This directory contains scripts and geospatial data used in, and output by, SkyTruth's updated surface mine analysis. These data are the result of adapting methods originally published in the PLOS ONE article: "Mapping the Yearly Extent of Surface Coal Mining in Central Appalachia using Landsat and Google Earth Engine". All data are exported from Earth Engine in EPSG:4326, conversions to EPSG:5072 are done locally, using GDAL and OGR.

The methodology outlined in the PLOS ONE paper utilizes a cleaning method that uses data from preceding and subsequent years to remove errors in detection (e.g. if a pixel is classified as a mine in 1985, non-mine in 1986, and mine in 1987 the data for 1986 is corrected to classify it as a mine. The opposite is also true for pixels classified as non-mine > mine > non-mine). Beginning in 2022, we are making the detections from the current year available, as a provisional dataset (this is indicated in file names). 

This data is provisional. Working with imagery from MSS requires a higher degree of processing and filtering, and the PLOS methodology was updated to try and address the needs differences between MSS and TM/OLI imagery. In addition to the cleaning methods used to remove errors in detection that arise from year to year, we also implement a size threshold to remove areas which are likely not associated with mining; we filter out any detections which are < 18,0000m2 (that is, areas less than 5 pixels in size). This data is subject to change as we improve our methodology for detecting mining using MSS imagery.

Please direct inquires to Christian Thomas (christian@skytruth.org).
------------------------------------------------------------------------------------------
------------------------------------ CONTENTS --------------------------------------------
------------------------------------------------------------------------------------------

1. Mining_Cumulative (Directory)
   - This directory contains the cumulative mining data as identified from 1973-1984 in a variety of spatial formats.
	* GeoJSON (Directory)
	* GeoTIFF (Directory)
	* Shapefile (Directory)

2. Mining_Yearly (Directory)
   - This directory contains the yearly identified active mining data in a variety of
     formats, for each year from 1973-1984.
	* GeoJSON (Directory)
	* GeoTIFF (Directory) - Footprints only, band value equal year of mining
			        there is no index info stored in these images
	* Shapefile (Directory)

3. readMe.txt (Text File)
   - Overview of the Data and Directories present here.

------------------------------------------------------------------------------------------
-------------------------------------- NOTES ---------------------------------------------
------------------------------------------------------------------------------------------
Every directory which contains spatial data (that is any directory named: GeoJSON, GeoTIFF, or Shapefile), provides the data in two CRSes, EPSG:4326 and EPSG:5072. These are found in subdirectories names 4326 and 5072. All spatial files also have their CRS 
specified in their filename, before the file extension. All conversions between CRSes were done using GDAL and OGR2OGR.
	e.g. 1973_activeMining_4326.shp is EPSG:4326
	     1973_activeMining_5072.shp is EPSG:5072


Vectors were exported from Earth Engine as GeoJSON files, rasters were exported as GeoTIFF files. Conversions to shapefiles were performed locally.