Difference between revisions of "Two step weather routing"
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'''Two step weather routing with VRTool''' | '''Two step weather routing with VRTool''' | ||
| − | Suppose you want to plan a route with an intermediary point.Say it is not a fixed point like a mark or an island, | + | Suppose you want to plan a route with an intermediary point. |
| − | but an strategic position, close to favourable winds.You don't know where it is yet, but you feel it is in | + | Say it is not a fixed point like a mark or an island, |
| − | a certain direction where winds are normaly stronger and/or in a suitable direction. | + | but an strategic position, close to favourable winds. |
| + | You don't know where it is yet, but you feel it is in | ||
| + | a certain direction where winds are normaly stronger | ||
| + | and/or in a suitable direction. | ||
| − | VRTool WR calculator can only work a single segment at a time, from Start to Destination. | + | VRTool WR calculator can only work a single segment at a time, |
| − | However you can create a composite route by doing as follow: | + | from Start to Destination. However you can create a composite |
| + | route by doing as follow: | ||
| − | Set WR destination far away in the direction you like and do a WR calculation. Plot only the isochrones to the chart. | + | Set WR destination far away in the direction you like |
| + | and do a WR calculation. Plot only the isochrones to the chart. | ||
Use the isochrones to choose your strategic intermediary position. | Use the isochrones to choose your strategic intermediary position. | ||
| − | Say you choose a position on the 108h isochrone. Set WR destination to that point and do a calculation | + | Say you choose a position on the 108h isochrone. |
| + | Set WR destination to that point and do a calculation | ||
up to 108h. Plot the best route. | up to 108h. Plot the best route. | ||
| − | Now you can do the second step, from that position to the leg final destination. The segment will start | + | Now you can do the second step, from that position to the |
| − | from 108h. Set WR start to your chosen 108h position and WR destination to the leg destination. | + | leg final destination. The segment will start from 108h. |
| + | Set WR start to your chosen 108h position and WR destination | ||
| + | to the leg destination. | ||
| − | In the program's main window, in "Track Designer Settings", "Wind Forecast Age" group, select option | + | In the program's main window, in "Track Designer Settings", |
| + | "Wind Forecast Age" group, select option | ||
"[x] a given date/time". | "[x] a given date/time". | ||
| − | Now you have to figure the date/time of the 108h isochrone. Go to the "Wind grids" and | + | Now you have to figure the date/time of the 108h isochrone. |
| + | Go to the "Wind grids" and | ||
select the current wind grid. The Timestamp will show. | select the current wind grid. The Timestamp will show. | ||
| − | Add 108h to it and convert back to date/time. This time is in UTC. Convert local time by adding | + | Add 108h to it and convert back to date/time. This time is in UTC. |
| − | the time zone. Input that date/time to the "Start" field in track designer settings. | + | Convert local time by adding the time zone. |
| + | Input that date/time to the "Start" field in track designer settings. | ||
Then you can calculate the second part of the WR track. | Then you can calculate the second part of the WR track. | ||
| − | Remember to set "Wind Forecast Age" back to "[x] Timestamp+time zone" (the default mode) | + | Remember to set "Wind Forecast Age" back to "[x] Timestamp+time zone" |
| + | in the end (the default mode). | ||
Revision as of 10:40, 27 October 2014
Two step weather routing with VRTool
Suppose you want to plan a route with an intermediary point. Say it is not a fixed point like a mark or an island, but an strategic position, close to favourable winds. You don't know where it is yet, but you feel it is in a certain direction where winds are normaly stronger and/or in a suitable direction.
VRTool WR calculator can only work a single segment at a time, from Start to Destination. However you can create a composite route by doing as follow:
Set WR destination far away in the direction you like and do a WR calculation. Plot only the isochrones to the chart. Use the isochrones to choose your strategic intermediary position.
Say you choose a position on the 108h isochrone. Set WR destination to that point and do a calculation up to 108h. Plot the best route.
Now you can do the second step, from that position to the leg final destination. The segment will start from 108h. Set WR start to your chosen 108h position and WR destination to the leg destination.
In the program's main window, in "Track Designer Settings", "Wind Forecast Age" group, select option "[x] a given date/time".
Now you have to figure the date/time of the 108h isochrone. Go to the "Wind grids" and select the current wind grid. The Timestamp will show.
Add 108h to it and convert back to date/time. This time is in UTC. Convert local time by adding the time zone. Input that date/time to the "Start" field in track designer settings. Then you can calculate the second part of the WR track.
Remember to set "Wind Forecast Age" back to "[x] Timestamp+time zone" in the end (the default mode).
