CN113553695B - Method for giving consideration to asteroid early warning and asteroid cataloguing in sun direction - Google Patents
Method for giving consideration to asteroid early warning and asteroid cataloguing in sun direction Download PDFInfo
- Publication number
- CN113553695B CN113553695B CN202110686723.1A CN202110686723A CN113553695B CN 113553695 B CN113553695 B CN 113553695B CN 202110686723 A CN202110686723 A CN 202110686723A CN 113553695 B CN113553695 B CN 113553695B
- Authority
- CN
- China
- Prior art keywords
- telescope
- asteroid
- earth
- time
- efficiency
- 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
Links
- 238000000034 method Methods 0.000 title claims abstract description 39
- 238000006243 chemical reaction Methods 0.000 claims abstract description 11
- 230000000007 visual effect Effects 0.000 claims description 4
- 238000012544 monitoring process Methods 0.000 abstract description 22
- 230000003287 optical effect Effects 0.000 description 34
- 238000005516 engineering process Methods 0.000 description 5
- 230000006855 networking Effects 0.000 description 4
- 238000004088 simulation Methods 0.000 description 3
- 230000000694 effects Effects 0.000 description 2
- 238000012795 verification Methods 0.000 description 2
- PEDCQBHIVMGVHV-UHFFFAOYSA-N Glycerine Chemical compound OCC(O)CO PEDCQBHIVMGVHV-UHFFFAOYSA-N 0.000 description 1
- 235000017899 Spathodea campanulata Nutrition 0.000 description 1
- 230000009286 beneficial effect Effects 0.000 description 1
- OIQPTROHQCGFEF-UHFFFAOYSA-L chembl1371409 Chemical compound [Na+].[Na+].OC1=CC=C2C=C(S([O-])(=O)=O)C=CC2=C1N=NC1=CC=C(S([O-])(=O)=O)C=C1 OIQPTROHQCGFEF-UHFFFAOYSA-L 0.000 description 1
- 238000004891 communication Methods 0.000 description 1
- 230000007547 defect Effects 0.000 description 1
- 238000013461 design Methods 0.000 description 1
- 238000011161 development Methods 0.000 description 1
- 239000002245 particle Substances 0.000 description 1
- 230000001360 synchronised effect Effects 0.000 description 1
- MYVIATVLJGTBFV-UHFFFAOYSA-M thiamine(1+) chloride Chemical compound [Cl-].CC1=C(CCO)SC=[N+]1CC1=CN=C(C)N=C1N MYVIATVLJGTBFV-UHFFFAOYSA-M 0.000 description 1
Images
Classifications
-
- G—PHYSICS
- G06—COMPUTING; CALCULATING OR COUNTING
- G06F—ELECTRIC DIGITAL DATA PROCESSING
- G06F30/00—Computer-aided design [CAD]
- G06F30/20—Design optimisation, verification or simulation
-
- G—PHYSICS
- G06—COMPUTING; CALCULATING OR COUNTING
- G06F—ELECTRIC DIGITAL DATA PROCESSING
- G06F17/00—Digital computing or data processing equipment or methods, specially adapted for specific functions
- G06F17/10—Complex mathematical operations
-
- G—PHYSICS
- G06—COMPUTING; CALCULATING OR COUNTING
- G06F—ELECTRIC DIGITAL DATA PROCESSING
- G06F2111/00—Details relating to CAD techniques
- G06F2111/04—Constraint-based CAD
-
- G—PHYSICS
- G06—COMPUTING; CALCULATING OR COUNTING
- G06F—ELECTRIC DIGITAL DATA PROCESSING
- G06F2111/00—Details relating to CAD techniques
- G06F2111/10—Numerical modelling
Landscapes
- Engineering & Computer Science (AREA)
- Physics & Mathematics (AREA)
- Theoretical Computer Science (AREA)
- General Physics & Mathematics (AREA)
- Mathematical Physics (AREA)
- Data Mining & Analysis (AREA)
- General Engineering & Computer Science (AREA)
- Software Systems (AREA)
- Computational Mathematics (AREA)
- Pure & Applied Mathematics (AREA)
- Databases & Information Systems (AREA)
- Mathematical Optimization (AREA)
- Mathematical Analysis (AREA)
- Algebra (AREA)
- Computer Hardware Design (AREA)
- Evolutionary Computation (AREA)
- Geometry (AREA)
- Emergency Alarm Devices (AREA)
Abstract
The invention relates to the technical field of asteroid monitoring and early warning, in particular to a method for giving consideration to asteroid early warning and asteroid cataloging in the sun direction. The method comprises the following steps: determining the position of a telescope positioned on the earth navigation orbit according to the set avoidance angle of the telescope to the sun; determining the limit observation capability of the telescope according to the conversion relation between the early warning range and the diameters of the minor planets and the sight stars and the like; establishing a visibility model of the telescope for the asteroid according to time constraint, instantaneous field of view constraint, sight star constraint and other constraints which are simultaneously met when the asteroid is visible; based on the established visibility model, the early warning efficiency and the cataloguing efficiency of the telescope on small planets from the sun direction are balanced, and the size of the observation day area in the yellow weft direction is optimized to determine the observation day area of the telescope; and according to the optimized and determined observation sky area, the early warning efficiency and the cataloguing efficiency of the telescope to the small planets from the sun direction are considered, and the time ratio of the telescope orientation to the time away from the earth is optimized to determine a telescope searching strategy.
Description
Technical Field
The invention relates to the technical field of asteroid monitoring and early warning, in particular to a method for giving consideration to asteroid early warning and asteroid cataloging in the sun direction.
