METHOD FOR THE EQUITABLE CONSTRUCTION OF A PLAN FOR ACQUISITIONS OF AREAS TO BE CARRIED OUT BY A SHARED OBSERVATION SYSTEM OVER A GIVEN PERIOD, SUCH AS A SATELLITE
The method addresses inequitable distribution in observation systems by calculating utility coefficients to prioritize requests based on user scores and system capacity, ensuring fair and efficient acquisition planning.
Patent Information
- Authority / Receiving Office
- FR · FR
- Patent Type
- Patents
- Current Assignee / Owner
- Filing Date
- 2014-01-22
- Publication Date
- 2026-03-06
AI Technical Summary
Existing observation systems fail to equitably distribute acquisition opportunities among multiple users due to iterative construction methods that favor majority users, disregarding initial disparities in user rights and temporal constraints.
A method for constructing an acquisition plan that calculates a utility coefficient for each request, prioritizing requests with higher utility based on user scores and system capacity, ensuring fair distribution by iteratively selecting and inserting requests while considering user rights and system constraints.
The method ensures equitable access to acquisition opportunities by accounting for user rights and system capacity, resulting in a more fair and efficient acquisition plan that balances the needs of all users.
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Abstract
Description
Title of the invention: Method for the equitable construction of a plan for acquiring areas to be covered by a shared observation system over a given period, such as a satellite. GENERAL TECHNICAL FIELD
[0001] The invention relates to a method for the equitable construction of a plan for acquiring areas to be carried out by a shared observation system, as well as a system for constructing a plan for acquiring areas to be carried out by an observation system. PRIOR TECHNOLOGY
[0002] Observation systems (including for example one or more satellites) make it possible in particular to take pictures of areas of the Earth.
[0003] Most often, the observation system must perform a series of acquisitions, for one or more users of the observation system, hereinafter referred to as users.
[0004] The sequence of the different acquisitions by the observation system, during its orbit, is defined by the operator of the observation system, in an acquisition plan. This plan defines the flight plan of the observation system over a given period.
[0005] Most often, a dedicated system receives as input the various desired acquisitions and deduces an acquisition plan based on the different temporal and kinematic constraints implied by these acquisitions. Therefore, these are not all compatible with each other.
[0006] According to pre-established rules, each user is entitled to a certain acquisition volume over a given period and the acquisition plan must take this into account in order to share the acquisition plan between these different users.
[0007] In some existing systems, the acquisition plan is built iteratively by considering the user who is "furthest behind" in terms of their usage rights. This approach has the drawback of not taking into account any potential disparities in rights from the outset of the plan's construction. However, since the plan is built iteratively, the order in which the desired acquisitions are considered is of major importance.
[0008] In other, more recent systems, the acquisition plan takes into account the sharing ratio between users. However, the acquisition plan is generally too favorable to the majority user. Indeed, this majority user will see a large number of their acquisitions inserted all at once, before those of other users, and therefore potentially to their detriment.
[0009] There is therefore a need to make the sharing of access to programming more equitable by seeking to ensure that it is fair "at every moment", from the beginning and as the acquisition plan is constructed. PRESENTATION OF THE INVENTION
[0010] The invention addresses the need described above by proposing a method for constructing a plan for acquiring areas to be covered by an observation system over a given period, based on acquisition requests from several users sharing said observation system, each user having an authorized acquisition volume(s) over the given period, the acquisition plan being constructed by inserting acquisition request(s), the observation system having an acquisition capacity over the given period, the method comprising the following steps:
[0011] El) creation by each user of a list of ordered acquisition requests, these acquisitions offering at least one access defined by at least one time slot for which said observation system is capable of carrying out said acquisition request;
[0012] E2) calculation of a utility coefficient for each acquisition request, the coefficient usefulness being a function of all the acquisitions possibly included in the plan under construction;
[0013] E3) selection of the acquisition request having the highest utility coefficient, taken from one or the other of the lists;
[0014] E4) attempt to insert the selected acquisition request into the plan acquisitions depending on the acquisition capacity of the observation system;
[0015] E5) update of each user's list based on the insertion result of the selected acquisition;
[0016] repetition of steps E2), E3), E4), E5) until the acquisition capacity of the observation system is reached or the acquisition request lists are exhausted,
[0017] the acquisition plan of the imaging system being constructed from acquisition requests selected in step E3) and inserted in step E4).
