Mitigating interferences on LEO satellite downlinks of Earth exploration services by cognitive radio, adaptive modulation and coding techniques.

Upcoming Earth Exploration Satellite Services (EESS) missions, especially to monitor Brazilian diversified biomes, will require progressively higher data rates for downlink transmissions, besides the ability to share its frequency spectrum with cellular base stations. Both impact issues on spectral efficiency (in bps/Hz) and coexistence in frequency, time, location, etc. This paper proposes a technique suitable for LEO Earth Observation Satellites (EOS) by combining two strategies.

Applying the perturbative integral in aeromaneuvers around Mars to calculate the cost.

The perturbative integral method was applied to quantify the contribution of external forces during a specific interval of time in trajectories of spacecraft around asteroids and under the Luni-solar influence. However, this method has not been used to quantify the contributions of drag in aerocapture and aerobraking. For this reason, the planet Mars is selected to apply this method during an aerogravity-assisted maneuver.