Re: [NTLK] newton toolkit

From: Johannes Wolf (mp2100_at_mail-gw.estec.esa.int)
Date: Tue Sep 14 2004 - 01:49:22 PDT


This is only the very very first step.
What is absolutely essential to know are the type of coordinate system the
map is based on and
of course at least 6 reference points on the Map with exact
longitude/latitude.
The NTK program from Gerd Staudenmaier provides an algorithm in order to
match the pixel position on the map to a geographic position in
longitude/latitude that can be used later from the GPSMap application on the
Newt to find your position on the map using the GPS provided
longitude/latitude data.
You see, this is quiet complex.
I have already thought myself about using map material from a route planner
software, but this is not so straight forward.
In case the route planner software is able to display longitude latitude
data for a given cursor position, the thing might be possible.
If you still have the route planner software, I would recommend you to print
out the map and draw a reference grid on it. For the intersection points you
search the longitude latitude data in the route planner and fill that in.
At minimum you need a grid of 3 by 3 lines with 6 intersection points.
One of the problems is that a map is a projection of geographical data on to
a straight sheet.
Thus the longitude/latitude lines in high quality maps are not straight, but
slightly curved, depending on the scale.
But the NTK program for Map creation from Gerd provides even an algorithm to
use a straight coordinate grid.
Before you do not have these prerequisites you do not need to start with
NTK.

On top of that you need some planning:
GPSMap provides the very useful feature to switch automatically between
maps.
It is clear that you cannot have a complete AND detailed map for a larger
area in one file, since the GPSmap files are NOT vector-based, but
pixel-based.
But GPSMap will automatically switch between Map-tiles if you move across
the border of a map tile and in case there is another Map with higher
resolution available, that covers your actual position (i.e. you have a city
map and move into the city).
So the planning has to be made with respect to creating map tiles with a
certain overlap in order to cover a larger area (country). Then you have to
decide which detail maps (cities) you want to create.
In order to do this of course you need a certain feeling what is the right
size of a map that would be optimal in resolution and size for the Newt.
Thsi is the point where the cat bites his tail, because in order to do that
you need to experiment a bit with NTK and the Map creation application from
Gerd Staudenmaier.

What I can do for you is sending the manual (sorry, in german only)as PDF
and then you eed to find somebody to translate that into italian ...

Cheers,
Johannes

> -----Original Message-----
> From: newtontalk-bounce_at_newtontalk.net
> [mailto:newtontalk-bounce_at_newtontalk.net]On Behalf Of Rocco Valentini
> Sent: Tuesday, September 14, 2004 10:08 AM
> To: newtontalk_at_newtontalk.net
> Subject: Re: [NTLK] newton toolkit

> I saved the maps from a route planner software,than I've
> converted them with
> graphic converter in a compatible format, but now?

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