Summary of the invention
In view of the defects existing in the prior art, the invention proposes the large-scale area observations under a kind of imaging of multi satellites jointDispatching method and system, to solve the technical issues of area observation repetitive rate is high, satellite resource wastes.
To realize the above-mentioned technical purpose, the specific technical solution that the present invention uses is as follows：
Large-scale area observation scheduling method under a kind of imaging of multi satellites joint, includes the following steps：
S1：Band division will be carried out to regional aim t respectively to the visible satellite of regional aim, and obtain candidate band setS={ si,O,j| i=1,2,3 ..., n；J=1,2,3 ..., n } wherein si,O,jIndicate satellite riRegional aim t is enclosed in oJ-th of band.
S101 obtains the satellite set R=that can be used for observation area target t in following one section of preset period of time [ts, te]{r1,r2,r3,...,rnAnd every satellite riWink root, wink root epoch time distance ts recently and before ts；
S102 carries out orbit prediction with corresponding wink root to the satellite in R, obtains every satellite at [ts, te] to region meshTarget SEE time window, excludes the satellite of no SEE time window, and remaining satellite set visible for regional aim t is fixedJustice is R'.[ts, te] is usually within user is to the requirement of the total period of the task of completion.
S103 requires the resolution ratio for excluding sensor to be less than defending for default lowest resolution according to the lowest resolution of imageStar.In this way, the image that the remote sensor of remaining satellite takes can reach resolution requirement.
S104 carries out band division to regional aim respectively with the satellite in R', obtains candidate band set S.
Subpoint of the satellite on ground is known as substar, and satellite motion and earth rotation move substar at the earth's surfaceForm sub-satellite track.Satellite push away sweeping along sub-satellite track direction to regional aim, and being formed with Satellite Camera breadth is widthThe a plurality of extending direction band identical with the extending direction of sub-satellite track successively arranged side by side of degree, realizes that band divides.Multi-satellite carries out band division along respective sub-satellite track direction, obtains the different band of a plurality of direction, width, constitutes and waitSelect band set.
S2：Select in candidate band set S to the maximum band of regional aim t coverage rate as candidate band, by itself plusEnter to have selected in band set S'.Coverage rate is the ratio of target area shared by banded zone and target area intersection.
S3：Each band is to the coverage rate for having selected each band in band set S' in calculating candidate band set S, hereReferred to as alternate covering rate；
S4：The smallest band of alternate covering rate in candidate band set S is selected, as best candidate band；
When alternate covering rate is identical, select in candidate band set S to the maximum candidate band of regional aim t coverage rateAs best candidate band；When alternate covering rate and coverage rate sequence all the same, when selecting task completion in candidate band set SBetween earliest candidate band as best candidate band；
The deposit of best candidate band has been selected and has been used to indicate satellite execution observation mission in band set S'.
S5：Best candidate band that this minor sort filters out is calculated to the coverage rate of regional aim t and preceding primary additionThe best candidate band of band set S' is selected to acquire coverage rate amplification to the difference of the coverage rate of regional aim t；Judgement, which acquires, to be coveredWhether lid rate amplification is greater than given threshold, if i.e. coverage rate amplification is greater than given threshold, then deletes band sa,b,j, a=i, b=O, that is, deleting has in the candidate band set of same satellite and identical circle time with the best candidate band that this minor sort filters outCandidate band, return step S2, continue band acquisition；Otherwise S6 is entered step.
If coverage rate amplification is greater than given threshold, return step S2 is needed, continues band acquisition.But due to satelliteOnly have side-sway attitude maneuver ability, is merely able to realize single imaging in the single to regional aim passes by, be defended for sameStar, same track circle time also can only just select a band to be observed, therefore return again to before step S2, need delete with mostExcellent candidate band has the candidate band in same satellite and the candidate band set of identical circle time.
If coverage rate amplification is less than or equal to given threshold, it is preferable that given threshold described in step S5 is 5%, thisWhen new band is added very little is influenced on the coverage rate of whole region target, it is contemplated that task completes timeliness, satellite costControl etc. stops continuing pick-up slip band.
