Re: DBT sentences

[Gary E. Miller]

Yo Владимир!

On Wed, 16 Jun 2021 19:00:45 +0300
Владимир Калачихин <v.kalachikhin@gmail.com> wrote:

> 14.06.2021 22:57, Gary E. Miller пишет:
> >> https://gpsd.gitlab.io/gpsd/gpsd_json.html#_poll  speaks about
> >> caching values -- it's reasonable.  
> > Yes, cached for the current epoch.  
> 
> When "current epoch" start and end?

Sadly, a hard question to answer exactly.  Time is slippery.

gpsd considers a new epoch to start when it receives a new fix timestamp
from the receiver.  Only rarely (UBX-NAV-EOE) does gpsd know when the
receiver is finished sending data on the current epoch.  In almost all
cases gpsd never knows the end of the epoch, it only knows the start of
the next epoch.  That is when a different (not always later) timestamp
is received from the receiver.

Any gpsd client should just look for the timestamp to change to know they
are in a new epoch.

RGDS
GARY
---------------------------------------------------------------------------
Gary E. Miller Rellim 109 NW Wilmington Ave., Suite E, Bend, OR 97703
        gem@rellim.com  Tel:+1 541 382 8588

            Veritas liberabit vos. -- Quid est veritas?
    "If you can't measure it, you can't improve it." - Lord Kelvin

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