Re: gpsprof: higher resolution

[John Ackermann N8UR]

On 8/16/20 4:41 PM, Gary E. Miller wrote:

> For the u-blox F9P: RELPOSNED is 1mm precision, and HPPOSLLH is 9
> decimal degrees of precision.
>
> For other 9-series POSLLH is 7 decimal digits of fractional degrees.
>
> For the 9-series xxRMC is ddmm.mmmmm, which is about 6 decimal digit or
> precision.
>
> To get the most from the F9P requires binary messages, not NMEA, and
> fiddling with the sentence mix.

What I'm seeing in the GGA sentence from any of the receivers that have 
the NMEA HIPREC config option is seven decimal places following the minute:

$GNGGA,134648.00,3943.7111969,N,08410.6922079,W,4,12,0.74,280.601,M,-33.483,M,1.0,0073*5C

which ought to translate to about 9 digits of precision.  So pretty 
similar to the 1mm of the binary. (And it also give three decimal places 
 or 1 mm for altitude.)

BTW, I discovered that while the only 8-series receiver to support NMEA 
HI PREC is the M8P, all three units of the 9 series that I've tested 
(M9N, M9P, and M9T) support it.

John