Re: gpsrinex - smaller than 1s epoch interval

[Gerry Creager - NOAA Affiliate]

Even in the old days, RTK was 1s intervals for Ashtech and Trimble. That said, NONE of those data were in RINEX specifically. Part of the issue, while we were waiting for the Earth's crust to cool was the speed of the hardware. I could go back to the history of GPS design and the use of shift registers for counters, as an example of how antiquated by today's standards things are but it'd be pointless.

I'd think RTCM would be a better choice than RINEX but with Gary's find that the interval can be millisec, that thought could change.

gerry

On Tue, May 19, 2020 at 5:22 AM Gary E. Miller <address@hidden> wrote:

Yo felix!

On Mon, 18 May 2020 22:19:03 +0200
felix <address@hidden> wrote:

> so i set up gpsd with rinex to output an epoch every 1s. For my
> application, pretty fast moving, it would be great to output data
> more often then every 1s, say every 100ms. The Gps, a u-blox F9, is
> certainly fast enough, to acquire enough raw data - 40hz are the max
> for HW.

I know of no service that can use RINEX data to faster than 1 HZ.
Most only use one fix every 30 seconds.

What consumer do you have of RINEX that can use faster than 1Hz data?


> In the the current 3.20 code the --interval seems to be clipped to 1,
> as  internally time is kept as an integer in seconds:

Yup.

> Would it require a lot of changes to track time internally not in
> seconds but in nanoseconds,

Conflating two issues.  Easy to make the interval in seconds, as a
float.  Very few GPS can work faster than 25 Hz.  nanoseconds is
pointless.

> Are there any fundamental
> reasons that make this hard or impossible?

Nope.  But with no known use, not worth doing.

RGDS
GARY
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