HANDLING EPHEMERIS EXTENSION DATA

摘要

Apparatus comprises: one or more memories configured to store data sets for each of plural positioning satellites, the data set for a satellite comprising ephemeris extension data and data relating to a lifetime or expiry of the ephemeris extension data, wherein the data relating to a lifetime or expiry of the ephemeris extension data is different for at least two satellites; and one or more processors. The processors are configured to execute computer code in the one or more memories such as to perform a method comprising: identifying one or more satellites for which ephemeris extension data is no longer valid; identifying one or more satellites for which ephemeris extension data is valid; determining whether to calculate a location based on the one or more satellites for which the stored ephemeris extension data is valid and, in response to a negative determination; sending a request for new ephemeris extension data; receiving new ephemeris extension data; storing the new ephemeris extension data; and using the new ephemeris extension data in calculating a location of the apparatus.