Design and implementation of a new spaceborne FPGA-based dual frequency GPS and Galileo software defined receiver

The use of GNSS receivers for on-board satellite orbit determination has become a common solution in new satellite design, as it considerably simplifies the overall architecture if compared to traditional orbit determination systems. Different challenges have to be faced while designing a GNSS system for these applications, since in general the terrestrial receivers are not designed to guarantee their performances if placed in an orbital environment. The differences are related to signal properties such as signal strength and Doppler, and to the space environment that affects the electronic systems. All these aspects are combined together in the design of a new spaceborne GPS and Galileo software defined receiver, which is part of the ALMASat-EO project, a small satellite for Earth observation. The paper describes the hardware details of the FPGA-based dual frequency receiver, together with the mission analysis results that have determined its architecture.