Hacker News Reader

There is no real disadvantage to dead reckoning as long as the system is always powered up.

The system just needs to know it's start location (the car factory) and can correct any errors in dead reckoning using the compass and maps.

GPS is so cheap now that there is no reason not to use it, but a system built with dead reckoning today would work just fine.

View on HN

> There is no real disadvantage to dead reckoning as long as the system is always powered up.

With dead reckoning the error accumulates over time. Because GPS provides absolute positioning it does not have that problem.

Not if your system is installed in a car which normally travels on roads...

A simple Particle Filter conditioned on "90% chance the car is on a road or other drivable space" will robustly get rid of any error accumulation, leaving you a position estimate that may even typically be more accurate than GPS.

I'm inclined to agree, but that requires your map to be consistently up-to-date, which may not always be practical.

Reply on news.ycombinator.com