S6:Moonscope scheduling is executed according to the band selected in band set S'.
As a further improvement of the present invention：
In step s 102, the satellite of the scheme of arrangement in preset time [ts, te] is deleted in R'.
After step S104, in candidate band set S, deletes and arranged task conflicting with global mission planningCandidate band corresponding to Meta task.
Step S3 includes the following steps：
S301：Sliding-model control is carried out to regional aim t, obtains the point set P of regional aim discretization；
S302：Calculate alternate covering rate Cri,o,k：
Wherein, Pi,o,kIndicate the discrete point set that satellite i covers k-th of band that regional aim decomposes in o circleIt closes, P indicates that the point set of regional aim discretization, N (C) indicate the element number of arbitrary collection C, PclBand set has been selected in expressionIn the discretization for having selected band for first point set, lcIt indicates to have selected the band number in band set S'.
Given threshold in step S5 is 5%.
As total technical concept, the present invention also provides the large-scale area observation schedulings under a kind of imaging of multi satellites jointSystem, including：
Division module is waited for that will carry out band division to regional aim respectively to the visible satellite of regional aimSelect band set；
Initial module, for selecting band deposit maximum to regional aim coverage rate in candidate band to select bandSet；
Computing module, for calculating each of candidate band set candidate band and having selected the band in band setAlternate covering rate；
Selecting module selects the smallest band of alternate covering rate to make for being ranked up according to alternate covering rate to bandFor best candidate band；When alternate covering rate is identical, candidate band is selected to make the maximum band of the coverage rate of regional aimFor best candidate band；In alternate covering rate and coverage rate sequence all the same, the band for selecting task completion time earliest is madeFor best candidate band, and the deposit of best candidate band is selected in band set；
Judgment module, for judging whether best candidate band is greater than given threshold to the coverage rate amplification of regional aim,If so, deleting the candidate band in the candidate band set that there is same satellite and identical circle time with best candidate band, returnComputing module is returned, execution module is otherwise entered；
Execution module, for executing moonscope scheduling according to the band selected in band set.
Further improvement as present system：
Further include screening module, before being divided for division module, filters out in following one section of preset time to regionThe visible satellite of target.
Further include the die block that disappears, after having been handled for division module, in candidate band set, deletes and advised with global taskBand corresponding to the conflicting Meta task of task has been arranged in drawing.
Computing module includes：
Discrete unit：Sliding-model control is carried out to regional aim；
Computing unit：Calculate alternate covering rate Cri,o,k：
Wherein, Pi,o,kIndicate the discrete point set that satellite i covers k-th of band that regional aim decomposes in o circleIt closes, P indicates that the point set of regional aim discretization, N (C) indicate the element number of arbitrary collection C, PclBand set has been selected in expressionIn the discretization for having selected band for first point set, lcIt indicates to have selected the band number in band set S'.
Threshold value in judgment module is 5%.
Beneficial effects of the present invention are as follows：
1. the large-scale area observation scheduling method under a kind of multi satellites joint imaging of the invention, divides regional aimSolution is capable of the band of single imaging to obtain, and selects band to carry out multiple target Combinatorial Optimization, target is to minimize selection observationBand number maximizes target coverage rate and minimizes task completion time, sees to reduce satellite to the repetition of regional aimIt surveys, enhances the timeliness of observation.
2. in a preferred approach, the calculating to alternate covering rate is carried out after regional aim progress sliding-model control again, avoidsIntegral on area greatly reduces calculation amount, saves and calculates time.
Other than objects, features and advantages described above, there are also other objects, features and advantages by the present invention.Below with reference to accompanying drawings, the present invention is described in further detail.
Specific embodiment
In order to which technical solution of the present invention and advantage is more clearly understood, with reference to the accompanying drawings and embodiments, to this hairIt is bright to be further elaborated.It should be appreciated that described herein, the specific embodiments are only for explaining the present invention, is not used toLimit the present invention.
