Patent ID: 9109910
Filing Date: 2015-08-18
Classification: G01C,G01S

Abstract:
1. A method for satellite-based navigation, comprising: receiving, by a device, satellite-based positioning information corresponding to a location of a vehicle; determining, by the device, that satellite-based positioning signal reception is impaired, using the received location of the vehicle as the vehicle's last known position, and determining a current location of the vehicle based on the vehicle's last known position and dead reckoning navigation since the vehicle was at the vehicle's last known position; determining and updating, by the device, a value of an error parameter based on the use of the dead reckoning navigation; receiving, by the device, a route calculation request; comparing, by the device, in response to the route calculation request, a current updated value of the error parameter and a threshold value, and determining that the current updated value exceeds the threshold value; initiating, by the device, in response to determining that the current updated value exceeds the threshold value, an error timer having an expiration; determining, by the device, that the error timer has reached the expiration, wherein the device does not provide route calculation failure notifications and does not provide route calculation during the time period after the error timer is initiated and before the error timer reached the expiration; and providing, by the device, in response to determining that the error timer has reached the expiration, a route calculation failure notification; wherein the updating the value of the error parameter includes updating the value of the error parameter during the time period after the error timer is initiated and before the error timer reached the expiration, wherein updated values of the error parameter during the time period after the error timer is initiated and before the error timer reached the expiration exceed the threshold value.