4 ms·
For context, the lander did have a radar altimeter. A radar altimeter has maximum distance from ground above which it will not establish a lock. If radar altim
by blutack 10y ago
For context, the lander did have a radar altimeter. A radar altimeter has maximum distance from ground above which it will not establish a lock.
If radar altimeter had never had a lock, either the radar altimeter has faulted in a way you can't detect, or you are above the lock range for your radar altimeter.
If the radar altimeter had locked, you have a very accurate measurement of height above ground.
- moioci 10y agoThat's the surprising thing, though: "its radar Doppler altimeter functioned correctly and the measurements were included in the guidance, navigation and control system. "
- pbhjpbhj 10y agoAnd presumably mission time was in use too? Presumably they know to the (milli?)second when the lander should touchdown, at least from the point where the lander starts its descent. Time of flight send like a very strong, reliable signal?