GPS Power Requirements

[Marcus Bauer]

On Thu, 2007-01-25 at 11:08 -0600, Jonathon Suggs wrote:
> Marcus Bauer wrote:
> 5mW if you get a fix every ten seconds.
> 
> 10 seconds is a pretty big interval.  Where did you get that information
> from?

I don't have a link at hand, but the GL chip consumes 50mW in continuous
mode and gets a fix within one second, i.e. ~50mW-s energy per fix. 

> Who is working on the drivers?

Global Locate does. They don't publish the protocol of the serial
interface of the chip. That's why this is closed source, called "Global
Locate Library".

The following are Global Locate's own statements about their chips on
their Website:

      * Autonomous or aided operation
      * -----------------------------
      * The new hardware approach can make use of aiding, such as
      * satellite orbit data, to compute the satellite
      * Doppler frequency.
      * 
      * However,
      * in a situation where aiding is not available, the
      * hardware approach can still operate, by using
      * the frequency feedback and by demodulating the
      * satellite data. In this mode the new design
      * operates almost like a conventional GPS
      * receiver, except that acquisition times are about
      * one thousand times faster, thanks to the
      * presence of the real time convolution processor.

The whole document repeats over and over again how good, fast and
precise their chips are *without any AGPS* at all. And they repeatedly
state to be able to get a fix in real-time.


Marcus