Patent ID: 9568587
Date: 2017-02-14
CPC Classifications: G01S

Claim:
1. A method of tracking an entity by monitoring at least one parameter of a signal, the signal tending to vary spatially and be generally time-invariant, the entity moving from a first location within an area to a second location within the area, the method being suitable for use when the location of the source of the signal is unknown, the method comprising: providing a plurality of particles for use with a particle filter, each particle being associated with a respective first particle location, each respective first particle location being an estimate of the first location of the entity; providing an estimate of the motion of the entity between the first location and the second location based on signals from a motion measurement device; using the estimate of the motion and using the particle filter, updating each particle thereby producing an updated respective particle location, each updated respective particle location being an estimate of the second location of the entity; for each updated particle, estimating at least one expected signal parameter at the updated respective particle location; measuring a signal parameter at the second location of the entity; assigning a weight to each updated particle depending on the expected signal parameter estimated for that particle and the measured signal parameter; estimating the second location of the entity by determining a function of the weighted updated particles; and inputting the estimated location and measured signal parameter, as a location/parameter data set, to a database.