It referring to Fig.1, is the flow chart of an of the invention specific embodiment, a kind of large-scale area sight that multi satellites joint imaging is lowerDispatching method is surveyed, is included the following steps：
S1：Band division will be carried out to regional aim respectively to the visible satellite of regional aim, and obtain candidate band set S={ si,O,j| i=1,2,3 ..., n；J=1,2,3 ..., n } wherein si,O,jIndicate satellite riRegional aim t is enclosed in oJ-th of band.
S101 obtains the satellite set R=that can be used for observation area target t in following one section of preset period of time [ts, te]{r1,r2,r3,...,rnAnd every satellite riWink root, wink root epoch time distance ts recently and before ts；
S102 carries out orbit prediction with corresponding wink root to the satellite in R, obtains every satellite at [ts, te] to region meshTarget SEE time window, excludes the satellite of no SEE time window, and remaining satellite set visible for regional aim t is fixedJustice is R'.[ts, te] is usually within user is to the requirement of the total period of the task of completion.Further, it is deleted in R'The satellite of scheme of arrangement in preset time [ts, te].
S103 requires the resolution ratio for excluding sensor to be less than defending for default lowest resolution according to the lowest resolution of imageStar.In this way, the image that the remote sensor of remaining satellite takes can reach resolution requirement.
S104 carries out band division to regional aim respectively with the satellite in R', obtains candidate band set S.FurtherIt deletes in candidate band set S and has arranged candidate corresponding to the conflicting Meta task of task with global mission planning in groundBand.Meta task is the task that single satellite can disposably complete observation.When in global mission planning single satellite in some timeTask has been arranged in carving, then cannot execute the band task selected in band, it is therefore desirable to which deletion mutually conflicts with task has been arrangedMeta task corresponding to band.
Subpoint of the satellite on ground is known as substar, and satellite motion and earth rotation move substar at the earth's surfaceForm sub-satellite track.Satellite push away sweeping along sub-satellite track direction to regional aim, and being formed with Satellite Camera breadth is widthThe a plurality of extending direction band identical with the extending direction of sub-satellite track successively arranged side by side of degree, realizes that band divides.Multi-satellite carries out band division along respective sub-satellite track direction, obtains the different band of a plurality of direction, width, constitutes and waitSelect band set.
S2：Select in candidate band set S to the maximum band of regional aim t coverage rate as candidate band, by itself plusEnter to have selected in band set S'.Coverage rate is the ratio of target area shared by banded zone and target area intersection.
The maximum band of coverage rate is selected in candidate band set in all candidate bands as initial and has selected band, energyIt is enough to reduce observation band number, improve observed efficiency.
S3：Each band is to the coverage rate for having selected each band in band set S' in calculating candidate band set S, hereReferred to as alternate covering rate.
S301：Sliding-model control is carried out to regional aim t, obtains the point set P of regional aim discretization；
Referring to fig. 2, to regional aim carry out sliding-model control use the equidistant discrete method taken a little, with it is a series of fromScatterplot describes regional aim.Computational accuracy can be controlled by the distance between discrete point, and discrete point obtains more intensive, meterThe precision of calculation is higher, but the complexity calculated also increases.
S302：Calculate alternate covering rate Cri,o,k：
Wherein, Pi,o,kIndicate the discrete point set that satellite i covers k-th of band that regional aim decomposes in o circleIt closes, P indicates that the point set of regional aim discretization, N (C) indicate the element number of arbitrary collection C, PclBand set has been selected in expressionIn the discretization for having selected band for first point set, lcIt indicates to have selected the band number in band set S'.
Referring to Fig. 3, the area of band in band set has been selected to take the union area for having selected band in band set, to regionUnion area after discrete is the point number of set, eliminates ask the step of having selected band overlapping area in band set in this way.Also, the calculating to alternate covering rate is carried out after regional aim progress sliding-model control again, avoids the integral on area, significantlyReduce calculation amount, saves the calculating time.