[0018] The invention is advantageously complemented by the following features, taken alone or in any technically possible combination thereof:
[0019] - each acquisition request has a score set by the corresponding user, the The utility coefficient of each acquisition request (Ai, Bj, Ck) of each user is a function of said score normalized by the best calculated sum of the scores of the ordered list of acquisition requests of user X obtained in step El), and compatible with the capacity of the observation system and the rights rights(X) of the user, without taking into account other users.
[0020] - the utility score is defined by the following functional
[0021] / A _ J \droits(X) ^Xi) u\^} “ sW)
[0022] with rights(X) the authorized acquisition volume of user X, is the difference between the authorized acquisition volume of a user and the volume of acquisitions inserted, S(Xi) is the score of the acquisition Xi requested by the user X, SN(X) is the best sum of the scores of the requested and compatible acquisitions of the system.
[0023] The invention also relates to a system for constructing a plan for acquiring areas to be carried out by an observation system, comprising:
[0024] a memory storing acquisition requests, each acquisition request being associated with an access characterizing the time slot and the attitude of the observation system for which it is capable of carrying out said acquisition,
[0025] a processor,
[0026] characterized in that the processor is configured to construct an acquisition plan in accordance with the method according to any one of the preceding claims.
[0027] And the invention finally relates to a method of acquiring a plurality of zones by means of an observation system, the zones corresponding to acquisitions defined by an acquisition plan obtained according to a method for constructing an acquisition plan according to the invention, the acquisition method comprising an acquisition step according to an access characterizing the time slot and the attitude of the observation system for which it is able to carry out said acquisition.
[0028] Thanks to the calculation of the utility coefficient which takes into account the inserted acquisitions as the acquisition plan is constructed, the construction of the plan is more egalitarian than with known methods. PRESENTATION OF THE FIGURES
[0029] Other features, objectives and advantages of the invention will become apparent from the following description, which is purely illustrative and not limiting, and which should be read in conjunction with the accompanying drawings on which: - [Fig.1] Figure 1 illustrates an observation system and area acquisitions to be carried out by the observation system; - [Fig.2] Figure 2 illustrates a system for constructing a plan acquisitions; - [Fig. 3] Figure 3 schematically illustrates the steps of a process of construction of an acquisition plan according to the invention; [Fig.4] [Fig.3] [Fig.4] [Fig.5] [Fig.6] [Fig.7] [Fig.8] [Fig.9] [Fig.10] [Fig. 11] [Fig. 12] [Fig. 13] Figures 4 to 13 illustrate an embodiment of a method for constructing an acquisition plan according to the invention. DETAILED DESCRIPTION OF THE INVENTION
[0030] Figure 1 shows an observation system 1. This is, for example, an Earth observation satellite 1.
[0031] Users of satellite 1 provide the operator with a plurality of requests for acquisitions of zones 2 to be carried out by satellite 1.
[0032] These acquisitions include in particular geographical coordinates indicating the position of zones 2 to be imaged.
[0033] Each acquisition is associated with at least one access, characterizing the time slot and the attitude of satellite 1 for which satellite 1 is capable of performing said acquisition. This access is calculated in a known manner from the orbit of satellite 1, and the known kinematics of satellite 1.
[0034] Other parameters can be associated with each acquisition, such as the type of acquisition desired (nature of the image, instrument to be used, etc.).
[0035] A system 13 for constructing an acquisition plan P is shown schematically in figure 2. This system 13 is configured to implement a method for constructing an acquisition plan of areas 2 to be carried out by the satellite 1.
[0036] The system 13 comprises a processor 5 and a memory 12. The memory 12 stores, in particular, acquisition requests and their access. Software, stored in the memory 12, controls the processor 5 so that it implements the steps of the process described below. The system 13 includes, where applicable, a user interaction tool 14, allowing an operator to enter data or configure the software. This is, for example, a keyboard connected to a screen.
