Phase tracking based on GPGPU and applications in Planetary radio Science

This paper introduces a phase tracking method for planetary radio science research based on GPGPU (General Purpose Computing on GPU) technology. Different from phase counting method based on phase-locked loop(PLL) Circuits applied by traditional Doppler data processing this method fits signal model expressed by Taylor series into baseband tracking data. The differential evolution(DE) algorithm is employed in polynomial fitting. Because the fitting of the original tracking data requires a large amount of calculation,We use GPGPU chips to accelerate data processing. Dual K80s graphics chips is applied in data processing and can achieve real-time data processing. The phase expression obtained by fitting is Taylor polynomial which can be used to calculate instantaneous phase,frequency,derivative of frequency and the total count phase of different integration scales. These observables can be conveniently used in planetary radio science research about planetary occultation and planetary gravity fields.