AMENDED CLAIMS Received by the International office on November 13, 2017 (11.13.2017)
1. A method for estimating the bearing of an optronic system in a
5 geographical reference frame, the optronic system being situated at a
first position and denoted first optronic system (S1), characterized in that it comprises the following steps: -A) a collaborative configuration being defined by:
- a geometry or positions of at least two optronic systems
10 including the first optronic system (S1) and at least one other optronic
system (S2, ..., Sm, ...Slvl), said optronic systems being respectively situated at separate positions and equipped with means for communication with one another and with devices for acquiring one or more objects in a scene, the first optronic system furthermore being
15 equipped with an elevation measurement device and with a relative
angle measurement device, each other optronic system furthermore being equipped with a distance measurement device and/or with an elevation, measurement device and/or with a relative angle measurement device and/or with an approximate azimuth
20 measurement device,
- K objects (01, ...Ok, ... OK) of the scene common to said optronic systems, whose positions are unknown,
- a nature of the measurements available for each optronic system,
25 - known statistical characteristics of the measurement errors,
determining a collaborative collaboration in order to achieve a predetermined desired precision (PGS), which comprises the following sub-steps:
o A1) defining a collaborative configuration,
30 o A2) for this collaborative configuration, calculating, by way of a
processing unit (110) fitted to the first optronic system, a
theoretical precision (PGT) using said collaborative
configuration,
o A3) comparing the calculated theoretical precision (PGT) and
35 the desired precision (PGS) and, if the comparison is not
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2
satisfactory, reiterating steps A1), A2) and A3) for another collaborative configuration, and if not moving to step B), - B) using the optronic systems of the collaborative configuration resulting from step A3), estimating a bearing ( Gi ) of the first optronic
5 system, which comprises the following sub-steps:
o B1) by way of the acquisition device of each optronic system,
acquiring, in the scene, one or more objects (01, ...Ok, ... OK)
common to said optronic systems, the direction of orientation
between each optronic system and each object being unknown,
10 o B2) determining two geodetic positions from among those of
said optronic systems, o B3) for at least one common object:
« measuring the relative angle by way of the relative angle
measurement device fitted to the first optronic system
15 (S1),
E measuring the elevation of the object by way of the
elevation measurement device fitted to the first optronic
system (S1),
a by way of the first optronic system (S1) and of the
20 measurement devices of each other optronic system
(S2, ..., Sm, ...SM), performing additional distance
and/or elevation and/or relative angle and/or
approximate azimuth measurements,
o B4) with the two positions and said measurements constituting
25 observations, communication, by each other optronic system
(S2, ..., Sm, ...SM) to the first optronic system (S1), of the
observations resulting from each other optronic system,
o B5) on the basis of the observations resulting from the first
optronic system and of the observations communicated by each
30 other optronic system, estimating the bearing ( d ) of the first
optronic system using a processing unit (110) fitted to the first optronic system, configured to solve a system of equations having at least one unknown which is the bearing ( Gi ) of the
first optronic system,
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13
-C) estimating a precision (PGE) of the estimated bearing ( Gi ) of the
first optronic system, comparing it with the desired precision (PGS) and, if the comparison is not satisfactory, reiterating steps A), B) and C), by choosing another collaborative configuration. 5
2. The bearing estimation method as claimed in the preceding claim, characterized in that the PGS is of the class of 1 mrd.
3. The bearing estimation method as claimed in either of the preceding
10 claims, characterized in that the steps are performed by way of two
optronic systems (S1, S2) and for a single common object, and in that the additional measurements are obtained as follows:
- measuring the distance between each optronic system (S1, S2) and
the object by way of a distance measurement device fitted to each
15 optronic system,
- measuring, in an approximate manner with precision better than 5°,
an azimuth of the object by way of an approximate azimuth
measurement device fitted to the first optronic system (S1),
and in that the observations are sufficient for estimating the beanng
20 ( Gi ) of the first optronic system.
4. The bearing estimation method as claimed In either of claims 1 and 2,
characterized in that the steps are performed by way of two optronic
systems (S1, S2) and for two common objects (01, 02), and in that
25 the additional measurements are obtained as follows:
- measuring the distance between each optronic system (S1,
S2) and each object (01, 02) by way of a distance measurement device fitted to each optronic system,
- measuring the elevation between each optronic system (S1,
30 S2) and each object (01, 02),
and in that the observations are sufficient for estimating the bearing ( Gi ) of the first optronic system.
