Weather Routing

[rgleason]

Yes, Peter has it correct, but conceptually there is a
"Boat.xml" file that contains the filenames for one or more of the boat's Polar Files (Beneteau38-power-light.pol. Beneteau38-sailset-light.txt, Beneteau38-sailset-medium.csv, Beneteau38-sailset-heavy.pol).

Also you could have multiple Boat.xml files for different boats that you do routing for, so you could save the Boat.xml as "Beneteau38.xml" and it will remember the previous polars that you have loaded.

[rgleason]

Dave, Sean, Jean Pierre or anyone.

Re: Dual Grib files & WRouting

Assume two grib files are loaded.
GFS wind 3hr interval 5 day
& RTOFS current 24hr 5 day files

Will WRouting interpolate the current into 3hr intervals or just skip those frames and do the routing without any current values for frames which have no data?

Thank you.

[gjorgensen]

Originally Posted by rgleason

Yes, Peter has it correct, but conceptually there is a
"Boat.xml" file that contains the filenames for one or more of the boat's Polar Files (Beneteau38-power-light.pol. Beneteau38-sailset-light.txt, Beneteau38-sailset-medium.csv, Beneteau38-sailset-heavy.pol).

Also you could have multiple Boat.xml files for different boats that you do routing for, so you could save the Boat.xml as "Beneteau38.xml" and it will remember the previous polars that you have loaded.

Thanks to you and Peter. That seems obvious now. Based on your comments I'm guessing i'll still have to go into the polar and delete 0 columns and clean it up. I'll try it over the weekend.

[rgleason]

I've determined that the Current gribs at 00h UTC are not interpolated to 3hrs to match the Wind grib. Current data is NA in the intervals between.
This is ok. We just need to be able to download 3hr Current data, hopefully eventually.

Re: Dual Grib files & WRouting
Assume two grib files are loaded.
GFS wind 3hr interval 5 day
& RTOFS current 24hr 5 day files

Will WRouting interpolate the current into 3hr intervals or just skip those frames and do the routing without any current values for frames which have no data?

[AedanC]

There is a small inconsistency in the date formats used in different parts of the Weather Routing plugin, version 1.10. In one place it's MM/DD/YYYY and in another it's DD/MM/YYYY. See the picture below. Elsewhere in OpenCpn I see DD-MMM-YYYY which at least is unambiguous.

[rgleason]

If you are trying to route in close in coastal areas, or short routings.
1. If it fails on polar or grib. First turn off Detect Land.
2. If that does on work define a longer route in an ocean area and get that routing working. Then go back to the short route and try a much shorter interval, say 15 minutes.
3. Once that is working, try checking the "Detect Land" box and see if the routing is in water rather than land. (Note that WR does NOT do depth checking and that the land boundary is as good as the underlying GSHHS data. Note: You should be be using High Resolution GSHHS data found here in the User Manual https://opencpn.org/wiki/dokuwiki/do...:chart_sources
4. If you wish to fine tune the routing and exclude areas use the Boundary checkbox and but first define a boundary using Opencpn Draw. (There seems to be a problem with WR Boundaries, see next post.)

[rgleason]

I am getting a "Boundary not Detected Error" when Boundary is checked in Weather Routing. I have defined an "Exclude Boundary" in Opencpn Draw.
Perhaps I am not using this tool properly, but I don't think so.

I the GUID being properly passed to WR? I believe the messaging protocal was expanded and changed and WRouting no longer uses the correct protocal to properly ""see" the boundary.

[rgleason]

If you don't see any routing or isobars and the routing was succfessuly completed, you probably don't have Setttings > Display > Advanced > Use Accelerated Graphics OpenGL turned on!

