NTS-1 /Timation-III/ quartz and rubidium oscillator frequency stability results

This paper describes frequency stability results obtained from the NTS-1 satellite. NTS-1 has three on-board frequency sources, one quartz oscillator and two rubidium resonators. These are used to derive the precise time and frequency signals radiated by the spacecraft. The data taken from each of three 2.5 hr daily passes are time difference or frequency difference. These data are incorporated into a single value for each pass which is subsequently used in the Allan Variance computation. The results presented here employ single frequency measurements at 335 MHz. Analysis of these results indicate an effect on frequency stability that correlates with the orbit. The results further indicate the rubidium frequency is dependent upon the spacecraft temeprature, which confirms previous NRL pre-flight analysis.