Global locating system

A Global Locating System (GLS) is any system that helps to determine the location of a transmitter on Earth's surface using satellites. In addition, most system implementations support tracking, reporting each sequentially determined position.

Commonly the terms "locating" (GLS = where is it?) and "positioning" (GPS = where does it go to?) are set equivalent. However the positioning task originates from the first military approaches on final locating, determining the cruise of a missile from launch to location of impact. Hence GLS refers to the surveying tasks and GPS refers to the navigating tasks.

An early example of GLS was the Sarsat Search and Rescue satellite system. In GLS, a minimal set of positioning data (e.g. signal arrival time or frequency offset or Doppler data) is collected and relayed via a satellite link. Equipment installed in the satellite Ground station demodulates the data and computes the latitude and longitude of the remote transmitter.

GLS used by Skybitz, Cospas-Sarsat and the Argos System.

See also

• Global localisation system