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davetoo's Diary

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Video trivia

Posted by davetoo on 30 August 2010 in English.

So I'm finding that I can render a 1/2 hour video (~ 1.2GB mpeg source) to WMV9 at high bitrate (1500-2000 Kpbs) in about 1/2 hour elapsed time, for a 300-500MB upload, or... at low bitrate (target=500Kbps) in about 1.5 hours elapsed time, for about a 75-150 MB upload. Question is: which mode will get all of the SOTM.US videos uploaded quicker? :)

I think I'm going to take the option that saves my upload quota, so that I can start helping with the Girona videos as soon as I finish the US videos.

Long day getting to Atlanta

Posted by davetoo on 13 August 2010 in English.

Got up at 3:00 AM (in California) because I wasn't done packing. Then the cab driver that took my call decided to pull the chute and never showed up, and the replacement guy kept getting lost. So I missed my flight, spent three hours at OAK wishing there was someplace to sleep :)

But then it all turned good: on my rescheduled hops I had first, the exit seat on an A319 with no seat in front of me so I could stretch my legs out completely, and then the second hop I had a whole row to myself. And at nightfall I was able to shoot some great video out the plane window of lightning in the clouds.

Yes, it's hot here :)

Location: Hotel District, Old Fourth Ward, Atlanta, Fulton County, Georgia, 30303, United States

While playing with my GIS software, I discovered that the USGS had released 1/9-arcsecond NED data for my county. This data is generated from LIDAR scans and has a resolution of about 1/3 meter in x/y/z.

After much trimming and fiddling to reduce the data size, I created 0.25m contour lines and picked those that looked "best" for the water body outlines. I then used the same GIS software to simplify the lines, reducing some of them from over 1000 points to less than 200 but still maintaining nice curves. I the used Ian Dees' shp2osm package (java, not the perl stuff in svn) to convert to .osm, and used josm to create relations for the islands and some other cleanup.

It was quite a bit of work; now that I have a better handle on the process I'll have to try it in other areas to see if it's useful for "production" mapping. But it was a worthwhile exercise. (I should try to come up with some before/after images to upload).

Location: Eberly, Fremont, Alameda County, California, 94536, United States

Hetch Hetchy Aqueduct: Done!

Posted by davetoo on 25 July 2009 in English.

*phew* I just traced over 200 miles of the Hetch Hetchy Aqueduct/pipeline, using USGS DRG, Urban Area, and Yahoo satellite; all the way from the head in Tuolmne to the terminus at Crystal Springs Reservoir, including pipelines 3 and 4 around the south of the Bay.

I'm not sure if this was easier than finding all the right NHD data, pulling it together, and converting to .shp and then to .osm.

Location: McHenry, Stanislaus County, California, 95350, United States

Been tracing out the details of Fremont (California) Central Park, in JOSM, from Terraserver USGS Urban Area orthophotography. I'll still have to go over there and validate some of the features, but this saves a huge amount of time.

Am I overdoing it by showing all ten soccer fields (football pitches)?

Location: Irvington District, Fremont, Alameda County, California, 94538, United States

GPS Data Overload

Posted by davetoo on 8 December 2008 in English.

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.

Location: Eberly, Fremont, Alameda County, California, 94536, United States

Mapping some racetracks

Posted by davetoo on 6 December 2008 in English.

Using Yahoo imagery and Potlatch to map some motorsports racetracks that I frequent. The first is Thunderhill Raceway Park:

http://www.openstreetmap.org/?lat=39.54439&lon=-122.32224&zoom=15&layers=B000FTF

The other for today is Reno Fernley Raceway:

http://www.openstreetmap.org/?lat=39.54068&lon=-119.24182&zoom=16&layers=B000FTF

(These links will show little or nothing until the renderers catch up.)

Location: Glenn County, California, United States

Yesterday, obtained GPS trace via bicycle of part of the trails in Coyote Hills Regional Park. Converted that to data layer in JOSM and cleaned up. Adding more that I didn't cover, via USGS Urban orthophoto. Getting the trails on top of the levees is requiring a good deal of manual cleanup of the ponds and marshes so that I don't have people riding through water :)

Location: Fremont, Alameda County, California, United States