Weather Routing

[rgleason]

Weather_routing_pi updated for windows

[skipperearly]

am using the latest weather_pi under win10 and plan routing from Estepona via Gibraltar - Cascais - Vigo - Brest - to Kinsdale.
Have created the waypoints in wr_pi - it is confusing to generate the waypoints in this strange format (W is minus) rather than using the waypoints already available in ocpn. Will this be available in a future version? - when?

I also seem to fail to get useful routings with various errors, don't really know what "land: failed" means when the minimum distance to land is already set to zero.
see attached screenshot.

hope the development of the weather_pi will continue to address the usability - great potential - thanks for all your work!

[rgleason]

There are many reasons a configuration may fail
Another paragraph about failures




Try uncheck "Detect Land" first.
Then download the highres gsshs using chartdownloader.


Consider the following:


“Complete” affirms that the computations completed. “Fail” indicates they did not and that some setup parameter may be out of range. The failure messages have been made to be more descriptive to help.
If your polar doesn't include boat speeds:

1. Above a windspeed that the grib tries to use, it will fail to route.
2. Below a windspeed that the grib tries to use, it will fail to route.

There are many reasons a Computation cannot complete, or fail. The computation is dependent on:

1. Wind Data (grib_pi or climatology_pi) - Start & End data/time of the file, interval downloaded.
2. Boat Polar File - Correct format, with a wind range that matches the grib data.
3. Time Interval Issues - Sometimes a 1/2hr or 1hr interval will yield a better route than 3hr or 3hr. Sometimes that is the difference between “Completion” and “Fail”.
4. Max Diverted Route - Normal setting is 100 degrees, which speeds up calculations, but with longer time intervals, you may have to set this on something like 140-160 degrees to complete the routing, particularly when the Finish is near land with Islands and Peninsulas around.
5. Configuration settings which must be made to be compatible with the data to Complete:
   1. Interval Issues - Too long a calculation interval for the distance between start and end.
   2. Land Detail - Detect land is checked and the High Resolution GSHHS Shoreline is not installed.
   3. Land Interface Issues - Routing near land is complex, if there is a failure at the interface with land zoom in and look at the Isobars. Sometimes they are not calculated for all locations due to the complexity of the land (limited by too many iterations). In that case try making a new Weather Routing Position nearby where there are isobars shown.
   4. Max Diverted Course - When “Polar:Fail” or “Polar:No Data” occurs near the “finish” using large Time Intervals (4hr - 24hr). Zoom in and look at the route, isochrones, finish, and land. If the route is almost completed to “Finish” (with land, islands and peninsulas around) try changing Max Diverted Course from 100 degrees to 150 degrees and run it again. It will probably complete.

Different Time Intervals - Everything Else is the same.
Beginners should first try a simple route, with starting point and end point, 5 degree steps, and possibly a 3 hour time interval until they see it is working. The time interval depends on the speed of the boat and distance traveled, grib file downloaded.

1. If the Configuration was completing Computation earlier and you changed a setting, check that first.
2. If a Configuration fails, another thing to try is Reset All, and go through the setup sequence above, again.
3. If “Polar:Failed” try increasing or reducing the Weather Routing ConfigurationWind Strength % (50%, 150%) because the Polar File may not have the required winds specified. The grib file may have periods of very high winds or very low winds which are not covered by the polar diagram wind range.
4. Then try using different data, either change the grib start date, moving it forward, or try using only Climatology Data, or change the Polar File to something else, or add multiple polar files, just to get the Configuration working.

[skipperearly]

Thanks Rick, for the detailed reply/suggestion. Had tried many of them already.
Will wait with further testing until thsi pi matures more. Its currently too cumbersome to use for anything else than long distance open ocean route planning.

Has great potential and hope this pi will be one day more user friendly and alined/consistent with the ocpn user i/f.

[Gilletarom]

This is not a test. This real life.


I used the June 29, 2018 version to build weather-roads.

Here are some unpleasant things we are experiencing.

1 ° I made a lot of weather-Routes that I exported.

The name given to the weather-tracks is always "Weather-route" (in French version). It would be nice if the planned departure time was added to the name of the weather-tracks. This would recognize them.

See the screenshot where I left two weather-tracks without the fame.

2 ° I chose to display the departure times using the PC time. For example, I have a weather-route search that starts at 11am (Local time). But when I display the report, it is written 09hours. In other words, this display is in UTC.

It would be nice if an effort was made to make this display consistent with the user's choices.



Best regards, Gilletarom.

[Gilletarom]

Here is another use "Real-life".

We are in the small port of St-Vaast-la-Hougue ", on the north-east of the almost Cotentin island in France.We want to go to Cherbourg which is to the north of this almost island.See the first copy of 'screen.

Currently, we have fairly strong westerlies. (Variable from 12 to 20 knots)

Currently, we are experiencing a strong tide, among the biggest of the year. And in this area, tidal currents are very important. Under these conditions, currently, near the north of Cotentin, currents reach 4 knots. And in areas near the coast, there are "Races".

