Re: gpsrinex - smaller than 1s epoch interval

[Greg Troxel]

"Gary E. Miller" <address@hidden> writes:

> So I took 1,000 epochs of RAWX data, at a 10 HZ rate, from a ZED-F9P,
> and converted it to RINEX with gpsrinx.  Then submitted to NRCAN
> for static and kinetic PPP processing.
>
> Both worked fine, for some definition of fine.
>
> Initially the kinematic data returned:
>
> Warning : Only your GPS RINEX data are processed. A combined GPS, GLONASS
>  solution will be performed once the necessary GLONASS products are available.
> Warning : Single-frequency only solution in kinematic mode. Please check
>  your results.
> Warning : Approximate position in RINEX header record was not used. Current
>  solution is using a priori position initialized using a pseudo-range only
>  solution.

My impression is that GPS Ultra Rapid orbits are available faster than
GLONASS Ultra Rapid orbits, but that once you wait a whole day or so
then you have Rapid for both.

> Then later, NRCAN returned:
>
> Warning : Your combined GPS, GLONASS RINEX observation file has been
>  processed with the available GLONASS products.
> Warning : Single-frequency only solution in kinematic mode. Please check
>  your results.
> Warning : Approximate position in RINEX header record was not used.
>  Current solution is using a priori position initialized using a
>  pseudo-range only solution.
>
>
> So the kinematic PPP solution is GPS L1 and GLONASS L1 only.  Thus making
> the L2 capable ZED-F9P overkill.  Very disappointing.

I wonder why that is true. I have downloaded a PhD thesis about PPP:
  
https://www.researchgate.net/profile/Boonsap_Witchayangkoon3/publication/34767912_Elements_of_GPS_precise_point_positioning/links/0a85e53b5254fd136a000000.pdf
but have not yet digested it.

> When I submitted the 10 Hz RINEX to NRCAN for static PPP, they gave me
> kinamatic PPP instead.  Maybe too few epochs.

Or too short a total time.   I guess someone can try 4h at 10 Hz.