System Studies

Callisto led a small industrial team to investigate the feasibility of a satellite mission for the measurement of atmospheric propagation in the 26 GHz band for EO satellites. The study, which was undertaken for ESA, considered the use of a CUBESAT flying a Ka-band transmitter payload in polar orbit.

Callisto has completed an architectural study for ESA investigating solutions for building ESA Deep-Space ground stations for future missions to the outer planets of the solar system. The solutions which were investigated include an option for building a very large antenna of diameter greater than 70m, or building an array of smaller antennas which can be combined together. The study addressed not only the engineering challenges associated with the various options, but also the cost, with a clear goal of identifying the most cost effective approach.

Callisto undertook a study into techniques of Fade Mitigation due to weather for K-Band SATCOM services. The objective of this study was to assess and quantify the benefits of using a dual mode LNA to improve communication link availability.

Callisto has undertaken an analysis of ground station RF equipment in the 26-27 GHz band which will be used by the third generation of METEOSAT to download payload data.

The study involved the analysis of end-to-end communications links and involved the development of simulation models using Matlab/Simulink. The study included the investigation of SRRC OQPSK and GMSK modulation schemes.

The study addressed the problem of the support of multiple missions simultaneously using a single Deep Space Antenna. Such scenarios are of interest when there are multiple spacecraft exploring the same planet in the Solar System. The main problem investigated was the uplink communications that is to be able to transmit two or more telecommand signals using a multiplexing scheme.

Callisto carried out a study on the cryogenics options for the Square Kilometre Array (SKA) Organization. The SKA is expected to use thousands of 15 metre diameter dishes, each equipped with multiple antenna feeds and cryogenic receivers. Callisto's study examined a range of potential technical solutions, aiming to maximize receiver sensitivity whilst keeping the overall cost of system ownership within budget.

Callisto has undertaken a study for CNES to devise a method for the measurement of the noise temperature of a Ka band active phased array antenna when mounted in a Compact Antenna Test Chamber.

Callisto conducted a study into the feasibility of upgrading ESAs Deep Station ground stations to support reception of high rate telemetry in the 26 GHz band.

Callisto undertook a communications study into the use of mixed CDMA & FDMA communications system over an Earth - satellite - Earth link. The objective was to assess the feasibility of overlaying a CDMA link on an existing FDMA communications service.

Callisto undertook a study into the introduction of Ka band into ESA ground stations and investigated suitable frequency plans for conversion of Ka band signals to ensure compatibility with existing frequency plans.