SWaP Characteristics, Time Deviation, and PSD Coefficients of the Five Clock Types Considered in This Case Study Analysis
SWaP and TDEV values were taken from (Schmittberger & Scherer, 2020) while PSD coefficients were computed from their respective Allan deviation plots. The Allan deviation plot for CSAC was taken from Lutwak, 2011. For the higher-grade RAFS clock and DSAC, the Allan deviation plots found in the literature (Almat, 2020; T. A. Ely et al., 2018) do not capture the effects of noise components related to the h−1 and h−2 coefficients. As a result, after a confirmation based on heuristic analysis, the process noise covariance Q terms depending on h−1 and h−2 are considered to be negligible for the RAFS and DSAC.
| Clock type | Size (cm3) | Weight (kg) | Power (W) | TDEV per day (μs) | PSD coefficients | ||
|---|---|---|---|---|---|---|---|
| h0 | h−1 | h−2 | |||||
| Microchip CSAC | 17 | 0.035 | 0.1 | 1.5 × 10−6 | 1.3 × 10−20 | 1.0 × 10−24 | 3.7 × 10−29 |
| Microchip MAC | 50 | 0.084 | 5 | 1.7 × 10−7 | 4.7 × 10−22 | 1.2 × 10−25 | 1.7 × 10−30 |
| SRS PRS10 | 155 | 0.6 | 14.4 | 7.0 × 10−8 | 1.3 × 10−22 | 2.3 × 10−26 | 3.3 × 10−31 |
| Excelitas RAFS | 1645 | 6.35 | 39 | 4.8 × 10−9 | 8.0 × 10−24 | - | - |
| NASA DSAC | 17000 | 16 | 47 | 4.0 × 10−11 | 1.8 × 10−25 | - | - |