Background
The asteroid monitoring is carried out by means of a foundation and a space-based platform and by means of various monitoring means such as radar technology (ranging, speed measuring and angle measuring), photoelectric technology (photoelectric angle measuring and laser ranging) and the like. The foundation platform is not limited by factors such as volume and mass, can obtain a far monitoring distance by adopting large transmitting power and obtain high spatial resolution by adopting a large-caliber antenna, and is a main means for monitoring the asteroid at present. However, there are two disadvantages to asteroid ground monitoring: firstly, the effective coverage range of the monitoring stations cannot achieve seamless coverage of airspace and time domain, and more monitoring stations are established and are limited by factors such as politics, geography and the like; secondly, in the existing monitoring means, the monitoring distance of the foundation radar is limited, the photoelectric monitoring of the foundation is easily influenced by weather, and the foundation can only work at fine night generally, and the asteroid from the sun direction cannot be warned. The space-based platform is positioned in a space orbit outside the earth atmosphere, has the advantages of flexible arrangement, no influence of atmosphere and weather, large monitoring range and the like, and greatly increases the monitoring capability on the small planets. In addition, the monitoring capability of the radar technology is inversely proportional to the fourth power of the distance, the monitoring capability of the photoelectric monitoring technology is inversely proportional to the square of the distance, the asteroid is generally far away, and the photoelectric monitoring technology is more beneficial to monitoring the asteroid. Therefore, space-based photoelectric monitoring is a development trend in the field of asteroid monitoring and early warning.
Aiming at the problem that the ground-based telescope can not early warn small planets from the sun direction, various solutions for the space-based optical telescope positioned on different tracks exist at present. The different orbital space-based optical telescope schemes are analyzed: the sun synchronous orbit and the middle/high earth orbit take the earth as the center, have better accessibility, but the advantage in the aspect of the early warning distance from the sun direction to the asteroid in comparison with a ground-based telescope is negligible, and the Middle Earth Orbit (MEO) can observe a fireball when the asteroid enters the atmosphere but cannot provide early warning; the telescope positioned on the back of the moon has a quiet observation environment, but the advantage in the aspect of early warning distance is also negligible; the early warning efficiency of the L1 point in the day is better, but the early warning distance from the sun to the small planet is at most 150 kilometers, and the early warning distance is shorter; the early warning distance of a large-amplitude retrograde orbit (DRO) of a solar-terrestrial system to a small planet from the sun direction can exceed ten million kilometers, but a constellation consisting of three telescopes is required to be arranged to completely cover the area inside the earth; the planet-like orbit can provide a long early warning distance, but cannot early warn the asteroid from the sun direction, and has high requirements on rocket carrying capacity and ground communication due to the long distance from the earth.
From the analysis, the selection of the space-based telescope orbit has important significance for the asteroid monitoring and early warning, and the space-based solution provided at present has the problems of short early warning distance or high economic cost caused by multi-star networking in the early warning of the asteroid from the sun direction.
Disclosure of Invention
The invention aims to overcome the defects of the prior art and provides a method for giving consideration to early warning of asteroids from the sun direction and cataloging of the asteroids, and aims to solve the problems that a foundation telescope cannot early warn the asteroids from the sun direction, the early warning distance of the space-based solution for early warning of the asteroids from the sun direction is short, or economic cost is high due to multi-satellite networking.
In order to achieve the above object, the present invention provides a method for considering asteroid warning and asteroid cataloging from the sun direction, wherein the method comprises:
determining the position of a telescope positioned on the earth navigation orbit according to the set avoidance angle of the telescope to the sun;
determining the limit observation capability of the telescope according to the conversion relation between the early warning range and the diameters of the minor planets and the sight stars and the like;
establishing a visibility model of the telescope for the asteroid according to time constraint, instantaneous field of view constraint, sight star constraint and other constraints which are simultaneously met when the asteroid is visible;
based on the established visibility model, the early warning efficiency and the cataloguing efficiency of the telescope on small planets from the sun direction are balanced, and the size of the observation day area in the yellow weft direction is optimized to determine the observation day area of the telescope;
and according to the optimized and determined observation sky area, the early warning efficiency and the cataloguing efficiency of the telescope to the small planets from the sun direction are considered, and the time ratio of the telescope orientation to the time away from the earth is optimized to determine a telescope searching strategy.
As an improvement of the method, the telescope position at the earth navigation orbit is determined according to the set avoidance angle of the telescope to the sun; the method specifically comprises the following steps:
according to the avoidance angle theta of the telescope to the sun, the relation between the distance d of the telescope positioned on the earth navigation orbit relative to the earth and the radius r of the space around the earth which can be completely covered by the telescope is obtained by the following formula:
r＝d*sin(90°-θ)
and when the telescope is positioned 1058 kilometers in front of the earth according to the set avoidance angle theta of the telescope to the sun, the telescope can realize full coverage on the space of 0.05AU around the earth.
As an improvement of the method, the limit observation capability of the telescope is determined according to the early warning range and the conversion relation between the minor planet diameter and the sight star and the like; the method specifically comprises the following steps:
the absolute star, etc. H is obtained according to the following formula:
wherein D is the minor planet diameter, the unit is km, pv is the albedo, and pv is set as 0.1428;
determining the V of the star and the like according to the conversion relation of the diameter D of the minor planet, the H of the absolute star and the like and the V of the star and the like:
wherein r is the distance between the asteroid and the sun centroid, and the unit is AU, and Delta is the distance between the asteroid and the telescope, and the unit is AU; g is a slope parameter, and G is set to be 0.15; phi is a1(κ) and φ2(κ) are two intermediate parameters relating to the phases of the sun, the asteroid and the telescope, κ being the angle formed by the sun, the asteroid and the telescope, and is given in rad.
