Earth Stations
A satellite orbits the planet and collects data as it travels, transmitting that data when it is in sight of a compatible earth station (also often referred to as a ground station, antenna or dish). A satellite typically passes within sight of an earth station in 10 minutes. All the data collected previously must be downlinked during that short time. Unlike other systems, the exactEarth satellites use a dedicated high-speed downlink channel for AIS data to ensure that all collected data is retrieved.
Both the location and number of earth stations determine the length of time delay created between data collection and data downlink. exactEarth currently uses a network of earth stations for its various satellites, ensuring at least one downlink per orbit for every satellite. Establishing new earth stations in a particular area can further reduce the wait time, as data can be collected just prior to and during the satellite's pass over the earth station. In future, we will be establishing a southern hemisphere network of earth stations that will provide at least two downlinks per orbit. Once complete, this will ensure that the time between data collection and data downlink will average 10-15 minutes. exactEarth automatically forwards all data to users as soon as it is available at our data center.
exactEarth Antenna in Svalbard
Photos courtesy of KSAT