3 ms·
"Real-time" is a bit relative (wink) when it takes minutes to get the data into the browser.
by ulkesh 11y ago
"Real-time" is a bit relative (wink) when it takes minutes to get the data into the browser.
- wrigby 11y agoThe locations are most likely calculated using orbit information published by NORAD and/or the spacecraft operators. This is called ephemeris data, and is usually published in a format called "two-line element," or TLE. A TLE contains a complete description of the spacecraft's orbit at a specific time, so you can then calculate where the spacecraft will be at any moment given that it stays in that orbit. See http://www.celestrak.com http://www.celestrak.com for a bunch more information on the subject. Of particular interest is the TLE format itself (http://www.celestrak.com/NORAD/documentation/tle-fmt.asp http://www.celestrak.com/NORAD/documentation/tle-fmt.asp).
- lloyd-christmas 11y agoIt's calculated using historical data (the most recent observation) using the Simplified General Perturbations model: https://en.wikipedia.org/wiki/Simplified_perturbations_models https://en.wikipedia.org/wiki/Simplified_perturbations_model... This is why it's a beast to run. It's looping through some hefty calculations for each satellite every second.