See the attached grib file which contains wind and current data.

It is therefore important to plan a route adapted to this situation.

I also created barriers with Draw to specify a "forbidden" zone.

The total distance to be traveled varies between 25 and 35 miles depending on the route taken.

Impossible to place the start of the "weather-route" close enough to St-Vaast. WR creates an area starting from the start and bouncing back to Cherbourg.

WR is unable to create a route. He bumps on the barriers. It's absurd. There is space to the east and north to get a weather-route through.

I have to start at least 4 miles or more, of St-Vaast, before WR can create a route. And I have also to change the DR boundary. Not good !



If you want recreate the same situation, you have to use the grib file using this link :


You have also to use the DR tools that I join hereand the polar file that Iuse (it is not in the stock of polar files that there is inside WR)





Gilletarom.

[rgleason]

Gille, yes it can be frustrating at times not getting a routing.

Weather routing will do routing with wind & tide information either as separate files or one.
How is it failing? Polar Fail? probably not, but if it is you might have to drop the wind speed to 80% or something.

What are your settings for:
Max diverted Course? More say 150 degrees, maybe 180? maybe more

Max course Angle? More to increase the area of calculation 180? Maybe more

Max search Angle? More to increase the area of calculation 180? Maybe more

Time Step? Smaller sometimes 10 minutes is necessary as we found earlier, but start larger and work down.

Also Is inverted routes checked?
I would uncheck land, since you have the boundary to speed things up since you will be asking it to do more with these changes.

I would suggest adjusting these so that it will complete. You need to create a greater calculation area for the plugin to find a route, do this by adjusting the settings. The area I see is too small to be practical.


Also Sean wrote this so read inverted regions, it may help.

[seandepagnier]

Originally Posted by Gilletarom

Here is another use "Real-life".

We are in the small port of St-Vaast-la-Hougue ", on the north-east of the almost Cotentin island in France.We want to go to Cherbourg which is to the north of this almost island.See the first copy of 'screen.

Currently, we have fairly strong westerlies. (Variable from 12 to 20 knots)

Currently, we are experiencing a strong tide, among the biggest of the year. And in this area, tidal currents are very important. Under these conditions, currently, near the north of Cotentin, currents reach 4 knots. And in areas near the coast, there are "Races".

See the attached grib file which contains wind and current data.

It is therefore important to plan a route adapted to this situation.

I also created barriers with Draw to specify a "forbidden" zone.

The total distance to be traveled varies between 25 and 35 miles depending on the route taken.

Impossible to place the start of the "weather-route" close enough to St-Vaast. WR creates an area starting from the start and bouncing back to Cherbourg.

WR is unable to create a route. He bumps on the barriers. It's absurd. There is space to the east and north to get a weather-route through.

Sorry to not have more answers, but I think you need to increase the max diverted course field to allow for this routing to succeed.

[Gilletarom]

Hello,


Here is the link to download the used grib file, link omitted yesterday :
http://dl.free.fr/jEjk3eSnv



Regarding maxdiverted I always use 180 °.

No, it is the curve generated by the construction of the isochrones which is in question. Curve which seems to have, for center, the point of arrival,.
The isochrones remain locked in this curve but in this configuration, it is there that the aberration is located.

Gilletarom.

[Rick Scali]

Well are you close by? Or up in ormond beach

[did-g]

Originally Posted by Gilletarom

Hello,


Here is the link to download the used grib file, link omitted yesterday :
http://dl.free.fr/jEjk3eSnv



Regarding maxdiverted I always use 180 °.

No, it is the curve generated by the construction of the isochrones which is in question. Curve which seems to have, for center, the point of arrival,.
The isochrones remain locked in this curve but in this configuration, it is there that the aberration is located.

Gilletarom.

Is 'safety margin set from land' set to 2mn in your actual run?
This parameter currently doesn't always work as intended but it may reject some route legs.

[Gilletarom]

Hello Did-g

Originally Posted by did-g

Is 'safety margin set from land' set to 2mn in your actual run?
This parameter currently doesn't always work as intended but it may reject some route legs.

But, this setting is taken into account even if the check box "Detect the landh" is not checked?

Moreover, every time I checked "Detect the landh", WR did not agree to operate.
So I got used to not ticking it and putting boundary built with Draw. And it works very well.

[seandepagnier]

can you turn off all charts and look at the gshhs background? This is what wr uses for land detection. If you have the low resolution it will not work well, but even higher resolution is not always great.

[rgleason]

As I said before, have you tried to check inverted?

No, it is the curve generated by the construction of the isochrones which is in question. Curve which seems to have, for center, the point of arrival,.
The isochrones remain locked in this curve but in this configuration, it is there that the aberration is located.

[Gilletarom]

Originally Posted by boat_alexandra

can you turn off all charts and look at the gshhs background? This is what wr uses for land detection. If you have the low resolution it will not work well, but even higher resolution is not always great.

I use hight resolution for gshhs.