Maps and GPS - An example

An example

If you start creating a JPR-file the first time, it is useful to have a real example at hand. I choose the Canadian 1:50,000 map sheet  82 J/11 "KANANASKIS LAKES" . A beautiful hiking area on the eastern edge of the Canadian Rocky Mountains, two hours drive from Calgary. For this map I created a JPR-file (and tested using Memory-map ®). You can download the grapics-file and the JPR-file (unzip file). For further documentation see JPR-files.

Be aware: The JPR-file must have the same name as the graphics-file

JPR-file notes
//Example JPR-file Comment line
nm=082J11_03 Name of the map. Isn't necessarily the filename
vr=0.1 Version number of JPR-file
dm=NAD83 Map datum
pr=UTM Map projection
zn=11u UTM-zone
st=0.0 Latitude datum shift in degrees
sn=0.0 Longitude datum shift in degrees
sc=50000 Scale of the map. 50000 means 1:50,000
sr=300 Scan resolution of original image in pixels per Inch (PPI)
cu=meters Altitude unit (contour lines) in meters
ci=40 Contour line interval
it=png Graphics-file type
Reference points on the map (latitude, longitude, X-pixel, Y-Pixel).
You must use at least 3 reference points. Start with the first reference
point in the  top-left corner. The other points clockwise.
In the western hemisphere the sign for the longitude is - (minus).
In the southern hemisphere the sign for the latitude is - (minus).
Pixel of vertex of polygon defining the boundary of the usable map
(X-pixel, Y-Pixel). You must use at least 3 vertices. Start with the
first vertex in the  top-left corner. The other vertices clockwise.
In the example I used three vertices because of the curved shape op
the top and the bottom.