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All imagery is in ERDAS Imagine format. If not specified in the file name, image resolution is 60 meters. Each sample may contain the following data:

File name convention for imagery is samp<ecoregion>_<sample>_<date>_<sensor>.
Date is in the format mmddyy, except ecoregion 14 where only the year is used. In rare cases, images from two dates were required for complete coverage, usually due to cloud cover. Both dates are listed on the web page and included in the file names.
Sensors are Landsat Multi-Spectral Scanner (mss), Landsat Thematic Mapper (tm), Enhanced Thematic Mapper (etm) and panchromatic data from ETM+ (pan).

Convention for land cover images is samp<eco>_<sample>_<date>_lc_final.

Land cover codes are:

  1. Water (blue)
  2. Developed (red)
  3. Mechanical Disturbed/Transitional (magenta)
  4. Mining (black)
  5. Natural Barren (gray)
  6. Forest (green)
  7. Grassland/Shrubland (yellow)
  8. Agriculture (orange)
  9. Wetland (cyan)
  10. Non-Mechanical Disturbed/Transitional (purple)
  11. Snow/Ice (white)

Change image codes are sequential, so 1 = change from class 1 to class 1, 2 = change from class 1 to class 2, 3 = change from class 1 to class 3, etc. Since the number of classes varies by ecoregion and sample, the codes will also vary. For example, if there are eight classes, then 9 = change from class 2 to class 1, but if there are nine classes, 9 = change from class 1 to class 9.

Multi change images codes are 0 to 4, representing the number of times the land cover in the pixel changed.

“Sliver” samples – In a very few cases, there was not enough land area in the sample block to derive statistically significant classification accuracies. In these cases, an adjacent sample was selected, and imagery from both samples was classified. Since the samples were treated as one entity, data for both samples are listed on the same page and can be accessed by clicking either sample in the map.

Samples that include area from multiple ecoregions - Where a sample contained area from more than one ecoregion, the land cover and change images depict the entire sample block, not just the portion inside the ecoregion of interest. The excel spreadsheet for these samples also represent information for the entire block.

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