GPS

I'm in Atlanta this weekend and happen to be riding in a rental with a GPS. I've been watching the GPS an notice that is occasionally screws up the heading really really bad. It can get completely turned around. Of course, we are amongst sky scraper and the bot is in a park, but the signal strength is still not good according to the GPS. I have my two-axis accelerometer+gyroscope IMU board and I've been studying up on dead-reckoning via encoder. I have even layer out a basic data flow model for a kalman filtering algorithm that incorporates GPS, IMU and encoder. Still, I might yet try to elevate my GPS antenna one more time as I think it may be a while before my current software plans become drivable. Also there is the Builder's Day Out this weekend and I like to have something that is closer to working that what I currently have. :)