Navionics track points

[Amulet]

I use Navionics on an android tablet. It records trackpoints every second. I have a track with over 200 thousand points. For my purposes it could record a hundred times less and still be useful. Can this be configured? I haven't found a way.

 

[coopec]

Have you had a look at this website?

Track your day on the water with our nautical GPS app!

Maybe if you click on support you might get your answer?

What about this?
Mobile: Users Guide/Manual "Help"

Mobile: Users Guide/Manual "Help"

 

[Amulet]

Have you had a look at this website?

Track your day on the water with our nautical GPS app!

Maybe if you click on support you might get your answer?

What about this?
Mobile: Users Guide/Manual "Help"

Mobile: Users Guide/Manual "Help"

I might be missing something, but I can't find anything in the help. This is not an issue if you stay within the navionics world. However, if you export a track as gpx to import into other mapping software you run into problems with a huge file, which could have been a hundred times smaller without any significant loss.

 

[Poignard]

I wonder if you might find the answer in this book



I bought it recently and haven't had time to read it but £2.99 isn't a lot for a book that might help.

 

[Bilgediver]

I use Navionics on an android tablet. It records trackpoints every second. I have a track with over 200 thousand points. For my purposes it could record a hundred times less and still be useful. Can this be configured? I haven't found a way.

This fellow has the same problem and offers a service.


Slim down your bloated GPX track files

 

[AntarcticPilot]

It's a very simple algorithm (Douglas-Peucker (various spellings of Peucker; the guy himself changed the way he spelt it!)) to do this; I'd be surprised if it isn't available within the Navionics system. But it can require a lot of memory, so it may not be available on older, memory limited devices. The algorithm has been around since the 1980s at least; I've implemented it several times! Basically, you find the point furthest from the straight line joining the ends of the track. If it's further from the line than a preset threshold, you mark it for keeping. You then divide the line into two parts at the point you've just found and repeat the process until no points are further away than your preset distance. You then read out the points marked for keeping. It can be programmed quite neatly as a recursive algorithm, but of course that is very memory intensive.

 

[Amulet]

This fellow has the same problem and offers a service.


Slim down your bloated GPX track files

Thanks I'll look into that again. I did try it, among many solutions but I can't remember why I couldn't get it to work. I think my file was to big to upload!

 

[Amulet]

I am a bit of a dipstick. gpsu (GPS Utility - Home) which I already have, does the job very well.

 

[Mark-1]

GPS Essentials records tracks at any rate you require.

 

[Amulet]

GPS Essentials records tracks at any rate you require.

I have many nav apps that can record tracks in various ways. For some purposes I use Navionics on Android. My interest here is in getting the tracks out of Navionics. Usually there are several people running Navionics on any cruise. Sometimes I like to make images of a cruise track shown on UKHO charts, Google Earth or UK OS maps. This can require me to export them from one nav system and import to another. If the track file is unnecessarily bloated it can make things extremely difficult. However it turned out that the solution was staring me in the face. I already had GPSU which can do it for up to 500,000 trackpoints, which is enough for now!
Problem solved.