[Loadstone] Checkpoint (route) files

Peter Wendorff wendorff at uni-paderborn.de
Tue Sep 7 13:50:36 BST 2010

  Hi again.
I did some tests using Loadstone yesterday, and I have some additional 
questions about assembling good checkpoint files:

The test file I assembled contained "interesting points" of the way. To 
be more concrete most of them were crossings and intersections of streets.
At hard turns that lead to the hairpin-curve problem also described 
somewhere at the loadstone-website.

The first question for that topic is: Why the current position at the 
route cannot be considered to avoid this partly? Is there a reason to 
not implement it (except time, too much effort)?

Second question: If I add more intermediate points between the ones I 
have now, would that really help? I figured out the point coordinates 
(taken from OpenStreetMap) differed from the GPS coordinates by around 
10 meters, so It would lead on the other hand to loadstone instructions 
like "10 meters at 3 o'clock" instead of "130 meters at 12 o 'clock", 
because at wide ranges the (in)precision is not as important.

Third question: The OpenStreetMap often has coordinates some meters 
wrong, but often they are good relative to each other (where mappers 
measured distances for example). If there is a more or less constant 
difference between map and gps coordinates - is it possible to save this 
offset for the next distance calculations?
That would also be useful to navigate along a sidewalk, where only the 
coordinates of the street itself are known and stored in the map file.

Fourth question: If I add intermediate points between two points I have 
good names for - is there any experience with adding kind of running 
numbers to point names? That could add the information, that I go into 
the right direction, what's not included in the software yet, as far as 
I could figure out.



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