title: LPS auto-calibration algorithm with predetermination of optimal zones.
abstract: Accurate coordinates for active beacons placed in the environment are required in local positioning systems (LPS). These coordinates and the distances (or differences of distances) measured between the beacons and the mobile node to be localized are inputs to most trilateration algorithms. As a first approximation, such coordinates are obtained by means of manual measurements (a time-consuming and non-flexible method), or by using a calibration algorithm (i.e., automatic determination of beacon coordinates from ad hoc measurements). This paper presents a method to calibrate the beacons' positions in a LPS using a mobile receiver. The method has been developed for both, spherical and hyperbolic trilateration. The location of only three test points must be known a priori, while the position of the other test points can be unknown. Furthermore, the paper describes a procedure to estimate the optimal positions, or approximate areas in the coverage zone, where the test-points necessary to calibrate the ultrasonic LPS should be placed. Simulation and experimental results show the improvement achieved when these optimal test-points are used instead of randomly selected ones.
authors.affiliation: Electronics Department, University of Alcalá de Henares, Escuela Politécnica. Ctra. Madrid-Barcelona, Km. 33,600, 28871 Alcalá de Henares, Spain. daniel.ruiz@depeca.uah.es
authors.forename: Francisco Daniel
authors.initials: FD
authors.lastname: Ruiz
authors.forename: Jesús
authors.initials: J
authors.lastname: Ureña
authors.forename: Juan C
authors.initials: JC
authors.lastname: García
authors.forename: Ana
authors.initials: A
authors.lastname: Jiménez
authors.forename: Alvaro
authors.initials: A
authors.lastname: Hernández
authors.forename: Juan J
authors.initials: JJ
authors.lastname: García