Nick Dolezal comments

I am the author of the Safecast iOS app and wanted to clarify a few things here:

Data Sources: For the Safecast map layers I am using the same CSV another poster indicated he downloaded. There are no additional data sources going into those layers.

Methodology: the points are projected and binned at Web Mercator tile level 13 (19m/pixel resolution). The Safecast interpolation layer was created using Empirical Bayesian Kriging in ArcGIS 10.1 at a resolution of 153m (tile level 10). EBK accounts for statistical error and can mitigate older outliers based off newer data in close proximity to it.

Also, in the new update (1.6.4) pending approval by Apple at the time of this posting, the binning process is selective for the more recent 270 days in each bin, creating more of a bias for newer data. (excluding older data altogether produced disappointing results)

Updating: I have code written that is capable of downloading, parsing, binning, and tiling the CSV data on device. Unfortunately the speeds are prohibitive which is why this is not used, except in the iOS simulator to generate the data tiles in the app package. Server capacity and bandwidth are not available to do this centrally either which would be my preferred solution.

Speaking of speed, the last EBK interpolation I did took 244 hours. (i7 3770k @ 4ghz)

Data Gathering: I am not involved in this. My understanding is there is a police presence in the exclusion zone and this may be a determining factor affecting the temporal resolution of that data.

Live Static Sensor Networks: I am currently working to support this on-device but it is still in development. My initial plans are for downloads of both Safecast and MEXT data.