3 ms·
That's how GPS works, it was initially intended for something else --- was it for detecting nuclear blasts?
by rongopo 4y ago
That's how GPS works, it was initially intended for something else --- was it for detecting nuclear blasts?
- hotpotamus 4y agoI thought the idea for GPS went back pretty much to Sputnik. People realized pretty quickly they could track it by timing its signals from a known location on Earth and then also quickly realized you could reverse that and figure out where on Earth you are once you have enough timing signals from known locations in space. It just took a bit for the computers to get small enough and for us to put up the satellites.
- dingaling 4y agoThat's correct and led directly to the US Navy's doppler-based Transit GNSS that operated from 1961 until 1996. Navstar / GPS emerged as a joint project in 1973 based on individual services' research into a better form of GNSS.
- MichaelCollins 4y agoNot for detecting nuclear blasts, but rather for directing them. The primary motivation for Transit/NNSS, the first satellite navigation system, was to provide location information to missile submarines so they could calculate firing solutions for SLBMs. The submarine needs to know where it is so it can tell the missile where to go. Detecting nuclear blasts from space came shortly later with Project Vela. Those satellites didn't depend on something like GPS because the position of each satellite at any given time could be calculated from its known orbital parameters; no need for radio navigation.
- outworlder 4y ago> The submarine needs to know where it is so it can tell the missile where to go. That reminds me of "the missile knows where it is because it knows where it isn't" https://www.youtube.com/watch?v=bZe5J8SVCYQ https://www.youtube.com/watch?v=bZe5J8SVCYQ