Wave action, current
, comfort, access to same data while on boat. Nevertheless, it helps to hone certain skills and become more familiar with the factors involved, including weather
Have a Pressure Isobar or simple grib overlay on the Spectator Vendee Globe Guest Map
with option to cycle the time (without moving the boats)
qtVlm - Route Optimization Program
Use of Routes and Routing:
Make a Routing
Start by making a Routing from the your boat to a particular POI that you have placed on the current
grib (cursor on the spot and use right mouse button "place new mark")
" is different than a "Route
". A "Routing
" is a good route
from the boat (or POI) to a POI/Mark. Routings show "isochrones" which indicate lines of identical sailing time. These are similar to isobars (shows lines of same pressure) but for sailing time. You will see "isochrones" that are close together, this means that sailing there is very slow (often caused by no or little wind). Conversely, if the isochrones are far apart you are sailing faster in heavier winds. A "Routing
" creates a good route optimization and shows the isochrones from the boat or the starting location. It is very important to select good destination
points, by thinking about what the winds and weather is likely to do afterwards. It is helpful to study multiple "Routing
"s. Once you have a "Routing
" you like, it is time to convert it into a "Route
". Pick the "Convert to routing" check box in the Routing
Convert a Routing to a Route
Done in the Routing
Dialogue box. Check the "Convert to Route" box. This is the best way and only way to get a route unless you have exported one and then import
it again. When you convert a Routing
to a Route
the program will ask if you want the newly converted route to be from the Boat or from a POI. If you select the route to be from a POI, the route can then be Frozen (see below). If you select the route to be from the boat, the route will follow the boat around as it moves, and you will continue to be able to optimize and simplify that route when you download and update new grib files.
Optimize a Route
Check the box in the Route Dialogue and watch the program cycle through an optimization.
Simplify a Route
Check the box in the Route
Dialogue after you have optimized the route, to simplify and reduce the number of Intermediate POI's used. Why is this necessary? Because at some point you will be sending the list of waypoints to the "Autopilot" and the Autopilot
only accepts six or seven intermediate waypoint instructions. Also it is often better to let the optimization between intermediate POI or waypoints occur in accord with how the actual winds blow. Fewer waypoints allow this to happen.
Freezing a Route
- The Route
must start from a POI (and end at a POI) and not be on VB-VLM. Routes
from point to point can be frozen. Freezing the route stores all time and waypoint information for the last optimization. As you cycle through time the position will be shown, but it is for a previous (not current) grib file. If you uncheck a frozen route, and try to optimize it, it will complain and the route will probably disappear. Don't do this. You can hide and unhide frozen routes or export them.
Hide and Unhide a Route
- Useful to identify a Route
(you can also use hover) or to clean up the screen
. Often I find myself eventually deleting hidden routes. It would be helpful to have the delete route
option show if a route is (hidden).
Routes from boats (rather than waypoints) to POI or points
can be re-run optimized/simplified with a newly download up to date grib. This is a shortcut if you are keeping the destination
point the same. Sometimes the weather has changed enough that it is wise to review weather, set a new point and create a new Routing and convert that. But this a a way to save time.
Export a Route
- Simply save a route to a file (csv, txt, etc) Asks for POI or Detail.
Import a Route
- Retrieve an older route.
It is a good idea to keep your POI clean and simple by deleting ones that are not needed. It would be nice to have a POI popup that allows you to highlight the POI and show the location, then allow a delete.
I hope this helps others who are interested in learning
the program. Maitai may be correcting some of this because he's the authority.