[time-nuts] iGPS?

[Jim Lux]

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.
>