例句與造句

1. This transfer to S-band was a major enhancement of the DSN capabilities in this era; another was the introduction of rubidium frequency standards which improved the quality of radio Doppler data and hence improved the trajectory determinations needed for interplanetary missions.
2. Another significant improvement at this time was the introduction of ranging systems that used a coded signal transmitted to and returned from the spacecraft . The time of travel was used to measure the range more accurately and to greater distances, and this improved trajectory determination and navigation.
3. It's difficult to find trajectory determination in a sentence. 用trajectory determination造句挺難的