Garmin vista hcx

[Robadog]

Hi guys .
Looking got advice / comments on current problem I'm having using the vista hcx device .started using this s fee yes ago with gpx tracks and had been reasonably successful .I've got a copy City Europe Navigator card in the device butnit seems that the mapd aren't quite synced with the gpx tracks which I install using Basecamp .
So what happens is that track often appears slightly off the road on the map.sometimes I can zoom out slightly to get them to get them together but this reduces the level of detail.the main problem is going through towns where it seems almost possible to determine the route .
Did a 600 pbp qualifier last weekend and ended up having to go to local fire station to navigate through Dumfries which is by no means a big /  complex town centre .
I should mention I'm a pretty much IT numpty !
Any advice appreciated as I don't really want to fork out a few hundred quid on s new see device

[Kim]

That's the nature of the beast, I'm afraid.  A Track is a line joining a series of coordinates and is independent of the map on your device.  Chances are the track was either created by a GPS moving around in the real world (complete with GPS error, being on the other side of the road, deviations into a field to inspect a hedge, whatever), or by some person or automated tool drawing lines on a map, which probably isn't the same map as your map, to varying degrees of precision^[1].

A new device won't improve this.  A different map might help, but probably won't.  (IME the City Navigator maps have the roads in the right place, so that isn't likely to be your problem.)

If a provided Track isn't good enough for your purposes, you'll have to sit down and do your audax homework, and create a Track (or Route) that you'll be able to follow reliably on the ground, just as you would if you were creating one based on a routesheet.


_{[1] One possible problem is that a perfectly good Track has been down-sampled to 500 trackpoints for compatibility with older devices, losing precision in the process.  The resulting corner-cutting tends to be a problem in urban areas.}

[Wycombewheeler]

i've always just navigated by the line with no map, its generally fine, except as you say in towns where roads are closer together or at junctions with multiple left/right turnings. But you soon know if you picked the wrong one.

I can always look up a map on my phone if i really need one.

[Kim]

Best technique for low-resolution line-based navigation is to put the points shortly *after* each junction.  That makes it reasonably clear which exit you want, and you don't care what happens to the line between junctions.

Best technique for follow-road routing is the opposite:  You put points in the middle of the sections of road you want it to use.

Best technique for least ambiguity is to have a Track with sufficient points that it just highlights the bit of road you want to follow.  If you're doing more than about 100km, you're going to need a lot more than 500 trackpoints to make it work.


Tracks, like routesheets, should be regarded with suspicion unless they've been created by someone you trust to do a decent job.

[simonp]

If you are trying to filter a 600k down to 500 points you'll have this kind of problem.

So if you have not already done this, split it into multiple sections, 200k ish would work a lot better than 600k. If it's bad at 200k, split it further.

200k at 500 points is 0.4km (on average) between points - this ought to be sufficient most of the time, but it depends on how complex the route is.

[Robadog]

Thanks guys the replies give me a few options to consider  .I'm thinking that I should probably look at the route sheet before getting into a town centre .sounds good idea to split the route furtaher into chunks . Thinking about LEL that was sent as 18 tracks I think (9 north + south )between controls and u didn't get these problems .
Looks like I'll be putting a further post to understand how I split the gpx tracks into shorter tracks !!

[fuaran]

You can use the City Nav maps in Basecamp. It should read them from the card, when the Etrex is plugged in.
Might be useful for drawing tracks or routes that match the map.

[simonp]

Thanks guys the replies give me a few options to consider  .I'm thinking that I should probably look at the route sheet before getting into a town centre .sounds good idea to split the route furtaher into chunks . Thinking about LEL that was sent as 18 tracks I think (9 north + south )between controls and u didn't get these problems .
Looks like I'll be putting a further post to understand how I split the gpx tracks into shorter tracks !!

Garmin Mapsource supported this. I'm not familiar with Basecamp, I found it a bit of a pain.

Online tools like RideWithGPS can do this kind of task if I remember correctly. If you split an Audax route up, split it at controls - so you switch routes when stopped at a control already. I create a route per section like this not so much because of a track point limit but because it splits the ride up into psychologically manageable chunks.

[Pingu]

Thanks guys the replies give me a few options to consider  .I'm thinking that I should probably look at the route sheet before getting into a town centre .sounds good idea to split the route furtaher into chunks . Thinking about LEL that was sent as 18 tracks I think (9 north + south )between controls and u didn't get these problems .
Looks like I'll be putting a further post to understand how I split the gpx tracks into shorter tracks !!

Garmin Mapsource supported this. I'm not familiar with Basecamp, I found it a bit of a pain.

Online tools like RideWithGPS can do this kind of task if I remember correctly. If you split an Audax route up, split it at controls - so you switch routes when stopped at a control already. I create a route per section like this not so much because of a track point limit but because it splits the ride up into psychologically manageable chunks.

Basecamp:

Select the track
Go to Tools > Divide
Click on the point of the track where you want make the cut

[pdm]

FWIW,
I use OpenFietsmap (free) maps on my HCx.
I have installed OpenFietsmap (free) into Garmin BaseCamp for creating ROUTES with points just after relevant junctions which are transferred to the HCx with drag and drop.Usually one route per stage/control although if they are all in the same direction, I combine up to 2 or 3. Usually about 10-30 points per route.
BaseCamp has a learning curve but once you get the hang of it and learn the shortcuts, it is easy and efficient to work with.
These work very well following roads and so on.
I do not usually use gpx tracks - they are not re-routable.
Very occasionally I have to break routes to allow usage of a road/track that the maps do not yet think are navigable.

