Ford has beaten General Motors for the first time in nearly a century, in terms of number of US factory workers. Ford has 50,703 to GM's 50,300 or so.
Answers. Well, the simplest answer is that the astrolabe pretty well had to be used at night and could not be used in bad weather. The compass, which relys on the magnetic field of the Earth rather than a visualiztion of the stars, works at any time, and in any weather.
I am aware of the following issues with the GPS in the reference hardware: 1  Location reports are sometimes zero'd out or missing digits. For example, if your latitude is 45.54 N you might find it reported as 4.54, 0.54, or just 0. 2  Speed and heading are always NULL values. 3  The estimated positional accuracy/error is always 0 meters.