ATTENUATION CONSTANT ESTIMATION SYSTEM FOR SENSOR NETWORK, NODE POSITION ESTIMATION SYSTEM, ESTIMATING METHOD AND PROGRAM THEREOF

摘要

PROBLEM TO BE SOLVED: To provide a system for estimating an attenuation constantαby using reception field intensity information received at a fixed node, and a position estimation system, or the like for estimating a mobile node position by using the system. SOLUTION: The system is provided with a plurality of fixed nodes 20 for receiving a signal from a mobile node 30 within a sensor network area and measuring its reception field intensity Pi, and a node position estimating device 40 for collecting the measured reception field intensity Pito estimate the position of a mobile node 30 on the basis of the reception field intensity Pi, wherein the node position estimating device 40 comprises: a temporary position specifying means 81 for temporarily specifying a three-dimensional temporary position of the mobile node 30 according to the received field intensity Pi; a distance function calculating means 82 for calculating a function D of the total amount about distances dito respective fixed nodes 20 on the basis of the temporary position of the mobile node 30; and an attenuation constant operating means 83 for operating and calculating an attenuation constantαof radio wave propagation about positional environment of the mobile node 30 on the basis of the total amount of the received field intensity Piand the function D. COPYRIGHT: (C)2009,JPO&INPIT