[0037] A method for constructing a plan for acquiring areas to be covered by the satellite is illustrated in Figure 3.
[0038] Several users A, B, C share an observation system. Each user A, B, C has an authorized volume of acquisitions (rights(A), rights(B), rights(C)) over a given period, for example, a day. This authorized volume of acquisitions (rights(A), rights(B), rights(C)) is measured according to a predetermined criterion (number of acquisitions, cumulative acquisition time, etc.). It is predetermined and generally depends on the user's participation in the observation system. A user referred to as the "majority user" will have a large volume of authorized acquisitions per day, while a user referred to as the "minority user" will have a small volume of authorized acquisitions per day.
[0039] The observation system has an acquisition capacity over the given period. This acquisition capacity depends on the system's dimensions: electrical and thermal capacities, number of instrument deployments, etc. Within the framework of a process for a plan P of area acquisitions to be carried out by the observation system, Each user A, B, C includes acquisition requests Ai, Bj, Ck with i=l,..., N(A), j=l,
[0040] N(B), k=l,..., N(C) with N(A), N(B), N(C) the number of acquisitions requested each user has their own number of acquisitions. The number of acquisitions requested may be higher or lower than the number of acquisitions allowed per user.
[0041] Thus, each user A, B, C provides the construction system of the acquisition plan P with a list L(A), L(B), L(C) of acquisition requests Ai, Bj, Ck.
[0042] During the process of constructing the acquisition plan P, in a first step El, for each user A, B, C, the system 13 creates a list of ordered acquisition requests, these acquisitions offering at least one access defined in particular by a time slot and an attitude of the observation system for which said observation system is capable of carrying out said acquisition request. The creation of the ordered list will not be described further here.
[0043] In a second step E2, a calculation of a utility coefficient U(Ai), U(Bj), U(Ck) of each acquisition request Ai, Bj, Ck, is carried out.
[0044] The utility coefficient is a function of a ratio between a number of acquisition requests N(A), N(B), N(C) from a user A, B, C and the volume of acquisition(s) rights(A), rights(B), rights(C) authorized for each user A, B, C.
[0045] In this way, each acquisition request is associated with a ratio taking into account the acquisitions to be made by the user in relation to the number requested and the number of acquisitions inserted in the acquisition plan P.
[0046] In a third step E3, the acquisition request having the highest utility coefficient is selected.
[0047] After the selection, in a fourth step E4, the process attempts to insert the selected acquisition request into the acquisition plan according to the acquisition capacity of the observation system.
[0048] Then, in a fifth step E5, an update of the list L(A), L(B), L(C) of each user A, B, C is carried out according to the acquisition request Ai, Bj, Ck selected and the insertion status of step E4.
[0049] Next, steps E2), E3), E4), E5) are repeated until all lists have been gone through, the imaging system acquisition plan (P) being constructed from the acquisition requests selected Ai, Bj, Ck in step E3.
[0050] Advantageously, each acquisition request has a score S(Ai), S(Bj), S(Ck) assigned by the corresponding user A, B, C. This score allows the requested acquisitions to be weighted. An acquisition request with a high score is more important than an acquisition request with a lower score.
[0051] In this case, the utility coefficient U(Ai), U(Bj), U(Ck) of each acquisition request Ai, Bj, Ck of each user is a function of this score (S(Ai), S(Bj) S(Ck)).
[0052] To allow different users to use any scoring scale, the score is normalized by the best calculated sum SN(X) of the scores from the list of acquisition requests submitted by user X, and compatible with the user's rights (X) capacity and the capacity of the observation system, without taking other users into account. This best sum is typically determined by a design calculation considering only the user in question.
[0053] Preferably, the utility score is defined by the following functional
[0054] / A _ J ^drorW) S(XÛ right dX) SN(X)
[0055] with rights(X) the volume of acquisitions of user X, rights(X) is the difference between the authorized volume of acquisitions of a user and the volume of acquisitions inserted (notion of "remaining rights"), S(Xi) is the score of the acquisition Xi requested by user X, SN(X) is the best sum of the scores described above. Finally, cp(X) is a weighting coefficient that can take into account the sharing ratio between users in relation to the capacity of the observation system and / or temporal regulation, for example based on the value of the sharing ratio, defined by the user's participation rate in the system, increased by the product of the Cp(X) of the previous programming period, by the programming constraint induced by the sharing of the resource, calculated as the ratio between the sum of the scores obtained and the sum SN(X) defined above.
