Method and system for localizing radio equipment using at least two satellite constellations
AssigneeThales
InventorsDenis Bouvet, Jean-Pierre Arethens
Life of this patent
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Abstract
A localization method, implemented in a satellite system includes at least a first constellation associated with a probability of occurrence of multiple failures lower than a given integrity risk, where the method may advantageously comprise the following steps implemented by a radioelectric device: receive a plurality of navigation signals; select failure modes to be monitored other than the multiple failures of the first constellation; determine a navigation solution and a plurality of navigation sub-solutions; calculate, for each navigation sub-solution, one or more corresponding detection thresholds; calculate one or more protection levels.
Claims12
A method for localizing radioelectric devices, implemented in a satellite system comprising a plurality of satellite constellations, each satellite constellation comprising one or more non-geostationary satellites, each satellite constellation being associated with probabilities of occurrence of failures comprising a probability of occurrence of single failures and a probability of occurrence of multiple failures, a single satellite failure being a failure involving only a single satellite of a constellation and a multiple failure being a failure involving at least two satellites of the same constellation breaking down for a common cause, said satellite system comprising at least a first constellation associated with a probability of occurrence of multiple failures less than a given integrity risk, at least a second satellite constellation, and at least one radioelectric device to be localized receiving navigation signals coming from a plurality of said non-geostationary satellites, wherein the method comprises the following steps implemented by a radioelectric device and comprising:
- receiving a plurality of navigation signals coming from a plurality of visible non-geostationary satellites belonging at least to said first and second satellite constellation;
- selecting failure modes to be monitored corresponding to failures of the satellite constellations;
- for each selected failure mode, determining a navigation solution representing a position of the radioelectric device within a given reference frame, using said plurality of received navigation signals, and determining a plurality of navigation sub-solutions, each of said navigation sub-solutions corresponding to a position of the radioelectric device within said given reference frame determined using the received navigation signals other than the navigation signals coming from one or more visible non-geostationary satellites associated with said selected failure mode;
- calculating, for each navigation sub-solution, one or more corresponding detection thresholds, a failure non-detection condition being satisfied if the differences between said navigation solution and the navigation sub-solution are less than said one or more corresponding detection thresholds;
- and
- calculating one or more protection levels associated with said navigation solution, if the failure non-detection condition is satisfied for all the navigation sub-solutions, said method being wherein said selected failure modes to be monitored are:
- a first failure mode corresponding to all of the single satellite failures of said first and of said second constellation;
- a second failure mode corresponding to the occurrence of a multiple failure or the combination of several single satellite failures in said second constellation;
- and
- a third failure mode corresponding to a plurality of combinations of a single satellite failure of said first constellation and of a failure, single or multiple, of said second constellation.
A radioelectric device implemented in a satellite system comprising a plurality of satellite constellations, each satellite constellation comprising one or more non-geostationary satellites, each satellite constellation being associated with probabilities of occurrence of failures comprising a probability of occurrence of single satellite failures and a probability of occurrence of multiple failures, a single satellite failure being a failure involving only a single satellite of a constellation and a multiple failure being a failure involving at least two satellites of the same constellation breaking down for a common cause, said satellite system comprising at least a first constellation associated with a probability of occurrence of multiple failures lower than a given integrity risk, at least a second satellite constellation, and at least one radioelectric device to be localized receiving navigation signals coming from a plurality of said non-geostationary satellites, said radioelectric device comprising:
- one or more processors;
- and
- memory storing instructions that, when executed by the one or more processors, cause the device to:
- receive a plurality of navigation signals coming from a plurality of visible non-geostationary satellites belonging at least to said first and second satellite constellation;
- select failure modes to be monitored corresponding to failures of the satellite constellations;
- for each selected failure mode, determine a navigation solution representing a position of the radioelectric device within a given reference frame, using said plurality of received navigation signals, and to determine a plurality of navigation sub-solutions, each of said navigation sub-solutions corresponding to a position of the radioelectric device within said given reference frame determined using the received navigation signals other than the navigation signals coming from one or more visible non-geostationary satellites associated with said selected failure mode;
- calculate, for each navigation sub-solution, one or more corresponding detection thresholds, a failure non-detection condition being satisfied if the differences between said navigation solution and the navigation sub-solution are less than said one or more corresponding detection thresholds;
- and
- calculate one or more protection levels associated with said navigation solution, if the failure non-detection condition is satisfied for all the navigation sub-solutions,
- wherein said selected failure modes to be monitored are:
- a first failure mode corresponding to all of the single satellite failures of said first and of said second constellation;
- a second failure mode corresponding to the occurrence of a multiple failure or the combination of several single satellite failures in said second constellation;
- and
- a third failure mode corresponding to a plurality of combinations of a single satellite failure of said first constellation and of a failure, single or multiple, of said second constellation.
Dependencies are inferred from the claim text.