As an improvement of the method, the visibility model of the telescope to the asteroid is established according to the time constraint, the instantaneous field of view constraint, the sight star constraint and other constraints which are simultaneously met when the asteroid is visible; the method specifically comprises the following steps:
for the early warning of the telescope to the asteroid from the sun direction, the time constraint satisfied by the asteroid at the moment t is tin≤t≤tpWherein, tinThe start time, t, for the asteroid to enter the 0.05AU range of the EarthpThe time of the asteroid in the range of 0.05AU of the earth;
for the cataloging efficiency of the telescope, the time constraint met by the asteroid at the time T is that T is more than or equal to 0 and less than or equal to T, wherein T is the service life of the telescope;
the asteroid is positioned in the instantaneous field of view of the telescope at the moment t, and the instantaneous field of view constraint is satisfied as follows:
wherein lambda (t) is the yellow longitude difference of the asteroid relative to the earth at the time t, beta (t) is the yellow latitude of the asteroid relative to the earth at the time t, and lambda (t) is the yellow latitude of the asteroid relative to the earth at the time tmin(t) and lambdamax(t) the minimum and maximum yellow-meridian differences, beta, of the instantaneous field of view of the telescope at time t relative to the earthmin(t) and betamax(t) the minimum yellow latitude and the maximum yellow latitude of the instantaneous field of view of the telescope relative to the earth at the time t are respectively;
the star etc. at the time t of the asteroid is V (t), the telescope limit star etc. is 24, then the star etc. constraint satisfied by the asteroid at the time t is:
V(t)≤24
and establishing a visibility model of the telescope for the asteroid by the time constraint, the instantaneous field of view constraint, the sight star constraint and other constraints which are simultaneously met when the asteroid is visible.
As an improvement of the above method, the telescope is determined by balancing the early warning efficiency and the cataloguing efficiency of the telescope on the small planets from the sun direction based on the established visibility model and optimizing the size of the observation day area in the yellow weft direction; the method specifically comprises the following steps:
according to the time constraint of the visibility model, defining the early warning efficiency of the telescope as the ratio of the number of visible asteroids in the period from the 0.05AU range of entering the earth to the near place to the total number of the asteroids in the 0.05AU range of entering the earth; the asteroid from the sun direction is defined as the asteroid with the absolute value of the difference between the sun meridian and the sun meridian less than 90 degrees when the asteroid enters the range of 0.05 AU;
defining the cataloguing efficiency of the telescope as the ratio of the number of visible asteroids in the service life of the telescope to the total number of the asteroids in the database according to the time constraint of the visibility model;
the early warning efficiency and the cataloguing efficiency of the balance telescope on the small planets from the sun direction are combined with the set on-orbit age of the telescope and the time constraint, the instant visual field constraint, the sight star constraint and the like of the visibility model to determine the observation sky area of the telescope.
As an improvement of the above method, the telescope search strategy is determined by optimizing the time ratio of the telescope orientation to the time away from the earth according to the optimally determined observation sky area, considering both the early warning efficiency and the cataloguing efficiency of the telescope to the small planets from the sun direction; the method specifically comprises the following steps:
respectively calculating the upper limit and the lower limit of the telescope positioned on the earth navigation orbit on the early warning efficiency and the cataloguing efficiency from the sun direction according to the optimized and determined observation sky area;
selecting time ratios of a plurality of groups of telescope orientations to the earth away from the earth, respectively calculating early warning efficiency and cataloging efficiency of the telescopes to the small planets from the sun direction, and selecting the time ratios which take the early warning efficiency and the cataloging efficiency into consideration from the plurality of groups of time ratios within the upper and lower limit ranges of the early warning efficiency and the cataloging efficiency of the telescopes to the small planets from the sun direction, thereby determining a telescope searching strategy.
A system for accounting for asteroid warning from the sun and asteroid cataloging, the system comprising: the system comprises a position determining module, a limit observation capability determining module, a visibility model establishing module, an observation day zone determining module and a searching strategy determining module; wherein,
the position determining module is used for determining the position of the telescope in the earth pilot orbit according to the set avoidance angle of the telescope to the sun;
the extreme observation capability determining module is used for determining the extreme observation capability of the telescope according to the early warning range and the conversion relation between the minor planet diameter and the sight stars and the like;
the visibility model establishing module is used for establishing a visibility model of the telescope for the asteroid according to time constraint, instantaneous field of view constraint, sight star constraint and other constraints which are simultaneously met when the asteroid is visible;
the observation day area determining module is used for balancing the early warning efficiency and the cataloguing efficiency of the telescope on the small planets from the sun direction based on the established visibility model, and optimizing the size of the observation day area in the yellow weft direction to determine the observation day area of the telescope;
the searching strategy determining module is used for determining a telescope searching strategy according to the optimized and determined observation day zone, considering the early warning efficiency and the cataloguing efficiency of the telescope to the small planets from the sun direction, and optimizing the time ratio of the telescope orientation to the time back to the earth.
Compared with the prior art, the invention has the advantages that:
1. the invention provides an optical telescope deployed on the earth navigation orbit, which utilizes the phase relation always approximate to the earth to early warn a asteroid from the sun direction;
2. by adopting the method, the early warning efficiency and the cataloging efficiency of the small planets from the sun direction can be considered, the early warning efficiency of the earth navigation orbit optical telescope with the ultimate observation capability of 24 planets to the small planets from the sun direction is 92.3 percent and is 2.7 times of the L1 point of the sun under the same condition, and the cataloging efficiency is basically the same as the L1 point of the sun.
Drawings
FIG. 1 is a comparison of the early warning method of asteroid from the sun direction between the point L1 of the day and the earth pilot orbit, wherein FIG. 1(a) is the point L1 of the day and FIG. 1(b) is the earth pilot orbit;
FIG. 2 is a flow chart of a method of the present invention that combines early warning of asteroids from the sun with cataloging of asteroids;
FIG. 3 is a relationship of the earth's navigation orbit optical telescope relative to the earth's distance and the coverage space;
FIG. 4 is the minimum diameter of a asteroid observable by an optical telescope with an ultimate observation capability of 24 equi-geostationary navigation orbits;
FIG. 5 is a time constraint on the early warning performance of asteroid;
FIG. 6 is the instantaneous field of view and scan pattern of the telescope;
FIG. 7 is an earth piloting orbit optical telescope observation sky plot;
FIG. 8 is an optical telescope search strategy for Earth's pilot orbit, wherein FIG. 8(a) is a plan view of the optical telescope search strategy for Earth's pilot orbit; FIG. 8(b) is a perspective view of an optical telescope search strategy for the earth's navigation orbit;
FIG. 9 is a comparison of early warning performance of the sun L1 point and the earth piloting orbit optical telescope against the asteroid from the sun direction;
fig. 10 is a comparison of the cataloging performance of the small planets at the point L1 of the day and the earth's navigation orbit optical telescope.
