文 *
基于干扰观测器的偏置动量卫星滚转偏航姿态控制及主动振动抑制;袁国平 等;《现代电子技术》;20130215;第36卷(第3期);全文 *
基于空间隔离的低轨卫星系统频谱共享方法;张泓湜 等;《北京航空航天大学学报》;20180930;第44卷(第9期);全文 *

Also Published As

Publication number Publication date
CN112054838A (en) 2020-12-08

Similar Documents

Publication Publication Date Title
CN112054838B (en) Design method of NGSO satellite bias scheme
CN111355559B (en) Encoding control method for satellite-to-ground directional distribution link of low-orbit constellation
Debruin Control systems for mobile satcom antennas
Miller et al. Satellite communications: mobile and fixed services
CN106954223B (en) Communication method of communication-in-motion end station system and communication-in-motion end station system
CN112399429B (en) Communication scene modeling method and system for satellite communication system
CN111447034B (en) Method for relieving same frequency interference of non-stationary orbit satellite to stationary orbit satellite
CN113691303B (en) Optical link relay communication system
CN115118363A (en) NGSO satellite system interference and channel capacity obtaining method based on spatial position probability
CN112083449A (en) Positioning method for minimum interference angle area of NGSO satellite coverage area
CN112887008B (en) Space-based VDES (vertical double-layer data storage) based downlink communication link parameter determination system and method
CN206790714U (en) A kind of communication in moving end station system
CN112383344A (en) Method and system for sharing frequency spectrum of NGSO satellite constellation system and ground system
US6633744B1 (en) Ground-based satellite communications nulling antenna
Arias et al. Small satellite link budget calculation
CN111953408B (en) Method for reducing off-axis angle of NGSO system terminal
Forti et al. Mobile communications: High-speed train antennas from Ku to Ka
CN113037359A (en) Low-orbit satellite feeder link communication method based on LoS MIMO architecture
Tan et al. Modern Low-Cost Phased Array Technologies and Accompanying Fixed Satellite Service (FSS) Regulatory Requirements
CN111180901B (en) High-frequency accurate-pressing broadband array method and device
Dessouky et al. MSAT-X: A technical introduction and status report
Hovstad et al. Future systems for mobile satellite communications
Kozhemyako et al. Energy calculation of a satellite communication system
Pattan The advent of land mobile satellite service systems
CN115733537A (en) Method and device for calculating minimum available elevation angle of low-orbit satellite communication during rainfall

Legal Events

Date Code Title Description
PB01 Publication
PB01 Publication
SE01 Entry into force of request for substantive examination
SE01 Entry into force of request for substantive examination
GR01 Patent grant
GR01 Patent grant