It starts with an expensive piece of gear called a "PTT"

Platform Transmitter Terminals (PTTs) are small, battery powered devices that are most often attached to the carapace of a sea turtle. These can be attached with epoxy to hard shelled turtles like loggerheads and green sea turtles or via a simple direct attachment for leatherback sea turtles. The PTT collects data and then sends regular updates to the Argos equipped satellites each time the turtle surfaces for air. After a period of time the batteries are exhausted, and the transmitter stops working and falls off the turtle or is removed by researchers when the turtle is encountered again.

Data from the turtles are relayed to satellites flying high overhead.

The Argos system is a satellite-based location estimation and data collection system. Researchers place small devices onto sea turtles that collect and transmit data to an Argos-equipped constellation of satellites. The Argos system receives data from a PTT and then uses a special algorithm to estimate its location at the time of transmission based on the Doppler shift of the signal frequency received during the passing of one of the polar-orbiting satellites. More information about Argos can be found here

Researchers share their data with us and our system processes data as it is received from the Argos system