Detailed Description
The technical solution of the present invention will be described in detail below with reference to the accompanying drawings and examples.
The invention provides a method for deploying an optical telescope in an earth navigation orbit and considering asteroid early warning and asteroid cataloging from the sun direction, which is shown in figure 1. Firstly, determining the position of a telescope through the avoiding angle of the telescope to the sun; secondly, considering the diameter distribution of the small planets, determining the limit observation capability of the telescope; then, considering the yellow weft distribution of the asteroid in the range of 0.05AU of the earth and the time interval of two adjacent asteroids in the range of 0.05AU around the earth, based on the established visibility model, the observation sky area and the search strategy of the earth navigation orbit optical telescope are optimized, and therefore the requirements of early warning and cataloguing of the asteroids from the sun direction are met by one optical telescope. The simulation verification is carried out on the asteroid group generated by the Granvik model, and the result shows that under the designed search strategy, the early warning efficiency of the earth pilot orbit optical telescope with the ultimate observation capability of 24 stars on the asteroid from the sun direction is 92.3 percent, which is 2.7 times of the L1 point of the sun under the same condition, and the cataloging efficiency is basically the same as the L1 point of the sun. In conclusion, the arrangement of the optical telescope on the earth navigation orbit provided by the invention can meet the requirements of asteroid early warning and asteroid cataloging from the sun direction.
Example 1
As shown in fig. 2, embodiment 1 of the present invention provides a method for both asteroid warning and asteroid cataloging from the sun.
The invention aims at the problems that the ground-based telescope can not early warn the asteroid from the sun direction and the space-based solution provided at present has short early warning distance or needs multi-satellite networking, so that the economic cost is high, and the like, and realizes the requirements of early warning and asteroid cataloging from the sun direction by deploying one space-based optical telescope by utilizing the natural advantage that the earth navigation orbit optical telescope observes the space of 0.05AU surrounding the earth in real time and further optimizing the design. The specific steps are as follows:
step 1) determining the position of the telescope
The avoidance angle of the telescope to the sun is theta, the distance d of the telescope positioned on the earth navigation orbit relative to the earth and the radius r of the space around the earth which can be completely covered by the telescope are shown in figure 3, and the d and the r have the following relation:
r＝d*sin(90°-θ) (1)
assuming that the avoidance angle theta of the telescope to the sun is 45 degrees, the telescope is located 1058 kilometers in front of the earth, and can just realize full coverage on the space of 0.05AU around the earth as can be seen from the formula (1).
Step 2) determining the limit observation capability of the telescope
When the distance between the asteroid and the earth is less than 0.05AU, the asteroid is considered to have impact threat on the earth, so the early warning range of the telescope is an area with the relative earth distance less than 0.05 AU.
The conversion relationship between the minor planet diameter D, the absolute star and the like H and the visual star and the like V is shown as the following formula:
where D is the asteroid diameter, the unit is km, H is absolute star, etc., pv is the albedo, which is the ratio between the brightness of the asteroid as seen from the sun and white diffuse reflection spheres of the same size and distance, pv is 0 when the asteroid totally absorbs, pv is 1 when the total reflection is total, and pv is 0.1428 when the absolute star, etc. 22 corresponds to the asteroid diameter of 140 m.
Wherein V is the vista of the little planet, H is the absolute star of the little planet, etc.,r is the distance between the asteroid and the sun centroid, with the unit of AU; delta is the distance between the asteroid and the telescope, and the unit is AU; g is a slope parameter, the value of which depends on the way light is scattered by the particles on the surface of the asteroid. Since few asteroids measure the value of G, the assumed value for most asteroids G is 0.15; phi is a1(κ) and φ2(κ) is a parameter related to the phase of the sun-asteroid-telescope, and κ is the angle formed by the sun-asteroid-telescope in rad.
The impact of the asteroid with the diameter of 50 meters on the earth can cause large and medium city-level disasters, and the diameter of the asteroid in the Tonggus event is 40-60 meters. The telescope with higher ultimate observation capability means higher engineering technical requirements and economic cost, when the ultimate observation capability is 24 stars, the minimum diameter of a asteroid which can be observed by the earth pilot orbit optical telescope located 1058 kilometres in front of the earth is shown in figure 4, a perfect circle which is shown by a dotted line with the earth as a circle center in the figure is a space of 0.05AU around the earth, other dotted lines marked with numbers are the minimum diameter contour lines of the asteroid which can be observed by the earth pilot orbit optical telescope, and the numbers on the dotted lines are the numerical values of the contour lines; for the asteroid with the size of more than 50 meters, the telescope can provide almost all-round early warning for the earth.
Step 3) establishing a planetoid visibility model
If the asteroid is visible at the time t, the time constraint, the instantaneous field of view constraint, the star of view constraint and other constraints are simultaneously satisfied, and the detailed description is as follows.
1) Time constraints
For the early warning of the telescope to the asteroid from the sun direction, the condition that the asteroid meets the time constraint at the moment t is tin≤t≤tpWith the aim of warning the asteroid before it arrives at the near site, where tinFor this purpose, the start time, t, of the entry of the asteroid into the 0.05AU range of the earthpFor this reason, the time of the asteroid at the near position within 0.05AU of the earth is shown in FIG. 5; for the cataloging efficiency of the telescope, the condition that the asteroid meets the time constraint at the time T is that T is more than or equal to 0 and less than or equal to T, wherein T is the service life of the telescope.