5. The beanng estimation method as claimed in either of claims 1 and 2,
35 characterized in that the steps are performed by way of two optronic
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systems (St, S2) and for two common objects (01, 02), and in that the additional measurements are obtained as follows by each optronic system:
- measuring the distance between the first optronic system
5 (S1) and each object (01, 02) by way of a distance
measurement device fitted to the first optronic system,
- measuring the elevation of each object (01, 02) by way of
an elevation measurement device fitted to each optronic
system (S1.S2),
10 - measuring the relative angle of each object (01, 02) by way
of a relative angle measurement device fitted to each optronic system (S1, S2),
- measuring an azimuth, with a precision better than 5°, on
one of the two objects (01 or 02) by way of an azimuth
15 measurement device fitted to each optronic system (S1,
S2),
or the second optronic system (S1 or S2), the bearing ( G2 )
of the second optronic system (S2) with a precision of at
20 least the PGS class,
and in that the observations are sufficient for estimating the bearing ( Gi ) of the first optronic system.
6. The bearing estimation method as claimed in either of claims 1 and 2,
25 characterized in that the steps are performed by way of two optronic
systems (S1, S2) and for at least two common objects, and in that the additional measurements are obtained as follows:
- measuring the distance between each optronic system (S1, S2) and
each object by way of a distance measurement device fitted to each
30 optronic system,
- measuring the elevation of each object by way of an elevation measurement device fitted to each optronic system (S1, S2),
- measuring the relative angle of each object by way of a relative angle measurement device fitted to each optronic system (S1, S2),
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- on the basis of the observations, estimating the bearing ( G2 ) of the
second optronic system with a precision of at least the PGS class, and in that the observations are sufficient for estimating the bearing ( d ) of the first optronic system.
5
7. The bearing estimation method as claimed in either of claims 1 and 2,
characterized in that the steps are performed by way of two optronic
systems (S1, S2) and for one common object, and in that the
additional measurements are obtained as follows:
10 - measuring the distance between each optronic system (S1, S2) and
the object by way of a distance measurement device fitted to each optronic system,
- measuring the elevation of the object by way of an elevation
measurement device fitted to each optronic system (S1, S2),
15 - on the basis of the observations, estimating the bearing ( G2 ) of the
second optronic system with a precision of at least the PGS class,
and in that the observations are sufficient for estimating the bearing ( d ) of the first optronic system.
20 8. The bearing estimation method as claimed in either of claims 1 and 2,
characterized in that the steps are performed by way of two optronic systems (S1, S2) and for one mobile common object, in that the measurements are performed over time intervals that at least partly overlap, and in that the additional measurements are obtained as
25 follows;
- measuring ihe,distance between each optronic system (S1, S2) and
the object by way of a distance measurement device fitted to each
optronic system,
- measuring the elevation of the object by way of an elevation
30 measurement device fitted to each optronic system (S1, S2),
- measuring the relative angle by way of a relative angle measurement
device fitted to each optronic system (S1, S2),
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u6
- measuring an azimuth between each optronic system and the object, with a precision better than 5°, by way of an azimuth measurement device fitted to each optronic system,
- on the basis of the observations, estimating the bearing ( G2) of the
5 second optronic system,
and in that the observations are sufficient for estimating the bearing ( G1 ) of the first optronic system.
9. The bearing estimation method as claimed in the preceding claim,
10 characterized in that the path of the mobile object is estimated at the
same time as said estimations, over the time range of the measurements.
10. The bearing estimation method as claimed in either of ciaims 1 and 2,
15 characterized in that the steps are performed for two common objects
(01, 02) and by way of two optronic systems (S1, S2), in that the communication means are optical means, in that the additional measurements are obtained as follows:
- measuring the distance corresponding to the sum of the distance
20 between an object (01) and an optronic system (S1) and the distance
between said object (01) and the other optronic system (S2) by way
of a distance measurement device comprising an emitter (206) fitted
to the other optronic system (S2) and a receiver (107) fitted to the
optronic system (S1),
25 - measuring the relative angle of each object by way of a relative
angle measurement device fitted to each optronic system,
- measuring an-azimuth, with a precision better than 5°, between each
optronic system and each object by way of an azimuth measurement
device fitted to each optronic system,
30 - on the basis of the observations, estimating the bearing ( G2) of the
second optronic system,
and in that the observations are sufficient for estimating the bearing
(■Gi ) of the first optronic system.
