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[on:]

How can we make one?  Anyone?
http://www.navipedia.net/index.php/Real_Time_Kinematics

[Reply #1 on:]

Get a base station - see the other thread where you asked about this.

[Reply #2 on:]

Please read the link.  Of course get a base station.  Can you be a little more specific?
I'd like to know relative position, relative to the base station.  No need to know the exact coordinates for me.

[Reply #3 on:]

Like this, only with an Arduino?
http://blog.makezine.com/2009/11/12/diy-real-time-kinematic-gps/

Has anybody done it already?  If not, want to work together?

[Reply #4 on:]

I can't see that link from  here, will read it when I get home.

[Reply #5 on:]

For anyone who is interested in working with me:

http://gpspp.sakura.ne.jp/rtklib/rtklib.htm
http://gpspp.sakura.ne.jp/rtklib/rtklib_beagleboard.htm
http://gpspp.sakura.ne.jp/paper2005/isgps_2009_rtklib_revA.pdf
http://www.gogps-project.org/
http://www.maximumpc.com/article/news/want_build_your_own_super_accurate_gps
http://blog.makezine.com/2009/11/12/diy-real-time-kinematic-gps/
http://www.sxbluegps.com/sx-rtk.html

[Reply #6 on:]

Is there anyone who would wish to have this capability using Arduino? 
Can you think of any applications? 
Am I the only one?

[Reply #7 on:]

Are you saying you're using a phase locked loop to detect variations in the distance traveled by the carrier based on phase changes of the carrier?

That sounds spectacularly difficult, and bloody brilliant if you can make it work.

[Reply #8 on:]

I have not.  Others have in the links above.  Do you think the Arduino would be a bottleneck?

[Reply #9 on:]

Do you think the Arduino would be a bottleneck?

I don't see how, since there doesn't seem to be any part of this problem that is within the capabilities of an Arduino. I imagine it'd need a dedicated hardware platform.

[Reply #10 on:]

Yet the beagleboard works?

[Reply #11 on:]

From viewing the links, it appears to be possible.  Question is how do you apply it?  Need to be able to navigate so the board needs to provide a signal that can be used by the flight controls.  It is one thing to have a transmitter in your hands and control the direction and the landing.  But to have your aircraft fly a mile, or a hundred miles, away and to land where you want, a navigation system must have apropriate signals from the GPS.

I like the approach here, using RTK to getfaster and more accurate coordinates.  For example, if your unmanned airplane is small and coming into an airstrip, a GPS signal that is off by a meter can cause the plane to veer off course and require constant corrections.  In the last seconds, even if you are controlling it via computer, cell phone, etc, standard GPS may be too slow and you're in for a rough landing.

Current successful drones, such as the Predator, have been developed from RC technology and the first people recruited to fly them were hobbyists from Minnesota.  UAV attempts that are scaled down airplanes have had major problems and cost much more to develop.  You guys are in the position to pioneer the development of an open source GPS navigation system.  Current systems I have found are quad copter specific and expensive.  One system from China and currently not available, uses Google Earth.  Click on a spot and go, but not likely super accurate.

[Reply #12 on:]

A tape measure? your local DIY store, a couple of dollars? -

0.01 accuracy - providing you've got good eyesight

[Reply #13 on:]

First let's get the data for a particular location, then I will apply it!  A tape measure will be difficult over 500m.

[Reply #14 on:]

A couple of things:

- I do not think the 8-bit Arduino will have the computational horsepower to be able to handle the required calculations in anything close to real time and memory may be a problem also.  The Due probably has the guts to do it, if you can access some of the libraries that are out there for the Arm.
- The open source Real Time Kinetics has been done published and scrutinized see some of the links from sbright33.

This stuff works I have seen it in practice and it is pretty neat for those who have the need for it.  I wonder whether SA would be turned back on if there were cheaply available RTK systems.  The combination of RTK and some of the emerging and established technologies is a scary mix for some people.

wade