2. Maps

Maps

About Geiger Bot's Mapping

By default, Geiger Bot's map display is optimized for speed. It uses the fastest base map possible (satellite) which is not the ideal base map for finding a location or data visualization.

Geiger Bot's mapping is somewhat unique in that it is not a static display of pre-rendered data, but rather, displayed according to the parameters you choose. By setting the colors (LUT), base map, radiological data layer, alpha blending, etc you can fully control how you want the map to look. In this way, it is a small, self-contained GIS server -- though a very specialized and limited one.

Manually controlling the min/max of the map scale, and changing the LUT allows you to fine-tune the contrast to better visualize the differences in a specific set of data.

Configuring the base map, alpha blending, and level of detail can optimize between showing where the data is, and showing what the data is.

Mapping is designed primarily to be interactive. Almost all mapping options are on the map interface itself. The intent of all of this is to give you options for exploring the data and best visualizing it.

A Japan Times writer called it "strangely addictive".

• • NOTE: The mapping module can be entirely deactivated as a failsafe if you experience any issues.

    • Settings -> Log File -> Disable Map

    • After changing this setting, you must force quit and restart the app (or restart your device). (you can also change the setting in Apple's main Settings.app on the home screen)

    • To force quit:

      • Press home.

      • Double-tap home so that the multitasking bar appears at the bottom of the screen.

      • Hold down on the Geiger Bot icon until a red "-" appears in the corner.

      • Tap the "-".

    • Notes about Disabling Mapping

      • When mapping is disabled, data will not be logged to the mapping database

      • To re-enable mapping, you must restart the app as described above

• Custom Map Layers (1.6.3+)

  • All preconfigured map layers are actually combinations of multiple individual data sources, with a few exceptions.

  • You can create custom map layers with the same flexibility and same options. The combinations aren't infinite, but probably multiply out to a relatively large number.

    • Example: The "Safecast" layer is a combination of:

      • Primary Layer: Safecast data uSv/h

        • Preprocessing effects: Smart Resize 3x3

        • Postprocessing effects: Halo

      • Sublayer 1: Safecast EBK interpolation uSv/h

        • Raster math: Overlay

        • Alpha: 50%

        • Sublayer 2: USGS/GSC NURE uSv/h

          • Raster math: Overlay

          • Alpha: 50%

        • Sublayer 3: Geoscience Australia uSv/h

          • Raster math: Overlay

          • Alpha: 50%

    • A custom map layer allows you to define your own combinations of any data source or combination of data sources. This is currently limited to a primary layer and 3 sublayers.

    • You must enable this in Settings -> Map before it will be displayed on the "Layers" list

• Mapping currently displays data from:

  • A local database of your recorded data

    • • Similarities to log file

        • Recorded at the same time

        • Use the same log time interval

      • Differences from log file

        • Requires GPS coordinates -- you must first enable GPS on the settings screen

        • Not cleared out by a "reset"

      • Your data is always displayed on top of all read-only databases listed below

  • Safecast Dose Rates

    • • A large collection of frequently updated ground vehicle surveys

      • Global coverage, but most data is focused on Japan due to Fukushima

      • The Safecast layer can now be updated on demand in-app!

    • (updatable) (data global; Japan primary)

  • Safecast Historical Dose Rates

    • • For historical perspective, both the data and interpolation layers for Safecast generated on 2013-04-15 are included.

      • These can be used in custom layers to see differences over time, and new areas surveyed.

    • (read only) (data global; Japan primary)

  • US DOE / NNSA AMS Fukushima Response Surveys

    • • Aerial and ground vehicle surveys of Japan from 2011 of fission product release from Fukushima

      • Including Cs-134 and Cs-137 activity, corrected for decay to date of you viewing the map

        • A simple decay rate calculation alone does not account for environmental dispersion. In reality measured levels of these isotopes will be lower as they have not remained in a fixed position since the surveys in 2011.

    • (read-only) (data Japan only)

  • US EPA Uranium Mines

    • • A database assembled by the US EPA from federal, state and local sources of uranium mines and claims in the US

    • (read-only) (data US only)

  • USGS/GSC NURE Dose Rates

    • • Aerial gamma radiation surveys of North America from the 1970s and 1980s, showing natural background radiation.

