3 ms·
Stupid question: how do they measure speed of the satellite? I mean, on the website they've mentioned the speed of one of their satellite as ~7.6 kmps. Is that
by os7borne 7y ago
Stupid question: how do they measure speed of the satellite? I mean, on the website they've mentioned the speed of one of their satellite as ~7.6 kmps. Is that the actual speed of the satellite or it's a measure of how much land the the satellite covers per second?
- TeMPOraL 7y agoThey can measure it by altitude. An orbiting object always has a defined velocity at any point of its orbit. For example, a circular orbit 500km above Earth's surface amounts to velocity of 7.61 km/s everywhere on it.
- os7borne 7y agoMakes sense. This is helpful. Thanks, TeMPOral!
- mrtnmcc 7y agoThe orbital velocity and the ground track velocity only differ by about 6.6% for their 450km orbit, so it's not a big difference. But because they have a relatively circular orbit, you can use the formula sqrt(G*M/R) which gives 7.639km/sec -- so it looks like they are referring to true orbital velocity.
- os7borne 7y agoThis is helpful, thanks!
- loneranger_11x 7y agoNot an expert. But there are a few ways to look at this. Bodies that are in stable orbit can have only a specific velocity which is a function of its distance from & mass of whatever it is orbiting. So orbiting satellite's speed can be inferred from its orbital height. There are ground based tracking stations that can technically measure the speed of any orbiting body. Also read somewhere that LEO satellites could use GPS receivers to get a fix on their position. measuring change in this position also gives velocity. There a bunch of limiting conditions around max-height and velocity for this to work though.
- os7borne 7y agoAh! Got it. Thanks!