5 ms·

Laying fiber isn't going to get your Tesla connected.

• cracell 10y ago
  Interesting idea but wouldn't a satellite to car connection be pretty unreliable? Since the line of sight would often have things in the way. I'm assuming trees, bridges, and being in a garage would interfere with it.
  • mentat 10y ago
    Yet GPS works.
    • grzm 10y ago
      AIUI, GPS isn't a connection. It's broadcast, one-way communication. Also, I assume the information transferred is much lower, not much more than time and position, plus redundancy to handle things like interruptions due to landscape.
  • Tloewald 10y ago
    Well, there's going to be 800 of the suckers. There are only about 33 GPS satellites. Although 700 miles is lowish orbit, it's still above the horizon over 2000 miles away.
    • WaxProlix 10y ago
      Wow. I read this comment and thought, "This has to be bullshit." But lo and behold, the core satellite 'constellation' is only 24 satellites[1]. That's mega impressive. https://www.faa.gov/about/office_org/headquarters_offices/ato/service_units/techops/navservices/gnss/faq/gps/ https://www.faa.gov/about/office_org/headquarters_offices/at...
      • Dylan16807 10y ago
        And they transmit with about 50 watts.
      • nickpsecurity 10y ago
        Look up the connection between Einstein's general relativity and GPS accuracy for more fun. Especially early on in its deployment.
        • bcook 10y ago
          That's actually a myth, since the GPS satellites all experience a similar relativistic time skew. http://www.alternativephysics.org/book/GPSmythology.htm http://www.alternativephysics.org/book/GPSmythology.htm "The presence of Special and General Relativity effects has no bearing on the accuracy of GPS operation. In summary, it wouldn’t matter whether clocks aboard GPS satellites ran faster or slower than Earth’s clocks or even changed their speed each day. Just so long as the satellites’ clocks remained synchronised with each other and the time-difference relative Earth’s clocks didn’t become too large, GPS receivers would continue to calculate their correct position."
          • dingaling 10y ago
            That page constructs its own argument and then deconstructs it. It doesn't actually disprove the OP's statement. The reason that GR and SR have "no bearing" is because they've already been designed into the system... From "Understanding the NAVSTAR" 2nd Edition, by Tom Logsdon ( one of the designers of the system ) the time-dilation is compensated through: 1. Off-setting the clock ticking-rate during manufacture of each satellite. 2. Applying a unique onboard corrective factor according to the eccentricity ( egg-shapedness ) of each satellite's current orbit. The latter is correction is constantly recalculated for each satellite. Without these corrections against relativistic effects the accuracy would suffer by 14 nm after 24 hours ( without tick-offsetting ) and 100 feet or so per day due to orbital eccentricity.
            • nickpsecurity 10y ago
              That's the one. There's pages one can get from Google with some of the data and illustrations if they can't get the book. It tripped me out when I found out they had to design relativity into it.
      • legolas2412 10y ago
        Well, GPS is more like radio, you only listen to the broadcast, you don't talk back. But this is more like cellular access points. You have a private channel.
    • legolas2412 10y ago
      You don't establish a communication channel with GPS. You merely listen to the broadcast. Like a radio tower can service an entire town, but you need many many cellular access points.
  • tim333 10y ago
    I used to have a sat phone (Thuraya) and it was pretty reliable if you were outside. They don't work well inside buildings.
    • damianknz 10y ago
      You'll get around that in your home by having the satellite module thing up on your roof and a cable to your wifi router. What I don't understand about this though is the number of frequencies available to connect to all these satellites and how it might extend to ~300 million people (let alone a billion potentially).
      • tim333 10y ago
        I think they focus a beam on each user in turn and so don't need different frequencies.