CONTROLLER FOR ON-VEHICLE SATELLITE RECEPTION ANTENNA

摘要

PROBLEM TO BE SOLVED: To surely detect a peak level of a signal level in the satellite tracking using step tracking. ;SOLUTION: An on-vehicle reception antenna 10 is driven to be rotated by a stepping motor 16 to trace a satellite. A reception signal from a BS tuner 14 is fed to a controller 26 to conduct step track tracking to drive the antenna 10 in a direction where the reception level is increasing. An extreme value where the reception level changes from an increasing state into a decreasing state during the step track tracking is stored and number of times when the reception level is less than a prescribed level is counted. A threshold level is set dependent on the number of times and only the extreme value with the threshold level or over is used to conduct mean value calculation thereby detecting a peak value. Since the extreme value with a low reception level is not adopted, the extreme value caused when the vehicle arrives under a shadow of tree is eliminated from the mean value calculation.;COPYRIGHT: (C)1997,JPO