2) Instantaneous field of view constraint
the asteroid is positioned in the instantaneous field of view of the telescope at the time t, the instantaneous field of view and the scanning mode of the telescope are as shown in FIG. 6, the instantaneous field of view of the telescope is 1.875 degrees multiplied by 7 degrees, and the light gray square at the lower right corner is the initial day area observed by the telescope. The azimuth of the asteroid relative to the telescope at the time t is described by adopting the yellow longitude difference lambda (t) and the yellow latitude beta (t) relative to the earth, and the minimum and maximum yellow longitude differences of the instantaneous field of view of the telescope at the time t relative to the earth are lambda (t)min(t)、λmax(t) minimum and maximum yellow picks of betamin(t)、βmax(t) of (d). The condition that the asteroid meets the instantaneous field of view constraint at the moment t is as follows:
3) restriction of sight and stars
The observation ability of the telescope is described by limit sight stars and the like, the sight stars and the like at the t moment of the asteroid are V (t), the limit sight stars and the like of the telescope determined by the above is 24, and the condition that the asteroid satisfies the constraint of the sight stars and the like at the t moment is as follows:
V(t)≤24 (5)
step 4) optimizing the telescope observation sky area
The early warning performance of the telescope is defined as the time period from entering the 0.05AU range of the earth to reaching the near place (i.e. t in the time constraint mentioned abovein≤t≤tp) The ratio of the number of visible asteroids to the total number of asteroids in the 0.05AU range around the earth, the asteroid from the solar direction being defined as the time when it enters the 0.05AU range (i.e. t in the time constraint mentioned above)inTime) and sun yellow meridian difference of less than 90 degrees; the cataloging efficiency of the telescope is defined as the ratio of the number of asteroids visible during the life of the telescope (i.e., t.ltoreq.T.ltoreq.0 in the time constraint described above) to the total number of asteroids in the database. The telescope observation sky region is shown in fig. 7, described laterally by the yellow longitude relative to the earth and longitudinally by the yellow latitude. With the increase of the observation sky area (the direction of the yellow latitude), the early warning efficiency of the telescope to the small planets from the sun direction is reduced, and the cataloguing efficiency is improved. Observation sky region (yellow latitude square)To) the increase causes the telescope to reduce the early warning efficiency of asteroid from the sun direction because: the residence time of the asteroid in 0.05AU of the earth is limited, the time for the telescope to finish scanning in an observation day area (in the direction of the yellow latitude) is increased due to the increase of the observation day area, the possibility that the asteroid enters the instantaneous field of view of the telescope is correspondingly reduced, and the early warning effect is finally reduced. For the cataloging efficiency, the residence time of the asteroid in the observation day area is long enough, and the number of the asteroids entering the observation day area is more when the observation day area (the direction of the yellow latitude) is increased, so the cataloging efficiency of the telescope on the asteroids is improved. The change range of the asteroid relative to the earth yellow latitude within the range of 0.05AU around the earth is analyzed, the telescope observation sky area (yellow latitude direction) is properly reduced, and the early warning efficiency and the cataloguing efficiency of the telescope on the asteroid from the sun direction are balanced. Assuming that the telescope is in orbit for 6 years, the instantaneous field of view is 1.875 degrees multiplied by 7 degrees, and the observation sky area (relative to the Earth's yellow meridian difference) is [ -45 degrees, 45 degrees °]∪[-135°,135°]The early warning efficiency and cataloguing efficiency corresponding to different observation day zones (in the yellow weft direction) are shown in table 1 when the limit sight star is 24 and the search strategy is 10:1, and the observation day zones (in the yellow weft direction) of the telescope are set to be [ -35 degrees and 35 degrees ] in comprehensive consideration]。
TABLE 1 early warning and cataloguing efficacy for different observation day zones (in the direction of the yellow weft) in size
Step 5) optimizing the telescope search strategy
The telescope search strategy is shown in fig. 8, and it is evident that as the time of the telescope facing away from the earth increases, the early warning performance of the telescope will decrease and the cataloging performance will increase. Assuming that the telescope is in orbit for 6 years, the instantaneous field of view size is 1.875 degrees multiplied by 7 degrees, the observation day zone (relative to the earth's yellow-meridian difference) is [ -45 degrees, 45 degrees [ -135 degrees, 135 degrees ], the observation day zone (in the direction of yellow latitude) is [ -35 degrees, 35 degrees ], the limit sight star and the like are 24, and the corresponding early warning efficiency and the corresponding cataloging efficiency of different search strategies are shown in table 2. According to the simulation result, when the telescope always faces the earth, namely the searching strategy is 1:0, the early warning efficiency of the telescope to the small planet from the sun direction is highest, and the cataloguing efficiency is lowest; when the search strategy is 10:1, although the early warning performance of the earth navigation orbit is reduced by 1.2% relative to the highest early warning performance, the cataloguing performance is improved by 8.8% relative to the cataloguing performance when the highest early warning performance is achieved, and is 27.1%. Therefore, the time that the telescope faces and backs to the earth is 10:1, and the telescope is used as an optical telescope search strategy for the earth navigation orbit, so that the early warning efficiency and the cataloguing efficiency of the telescope on small planets from the sun direction are considered.
TABLE 2 early warning and cataloguing efficiencies corresponding to different search strategies
The invention provides a method for deploying an optical telescope in an earth pilot orbit and considering early warning of asteroids from the sun direction and inventory of the asteroids, wherein the change curves of the early warning efficiency of the earth pilot orbit and a sun-ground L1 point optical telescope on the asteroids from the sun direction and the inventory efficiency of the asteroids along with the service life of the telescope are shown in figures 9 and 10, wherein in figure 9, a curve representing data points by dots is used as the earth pilot orbit optical telescope, and a curve representing the data points by triangles is used as the sun-ground L1 point optical telescope. In fig. 10, a curve in which dots indicate data points is an optical telescope for earth navigation orbit, and a curve in which data points are triangular is an optical telescope for day and earth L1 points. Obviously, the earth navigation orbit optical telescope meets the requirements of asteroid early warning and asteroid cataloging from the sun direction.