[0056] An example of the construction of a plan for acquiring areas to be carried out in relation to figures 4 to 12 is now described.
[0057] Figure 4 illustrates three lists L(A), L(B), L(C) of acquisition requests Ai, Bj, Ck from three users A, B, C. These are the ordered lists created in step El.
[0058] In this simplified example, it is assumed that the capacities and rights are expressed in number of acquisitions, and that the observation system has a total capacity of 8 acquisitions per day, two of which are in the same area.
[0059] In addition, user A has rights (A)=10 acquisitions per day, user B has rights (B)=3 acquisitions per day, user C has rights (C)=1 acquisition per day.
[0060] Finally, the weighting coefficients are respectively Cp(A)=10, Cp(B)=3 and Cp(C)=1.
[0061] As illustrated in Figure 4, the first user A requests N(A)=9 acquisitions, the second user B requests N(B)=4 acquisitions, and the third user C requests N(C)=2 acquisitions. It can already be seen that The second and third users request a number of acquisitions greater than their acquisition volumes, while the first user A requests a number less than their acquisition volume rights(A).
[0062] Acquisition requests Ai, Bj, Ck are geographical areas named after the region in which they are located: Paris 1, Paris 2, Toulouse 1, Toulouse 2, Algiers, London, Iceland, Ivory Coast. It is observed that several users request geographically close acquisitions, with acquisitions being requested within the same area.
[0063] As will be understood, each user establishes their list as they see fit.
[0064] Each acquisition request is associated with a score S(Ai), S(Bj), S(Ck).
[0065] For the first user A, four acquisition requests A3, A4, A5, A6 have a score of 50, five acquisition requests A7, A2, A1, A8, A9 have a score of 20. For user B, one acquisition request B2 has a score of 50, two acquisition requests B3, B4 have a score of 20, one acquisition request B1 has a score of 10. For user C, one acquisition request C2 has a score of 50, one acquisition request C1 has a score of 20.
[0066] Figure 5 illustrates the ordered lists L(A), L(B), L(C) of each user with the utility coefficient U(Ai), U(Bj), U(Ck) of each acquisition request Ai, Bj, Ck.
[0067] For the first user A, the utility coefficient of the acquisition request A3 is calculated from the following functional [00681 U(A3)= C p(A)f^| = l.79
[0069] with cp(A)=10, rights(A) = 10 since at this stage of figure 5, no acquisition request has yet been selected, S(A3)=50 (see figure 4), SN(A)=S(A3)+S(A4)+S(A5)+S(A6)+S(A7)+S(A2)+S(A1)=50+50+50+50+20+20+20+20=280 (only the first 8 acquisitions are possible given the total acquisition capacity of the day in question).
[0070] For the second user B, the utility coefficient of the acquisition request B2 is calculated from the following functional
[0071] S(B2) . U(B2) = cp(By^^
[0072] with cp(B)=3, cp(B) =3 since at this stage of Figure 5, none no acquisition request has yet been selected, S(B2)=50 (see figure 4), SN(B)=50+20+20=90 (only the first 3 acquisitions are possible because rights(B)=3).
[0073] And so on for the other acquisition requests.
[0074] In Figure 6, for the acquisition plan P, the acquisition request A3 which has the highest utility coefficient is selected (circled in this figure).
[0075] After the selection of acquisition request A3, its insertion is attempted. Insertion is possible here since it is the first acquisition request.
[0076] In figure 7 the update of the list L(A) of the first user A is carried out taking into account the insertion of the acquisition request A3 (the previously selected acquisition request A3 has been crossed out in this figure).
[0077] Still on this figure 7, the utility coefficient of the unselected acquisition requests Ai is calculated.
