Routes, tracks and general confusion!

[ggb1979]

HI

 

Please forgive me if these are daft questions - Im quite new to all this.

 

I have had my garmin etrex vista HCx for about a year now and have mainly used it for geocaching and recording my bike rides / runs, which I have been fine with so Im not completely useless.

 

I have just started going mountain walking again (in northwales) and for safety reasons wanted to put my intended route, along with various 'escapes' into my GPS for use on the trail.

 

I realised the 'mapsource' package is not detailed enough for accurate mountain path planning so I purchased 'tracklogs' and the relevant sections of 1:25000 OS maps (Snowdonia) for where I go walking.

 

I have been able to create waypoints and routes (tracks?) within the tracklogs software and then upload them on to my GPS.

 

The problem is that I can either send the 'route' to my GPS as a track, where upon I can access it from the tracks section of my GPS, view on the GPS the line (or waypoints if required), but it is not 'routable' in the sense that my GPS's compass will point me to the next 'point'on the course. I can visually navigate along the line or set userwaypoints to navigate to but it wont navigate the track as a route (hope that makes sense). If however I plot my track backwards (finsh to start) in tracklogs I can use 'trackback' then the GPS navigates the track for me as if its a route. This seems a bizarre fix to the problem as the GPS clearly has the ability to navigate point to point along a track so why cant it just work forwards and navigate my track start to finish?

 

The other option is save the tracklogs 'route' as a route in my GPS, and here is the wierd bit. All the points of my route are transferred to the GPS so the whole route is shown on the map screen but the GPS only counts the route as the first 250 waypoints (I think the GPS may have a route point limit of 250) - although I dont understand why all the waypoints of the route (more than 250) transfer but the GPS wont regard the whole thing as a route, yet it is capable of 'tracking back' (i.e. routing) more than 250 points in 'track back' mode.

 

Am I missing something here or doing things in the wrong way or is it just a clunky unintuitive system?

 

Its not a massive problem as I can obviousy visually follow my track on the screen and /or set user paypoints on my track as Im on the go, but thought it would be farily simple to get the GPS to navigate the track, in the correct order (seems bizarre I can get it to navigate a track backwards but not forwards!)

 

Is the best fix to plan my routes in reverse on tracklogs, save as tracks to my GPS, then use trackback to navigate the desired route??? - this cant be right can it?

[Ken in Regina]

... or is it just a clunky unintuitive system?

That's the most likely answer. It would not be the only glaring inconsistency in Garmin's programming.

 

Is the best fix to plan my routes in reverse on tracklogs, save as tracks to my GPS, then use trackback to navigate the desired route??? - this cant be right can it?

It looks like Garmin has placed the abilities you need in the trackback functions and has not bothered to make them available in the normal autorouting functions. That would not be unusual for Garmin.

 

<rant>It might even be a Marketing decision. There is so little real difference among many of their various devices that the Marketing people impose arbitrary software function differences, like, this one can't store routes and that one can store one route and that one can store 10. Silly stuff like that.

 

Similar to what you've run into, the devices will capture tracklogs with many hundreds of trackpoints in them -- most will do more than a thousand in the log -- but when you save the track log or transfer it to Mapsource or Basecamp they trim the resulting file to 500 trackpoints. What's with that?? It seems reasonable to assume that your computer will have far more hardware capacity than the navigation device so why arbitrarily limit the size of the track file to something less than what the track log contains.

</rant>

 

For the record, I've been a Garmin user for about six years (iQue 3600, Legend HCx, GPS10x, Mobile PC, Mobile XT, many of their maps) and reasonably happy with their stuff mostly. It's annoying but there is usually some sort of workaround to most of their cockups. Looks like you've found a particularly good one for your situation. Good work, even though it should be unnecessary.

 

...ken...

[+Rifty]

From my experience, routes should never be used unless plotting a route on the gps unit itself. Route points are always truncacted to some ridiculously unusable number.

 

Paths you wish to follow should always be downloaded to the gps as a track and should always be followed on the map screen rather than relying on the compass pointer.

 

The compass pointer will always dodge about a bit given tree cover, speed variations etc. I found it impossible to use to navigate a plotted path by but find the map screen excellent in every situation : you can see how far off you are from the plotted track and are always aware of geocaches and escape routes coming up.

 

Give it a try - you'll never look back !

[ggb1979]

Hi Guys

 

Thank you for your input.

 

After digging around on the net and messing with my GPS this weekend I think I sort of answered my own questions. For what its worth here what I think happens in case anyoone else has a similar problem.

 

The 'route' function in GPS's (or my vista at least) is intended for road (or road type track) navigation where the route points mark junctions or turns - the gps fore-warns you of approaching turns so you can prepare (like a typical car sat nav). For whatever reason the number of turns is limited to 250. The GPS works by having each turn as a waypoint and then using the 'proximity' function to advise of the direction of the next turn. If your GPS has a waypoint capability of more than 250 (as mine does) then routes will transfer to your GPS up to the 250th 'turn', then only the waypoints will be displayed. You can bizarrely have more than 1 route end-on-end to get over the 250 point problem but would have to manually select to follow your 2nd route.

 

As the gnetleman above kindly pointed out the best way to plot intricate walking routes (say a mountain path with twists and turns, but no obvious junctions) is to import to your GPS as a track - this allows for far more 'points' in your route and therefore a more intricately planned route. The route points are not considered as waypoints by your GPS and most GPS can store far more track points than route points (dont ask why).

 

Using the poorly named 'tracback' you can follow the track just as you would a route, except that you dont get pre-emptive proximity warnings before each 'turn' (wouldn't be much use when walking anyway). As was pointed out above you could just follow the visual line on your map screen, or using trackback you can utilise the compass which points you to the closest next point on the track. Waypoints can be added to the track to mark significant junctions (escape routes), where you may choose to follow a different pre-programmed track or have lunch!

 

Where I got confused was reading the garmin manual about tracback, the name of the function and the manual itself made tracback purely sound like a track re-tracing facility (back the way you came) whereas in practice you can use track back to select any point on your track to head to, your GPS will firstly guide you towards the closest track point, and then point-to-point toward your preselected track point regardless of the direction of your track (beginning /end dont matter).

 

I hope this makes sense now - i was close to going insane trying to understand it myself!

 

If anyone wants further clarification please let me know.

 

For info this is how I planned my route (tested in fine weather this weekend - but would be confident in the mist now!).

 

Plot your intended route, start to finish as normal in tracklogs or similar. Put waypoints at significant junctions / points - i.e. split in paths, start of escape routes, summits, points of interest (near by peaks are also useful to aid orientation). Upload these to your GPS as a track. Also separately plot and upload tracks for each of your escape routes, starting at the waypoint previously marked - this way they can be hidden from view to avoid confusion. I named my waypoints (escape point 1, escape point 2 etc. etc.) then my escape tracks by the corresponding number. That way if the mist came down or I was attacked by seagulls I would find my way along my main track to my nearest escape waypoint, then switch tracks on my GPS to the corresponding escape track. To avoid any confusion I would also turn off track logging when using 'tracback' to avoid overlaying another track ontop of the one you want to follow.

 

In my opinion:-

 

Tracback should be called 'follow track'

 

Routing should be called 'road / waypoint navigation'

[Ken in Regina]

Thanks for analyzing and explaining the trackback feature. Excellent description and very useful to know for biking/hiking. Thanks.

 

...ken...