GPS makes finding places and people very easy but what exactly is it?

GPS – Global Positioning System
.. is comprised of 32 satellites orbiting at an altitude of ~20,200kms, with about 9 satellites visible from any point on the ground at any given time.

The system has extensive redundancy as only 4 satellites are actually needed to calculate a position.

There is more than just one satellite system up there. Another is GLONASS, Russia’s fully operational global navigation system comprised of 24 satellites. It is the only other navigational system with global coverage and comparable accuracy.

New smartphones are being sold now with both GPS and GLONASS support which work together for high precision positioning.

Galileo – global system being developed by the European Union and other partner countries, planned to be operational by 2014 (and fully deployed by 2019)

COMPASS – People’s Republic of China’s global system, planned…