[OSM-talk] unkown coordinate encoding

Ovidiu Constantin ovidiu at mybox.ro
Mon Mar 27 20:42:10 BST 2006

A friend of mine uses a navigation software called i-Go - it's the best
so far for Romania. This program has the ability to record tracks. So I
asked him to record one and send me the data. Unfortunatly, this program
saves all its data in a sqlite3 database. I dumped the database and I
found out that the tracks are stored in binary format, here is a sample:

E6 0F 28 44 E2 AA 0E 0D 6A 13 3D 16
E7 0F 28 44 8A AB 0E 0D BE 13 3D 16
E8 0F 28 44 5C AC 0E 0D 3B 14 3D 16
E9 0F 28 44 2D AD 0E 0D E3 14 3D 16

The first 32 bit of each line form an unsigned int - a unix time of the
capture. Then there are 2 more 32 bit values that should be the latitude
and longitude.

Normal values for that location (from a previous capture by me):
<trkpt lat="44.477135" lon="26.114385">

Values from that dump (unsigned int)
219065058 and 373101418

so the first is the longitude and the second the latitude. If we divide
lat/long, the proportion is the same, so the data is valid and is not
scrambled  in any way.

This is where I'm stuck. I don't know how to convert those numbers to
valid data for my location - Bucharest/Romania.

Help? :(

Thank you,

PS: This is not a simple "hacking" exercise. I know some people on a
forum, plus some of my friends, that use this software. I'm sure they
would record their tracks and give me the data, because it's no trouble
for them, the navigation works perfectly while recording.

More information about the talk mailing list