Mark, You could use the GDAL/OGR .csv driver with a VRT to access the data and spit it out into a different, filtered file.
http://www.gdal.org/ogr/drv_csv.html You could also use the VSI to pull from a .zip'd file via URL. You could also likely use args with ogr2ogr to filter by attribute or bbox, and even reproject the data on the way out. http://www.gdal.org/ogr2ogr.html David. On Mon, May 5, 2014 at 3:29 PM, Mark Coletti <[email protected]> wrote: > Thank you Even and Sean for your very quick and salient replies! I'll > notify the Safecast folks that their data might be better served using > GeoJSON; meanwhile, they also make their open source data available as a > single downloadable file in CSV format. Since qgis can import files of > that type, I've been using that; it's just that I have to do a lot more > work on my end to pare the data down to the region of interest. (And deal > with the inevitable data corruption. E.g., I suspect the observations from > 2020 are bogus unless they have a time traveler volunteering radiation > readings. =) ) > > Again, thank you for your help! > > Cheers, > > Mark > > > On Mon, May 5, 2014 at 4:12 PM, Sean Gillies <[email protected]> wrote: > >> Hi Mark, >> >> Safecast's JSON isn't GeoJSON, but wouldn't be too hard to crosswalk over >> to GeoJSON... make a geometry from its latitude/longitude, stuff all the >> other attributes in properties. >> >> >> On 5/5/14, 1:56 PM, Mark Coletti wrote: >> >>> >>> Safecast is user sourced radiation data, and has a public API serving >>> data in GeoJSON format (https://api.safecast.org/en-US/home). However, >>> I'm having difficulty in accessing this data via OGR: >>> >>> % ogrinfo -so >>> "https://api.safecast.org/en-US/measurements?distance=10&; >>> latitude=37.42&longitude=141.033" >>> ERROR 4: Failed to read GeoJSON data >>> ERROR 4: Failed to read GeoJSON data >>> FAILURE: >>> Unable to open datasource >>> `https://api.safecast.org/measurements.json?distance=10&; >>> latitude=37.42&longitude=141.033' >>> with the following drivers. >>> >>> So OGR sees that the data is formatted as GeoJSON, but is unable to read >>> it for some reason. >>> >>> Using curl to manually make the query I get: >>> >>> % curl -i -H "Accept: application/json" >>> "https://api.safecast.org/en-US/measurements?distance=10&; >>> latitude=37.42&longitude=141.033" >>> HTTP/1.1 200 OK >>> Server: nginx >>> Date: Mon, 05 May 2014 19:43:55 GMT >>> Content-Type: application/json; charset=utf-8 >>> Transfer-Encoding: chunked >>> Connection: keep-alive >>> Status: 200 OK >>> Strict-Transport-Security: max-age=31536000 >>> Access-Control-Allow-Origin: safecast.org <http://safecast.org> >>> >>> Access-Control-Allow-Methods: POST, GET, OPTIONS >>> Access-Control-Allow-Headers: *, X-Requested-With >>> Access-Control-Max-Age: 100000 >>> X-UA-Compatible: IE=Edge,chrome=1 >>> ETag: "e4650539a53d3698d8deb02e912b9ae3" >>> Cache-Control: max-age=0, private, must-revalidate >>> X-Request-Id: a30a38247c16374a39ada0a8d4d2fcde >>> X-Runtime: 0.022855 >>> X-Rack-Cache: miss >>> X-Powered-By: cloud66 >>> >>> [{"captured_at":"2014-01-30T05:03:25Z","device_id": >>> null,"id":30981293,"location_name":null,"original_id":null, >>> "unit":"cpm","user_id":3,"value":4675.0,"latitude":37. >>> 41997666666666,"longitude":141.03297166666667},{" >>> captured_at":"2014-01-30T05:25:26Z","device_id":null,"id": >>> 30981556,"location_name":null,"original_id":null,"unit":" >>> cpm","user_id":3,"value":2470.0,"latitude":37. >>> 42001666666667,"longitude":141.03303666666667},{" >>> captured_at":"2014-01-30T05:00:54Z","device_id":null,"id": >>> 30981263,"location_name":null,"original_id":null,"unit":" >>> cpm","user_id":3,"value":5428.0,"latitude":37. >>> 41996666666667,"longitude":141.03301666666667},{" >>> captured_at":"2014-01-30T05:21:20Z","device_id":null,"id": >>> 30981507,"location_name":null,"original_id":null,"unit":" >>> cpm","user_id":3,"value":12191.0,"latitude":37. >>> 420003333333334,"longitude":141.03305333333333},{" >>> captured_at":"2014-01-30T05:00:49Z","device_id":null,"id": >>> 30981262,"location_name":null,"original_id":null,"unit":" >>> cpm","user_id":3,"value":5199.0,"lat >>> >> i >> tude":37.41999666666667,"longitude":141.03306166666667} >> ,{"captured_at":"2014-01-30T05:25:21Z","device_id": >> null,"id":30981555,"location_name":null,"original_id":null, >> "unit":"cpm","user_id":3,"value":2423.0,"latitude":37. >> 42006833333333,"longitude":141.03301333333334},{" >> captured_at":"2014-01-30T05:03:30Z","device_id":null,"id": >> 30981294,"location_name":null,"original_id":null,"unit":" >> cpm","user_id":3,"value":4456.0,"latitude":37.41992833333333,"longitude": >> 141.03297333333333},{"captured_at":"2014-01-30T05: >> 00:59Z","device_id":null,"id":30981264,"location_name":null, >> "original_id":null,"unit":"cpm","user_id":3,"value":5672.0,"latitude":37. >> 419963333333335,"longitude":141.03291666666667},{" >> captured_at":"2014-01-30T05:00:44Z","device_id":null,"id": >> 30981261,"location_name":null,"original_id":null,"unit":" >> cpm","user_id":3,"value":5135.0,"latitude":37.420035," >> longitude":141.03309},{"captured_at":"2014-01-30T05: >> 21:14Z","device_id":null,"id":30981506,"location_name":null, >> "original_id":null,"unit":"c >> p >> m","user_id":3,"value":12164.0,"latitude":37.42006333333333,"longitude": >> 141.03293666666667}] >> >>> >>> Those do look like legitimate observations, but I don't know if they >>> comply to the GeoJSON format since I'm new to JSON. >>> >>> I'm using this version of GDAL/OGR, which was part of the pre-packaged >>> binaries for qgis for my Mac: >>> % ogrinfo --version >>> GDAL 1.10.1, released 2013/08/26 >>> >>> Eventually I'd like to use GDAL/OGR to conveniently create a local >>> spatial database from such a query. However, I need to get over this >>> hurdle first. >>> >>> Cheers, >>> >>> Mark >>> -- >>> [email protected] <mailto:[email protected]> >>> >>> >>> >>> _______________________________________________ >>> gdal-dev mailing list >>> [email protected] >>> http://lists.osgeo.org/mailman/listinfo/gdal-dev >>> >>> >> -- >> Sean Gillies >> [email protected] >> _______________________________________________ >> gdal-dev mailing list >> [email protected] >> http://lists.osgeo.org/mailman/listinfo/gdal-dev >> > > > > -- > [email protected] > > > _______________________________________________ > gdal-dev mailing list > [email protected] > http://lists.osgeo.org/mailman/listinfo/gdal-dev >
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