For more than 20 years, the European Sentinels of the Copernicus program have been watching over our planet. The core tasks thereby are in the area of high-quality Earth observation data in order to better understand our planet and the effects of climate change and above to contribute to civil security. In addition, one of the vital advantages of the Copernicus program is that all data collected, whether from orbit, on ground, on water or in the air, is freely accessible and free of charge for everyone.
Sentinel-1A & B as well as Sentinel-2A & B are equipped with laser communication terminals (LCT). While 1A and B primarily provide weather data as well as day and night radar images for land and sea services, Sentinels-2A and 2B provide high-resolution photos for land services, such as images of the status of vegetation, the land and sea surface, inland waterways and coastal areas.
What does laser communication have to do with all of this?
Our “LCT135” laser communication terminals are responsible for sending the data collected by all mentioned Sentinels to Earth as quickly as possible, so it can be made available to the whole world directly and in near real time. Each individual Sentinel has the option of connecting directly to an LCT on the European Data Relay Satellite System (EDRS) using an optical inter-satellite link (OISL). The EDRS, as the name may suggest, serves as a relay station and is permanently in direct contact with a ground station on Earth's surface. Due to the strategic placement of these satellites around the planet, each Sentinel has almost uninterrupted “visual contact” with one of EDRS’ relay satellites and therefore has the option to nearly steadily transmit data to the ground.
The advantages of laser communication
The time-critical advantage that results from this transmission technology becomes particularly eminent in the event of natural disasters, as every second counts when destiny deals with human lives.
Another benefit is the amount of data that can be collected and the efficiency of every single satellite in orbit that uses laser communication technology. Since satellites have limited data storage and new data can only be collected when the already collected data has been sent to Earth, laser communication not only enables more Earth observation data to be collected in a shorter time, but also to transmit in even higher resolution.
Especially in the battle for climate protection this advantage cannot be stressed enough, as more data and – above all – more detailed data, is the only key to better understand and analyse all processes going on around the globe and finally providing solutions.
By now, more than 51,000 optical inter-satellite links have been established and hundreds of terabytes of data have been transmitted by TESAT LCTs. Over 1,000 new links are added every month.
Laser communication terminals from TESAT are helping today preserving our planet for tomorrow.