[FOSS-GPS] AGPS for newbies?
lauri.hahne at gmail.com
Mon Jan 19 08:55:11 EST 2009
2009/1/19 Timo Jyrinki <timo.jyrinki at gmail.com>:
> In three kilobytes?
That sounds credible. One full gps navigation message takes 25 frames
to transmit (12.5 minutes) and one frame is 1,500 bits long. That
makes about 4.5 kilobytes which basically contains the ephemeris of
one satellite 25 times and the full almanac. If you throw out the
extra copies of ephemeris, clock times, and other redundant
information and replace that with some extra ephemeride, three
kilobytes sounds pretty ok. I think your program requires coordinates
only because the chip expects them with the agps data.
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