[gdal-dev] Difficulty opening Safecast GeoJSON data

[Sean Gillies]

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,"lati
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":"cp
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
> --
> mcoletti at gmail.com <mailto:mcoletti at gmail.com>
>
>
>
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-- 
Sean Gillies
sean at mapbox.com