If you are trying to do a Walking/Moving Grib routing and the error keeps showing "Polars" you may have a problem with the timing of the walking grib, where there is no data at some point in the calculation. First make sure your polars are working by doing a very simple routing. Using Grib_pi Download a short 2 day, with an interval of 3 or 6 hrs grib about 100 miles wide, with just Wind data in an open ocean area.
Make sure you set the grib at the beginning frame or the second or third frame, Then in WR Configurations > Configuration Menu
1. Make sure to pick the proper Start & End points about 80 miles apart.
2. Make sure these points are within the Grib area that you have downloaded.
3."Grib Time"
4.Detect Land off
5. Disable Climatology
6. Set the time step to 2 or 3 hours.
7. Try compute. If it fails, read the message.
8. It may be a Polar problem. If you do not know if your polar works, try a different one.
9. Work with this until you get a routing.

Then go back to the Walking/Moving Grib and determine if the speed, distance, or size of the Lat/Long box need to be changed.

I found that a "polar" error was fixed by expanding my lat/long area.

[rgleason]

In preparing for a race on a friends boat I had to improve and fix a polar file that had vertical columns of 0"s and would not work in WRouting. So I created a step by step spreadsheet showing how you can modify and improve your polar for use with WRouting. Please go to the Polar_pi thread to get the spreadsheet.

http://www.cruisersforum.com/forums/...ml#post2403111

Please post or details about what you have done to fix or make your polars work with WRouting. This information will be very helpful in improving our tools for using polars!

[rgleason]

If a routing fails with "Polar: No data" and the finish is near to land.
Check to see if the grib file shows wind data around the finish. If there is no wind in that area it is likely that the High Resolution GSHHS that you should be using, does not have high enough accuracy for the landmass edge, and consequently some of the grib data is not available and has been programatically masked by the "high res gshhs" landmass edge which is not detailed enough.

What should I do? Just move the destination out where there is grib data to get the routing working.

[rgleason]

If you get "Polar Failed" -The polar diagram should look like 1/2 of a complete heart.
First check your polar file. Not all the polar files are the correct format.
The polar diagram must be shown complete to the centerline for both upwind and downwind, such that if you mirror the polars they will look like a series of hearts. If upwind polars stop short at 40 degrees or so they should be extended by inserting a column of zeros at to first column for 0 TWA. If the downwind polars are not completed, try to complete them the best you with Polar_pi using "Load" the Polar and then adjust the downwind to complete the 180 degrees and then SAVE the Polar file as Ocpn *.pol

Then it should work.
If it doesn't work try another polar that you know does work. Get that working with the grib. Then switch back to the previous polar. If is doesn't work now, make sure it looks like a 1/2 heart.

If it still doesn't work, go back and check your grib file. It may be that you are lacking grib data (particularly if you are using a walking grib and the polar is faster than the one that tested properly).

Be smart about how you test. Simplify things first, get it working. Then change one thing at a time and run Compute, if it works then add one more feature, like turning on detect landmass.

If you think you are having troubles with gribs, try turning off gribs and just use Climatology on "most likely" Climatology should provide reliable 30year average grib data almost anywhere. Get your polar working with that. Then download a fresh grib file, set it to the begining frames, perhaps two or three frames in, then in the Configuration menu Select "Grib Time". Now "compute". It should work.

[rgleason]

I think we should make an effort to get all the polar files into Ocpn *.pol format that works and include only those files in the download package.

The question then is, what do we do about incomplete downwind polars?
Just draw a line perpendicular to the centerline that connects to the last downwind data? Or is there a better way to complete the data?

Without the diagram complete in a heart shape the Weather_routing algorithm fails with "Polar: Failed"

Try using C_C34.pol for an example.

[rgleason]

Sean,
Help?
Weather routing no longer compiles under windows.

https://github.com/seandepagnier/wea...g_pi/issues/76

[jongough]

Rick,
What version of OD and WR are you using?

Jon

Originally Posted by rgleason

I am getting a "Boundary not Detected Error" when Boundary is checked in Weather Routing. I have defined an "Exclude Boundary" in Opencpn Draw.
Perhaps I am not using this tool properly, but I don't think so.

I the GUID being properly passed to WR? I believe the messaging protocal was expanded and changed and WRouting no longer uses the correct protocal to properly ""see" the boundary.

[rgleason]

These polars currently fail. See what Sean suggests here.

http://www.cruisersforum.com/forums/...ml#post2406541