Re: Getting PDOP, VDOP and HDOP in C

[Matha Goram]

Hello David,

You may be familiar with

    GPS
    Essentials of Satellite Navigation
    Compendium
    Jean-Marie Zogg
    GPS-X-02007-D
    www.u-blox.com

It has formulae for the parameters of interest to you. Apologies if this 
reply is a redundant.

Regards,
--- Matha.

On 3/28/22 23:29, David Taylor wrote:
> I have a program which returns a valid gps_data_t named gps_data.  My 
> knowledge and reading of the headers isn't good enough to find how to 
> get the three variables: pdop, hdop and vdop, although I suspect they 
> are available.  Could some kind soul show me how, please?
>
> given in outline:
>
>   struct gps_data_t gpsdata;
>   status = gps_open (GPSD_SHARED_MEMORY, DEFAULT_GPSD_PORT, &gpsdata);
>   gps_read (&gpsdata, NULL, 0);
>
>   hdop = gpsdata.<what>
>   vdop = gpsdata.<what>
>   pdop = gpsdata.<what>
>
> Thanks,
> David