Example 2
The embodiment 2 of the invention provides a system for giving consideration to asteroid early warning and asteroid cataloging in the sun direction, which comprises the following components: the system comprises a position determining module, a limit observation capability determining module, a visibility model establishing module, an observation day zone determining module and a searching strategy determining module; the method is realized by adopting the method of the embodiment 1, wherein,
the position determining module is used for determining the position of the telescope in the earth pilot orbit according to the set avoidance angle of the telescope to the sun;
the extreme observation capability determining module is used for determining the extreme observation capability of the telescope according to the early warning range and the conversion relation between the minor planet diameter and the sight stars and the like;
the visibility model establishing module is used for establishing a visibility model of the telescope for the asteroid according to time constraint, instantaneous field of view constraint, sight star constraint and other constraints which are simultaneously met when the asteroid is visible;
the observation day area determining module is used for balancing the early warning efficiency and the cataloguing efficiency of the telescope on the small planets from the sun direction based on the established visibility model, and optimizing the size of the observation day area in the yellow weft direction to determine the observation day area of the telescope;
the searching strategy determining module is used for determining a telescope searching strategy according to the optimized and determined observation sky area, considering the early warning efficiency and the cataloguing efficiency of the telescope to the small planets from the sun direction, and optimizing the time ratio of the telescope orientation to the time away from the earth
The innovation points are as follows:
1) the invention provides an optical telescope deployed on the earth navigation orbit, which utilizes the phase relation always approximate to the earth to early warn a asteroid from the sun direction;
2) determining the limit observation capability which the telescope should have according to the diameter distribution of the small planets;
3) and establishing a visibility model, optimizing a telescope observation sky area and a searching strategy, and considering both the early warning efficiency of the telescope on the small planets from the sun direction and the cataloging efficiency of the telescope on the small planets.
The technical effects are as follows:
the american proposed cataloging of asteroids at point L1 on the day-ground (NEOCAM task), so the present invention performed simulation verification of the asteroid population generated using the Granvik model with point L1 on the day-ground as a comparison target. The result shows that under the designed search strategy, the early warning efficiency of the earth navigation orbit optical telescope with the ultimate observation capability of 24 stars on the small planet from the sun direction is 92.3 percent, which is 2.7 times of the L1 point of the sun under the same condition, and the cataloging efficiency is basically the same as the L1 point of the sun. In conclusion, the arrangement of the optical telescope in the earth navigation orbit can give consideration to asteroid early warning and asteroid cataloging from the sun direction. The reason is that the earth navigation orbit optical telescope always keeps approximate phase relation with the earth due to natural orbit advantages, and an observation sky area covers 0.05AU space around the earth in real time.
Aiming at the problems that a ground-based telescope cannot early warn asteroids from the sun direction and the problem that the early warning distance is short or the economic cost is high due to the fact that multi-satellite networking is needed in the space-based solution proposed at present, the invention provides a method for deploying an optical telescope on the earth navigation track and integrating early warning of asteroids from the sun direction and inventory of the asteroids, and the requirement of asteroid inventory can be met on the premise that early warning of the asteroids from the sun direction is guaranteed. The telescope with extreme observation capability of 24 stars is deployed in an earth pilot orbit 1058 kilometres in front of the earth, a sky area with the relative earth yellow longitude difference of [ -45 °,45 ° ] [ -135 °,135 ° ] and yellow latitude of [ -35 °,35 ° ] is observed, and a search strategy with the earth facing and earth back facing time of 10:1 is adopted, so that the purposes of enabling the telescope to be deployed and giving consideration to asteroid early warning and asteroid cataloguing from the sun direction are achieved.
Finally, it should be noted that the above embodiments are only used for illustrating the technical solutions of the present invention and are not limited. Although the present invention has been described in detail with reference to the embodiments, it will be understood by those skilled in the art that various changes may be made and equivalents may be substituted without departing from the spirit and scope of the invention as defined in the appended claims.
Claims (4)
1. A method of accounting for asteroid warning from the sun and asteroid cataloging, the method comprising:
determining the position of a telescope positioned on the earth navigation orbit according to the set avoidance angle of the telescope to the sun;
determining the limit observation capability of the telescope according to the conversion relation between the early warning range and the diameters of the minor planets and the sight stars and the like;
establishing a visibility model of the telescope for the asteroid according to time constraint, instantaneous field of view constraint, sight star constraint and other constraints which are simultaneously met when the asteroid is visible;
based on the established visibility model, the early warning efficiency and the cataloguing efficiency of the telescope on small planets from the sun direction are balanced, and the size of the observation day area in the yellow weft direction is optimized to determine the observation day area of the telescope;
according to the optimized and determined observation sky area, the early warning efficiency and the cataloguing efficiency of the telescope to the small planets from the sun direction are considered, and the time ratio of the telescope orientation to the time away from the earth is optimized to determine a telescope searching strategy;
establishing a visibility model of the telescope for the asteroid according to time constraint, instantaneous field of view constraint, sight star constraint and other constraints simultaneously met when the asteroid is visible; the method specifically comprises the following steps:
for the early warning of the telescope to the asteroid from the sun direction, the time constraint satisfied by the asteroid at the moment t is tin≤t≤tpWherein, tinThe start time, t, for the asteroid to enter the 0.05AU range of the EarthpThe time of the asteroid in the range of 0.05AU of the earth;
for the cataloging efficiency of the telescope, the time constraint met by the asteroid at the time T is that T is more than or equal to 0 and less than or equal to T, wherein T is the service life of the telescope;
the asteroid is positioned in the instantaneous field of view of the telescope at the moment t, and the instantaneous field of view constraint is satisfied as follows:
wherein lambda (t) is the yellow longitude difference of the asteroid relative to the earth at the time t, beta (t) is the yellow latitude of the asteroid relative to the earth at the time t, and lambda (t) is the yellow latitude of the asteroid relative to the earth at the time tmin(t) and lambdamax(t) the minimum and maximum yellow-meridian differences, beta, of the instantaneous field of view of the telescope at time t relative to the earthmin(t) and betamax(t) the minimum yellow latitude and the maximum yellow latitude of the instantaneous field of view of the telescope relative to the earth at the time t are respectively;
the star etc. at the time t of the asteroid is V (t), the telescope limit star etc. is 24, then the star etc. constraint satisfied by the asteroid at the time t is:
V(t)≤24
establishing a visibility model of the telescope for the asteroid by time constraint, instantaneous field of view constraint, sight star constraint and other constraints which are simultaneously met when the asteroid is visible;
based on the established visibility model, the early warning efficiency and the cataloguing efficiency of the telescope on small planets from the sun direction are balanced, and the size of the observation day area in the yellow weft direction is optimized to determine the observation day area of the telescope; the method specifically comprises the following steps:
according to the time constraint of the visibility model, defining the early warning efficiency of the telescope as the ratio of the number of visible asteroids in the period from the 0.05AU range of entering the earth to the near place to the total number of the asteroids in the 0.05AU range of entering the earth; the asteroid from the sun direction is defined as the asteroid with the absolute value of the difference between the sun meridian and the sun meridian less than 90 degrees when the asteroid enters the range of 0.05 AU;
defining the cataloguing efficiency of the telescope as the ratio of the number of visible asteroids in the service life of the telescope to the total number of the asteroids in the database according to the time constraint of the visibility model;
the early warning efficiency and the cataloguing efficiency of the balance telescope on the small planets from the sun direction are combined with the set on-orbit age of the telescope and the time constraint, the instant visual field constraint, the sight star constraint and the like of the visibility model to determine the observation sky area of the telescope;
according to the optimized and determined observation sky area, the early warning efficiency and the cataloguing efficiency of the telescope to the small planets from the sun direction are considered, and the time ratio of the orientation of the telescope to the time away from the earth is optimized to determine a telescope searching strategy; the method specifically comprises the following steps:
respectively calculating the upper limit and the lower limit of the telescope positioned on the earth navigation orbit on the early warning efficiency and the cataloguing efficiency from the sun direction according to the optimized and determined observation sky area;
selecting time ratios of a plurality of groups of telescope orientations to the earth away from the earth, respectively calculating early warning efficiency and cataloging efficiency of the telescopes to the small planets from the sun direction, and selecting the time ratios which take the early warning efficiency and the cataloging efficiency into consideration from the plurality of groups of time ratios within the upper and lower limit ranges of the early warning efficiency and the cataloging efficiency of the telescopes to the small planets from the sun direction, thereby determining a telescope searching strategy.
