Re: [Gpsbabel-code] Conversion to and from SatMap .map format.

[Robert L. <rob...@gm...>]

On Sun, Aug 10, 2008 at 3:15 PM, Mike Ogden <mik...@ho...>wrote:
>
>
> File 1 - babemap.trl:-
> <CXMLSafe>
> <Version>1</Version>
> <Length>11213</Length>
>
> <Data>789ced9acb6ee3361486bb9d01e61d02742ff3f04ec0109a3b0a74324533eda0dd29b6e008b12dc3912798b7efa164c9541bc6a614ede485c3cba1447d24ff9f543cbdfcba4d664f37d932
>

Every time I see one of these files, I sigh out loud.   These has to be the
most insane possible way to represent data in XML.  "Let's zip our old file
format, then hex encode it and stuff it all into one giant field."  Talk
about not getting the point of XML...



File 2 - babemap.gpx:-
> <gpx version="1.1" creator="TrackLogs Digital Mapping v3.12.03 -
> http://www.tracklogs.co.uk<http://www.tracklogs.co.uk/>"
> xsi:schemaLocation="http://www.topografix.com/GPX/1/1
> http://www.topografix.com/GPX/1/1/gpx.xsd" xmlns="
> http://www.topografix.com/GPX/1/1" xmlns:xsi="
> http://www.w3.org/2001/XMLSchema-instance">
> [ ... ]
>


> <extensions>
> <View>
> <Id>0</Id>
> <Datum>OSGB36</Datum>
> <Grid>BNG</Grid>
> <Easting>320003.00000000000000000000</Easting>
> <Northing>174201.00000000000000000000</Northing>
> <Altitude>7.04059982299804690000</Altitude>
> </View>
> <Id>0</Id>
>

I hadn't seen this variation before, but it's doing the same thing.  "Let's
put all our data in the 'extensions' field of an open file format.    Wow!


> <trkpt lat="51.465133" lon="-3.164078">
> <ele>9.07680034637451170000</ele>
>

...and then we'll represent elevation to a quazillionth of a meter.


> File 3 - bademap.map:-
> PK
> @{}5À Cnæ æ S1nclair Rul3z!.txt<Route Name="bademap" Text="" Order="0"
> Closed="0">
> <Point North="1227923015" East="-37708188" Elev="7.33640003204346" Text="1"
> Visible="1"/>
> [...]
>
</Route>
> PK
> @{}5À Cnæ æ S1nclair Rul3z!.txtPK A
>

The XML stuff inside the <Route> is pretty straight-forward.   Do you know
what the @{}5A S1nclair stuff is about?  Is it invariant?   Is this what's
actually in the file or is this what you see in some text editor?  My guess
is that it's a semi-binary file format.   In that case, we'd need an
unchanged .map file for study, too.   But let's see about that XML first.

If that first point maps to the first point in your GPX file...



> <rtept lat="51.461660"
> lon="-3.160664"><name>1</name><ele>7.336400</ele><sym>Dot</sym></rtept>
>

...then I don't really see what the conversion rate is.

It's not UTM and it's not British Grid.  Do you have any idea what format
those coordinates are in? Do you recognize them from anything that's visible
in the program that describes them?

It appears to be some kind of linear scaling.