[FOSS-GPS] Mobile Robot Experimentation

[António Pestana]

If rover and base are close enough (say, no more than a few hundred meters
apart) ionospheric refraction pseudoranges disturbances will be pretty much
the same both for base and rover. Therefore mono-frequency observations
will suffice.

Antonio

2014-09-18 8:50 GMT+01:00 Yanqing <fishloveocean at gmail.com>:

> Dual frequency receivers could solve this problem. You need both the rover
> and the base station receivers to be dual frequency.
>
> Kind regards,
> Yanqing
>
> On 18 Sep 2014, at 03:02, "Sean Hyde" <sean.a.hyde at gmail.com> wrote:
>
> Thanks for the responses!  I apologize for breaking the thread, but I had
> turned on Digests by accident and couldn't figure out how to reply to
> individual messages.
>
>
>
> "I'm not sure what receivers you are using, but if it's this one:
>
> http://www.nvs-gnss.com/products/receivers/item/2-nv08c-csm.html it seems
>
> to be L1 only, not L1+L2.  The antenna you are using covers 1574-1610 MHz,
>
> so while multi-system (GPS/Glonass) it is also L1 only. The GPS L2
>
> frequency is quite a bit lower, at 1227.6 MHz.
>
> http://en.wikipedia.org/wiki/GPS_signals#Frequencies_used_by_GPS
>
>
>
> As far as I know, GPS L1+L2 receivers start around $750 used (eg. Trimble
>
> 4000ssi on ebay) and much more new.
>
> "
>
>
>
> Hi John.  I had completely overlooked the fact that the NV08C couldn't
> utilize L2 as I had read a lot of information about using it in RTK
> setups.  I'm rather new to GPS.  My understanding is that without L2 I will
> not be able to get rid of ionospheric delay, which will increase error.
> Could this be why my system isn't performing as I hoped?  Can I get away
> with using an L1+L2 receiver on the Base Station and not on the Rover?
>
>
>
>
>
> "Did you try with simultaneous mode of ambiguity resolution and use a smaller min ratio to fix ambiguity, such as 2 or 1.5?
>
>
>
> Kind regards,
>
> Yanqing
>
> "
>
>
>
> Hello Yanging.  I tried instantaneous mode and it seemed much worse.  My
> Float solutions oscillated by several meters (instead of a tens of
> centimeters with a drift) and I couldn't get a Fix.  I tried reducing the
> ratio in the other modes.  Although that got me a fix more easily, I was
> concerned that it wasn't accurate, as it was not repeatable.
>
>
>
> -Sean
>
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