[0078] The acquisition request A4 from the first user A has the utility coefficient calculated from the following functional 100791 U(A4) = cp(A)^^ = l.61
[0080] with rights(A)=10, rights(A) = 9 since an acquisition request has been inserted in the acquisition plan P.
[0081] All acquisition requests Ai from the first user A are updated in the same way to obtain the values shown in Figure 7.
[0082] Again in Figure 7, it is the acquisition request B2 which is selected for the acquisition plan P. It is indeed this acquisition request which has the highest utility coefficient at this stage of the construction of the acquisition plan P.
[0083] An attempt is made to insert acquisition request B2. Here again, insertion is authorized because, although this acquisition request B2 is in the same geographical area as acquisition request A3, the acquisition capacity of the observation system allows it (2 acquisitions in the same area are possible).
[0084] Following the insertion of the acquisition request B2, as before, the list L(B) is updated and steps E2, E3, E4 are repeated until an acquisition request is inserted.
[0085] Figure 8 illustrates the updated lists of the three users A, B, and C after the insertion of acquisition request A5. The result shown in this figure demonstrates that, for this simplified example, acquisition requests C2, A4, and B3 were selected, but their insertion failed due to the capacity of the observation system, which, as mentioned previously, can perform two acquisitions in the same area. However, as illustrated in Figure 7, acquisition requests A3 and B2 were selected, and as illustrated in Figure 4, these two acquisition requests correspond to Paris, so that after this selection, the observation system can no longer perform acquisitions in this area. Consequently, in Figure 8, and for this simplified example, the acquisition requests C2 (Paris 1), A4 (Paris 2), B3 (Paris 2) are crossed out and could not be inserted during the construction of the P acquisition plan.
[0086] In addition, still on figure 8, the utility coefficients of the acquisition requests of the second user B not selected are recalculated to take into account the one previously selected.
[0087] It is therefore the acquisition request A5 of the first user A that is inserted since at this stage it is the one which has the highest utility coefficient.
[0088] In Figure 9, the update of the list of the first user A is carried out by recalculating the utility coefficients of the unselected acquisition requests and the acquisition request A6 is selected and inserted.
[0089] In Figure 10, the list of the first user A is updated by recalculating the utility coefficients of the unselected acquisition requests, and acquisition request A7 is selected and inserted. Furthermore, also in this figure, acquisition request B4 is crossed out because the area corresponds to that of Toulouse, which is already saturated by two acquisitions, A5 and A6.
[0090] In Figure 11, the update of the list of the first user A is carried out by recalculating the utility coefficients of the unselected acquisition requests and the acquisition request A2 is selected and inserted.
[0091] In Figure 12, the update of the list of the first user A is carried out by recalculating the utility coefficients of the unselected acquisition requests and the acquisition request Cl is selected and inserted.
[0092] In Figure 13, the update of the list of the third user C is carried out (the acquisition request Cl is crossed out) and the acquisition request Al is selected and inserted.
[0093] At the end of the selection of the acquisition request Al, the process stops since the capacity of the observation system (equal to eight acquisitions) is reached.
[0094] The acquisition plan P is therefore made up of the acquisitions A3, B2, A5, A6, A7, A2, C1, A1.
[0095] Such an acquisition plan is advantageously used in a method of acquiring a plurality of zones by means of an observation system, the zones corresponding to acquisitions defined by an acquisition plan obtained according to a method for constructing an acquisition plan P described above.
