Patent ID: 11867541
Assignee: OPTASENSE HOLDINGS LIMITED
Field: Transport (Mechanical engineering)
Classification: CPC G  B | IPC B  G

Claim 15:
16. A method of distributed fibre optic sensing, comprising;
performing distributed fibre optic sensing on an optical fibre deployed at least partly along the path of a rail track so as to generate a set of measurement signals over a period of time from each of a plurality of sensing channels of said optical fibre for each of one or more train passing events of a known type;
determining a first parameter of each of the measurement signals, comparing the determined first parameters for different sensing channels with one another, identifying sensing channels where the determined first parameters differ by less than a defined amount as being associated with one another and forming an association matrix indicative of the sensing channels that are determined to be associated with one another;
acquiring a further set of measurement signals from each of a plurality of sensing channels over a period of time in response to a further train passing event of an unknown type; and
determining whether the further set of measurement signals exhibits a difference in channel association from the association matrix.