1、Dezember 2014DEUTSCHE NORM DIN-Normenausschuss Luft- und Raumfahrt (NL)Preisgruppe 18DIN Deutsches Institut fr Normung e. V. Jede Art der Vervielfltigung, auch auszugsweise, nur mit Genehmigung des DIN Deutsches Institut fr Normung e. V., Berlin, gestattet.ICS 49.140!% 1 MHz 1 MHz 1 MHz 1 MHz 111 dB
2、c/Hz 6. Space-to-Earth link carrier frequency stability (a) reference frequency Figure 4-6, curves B and D (b) frequency converters Figure 4-6, curve C 7. Group delay variation vs. time (a) Category A 20 ns/12 h pp (b) Category B 2 ns/12 h pp 8. Group delay variation over 3 MHz bandwidth (a) Categor
3、y A 5 ns pp (b) Category B 2,5 ns pp NOTE In case of polarization diversity combination, these conditions can be achieved only with a proper compensation of the differential delay. 9. Timing accuracy (a) Category A 10 s relative to UTC (b) Category B 1 s relative to UTC 4.4.2.2 Suppressed carrier mo
4、dulation 4.4.2.2.1 Overview Only Doppler tracking can be used in this mode. 4.4.2.2.2 Requirements a. The following requirements shall be met by the Space-to-Earth link: 1. Minimum C/N ratio in carrier loop 2BL 15 dB NOTE Equivalent C/N ratio taking into account squaring loss. 2. Doppler tracking (a) Carrier PLL loop order second DIN EN 16603-50-02:2014-12