Claims
1. Demands A method for acquiring data from a plurality of areas using an observation system, the areas being defined by geographic coordinates in an acquisition plan constructed for a period during which the observation system has acquisition capacity, the acquisition plan being constructed from acquisition requests (Ai, Bj, Ck) from several users (A, B, C) sharing the observation system, each user having an authorized volume (rights(A), rights(B), rights(C)) of acquisition(s) over the period, the method comprising steps consisting of: El) receive by a processor, for each user (A, B, C), a list (L(A), L(B), L(C)) of ordered acquisition requests (Ai, Bj, Ck), these acquisitions offering at least one access defined by at least one time slot for which the observation system is able to carry out the acquisition request; E2) calculate by the processor a utility coefficient (U(Ai), U(Bj), U(Ck)) of each acquisition request (Ai, Bj, Ck), the utility coefficient being calculated as a function of all acquisition requests possibly inserted in the plan (P) under construction and the volume of acquisitions authorized for each user during the period; E3) select by the processor an acquisition request (Ai, Bj, Ck) having the highest utility coefficient (U(Ai), U(Bj), U(Ck)), taken from one of the lists (L(A), L(B), L(C)) of acquisition requests; E4) attempt to insert the selected acquisition request into the acquisition plan using the processor, according to the acquisition capacity of the observation system; E5) update by the processor the list (L(A), L(B), L(C)) of acquisition requests from each user (A, B, C) according to the insertion result of the selected acquisition; repeat by the processor steps E2), E3), E4), E5) until the acquisition capacity of the observation system is reached or the lists (L(A), L(B) and L(C)) of acquisition requests are exhausted, the acquisition plan (P) of the observation system being built from the selected acquisition requests (Ai, Bj, Ck) in step E3) and inserted in step E4); and chain the acquisitions by the observation system according to the acquisition plan.
2. A method according to claim 1, wherein each acquisition request has a score (S(Ai), S(Bj), S(Ck)) fixed by the corresponding user (A, B, C), the utility coefficient (U(Ai), U(Bj), U(Ck)) of each acquisition request (Ai, Bj, Ck) of each user being calculated as a function of the score (S(Ai), S(Bj), S(Ck)) which is normalized by the best calculated sum (SN(X)) of the scores of the user's ordered acquisition request list obtained in step El), and compatible with the capacity of the observation system and the user's rights (X), without taking into account other users.
3. A method according to any one of the preceding claims, wherein the utility score is defined by the following functional: TtIyÙ _ y-Wroit.s(X) ^Xî) “ C^}droiUX) SN(X) with rights(X) the authorized acquisition volume of user X, right^X) is the difference between the authorized acquisition volume of a user and the volume of acquisitions inserted (remaining rights), S(Xi) is the score of the acquisition Xi requested by user X, SN(X) is the best sum of the scores of the requested and compatible acquisitions of the observation system.
4. A system for acquiring data from a plurality of areas by an observation system, the areas being defined by geographic coordinates in an acquisition plan constructed for a period during which the observation system has an acquisition capacity, the acquisition plan being constructed from acquisition requests (Ai, Bj, Ck) from several users (A, B, C) sharing the observation system, each user having a volume (rights(A), rights(B), rights(C)) of acquisition(s) authorized over the period, the system comprising: a memory (12) storing the acquisition requests, each acquisition request being associated with an access (4) characterizing the time slot and the attitude of the observation system for which it is capable of performing the acquisition, and
5. a processor (5) configured to implement steps consisting of: El) receive, for each user (A, B, C), a list (L(A), L(B), L(C)) of ordered acquisition requests (Ai, Bj, Ck), these acquisitions offering at least one access defined by at least one time slot for which the observation system is capable of carrying out the acquisition request; E2) calculate a utility coefficient (U(Ai), U(Bj), U(Ck)) of each acquisition request (Ai, Bj, Ck), the utility coefficient being calculated as a function of all acquisition requests possibly inserted in the plan (P) under construction and the volume of acquisitions authorized for each user during the period; E3) select an acquisition request (Ai, Bj, Ck) having the highest utility coefficient (U(Ai), U(Bj), U(Ck)) from one of the lists (L(A), L(B), L(C)) of acquisition requests; E4) attempt to insert the selected acquisition request into the acquisition plan according to the acquisition capacity of the observation system; E5) update the list (L(A), L(B), L(C)) of acquisition requests for each user (A, B, C) based on the insertion result of the selected acquisition; repeat steps E2), E3), E4), E5) until the acquisition capacity of the observation system is reached or the lists (L(A), L(B) and L(C)) of acquisition requests are exhausted, the acquisition plan (P) of the observation system being constructed from the acquisition requests selected (Ai, Bj, Ck) in step E3) and inserted in step E4), the observation system being configured to chain acquisitions according to the acquisition plan. Acquisition system according to claim 4, wherein the observation system is an Earth observation satellite (1).