GPS App idea

[Sean Moss-Pultz]

On 11/23/06 4:19 AM, "Richard Franks" <richard.franks at drdc-rddc.gc.ca>
wrote:

>>>> does agps require a sutiable infrastructure at the network operator
>>>> side or does it just work?
>>> 
>>> The 'assisted' part suggests remote (charged) computation. I was
>>> thinking of something more sneaky, bearing in mind increased access to
>>> the metal -- mind you, when I read the spec I missed the point that the
>>> Neo1973 uses AGPS, *not* satellite GPS anyway!
>> 
>> AGPS uses satelites when available.
> 
> Indeed, I'm not A GPS-ologist :-)
> 
>> From reading up on various sources, I'm still unclear as to whether the
> Global Locate chip in question can function:
> * Exclusively via the network operator (basis of IndoorGPS?).
> * Exclusively via GPS signals where network coverage is absent.
> 
> Obviously, the features available determine the scope of applications to
> be developed.
> 
> Any info on whether the particular GPS mode chosen, and/or
> satellite/tower details will be available to the OM API? I'm thinking
> along the lines of star-finding/satellite-spotting!

GPS is one of the most important parts of this system in my mind. Since
there seems to be quite a bit of confusion, let me clarify exactly what we
have.

Global Locate's AGPS chipsets support three standard modes and one
proprietary mode:

    1) MS-Based (aiding info is good for hours) --Computes fix in MS
    deviceFastest update-time fix mode
    
    2) MS-Assist (aiding required for each fix)-- Acquisition-assistance
    from networkNetwork time impacts compute time

    3) Autonomous (aiding directly fromsatellite, thus not for
    high-performance TTFF)Ephemeris data from satelliteOff-network,
    slowest time-to-fix

    4) Enhanced Autonomous Mode (ephemeris data good for days)Autonomous
    mode with LTO (long-term orbits)

Obviously the first two modes will only work if the carriers support these
features. So don't count on this for a while. The third mode is what a pure
(unassisted) GPS device will offer, and the last mode is cool as hell --
exclusive to Global Locate. It will download ephemeris data over the
internet. 

Assisted GPS devices rock. I've been inside Global Locate's building and
received a positional fix. I really think you guys will have fun with this
thing. 

-Sean