[FOSS-GPS] Mobile Robot Experimentation

[Fred Labrosse]

Hi,

Sorry, no answer for you, but rather a question.  We are trying to create a 
similar setup and I was wondering if you could share your custom pcb.

Cheers,

Fred


On Wednesday 17 September 2014 17:05:35 Sean Hyde wrote:
> Hey Guys,
> 
> 
> 
> I've been playing around with RTKLib for a couple months now and have run
> into some issues and I was wondering if anyone had any idea on how to
> improve performance.
> 
> 
> 
> ---Setup---
> 
> Base Station:
> 
> NVS08C on custom PCB using the receiver to power the antenna
> 
> Antenna is Taoglas Limited AA.161.301111
> (http://www.taoglas.com/images/product_images/original_images/AA.161.3011
> 11. pdf)
> 
> Antenna is on a 12" x 24" steel plate
> 
> Connected via FTDI->USB to Rasperry Pi
> 
> Raspberry Pi runs str2str to send the data to Windows laptop running
> rtknavi using wifi backhaul
> 
> 
> 
> Rover:
> 
> NVS08C on custom PCB using the receiver to power the antenna
> 
> Antenna is Taoglas Limited AA.161.301111
> (http://www.taoglas.com/images/product_images/original_images/AA.161.3011
> 11. pdf)
> 
> Antenna is on a 18" x 18" steel plate
> 
> Connected via FTDI->USB to Rasperry Pi
> 
> Raspberry Pi runs str2str to send the data to Windows laptop running
> rtknavi using wifi backhaul
> 
> 
> 
> The Rover setup is on a small mobile robot with a top speed of about
> 3mph. It is in a city (Pittsburgh), but the sky is relatively
> unobstructed.
> 
> 
> 
> I'm running rtknavi in Kinematic mode using only GPS, L1+L2, 15deg
> elevation mask.  The position that I input for the base station is a 5
> hour average (though it seems to have lost some precision when I pasted
> it?).  I have tried both Continuous and Fix and Hold Integer Ambiguity
> Res.  I'll try to attach screen shots of rtknavi.
> 
> 
> 
> Right now, it kind of works.  I can get relatively jitter-free floats and
> occasionally fixes, but these fixes don't last long and I'm not sure
> they are actually globally accurate (ie: if you restart the software,
> you may get a fix, but it may be several meters from your last fix). 
> Sometimes a fix goes away and never seems to come back.
> 
> 
> 
> I'm wondering if you guys have any suggestions to improve these results.
> 
> Better antennas? (Which ones?)
> 
> Trying to get better placement of the base station?
> 
> Different settings in rtknavi?
> 
> Continuous vs Fix and Hold?
> 
> 
> 
> Thanks!
> 
> -Sean