Direction Finder

A strap-down inertial-navigation system uses silicon sensors to measure displacement without entailing the bulk and expense of moving parts or GPS receivers. For example, a three-axis accelerometer and three angular-rate sensors can determine the position and velocity of a vehicle such as a robot or radio-controlled aircraft...

This highly integrated GPS receiver IC improves upon earlier-generation devices by including more components in a smaller package with a reduction in power consumption...

APRS stands for Automatic Position Reporting System and now is taken to refer to a protocol that uses a subset of AX25 packet radio to provide a range of facilities not available to amateur radio before. The cornerstone of APRS is that the packets are sent using the BEACON text format - and do not require `connects` to occur first...