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7

11. The bearing estimation method as claimed in either of claims 1 and
2, characterized in that the steps are performed for at least two
common objects and by way of at least two optronic systems, in that
the additional measurements are obtained as follows:
5 - measuring the relative angle of each object by way of the relative
angle measurement device fitted to the first optronic system,
- measuring the elevation of each object by way of the elevation
measurement device fitted to the first optronic system,
- measuring the distance between each optronic system and each
10 object by way of a distance measurement device fitted to each
optronic system,
and in that the observations are sufficient for estimating the bearing
( Gi ) of the first optronic system.
12. The bearing estimation method as claimed in either of claims 1 and 2,
characterized in that the steps are performed for at least one common
object and by way of at least three optronic systems, in that the
additional measurements are obtained as follows:
20
- measuring the relative angle of each object by way of a relative
angle measurement device fitted to each optronic system,
- and the elevation of each object by way of an elevation
measurement device fitted to each optronic system,
- determining the position of a third optronic system,
- on the basis of the observations, estimating the bearing ( G2 , G3 ,
etc.) of each optronic system,
and in that the observations are sufficient for estimating the bearing
( G-\ ) of the first optronic system.
13. The bearing estimation method as claimed in either of claims 1 and 2,
30 characterized in that the steps are performed for at least two common
objects and by way of at least two optronic systems, in that the
additional measurements are obtained as follows:
- measuring the relative angle of each object by way of a relative angle measurement device fitted to each optronic system,
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\8
- measuring the distance between each optronic system and each
object by way of a distance measurement device fitted to each
optronic system,
- measuring an azimuth between each optronic system and each
5 object, with a precision better than 5°, by way of an azimuth
measurement device fitted to each optronic system,
- on the basis of the observations, estimating the bearing ( G2 ,
etc.) as well as the roll and pitch ( G-i , 91 , G2 , 92 ) of each
optronic system,
10 and in that the observations are sufficient for estimating the
bearing ( G1 ) of the first optronic system.
14. The bearing estimation method as claimed in any one of the preceding
claims, characterized in that the positions of the optronic systems are
15 determined by way of a positioning device fitted to said optronic
systems.
15. The bearing estimation method as claimed in either of claims 1 and 2,
characterized in that the steps are performed by way of the first and of
20 a second optronic system (S1, S2), for a common object and another
object having a known position not common to the two optronic systems, that is to say visible only to the second optronic system, in that the additional measurements are obtained as follows:
- measuring the elevation of each object by way of an elevation
25 measurement device fitted to the second optronic system,
- measuring the distance between the first optronic system and
the common object by way of a distance measurement device
fitted to the first optronic system,
- measuring the distance between the second optronic system
30 and each object by way of a distance measurement device fitted to
the second optronic system, in that the position of the first optronic system is determined by way of a positioning device fitted to said optronic system and in that the position of the second optronic system is determined by estimation,
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n9
and in that the observations are sufficient for estimating the bearing ( Gi ) of the first optronic system.
16. The bearing estimation method as claimed in one of the preceding
5 claims, characterized in that the means for communication between
the optronic systems are formed by a radio link.
17. The bearing estimation method as claimed in one of the preceding
claims, characterized in that it comprises a step of calculating the
10 coordinates and/or the direction of the acquired objects on the basis of
the observations.
18. The bearing estimation method as claimed in one of the preceding
claims, characterized in that at least one optronic system Sm, m
15 varying between 2 and M, is a mobile optronic system having a known
path, and in that the measurements performed from the mobile systern(s) are temporally synchronized.
19. The bearing estimation method as claimed in one of the preceding
20 claims, characterized in that at least one acquisition device is an
omnidirectional sensor.
20. The bearing estimation method as claimed in one of the preceding
claims, characterized in that at least one relative angle measurement
25 device is a magnetic compass.
21. The bearing estimation method as claimed in the preceding claim,
characterized in that the magnetic compass is calibrated by way of
measurements on one or/and several objects.
30
22. The bearing estimation method as claimed in one of the preceding
claims, characterized in that the observations are stored and able to
be communicated by each optronic system.
35 23. The method for estimating a direction of orientation as claimed in one
of the preceding claims, characterized in that it comprises,
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beforehand, a step of selecting the objects of the scene using a common visibility criterion and/or a performance criterion regarding the direction of orientation.
5 24. The method for estimating a direction of orientation as claimed in one
of the preceding claims, characterized in that it comprises, beforehand, a step of selecting positions of the optronic systems.
25. A computer program product, said computer program comprising code
10 instructions for carrying out the steps of the method as claimed in any
one of the preceding claims when said program is executed on a computer.
15
Dated this 11th day of December, 2018
OF REMFRY & SAGAR ATTORNEY FOR THE APPLICANTS]
AEvi^'DED S:-:EET (ART'CLf --3)