Have you seen the orbit of the Sirius satellites? http://www.tiger-usa.com/satellite_animation.htm
Dave > -----Original Message----- > From: time-nuts [mailto:[email protected]] On Behalf > Of Jim Lux > Sent: Monday, May 18, 2015 21:52 > To: [email protected] > Subject: Re: [time-nuts] iGPS? > > On 5/18/15 7:59 PM, Chris Albertson wrote: > > Yes GPS can do better than 50M but we are talking about a single fix > > from a cell phone in a moving car not a survey receiver. . The > > displayed location is better because the phone applies a > filter to the > > location data. Some thing like a Kalman filter. I doubt > the iPhone > > can get within 10M from a moving car. > > > > As for Iridium being an expensive for pay service. But that is > > because most users SEND data. This new service is > broadcast and costs > > do not depend on the number of users. Apple has sold 130,000,000 > > phones already just in this half of 2015. A one time > payment of about > > $1 per phone might cover the costs. > > Why iridium? Why not Sirius or XM or DBS. Unless you want something > world wide, as opposed to "populated areas served by > broadcast radio and > TV" > > Heck, you could probably buy transponder time on a C-band > satellite and > radiate a GPS assist signal (that's what WAAS is, after all) > > > >>> hmmmmm..I do believe the marketing boys have been playing with the > >>> numbers. You would have to start > >>> from a >50 M error to get them to make much sense based > on what they are > >>> doing. > > > > _______________________________________________ > time-nuts mailing list -- [email protected] > To unsubscribe, go to > https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts > and follow the instructions there. _______________________________________________ time-nuts mailing list -- [email protected] To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
