Analysis and Comparison of new Downlink Technologies for Earth Observation Satellites

Anotace: New generation of Earth observation sensors are creating an increasing amount of data which has to be delivered from space-to-ground. Additionally, many applications require timely availability of this sensor data. As new link technologies have been made available in the last years and data rate requirements are still increasing a revise of the conventional direct-downlink technology at X-band frequencies is essential. This work aims in a trade-off of the available direct-downlink technologies for satellites in low, polar orbits. Generally, there are two approaches to fulfill the requirement of timely delivery of a huge amount of data from space-to-ground. This is either increasing space-to-ground contact time resulting in a more complex ground station network or increasing carrier frequency whereas link reliability is limited by atmospheric effects. In this work different approaches like using K$_a$-band or utilizing ground station network with additional locations are compared against each other.