Citation
Abstract
The extent of phase noise introduced by the coherent reference generator (CRG) unit in the DSN’s Frequency and Timing Subsystem (FTS) has not so far been measured or analyzed. This report calculates approximate phase stability estimates for the CRG. The method used involves estimating the phase noise introduced by CRG components based upon measurements made in the past on similar components in other parts of the FTS and obtaining the CRG phase noise from the component phase noises. Three estimates of phase stability are calculated — the fractional frequency change for a 5°C step in temperature, the phase noise spectral density and the Allan standard deviation. It is found from these estimates that the CRG phase stability is better than that of the H-maser physics unit + receiver, which has been measured in the past. Thus, the first step in improving FTS phase stability would be to make improvements in the H-maser physics unit + receiver. These results are corroborated by indirect clock stability estimates calculated from Doppler data by R. W. Hellings.
Details
- Volume
- 42-64
- Published
- August 15, 1981
- Pages
- 222–231
- File Size
- 693.3 KB