john12566 wrote: ↑Sat Dec 21, 2024 1:41 am
jfheath said, " But the XT will still accept gpx files created on Basecamp..."
Are "GPX" files the type of files that the XT is automatically (ie, by default) making when i create a route in BC?
Yes. ish. It doesn't work like that, but the answer is positive.
- When you create a route on the in Basecamp, It creates the GPX file
- The GPX file is transferred to the Zumo and the XT understands it completely
- Unless there is a map change or an error, the XT uses the GPX route as it is. ****
- If you create a route using the Trip planner app on the XT screen, the XT creates its own GPX file which Basecamp can read.
Most route planning software will use GPX files so that a route or track in one program can be loaded into another program, app, or device.
**** That statement isn't quite true because I think that the XT tries to make sense of gpx files that come from other route planner software. Because maps in other software are slightly different, the route points end up being slightly misplaced on Garmin's maps.
I think (I don't know this as a fact) that the XT looks at each route point, and looks on its own map database for a known point nearby. It may then use its own point with its own name. The result of this is that the XT appears to rename your Basecamp points, but it ensures that the point is plotted correctly on a road.
A gpx file can contain all sorts if information.
Waypoints - defined by Basecamp as saved locations lat, long, name, address, phone etc.
Tracks which are a series of points which can be joined with short straight lines to represent a line on a map. Tracks can be created by you on Basecamp or they can be a record of where you have ridden - the XT can record one as you ride.
Routes which are simply a sequence of route points which the XT must pass through. So a 500 mile route could consist of just 2 route points - a start and an end; or (say) 4 route points - start, end, and a couple of locations that you want to pass through. In these cases, it is up to the XT to calculate the best roads to take between the route points. If you want to ride particular roads, then you will need more route points to pin it down.
When Basecamp prepares a route it adds hundreds of invisible route points. I call them ghost points. These are plotted close together so that the XT knows exactly which roads you plotted. The XT understands these points and it doesn't bother calculating its own route. It can draw the one that Basecamp created. Exactly.
But if the XT has to recalculate the route - eg if you have to stop for fuel, or take a diversion, then the route is recalculated and the Basecamp line is lost. You can turn off automatic recalculation on the XT to prevent this.
Or you can use Basecamp to create a track version of your route. The XT can display a track and a route at the same time. Tracks do not alter. So if the route is recalculated, the track remains in place so you can see where your original Basecamp route was drawn.
GPX files can be used to send routes and tracks to other software. I keep all if my old track logs, recorded by the Zumo in a program called MemoryMap. It displays tracks accurately plotted on high resolution Uk ordnance survey maps at a scale of 1:25,000 (2.5 inches to a mile) - typically used by walkers.
Some programs use a different format. eg KML. Basecamp can also create KML files from your gox files and these can be loaded into Google earth. In there you can 'fly' the track 3D rendered satellite imagery.
Sorry, I seem to have been rambling on a bit !
