3 ms·
> satellites without much modification (most important one I can think of would be more panels to cope with the reduced solar irradiance)? atomic clocks
by the8472 5y ago
> satellites without much modification (most important one I can think of would be more panels to cope with the reduced solar irradiance)?
atomic clocks
- gpm 5y agoAre those actually necessary? Not an expert, but the whole network is on communication (with perfect understanding of the satellites locations no less), shouldn't they be able to run an ntpd like protocol to stay in sync, and just sync ground clocks to "starling consensus time" instead of "real time".
- cryptoz 5y agoThere is a pretty decent description of the problem here: https://physicscentral.com/explore/writers/will.cfm https://physicscentral.com/explore/writers/will.cfm I'm also not an expert so I don't know if you can solve it with syncing. Maybe you can. But that doesn't sound like a "just" concept to me - any solution to this is going to be complicated.
- creatornator 5y agoThis got me interested so I brushed off my notes from grad school--GPS predecessors like the US Navy's Timation first used quartz oscillators, then graduated to atomic clocks in orbit. However, even now ground station atomic clocks issue periodic time corrections to satellites in orbit. Since we can get accurate time of flight to Mars, I imagine satellites without atomic clocks could be used, albeit with less stable pseudo-range estimates. This could be overcome by using more satellites, giving more favorable pseudo-range variances.