[frankly frankie]

So what happens is that track often appears slightly off the road on the map.sometimes I can zoom out slightly to get them to get them together but this reduces the level of detail.the main problem is going through towns where it seems almost possible to determine the route .
Did a 600 pbp qualifier last weekend and ended up having to go to local fire station to navigate through Dumfries which is by no means a big /  complex town centre .

Does your Tracklog as recorded accurately follow the roads?  I ask this to eliminate the small possibility of the GPS being faulty.

As others have said, 500 trackpoints for 600km ain't gonna work, especially in urban areas.  The max distance for one such Track is about 300km and that is stretching it, most people would be unhappy with anything over 200km. 
500 points is your max, but you can store 20 Tracks so the ideal is something like 6x Tracks, one per 100km, or simply 1 Track per one or two legs, split at controls.  You can display all your Tracks simultaneously (maybe try alternate colours, green/blue perhaps) so there's nothing to do to change from one to the next.  In Setup, Tracks, set each Track to 'Show on Map' and choose a colour.

I'm afraid people talking about Routes are just clouding the issue whilst trying to be helpful - and be warned there are almost as many ways of doing this as there are people on this forum.  To be clear - I would use Routes myself - but advising on that subject is a much bigger topic and fraught with differences of opinion.

[Robadog]

Thanks again guys for your valued comments .I will need to discuss the suggestions with my IT guru Mrs D !. Doing the Inverness 1200 in a few weeks so probably have a bash at splitting the tracks into smaller sections .👍💯

[Kim]

Does your Tracklog as recorded accurately follow the roads?  I ask this to eliminate the small possibility of the GPS being faulty.

Good question.  Would the unit being set to the wrong datum cause this?  Or does it know what datum the map is using and compensate?  Same would go for tracks/waypoints/etc. - I know the GPX standard implies WGS84 coordinates, but I've no idea how the unit handles the conversion if set to a different datum.

The shift between WGS84 and OSGB36 is significant (several tens of metres) for most of the UK.  That would certainly make navigating in urban areas a challenge.

Bottom line:  Check the datum on your unit is set to WGS84, which is generally conducive to everything working properly.

[fuaran]

The datum doesn't make any difference. Changing the datum/position format only changes the coordinates displayed on the GPS.
Internally, everything else on the GPS uses WGS84. Recorded tracks are always WGS84, as are the maps.

I always have my Etrex set to OSGB - it still displays tracks in the correct place, and records the correct tracklogs and waypoints

[frankly frankie]

Well as road cyclists we have a big advantage, in areas where the choice of roads is limited (eg Scottish Highlands) for most of the time it really doesn't matter if your Track and the road don't co-incide - all that matters is that junctions are properly defined, and everything in between can go hang because all you can do is follow your nose anyway.  In theory you might be able to go say 20km between two trackpoints - although in practice very few people are comfortable with that - but say 1 point per km becomes very doable in remote country.

The various downsampling utilities that are available (in online planners, or built into Basecamp/Mapsource/Track Manager) are very good at getting this right - if you are supplied with a Track of say 12,000 points then provided the total Track distance is not too great (say 300km absolute max) you can downsample it to 500 with confidence - the resulting Track will still define any turns even in urban areas, at the expense of using widely-separated points in rural areas where it doesn't matter much.  Downsamplers are very clever this way.

If (hypothetically) you are working with a Track of many thousands of points and longer distance - eg 1200km - first you need to divide it into approximately 200km lumps - or at every control, whichever method you prefer - then you need to downsample each separate lump to no more than 500 points.  Colour each Track a nice bright colour (blue may be better than green because in Scotland a lot of the base map is forested=green) and set to 'show on map' which in the HCx is on by default anyway.
The 500 points is a limitation of the Vista HCx that does not apply to any Garmin models introduced after 2009.

[Kim]

The datum doesn't make any difference. Changing the datum/position format only changes the coordinates displayed on the GPS.
Internally, everything else on the GPS uses WGS84. Recorded tracks are always WGS84, as are the maps.

I always have my Etrex set to OSGB - it still displays tracks in the correct place, and records the correct tracklogs and waypoints

Good to know.  I do remember getting an offset when using a yellow eTrex outputting NEMA sentences over serial to a PC running mapping software, cured by changing the datum from OSGB to WGS84.  But that was ...some time ago.

[andyoxon]

I also still use an Etrex Vista HCx, following track only, with free osm maps from 'garmin.openstreetmap.nl' (not loading atm) There is a version to install into basecamp too.  I find that filtering to <500 trk points for 'longer' rural rides e.g. <200km, works quite well, in that the track line is not well superimposed on the map road and so slightly more visible.  As others, I would probably tend to split a 200km track, depending on the route.  One trick for extra clarity of the track line, which possibly works better in built up areas, is to upload duplicate (split) tracks but with the track points filtered to <500 with different algorithms/websites. e.g.  basecamp, ridewithgps or WinGDB3.  This means the two trk lines, which aren't mostly superimposed tend to be more visible.

Unfortunately my current HCx, already in franken form, has a detaching 'rubber band' and perma-incorrect date, so it's days may be are numbered.

[Kim]

Unfortunately my current HCx, already in franken form, has a detaching 'rubber band' and perma-incorrect date, so it's days may be are numbered.

I've got a perfectly good Vista HCx on the shelf, for values of perfectly good that mean completely non-waterproof and you have to get bodgy to press any of the buttons.  (Admittedly I haven't checked the date recently.)

Getting rid of that rubber band was the best thing Garmin ever did.