S4：The smallest band of alternate covering rate in candidate band set S is selected, as best candidate band.Work as friendshipWhen fork coverage rate is identical, select in candidate band set S to the maximum candidate band of regional aim t coverage rate as best candidateBand；When alternate covering rate and coverage rate sequence all the same, the candidate that task completion time is earliest in candidate band set S is selectedBand is as best candidate band.
The deposit of best candidate band has been selected and has been used to indicate satellite execution observation mission in band set S'.
According to the calculation formula of S3 step, each of candidate band set candidate band can be successively calculated toThe alternate covering rate for selecting the band in band set, is ranked up candidate band according to alternate covering rate, selects alternate coveringFor the smallest band of rate as best candidate band, deposit, which has been selected, is used to indicate satellite execution observation mission in band set.IntersectCoverage rate minimum is that the overlapping of an interband is minimum, this is the very important factor considered in planning, can reduce defend in this wayStar is to the repeated measures of regional aim, so that entire programme be enable to realize with least band number to regional aimSatellite resource is saved in observation.
When the sequence of alternate covering rate is identical, select candidate band to the maximum band of the coverage rate of regional aim as mostExcellent candidate band, maximizing target coverage rate formula is：
Wherein nsFor to the visible number of satellite of regional aim, nbFor the rail ring number in following one section of preset time, nk(i, o) is the band number that satellite i decomposes regional aim in o circle, Pi,o,kFor satellite i to regional aim in o circleThe discrete point set that k-th of the band decomposed is covered.S(Pi,o,k) and C (Pi,o,k) determined respectively by following formula：
Wherein, xi,o,kFor the variable of 0-1, indicate whether satellite i encloses interior k-th of the band decomposed to regional aim in oIt is observed by selection, S (Pi,o,k) represent band it is selected then whether.
Wherein, N (P) is the element number of arbitrary collection P, C (Pi,o,k) it is then coverage rate.
When the sequence of alternate covering rate is identical, for example band initial stage is chosen, and has selected the item that band alternate covering rate is zeroBand has many items, at this moment can successively calculate each of candidate band set candidate band according to above-mentioned formulaPi,o,kTo the coverage rate C (P of regional aimi,o,k), candidate band is ranked up according to coverage rate, selects coverage rate maximumFor band as best candidate band, deposit, which has been selected, is used to indicate satellite execution observation mission in band set, can expand in this wayTo the observation scope of regional aim, so that entire programme be enable to cover with the realization of least band to the maximum of regional aimLid.
When alternate covering rate and coverage rate sequence all the same, the band for selecting task completion time earliest is as optimal timeBand is selected, minimizing task completion time formula is：
min(xi,o,k(ti,o,k+cti,o,k))
Wherein, ti,o,kThe beginning observation time of interior k-th of the band decomposed to regional aim is enclosed in o for satellite i,cti,o,kFor satellite i to the lasting observation time of k-th of band of goal decomposition in o circle.
According to above-mentioned formula, ti,o,kTo start observation time, cti,o,kFor lasting observation time, (ti,o,k+cti,o,k) be thenSatellite i, to the end time of k-th of band of goal decomposition, can successively be calculated in candidate band set in o circleEach candidate band Pi,o,kTask completion time.Since satellite only has side-sway attitude maneuver ability, to regional aimSingle is merely able to realize single imaging in passing by, and for same satellite, same track circle time also can only just select an item to bring intoRow observation selects satellite i to continue the longest band of observation time in the band in o circle to goal decomposition herein, defends in this wayStar is bigger in the range that same track circle time can be observed, and improves observed efficiency.It is the longest selection satellite i of selector bar band in oTo the band of end time the latest in the band of decomposition in circle, candidate band is ranked up according to task completion time, is selectedAs best candidate band, deposit has been selected to be used to indicate satellite in band set and executes observation the smallest band of task completion timeTask can reduce the time for completing polygon target observing, to enable entire programme with the least time, most in this wayFew band number realizes the maximal cover to regional aim.
S5：Judge whether best candidate band is greater than given threshold to the coverage rate amplification of regional aim, if so, deletingThere is the candidate band in the candidate band set of same satellite and identical circle time with best candidate band, return step S2 is noThen enter step S6.
