Patent ID: 7400291
Filing Date: 2008-07-15
Classification: G01S

Abstract:
1. A system comprising: a transmitter for transmitting wireless signals in all directions within a range of directions, the range of directions including at least all directions in a plane; a receiver for receiving echoes of the wireless signals from any direction in the range; a processor for processing the received echoes to derive echo data signals indicative of the distance of the system to a plurality of reflective surfaces; an adaptive system for: during a training stage, learning at least one association between the echo data signals and the position of the system based on training data composed of records of echo data signals and associated system position data, and during a working stage, using the echo data signals and the learnt association to determine the position of the system; and a clustering and classifying unit, the clustering and classifying unit being arranged: during the training stage, to partition the echo data signals of the training data into clusters, the adaptive system learning an association for each cluster between the echo data signals of that cluster and the associated positions of the system, wherein a linear transformation between a vector of distances and two-dimensional coordinates are estimated for a corresponding cluster, wherein the linear transformation between the distance vector and the two-dimensional coordinates are estimated for a variable amount of training points, and wherein the accuracy of the estimations is a function of a selection of the points; and during the working stage, to determine which cluster the echo data signals belong to, whereby the adaptive system determines the position of the system using the learnt association of the corresponding cluster.