Patent NZ-575390-A (NZ)
Title: A method of determining the probability that data is associated with a source of a plurality of sources
Inventor: BELL GRAHAM
IPC: G06F17/18
Filed: 2007-08-23
Abstract: A method and a system for determining the probability that sampled data, that is indicative of a molecule which is associated with a source, and that is obtained from a plurality of data input sources, is from a known source, given prior observed data obtained by the plurality of data input sources for· one or more known sources are disclosed. The system comprises a) a first calculator for calculating probability density functions for each known source for the sampled data being associated with that source and/or calculating probability density functions for the sampled data not being associated with anyone of the known sources using the sampled data and the prior observed data; b) a second calculator for calculating a first set of probabilities that the sampled data is associated with at least one of the known sources or none of the known sources using a predetermined prior probability and the probability density functions from a); and c) a third calculator for calculating a subsequent set of probabilities that the sampled data is associated with at least one of the known sources or none of the known sources using the probabilities calculated in b) and the probability density functions from a) calculated from the sampled data. A method and a system for identifying the source of a predetermined type of molecule conveyed through a gaseous medium and sampled by a plurality of sensors, given prior observed data measured by the plurality of sensors in respect of the predetermined type of molecule from one or more known sources are also disclosed. The system comprises a plurality of sensors for detecting the molecule conveyed through the gaseous medium with each sensor being arranged for detecting the molecules of the predetermined type to detect a quantity of the molecules and to produce electronic data associated with the quantity of the molecules; and a processor for a) calculating probability density functions for each known source that the detected molecules originate from that source and/or probability density functions for detected molecules not being associated with anyone of the known sources using the sampled data associated with the detected molecules and the prior observed data; b) calculating a first set of probabilities that the detected molecules originate from at least one of the known sources or none of the known sources using a predetermined prior probability and the probability density functions from a); c) calculating a subsequent set of probabilities that the detected molecules originate from at least one of the known sources or none of the known sources using the probabilities calculated in b) and the probability density functions from a); and d) assigning a source identity to the detected molecules when one of the probabilities calculated in c) is equal to or above a threshold probability. A method and an apparatus for determining information about the position of at least one sensor relative to a previously known type of source with data is associated, the data relating to a property that is detectable at a plurality of locations and the property being dependent on a distance from the at least one source are also disclosed. The apparatus comprises at least one sensor for obtaining data at the plurality of locations; and the above described system for determining the probability that the obtained data is associated with a previously known type of source, with the probability being calculated for each of the plurality of locations; selecting, dependent on the calculated probabilities, at least one previously known type of source; and comparing the data for the plurality of locations and from relative differences between the data determining information about a position of the at least one sensor relative to the location of the at least one selected source of the data.