It calculates the best candidate band that this minor sort filters out and time has been selected to the coverage rate of regional aim and preceding primary depositThe best candidate band of band set is selected to acquire coverage rate amplification to the difference of the coverage rate of regional aim.
If coverage rate amplification is greater than given threshold, return step S2 is needed, continues band acquisition.But due to satelliteOnly have side-sway attitude maneuver ability, is merely able to realize single imaging in the single to regional aim passes by, be defended for sameStar, same track circle time also can only just select a band to be observed, therefore return again to before step S2, need delete with mostExcellent candidate band has the candidate band in same satellite and the candidate band set of identical circle time.
If coverage rate amplification is less than or equal to given threshold, it is preferable that given threshold described in step S5 is 5%, thisWhen new band is added very little is influenced on the coverage rate of whole region target, it is contemplated that task completes timeliness, satellite costControl etc. stops continuing pick-up slip band.
S6:Moonscope scheduling is executed according to the band selected in band set.
The band in band set has been selected in output, according to the corresponding Meta task of each band, cooks up moonscope schedulingScheme completes the observation scheduling to regional aim.
By above step, regional aim is decomposed to obtain the band for capableing of single imaging, to band select intoRow multiple target Combinatorial Optimization, target are complete to minimize selection observation band number, maximization target coverage rate and minimum taskAt the time, to reduce satellite to the repeated measures of regional aim, enhance the timeliness of observation.
On the basis of the principle of uniformity of the above method, the large-scale area under a kind of multi satellites joint imaging of the present embodiment is seenSurvey scheduling system, including division module, initial module, computing module, selecting module, judgment module and execution module.Divide mouldBlock obtains candidate band set for that will carry out band division to regional aim respectively to the visible satellite of regional aim；InitiallyModule, for selecting band deposit maximum to regional aim coverage rate in candidate band to select band set；Calculate mouldBlock, for calculating the alternate covering rate of each of candidate band set candidate band with the band selected in band set；Selecting module selects the smallest band of alternate covering rate as optimal time for being ranked up according to alternate covering rate to bandSelect band；When alternate covering rate is identical, select candidate band to the maximum band of the coverage rate of regional aim as optimal timeSelect band；In alternate covering rate and coverage rate sequence all the same, the band for selecting task completion time earliest is as optimal timeBand is selected, and the deposit of best candidate band has been selected in band set；Judgment module, for judging best candidate band to regionWhether the coverage rate amplification of target is greater than given threshold, if so, deleting with best candidate band with same satellite and identicalCandidate band in the candidate band set of circle time returns to computing module, otherwise enters execution module；Execution module is used for rootMoonscope scheduling is executed according to the band selected in band set.
System further includes screening module, and before dividing for division module, it is right in following one section of preset time to filter outThe visible satellite of regional aim.
System further includes the die block that disappears, and after having handled for division module, in candidate band set, deletes and appoints with globalBand corresponding to the conflicting Meta task of task has been arranged in business planning.
Computing module includes：
Discrete unit：Sliding-model control is carried out to regional aim, obtains the point set P of regional aim discretization；
Computing unit：Calculate alternate covering rate Cri,o,k：
Wherein, Pi,o,kIndicate the discrete point set that satellite i covers k-th of band that regional aim decomposes in o circleIt closes, N (C) indicates the element number of arbitrary collection C, PclIt indicates to have selected first in the band set discretization for having selected bandPoint set, lcIt indicates to have selected the band number in band set S'.
Threshold value in judgment module is 5%.
Large-scale area observation scheduling system under the multi satellites joint imaging of the present embodiment, reduces satellite to regional aimRepeated measures enhance the timeliness of observation.
Although in conclusion the present invention has been disclosed as a preferred embodiment, however, it is not to limit the invention, anyThose of ordinary skill in the art, without departing from the spirit and scope of the present invention, when can make it is various change and retouch, therefore this hairBright protection scope is subject to the range defined depending on claims.