2. The method for giving consideration to both asteroid warning and asteroid cataloging in the sun direction as claimed in claim 1, wherein the telescope position on the earth navigation orbit is determined according to the set avoidance angle of the telescope to the sun; the method specifically comprises the following steps:
according to the avoidance angle theta of the telescope to the sun, the relation between the distance d of the telescope positioned on the earth navigation orbit relative to the earth and the radius r of the space around the earth which can be completely covered by the telescope is obtained by the following formula:
r＝d*sin(90°-θ)
and when the telescope is positioned 1058 kilometers in front of the earth according to the set avoidance angle theta of the telescope to the sun, the telescope can realize full coverage on the space of 0.05AU around the earth.
3. The method for giving consideration to both asteroid early warning and asteroid cataloging in the sun direction as claimed in claim 1, wherein the telescope limit observation capability is determined according to the early warning range and the conversion relationship between the asteroid diameter and the sight stars and the like; the method specifically comprises the following steps:
the absolute star, etc. H is obtained according to the following formula:
wherein D is the minor planet diameter, the unit is km, pv is the albedo, and pv is set as 0.1428;
determining the V of the star and the like according to the conversion relation of the diameter D of the minor planet, the H of the absolute star and the like and the V of the star and the like:
wherein r is the distance between the asteroid and the sun centroid, and the unit is AU, and Delta is the distance between the asteroid and the telescope, and the unit is AU; g is a slope parameter, and G is set to be 0.15; phi is a1(kappa) andφ2(κ) are two intermediate parameters relating to the phases of the sun, the asteroid and the telescope, κ being the angle formed by the sun, the asteroid and the telescope, and is given in rad.
4. A system for accounting for asteroid warning from the sun and asteroid cataloging, the system comprising: the system comprises a position determining module, a limit observation capability determining module, a visibility model establishing module, an observation day zone determining module and a searching strategy determining module; wherein,
the position determining module is used for determining the position of the telescope in the earth pilot orbit according to the set avoidance angle of the telescope to the sun;
the extreme observation capability determining module is used for determining the extreme observation capability of the telescope according to the early warning range and the conversion relation between the minor planet diameter and the sight stars and the like;
the visibility model establishing module is used for establishing a visibility model of the telescope for the asteroid according to time constraint, instantaneous field of view constraint, sight star constraint and other constraints which are simultaneously met when the asteroid is visible;
the observation day area determining module is used for balancing the early warning efficiency and the cataloguing efficiency of the telescope on the small planets from the sun direction based on the established visibility model, and optimizing the size of the observation day area in the yellow weft direction to determine the observation day area of the telescope;
the searching strategy determining module is used for determining a telescope searching strategy according to the optimized and determined observation day zone, considering the early warning efficiency and the cataloguing efficiency of the telescope on the small planets from the sun direction, and optimizing the time ratio of the telescope orientation to the time away from the earth;
the processing procedure of the visibility model establishing module specifically includes:
for the early warning of the telescope to the asteroid from the sun direction, the time constraint satisfied by the asteroid at the moment t is tin≤t≤tpWherein, tinThe start time, t, for the asteroid to enter the 0.05AU range of the EarthpThe time of the asteroid in the range of 0.05AU of the earth;
for the cataloging efficiency of the telescope, the time constraint met by the asteroid at the time T is that T is more than or equal to 0 and less than or equal to T, wherein T is the service life of the telescope;
the asteroid is positioned in the instantaneous field of view of the telescope at the moment t, and the instantaneous field of view constraint is satisfied as follows:
wherein lambda (t) is the yellow longitude difference of the asteroid relative to the earth at the time t, beta (t) is the yellow latitude of the asteroid relative to the earth at the time t, and lambda (t) is the yellow latitude of the asteroid relative to the earth at the time tmin(t) and lambdamax(t) the minimum and maximum yellow-meridian differences, beta, of the instantaneous field of view of the telescope at time t relative to the earthmin(t) and betamax(t) the minimum yellow latitude and the maximum yellow latitude of the instantaneous field of view of the telescope relative to the earth at the time t are respectively;
the star etc. at the time t of the asteroid is V (t), the telescope limit star etc. is 24, then the star etc. constraint satisfied by the asteroid at the time t is:
V(t)≤24
establishing a visibility model of the telescope for the asteroid by time constraint, instantaneous field of view constraint, sight star constraint and other constraints which are simultaneously met when the asteroid is visible;
the processing procedure of the observation sky region determining module specifically includes:
according to the time constraint of the visibility model, defining the early warning efficiency of the telescope as the ratio of the number of visible asteroids in the period from the 0.05AU range of entering the earth to the near place to the total number of the asteroids in the 0.05AU range of entering the earth; the asteroid from the sun direction is defined as the asteroid with the absolute value of the difference between the sun meridian and the sun meridian less than 90 degrees when the asteroid enters the range of 0.05 AU;