      • NURE was actually a program begun in the 1970s under the US AEC (Atomic Energy Commission). It was later transfered to the DOE which assumed the AEC's functions, and then later maintained and processed by the USGS. (the original records were on tape and microfilm)

      • This data is a further update of the original NURE data and contains a number of Canadian studies from the Geological Survey of Canada

      • This dose rate is a combination of both the terrestrial and cosmic ray dose rates. It is an approximation, as natural background rates will vary over time. Note the cosmic ray dose rate does not include neutron radiation.

      • While the original data was not intended to show manmade activity, examples can be found. Consider Gunnar Mine in Saskatchewan, Canada. If you zoom in you will see a statistically significant elevation in the dose rate, presumably from mining tailings. While there is no singular hotspot, due to the natural high grade of the ore once mined there, it remains elevated over a large area. The mine itself was closed down in the 1960s, before the surveys were performed. (The ore was sold to the US. Nearby Uranium City lasted into the 1980s, holding out hope for another boom due to the oil crisis, but by then the demand and price for uranium had dropped sharply, and the world had moved on.)

    • (read-only) (data US/Canada only)

  • AIST Japan Natural Background

    • • Similar to the NURE dose rate dataset, this is an approximation of natural background radiation, as a combination of terrestrial and cosmic dose rates

      • The terrestrial data was derived from AIST mineral sample data (~3k points) using Empirical Bayesian Kriging in ArcGIS 10.1 and clipped to Japan's administrative boundaries.

      • The cosmic dose rate was derived from a NGA DTED0 DEM product and added to the terrestrial dose rate.

    • (read-only) (data Japan only)

  • USGS Uranium Concentrations

    • • This is a somewhat less complete (Canada omitted) and lower resolution version of the above NURE data, for uranium concentrations, in ppm.

      • Naturally, there is quite a bit of correlation between uranium mines and uranium concentrations.

      • This is the only layer that the default LUT scale does not work well for. I recommend changing it to linear scaling, range 0.03 - 10.0.

    • (read-only) (data US only)

  • NOAA Global Radiance

    • • This is the "Earth at Night" or "Night Lights" dataset.

        • Specifically, it is the 2006 F16 DMSP OLS dataset with a gamma stretch and histogram clip.

      • It is *not* radiological data. It shows human-created light sources captured with satellite imagery.

      • In industrialized nations, it correlates with population density.

      • Data has been rescaled to 0 - 10 (arbitrary).

    • (read-only) (global)

Mapping Controls - Bottom Toolbar

• [LUT]

  • Change LUT

    • • Changes the false-color palette lookup table (LUT) that is coloring the data points

      • These are used to enhance contrast to the human eye, as it is usually easier for the human visual system to discriminate between color and brightness, than brightness alone.

      • The color is *NOT* an indication of frequency (energy / wavelength) of radiation. Merely the intensity (dose rate / count rate).

  • LUT Options

    • • Scale type: (Linear | LN | LOG10)

        • LN and LOG10 scaling use logarithms to emphasize differences in the lower range of values more. This is similar to gamma correction.

        • Like gamma correction, the cost is decreased contrast in the upper range.

        • Changing the scale type also sets the corresponding default range

        • It is a faster alternative to the rather imperfect 3-finger swipe gesture

      • Range: (0.03 - 1.0 | 0.0 - 1.72 | 0.03 - 65.54)

        • This is selected when changing the scale type, but can also be selected manually directly

        • For precise control over the range, swipe on the LUT control directly

      • Invert: (ON | OFF)

        • This reverses the order of the LUT

      • Discretize: (4 | 8 | 16 | 32 | OFF)

      • Discretize significantly reduces the color depth of a LUT

      • This is usually done to provide more distinct classification "steps" on a map and be simpler to look at

• [Layer]

  • Change Layer

    • • This allows you to select a collection of data layers

      • User points and EPA Uranium mine point features can be turned on/off independantly of data layers at the bottom

      • This also includes the "Update Safecast Data" command