I've read about various robots using a 2D lidar system for SLAM ( such as at IGCV, http://www.igvc.org/ ) but I'm wondering how good exactly does the sensor have to be? Specifically:
What accuracy is necessary?
What field of view is necessary? Is it enough just to have lidar scanning forward in a 90 degree sweep?
What angular resolution is needed?
I realize that probably with super clever software you could probably do SLAM with a couple ultrasonic sensors, but using standard packages for software navigation what's a reasonable minimum value for these parameters? (and any other important ones I've forgotten)