Re: [Question] gpsd, ntrip & C94-M8P (u-Blox)

[Greg Troxel]

Florian Kiera <address@hidden> writes:

> The rover's green LED is flashing which the user guide is saying to
> mean the M8P is in RTK Float mode (status).
> I am using gpsd to receive all informations from the rover and check
> the gps_data_t => status (github: gps_fix_t.status).
> The status returns me a 2 (DGPS). How is that?

SO you are saying that the lights on the receiver (what do you mean by
"rover's green LED", exactly) indicate one thing and gpsd another.  It
would be good to really look into this, which involves really
understanding the data path to the green light and to the fix_t values.
I would be very hesitant to assume either one is correct here.

> Is it because my base
> has a too less accuracy for RTK? (20m accuracy)
> If so could you please tell me what accuracy of the base I should seek
> for? (What accuracy is needed for RTK?)

I don't know what you mean by accuracy of base.  If you mean that the
configured coordinates of your base are incorrect by 20m from their true
(unknown) values, I don't know how much trouble that would cause, but it
seems like a needless source of error and confusion.  It seems obvious
that you should collect 24h of raw data from the base and then process
it with PPP at NRCAN, or something like that, to get accurate base
coordinates.

> My target is to get the status 3 (RTK float) from the rover. My
> assumption is that my base isn't accurate enough. You've got other
> ideas that could improve it?

I think you need to look at the docs for the receiver and get diagnostic
output from it about why it does or does not accept the reference
station phase inputs.  Easier said than done of course.