Seeking Nmea Data files for testing.

[rgleason]

WE need some good recorded nmea data files for testing the plugin TackandLay_pi. Specifically upwind and downwind recordings for the purpose of creating polar files and testing TnL.

We are looking for files with GPS data (position, Sog, Cog) and Wind (apparent and true) and Heading. It can have AIS in it.

What we are looking for is upwind tacking (both tacks) and downwind tacking (both tacks).

Any size file, I will advise how to upload.

Thanks.

[rgleason]

I believe this is the data we need at the moment to run TackandLay_pi

This is a pure guess about what data is needed by the plugin at the moment.

COG & SOG from Gps
HDG magnetic (Learned necessary -tried nmea 08.09.15A.txt)
True Wind Speed
True Wind Direction (magnetic)
STW (may not be needed for simple laylines*)
Mag HDG (may not be needed for simple laylines*)

* no set and drift calculated (leeway + current)

Still looking for upwind tacking and downwind tacking nmea files with the above data
Upwind and downwind files with apparent wind (speed, angle, direction) may also become useful with some improvements to the plugin.)

[muttnik]

Should data be timestamped and if so how? A bunch of sentences don't necessarily reflect the inter-sentence spacing.

[rgleason]

Muttnik,
I don't see any time stamps in the files that work.
However attached is a snippet of what I know works.
You can take the .doc of if you'd like.
I think the timing is simply set by the baud speed of the connection.
I certainly speed it up when using VDR and VDRplayer.

[rgleason]

Here is a brief summary of the Nmea Sentences used.
There is timestamp data in the GLL sentence perhaps some others.

[Paul Elliott]

Here is a zipped NMEA0183 logfile that I think has the type of data you are looking for. This came from the "2012 Pacific Cup Start" logfile I have on the downloads page for NavMonPc. The original file doesn't have TWS/TWA, so I had NavMonPc create these from the available data and save everything in a new logfile. The sentence types are:
MWD, MWV, HDG, HDM, RMC, HDT, HDG, VHW, VDM, DBT, VWR, MTW, GBS, VDO, and a few others.

https://drive.google.com/open?id=0B1...2l3SWktWnd0LTg

I wouldn't trust the wind angle calibration too much, but it's close enough for testing purposes. We've got COG/SOG. HDG/STW, AWA/AWS, and TWA/TWS data for your polar generation. Again, garbage in, garbage out, but it should be good enough to play with.

This is mostly upwind, but we did do a a jibe or two before the start.

[rgleason]

Dear Paul
I can't thank you enough! I am going to have to try creating tws/ twa from available data for some other files too. I did not realize it would help in this way. Could I filter out ais data in the same way and save the file as well?
Cant wait to try it.

[rgleason]

Also to use your file for tnl!

[rgleason]

Paul, the file (San Francisco) works very well for upwind. Thank you. I'll be posting it in the TnL thread.

[Paul Elliott]

You can use the NMEA Router feature of NavMonPc to do NMEA filtering. Here's one way to modify a raw NMEA0183 logfile:

Start NavMonPc.

Play a previously recorded NMEA logfile. Set up the NMEA router to Collect all the NMEA sentence types. Set up the router to forward only the desired message types to the NMEA Log.

Once this is done, stop the playback, configure NavMonPc to record a new logfile (use a different name than the one you are playing), and restart the playback. This new logfile will contain only the NMEA sentence-types you want.

Of course there are many ways to edit an ascii NMEA logfile, but this is method is easier than it sounds.

I just did this for the previous logfile, removing the AIS stuff. Here's a link to the file:
https://drive.google.com/open?id=0B1...DFWZkhpaW44cW8

[rgleason]

What a great tool. I am going to modify some of the nmea data files I have accordingly, so that TacknLay will work better for testing..