OpenStreetMap
I picked up a Garmin eTrex Vista Hcx last week, as my Zumo 550 just wasn't going to cut the mustard in areas without USGS Urban Area coverage; the tracklog sample rate is too rough. On the Vista I set the tracklog interval to 1 second; a 19-mile bicycle ride gave me a track with over 9,000 points, over 1GB in size :)
It turns out that another tool I own (ExpertGPS) does a good job of simplifying and manipulating GPX tracks, so I reduced that to 122KB and about 1,000 points. At that level I didn't feel so bad about converting it to an OSM layer (in JOSM) and uploading it. (I did clean it up a bit). Although it most cases so far I've been tracing my routes in JOSM on the USGS Urban Area map, I think this might be my new M.O.
Subject of today's mapping: Alameda Creek Trail, beginning at Coyote Hills and including at the other end a trip through Quarry Lakes Regional Rec Area in Fremont.
Arutelu
Kommentaar kasutajalt SuborbitalPigeon 9. detsember 2008, kell 01:05
It must be impossible for 9000 points to be a Gigabyte without each point having a lot of data logged. Are you sure it was that big?
Directly uploading GPS data as OSM data is frowned upon.
Kommentaar kasutajalt davetoo 9. detsember 2008, kell 02:45
Indeed, I misread the file size by three decimal places, but not the number of trackpoints. I am trying to find a compromise between laboriously hand-tracing the features on the Urban Area DOQ (which I won't have most places) and just dumping raw GPS data into the map. The high sampling rate is important for some of the complex footpaths and cycle paths I'm mapping. I may be able to split the tracks apart on either side of the very complex bits and simplify the straighter bits even more.