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If a plane can only get a GPS fix to within a 15m radius that's no big deal, whereas if a car has a 15m fix it's running down pedestrians on the sidewalk. Plane
by kec 8y ago
If a plane can only get a GPS fix to within a 15m radius that's no big deal, whereas if a car has a 15m fix it's running down pedestrians on the sidewalk. Planes also don't have a habit of flying in tunnels or urban canyons where obtaining a gps fix is even more problematic.
- Robotbeat 8y agoIndeed. But this is an addressable problem. The new GPS satellites (GPS III) have just started launching (on a SpaceX rocket in December 2018), and they should triple the accuracy: https://www.geospatialworld.net/blogs/what-is-gps-iii-and-how-will-it-stand-apart/ https://www.geospatialworld.net/blogs/what-is-gps-iii-and-ho... But even before that's complete: High precision GPS (i.e. with compensation for atmospheric effects) can get better than 10cm accuracy by tracking the carrier wave: https://en.wikipedia.org/wiki/Real-time_kinematic https://en.wikipedia.org/wiki/Real-time_kinematic Single-digit-centimeter-accuracy is possible near GPS signal compensating base stations (~20km). This level of precision is regularly used by surveyors. There are several options for improving geolocation beyond inside-out (i.e. vision or lidar) tracking.
- lutorm 8y agoPlanes already have a problem with GPS outages or military jamming exercises. Imagine if all cars within a 100 mile radius all of a sudden would stop working.
- Robotbeat 8y ago...that's why you develop systems designed to bring them to a safe stop (in addition, stable IMUs can assist for several seconds, plenty of time to come to a safe stop). That should be standard on all autonomous systems, TBH. And BTW, there are 4 GNSS systems, each run by a different country/entity. The odds of them all failing at the same time is very small.
- ksherlock 8y agoGPS is (negatively) affected by atmospheric variability. Are the other 3 systems immune from it?