defining the cataloguing efficiency of the telescope as the ratio of the number of visible asteroids in the service life of the telescope to the total number of the asteroids in the database according to the time constraint of the visibility model;
the early warning efficiency and the cataloguing efficiency of the balance telescope on the small planets from the sun direction are combined with the set on-orbit age of the telescope and the time constraint, the instant visual field constraint, the sight star constraint and the like of the visibility model to determine the observation sky area of the telescope;
the processing procedure of the search strategy determination module specifically includes:
respectively calculating the upper limit and the lower limit of the telescope positioned on the earth navigation orbit on the early warning efficiency and the cataloguing efficiency from the sun direction according to the optimized and determined observation sky area;
selecting time ratios of a plurality of groups of telescope orientations to the earth away from the earth, respectively calculating early warning efficiency and cataloging efficiency of the telescopes to the small planets from the sun direction, and selecting the time ratios which take the early warning efficiency and the cataloging efficiency into consideration from the plurality of groups of time ratios within the upper and lower limit ranges of the early warning efficiency and the cataloging efficiency of the telescopes to the small planets from the sun direction, thereby determining a telescope searching strategy.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202110686723.1A CN113553695B (en) | 2021-06-21 | 2021-06-21 | Method for giving consideration to asteroid early warning and asteroid cataloguing in sun direction |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202110686723.1A CN113553695B (en) | 2021-06-21 | 2021-06-21 | Method for giving consideration to asteroid early warning and asteroid cataloguing in sun direction |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN113553695A CN113553695A (en) | 2021-10-26 |
| CN113553695B true CN113553695B (en) | 2022-02-08 |
Family
ID=78130739
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN202110686723.1A Active CN113553695B (en) | 2021-06-21 | 2021-06-21 | Method for giving consideration to asteroid early warning and asteroid cataloguing in sun direction |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN113553695B (en) |
Citations (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN106643742A (en) * | 2016-12-12 | 2017-05-10 | 东南大学 | Satellite-based automated successive asteroid observation method |
| CN112083445A (en) * | 2019-12-16 | 2020-12-15 | 中国科学院微小卫星创新研究院 | Method for reducing number of observation satellites for observing space target |
Family Cites Families (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN104176273B (en) * | 2014-07-15 | 2017-04-26 | 北京航空航天大学 | Target asteroid selection method for manned asteroid exploration |
| CN109269508A (en) * | 2018-10-09 | 2019-01-25 | 东南大学 | A kind of satellite is with respect to asteroid vision autonomous navigation method |
| CN112180722A (en) * | 2020-09-11 | 2021-01-05 | 中国空间技术研究院 | Planning method and device for spacecraft attitude maneuver path |
-
2021
- 2021-06-21 CN CN202110686723.1A patent/CN113553695B/en active Active
Patent Citations (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN106643742A (en) * | 2016-12-12 | 2017-05-10 | 东南大学 | Satellite-based automated successive asteroid observation method |
| CN112083445A (en) * | 2019-12-16 | 2020-12-15 | 中国科学院微小卫星创新研究院 | Method for reducing number of observation satellites for observing space target |
Also Published As
| Publication number | Publication date |
|---|---|
| CN113553695A (en) | 2021-10-26 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| US5582367A (en) | Elliptical orbit satellite, system, and deployment with controllable coverage characteristics | |
| Brozović et al. | Radar and optical observations and physical modeling of triple near-Earth Asteroid (136617) 1994 CC | |
| Ackermann et al. | A systematic examination of ground-based and space-based approaches to optical detection and tracking of artificial satellites. | |
| National Research Council | The global positioning system: A shared national asset | |
| WO2022064721A1 (en) | Monitoring system, satellite information transmission system, monitoring satellite, communication satellite, flying object response system, data relay satellite, equatorial satellite group, polar orbit satellite group, and inclined orbit satellite group | |
| US20130211778A1 (en) | Method for realizing a space survey system for monitoring near-earth space | |
| US20220135255A1 (en) | Space surveillance orbit | |
| CN106679653A (en) | Relative measurement method of HEO (High Elliptical Orbit) satellite group based on satellite sensor and inter-satellite link | |
| US20020036766A1 (en) | Satellite constellation for measuring atmospheric wind speeds using doppler lidar | |
| CN113591263A (en) | Wide-area target search constellation design method based on geometric analysis method | |
| CN113108776B (en) | Space target observation method with high coverage rate | |
| CN113553695B (en) | Method for giving consideration to asteroid early warning and asteroid cataloguing in sun direction | |
| Benner et al. | Radar observations of asteroid 1999 JM8 | |
| CN112083445B (en) | Method for reducing number of observation satellites for observing space target | |
| Rongzhi et al. | Spacecraft collision avoidance technology | |
| CN106855408A (en) | A kind of space multirobot towards GEO satellite in-orbit service is with respect to observation procedure | |
| CN115048817B (en) | Decision-making auxiliary method and system for analyzing ground deterrence | |
| RU2791102C1 (en) | Global satellite communications using medium circular orbits | |
| US20230071678A1 (en) | Spacecraft orbit determination system | |
| CN115688385B (en) | Method for constructing observation model of star sensor of single observation platform | |
| CN115583369B (en) | Ubiquitous perception observation method for GEO space debris by low-orbit multi-observation platform | |
| CN118348577B (en) | High orbit target real-time monitoring satellite system based on earth-moon panning point | |
| Кузьмина | Английский язык | |
| Kiselev et al. | The Ground-Based Infrastructure | |
| Dideriksen et al. | DISCO-2–an ambitious earth observing student CubeSat for arctic climate research |
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 |