ADAPTIVE SYNTHETIC POSITIONING

摘要

Methods, systems, and portable devices capable of adaptive synthetic positioning while in a dead zone are described. In one method, when a portable device having a Global Navigational Satellite System (GNSS) receiver and a dead zone database enters a dead zone, it determines whether the dead zone database has a record for the dead zone. If it does, it retrieves parameters corresponding to the dead zone from the database and calculates synthetic position solutions using the retrieved parameters while in the dead zone. The portable device may also use the synthetic position solutions to help calculate position solutions when exiting the dead zone. If a dead zone database record does not exist, the portable device determines parameters for calculating synthetic position solutions in the dead zone and a new dead zone database record indicating a set of parameters based on the determined set of parameters is created.

主权项

1. A method for a portable device having a Global Navigational Satellite System (GNSS) receiver, comprising:
when a dead zone is entered, determining whether a dead zone database has a record for the dead zone; if a dead zone database record exists for the dead zone:
retrieving polynomial coefficients corresponding to the dead zone from the dead zone database;calculating one or more synthetic position solutions using the polynomial coefficients while in the dead zone; andusing at least one of the one or more synthetic position solutions to calculate one or more position solutions when exiting the dead zone, wherein the dead zone comprises an area where either no or insufficient GNSS satellite signals are received by the portable device.