[OSM-talk] unkown coordinate encoding
nick at nickhill.co.uk
Mon Mar 27 21:30:43 BST 2006
Just divide the numbers by 8388611 to get the regular lat/lon co-ordinates.
373101418 becomes 44.477
219065058 becomes 26.114
Ovidiu Constantin wrote:
> 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.
> talk mailing list
> talk at openstreetmap.org
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