UBLOX ZED-F9P and NEO-F10N

[AI6MK]

Hi,

New to forum so forgive me if these are already answered questions.

I'm using GPS for surveying and would like to get <1m accuracy autonomously. I am quite familiar with RTK using a BASE station but have never used NTRIP, yet.

I've used a variety of UBLOX devices including C94-M8P in ROVER/BASE STATGION configuration and got excellent results but only under ideal conditions where both ROVER and BASE were in the open.

To achieve better results for just ROVER config (autonomous) I'm now using NEO-F10N from Ardusimple which uses L1 and L5. The "high precision" device offered by UBLOX is the ZED-F9P. So I'm trying to understand what is the major differences between these two devices ?

Looking at the specs the major differences are:
ZED-F9P: Bands = L1/L2/L5, supports all GNSS constellations
NEO-F10N: Bands = L1/L5, all GNSS except GLONASS

As I understand L2 provides same CA (1Mb/s) as L1, and is used compensate for ionospheric errors.
L5 uses the same CA as L1 and L2 but is higher power and greater bandwidth (?). L5 is supposed to give better results in built up areas,

Q1: With a good view of the sky in the open, what is the impact of not having GLONASS satellites on NEO-F10N.
Q2: If L5 uses the same CA, then what is the impact of not having L2 for NEO-F10N ?
Q3: To achieve cm performance in autonomous mode, ie no BASE corrections, I thought that using the carrier on L1/L2 or L5 along with the CA codes would produce the best results. Do any of the UBLOX devices do this ?

Regards,
BRIAN

 

[AI6MK]

Update after further researching:

1.  GLONASS does not currently support L5, but is scheduled to start by 2025.
2.  From e-education.psu.edu/geog862/node/1864

"Both L5 codes have a 10.23 MHz chipping rate, the same as the fundamental clock rate. This is the same rate that has been available on the P(Y) code from the beginning of the system. However, this is the fastest chipping rate available in any civilian code. L5 has the only civilian codes that are both ten times longer and ten times faster than the C/A code. Since the maximum resolution available in a pseudorange is typically about 1% of the chipping rate of the code used, the faster the chipping rate, the better the resolution."

So there should be a substantial improvement in the spatial accuracy for NEO-F10N and ZED-F9P using L5 due to 30m chips compared to 300m chips for devices which use only L1/L2.

Regards,
BRIAN

 

[Nuvi-Nebie]

This link may answer some of your questions :-
https://www.everythingrf.com/community/navigating-the-l1-l2-and-l5-band-options-for-gnss

 

[AI6MK]

Who wasn't reminded as the owner of shiny new hardware to "Read the Manual".

I'm using an Ardusimple GNSS L1/L5 Arduino shield and I assumed that both L1 and L5 frequencies were in use. The Ardusimple manual has a section called "Enabling GPS L5". Since L5 is not yet operational, all UBLOX NEO-F10N L1/L5 modules are shipped with L5 disabled by default. The manual provides a link to a configuration file which will enable L5. I'm not sure if the same is true for the ZED F9P module.

 

[Nuvi-Nebie]

L5 is available now (started in 2014), it is being added to as time goes on but it is useable today, there is some more reading in the Wikipedia link HERE