RETROCHANGE - UC1 / RETROCOVER EXAMPLE DATA
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DESCRIPTION
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This directory contains a 3 x 3 km subset of historical KH-9
(HEXAGON) satellite imagery for Hrebienok in Tatra National Park
(TANAP), High Tatras, Slovakia. The image supports UC1 / RETROCOVER:
historical land-cover mapping through segmentation and expert
interpretation in the Landscape application.

The source image was acquired on June 27, 1975, according to the
supplied parent-dataset metadata. The distributed raster covers
900 ha. This footprint differs from the larger 2,500 ha Hrebienok
demonstration area described in broader project materials.


FILES IN THIS DIRECTORY
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uc1_1_3x3_hrebienok.tif
    Historical single-band GeoTIFF, 6,000 x 6,000 pixels,
    0.5 m pixel size, UInt16, LZW compression, NoData = 256.

uc1_1_3x3_hrebienok.tfw
    Companion world file with matching pixel size and placement.
    The GeoTIFF itself includes georeferencing and CRS information.

METADATA.txt
    Source, acquisition, processing, raster properties,
    projected extent, limitations, and recommended citation.

LICENSE.txt
    Dataset license notice and attribution requirements.

README.txt
    Dataset overview and instructions for using this subset.

Keep these documentation files with the imagery when sharing it.


SPATIAL REFERENCE
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CRS: EPSG:5514 - S-JTSK / Krovak East North
Units: meters
Raster footprint: 3,000 x 3,000 m (9 km2; 900 ha)
Pixel size: 0.5 x 0.5 m

The 0.5 m pixel grid describes output sampling, not independently
verified positional accuracy or original sensor resolution.
See METADATA.txt for the projected bounding box.


USING THE DATA IN UC1 / RETROCOVER
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The image is stored directly in the application's data directory:
    data/uc1_1_3x3_hrebienok.tif

It is not automatically in the configured raw-raster directory,
which is data/raw for the bundled example project.

In the web interface:
1. Create or open a project.
2. Use the local raster import or browser upload control to add
   uc1_1_3x3_hrebienok.tif to that project.
3. Prepare working resolutions suitable for the mapping scale,
   segment the image, and review and classify candidate polygons.
4. Export the reviewed land-cover layer, statistics, and maps.

In the notebooks:
- Set the input raster path to data/uc1_1_3x3_hrebienok.tif when
  running from the application root, wherever an explicit input
  path is supported.
- For notebooks that list only the project's raw-raster folder,
  import or copy the GeoTIFF into that configured folder first.
- Preserve the NoData value and CRS when creating derived rasters.

Application setup and operation are described in
../docs/retrocover_guide.md and ../README_EOSC_EN.md.


INTERPRETATION AND LIMITATIONS
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This is a historical image input, not a classified land-cover map.
Segmentation proposes candidate objects; expert review is needed
to assign classes and resolve ambiguous boundaries and features.

The raster footprint is not a class-area statistic. Quantify land
cover from reviewed mapped polygons under a documented legend.

A 1975 image provides a historical baseline. Measuring change
requires comparable observations from another acquisition period.
Comparisons between editing versions of this same image describe
classification progress, not temporal landscape change.

Positional and radiometric quality may vary because of the original
imagery and its processing. The dataset is not intended for
cadastral, legal, engineering, or survey-grade applications.


SOURCE, LICENSE, AND ATTRIBUTION
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Parent dataset:
RETROCHANGE High Tatras 1975 KH-9 Satellite Image Mosaic, version 1.0.

Source imagery:
Declassified KH-9 (HEXAGON) satellite imagery courtesy of the U.S.
Geological Survey (USGS), Earth Resources Observation and Science
(EROS) Center. Source collection DOI: https://doi.org/10.5066/F7WD3Z10

Processing organization:
Technical University in Zvolen, RETROCHANGE project, 2026.

License:
Creative Commons Attribution 4.0 International (CC BY 4.0)
https://creativecommons.org/licenses/by/4.0/

The license applies to rights held by the Technical University in
Zvolen in the derived dataset. It does not impose additional
copyright restrictions on the original public-domain USGS imagery.
Follow LICENSE.txt for attribution and license details.

Recommended dataset citation:
Technical University in Zvolen (2026).
RETROCHANGE UC1 RETROCOVER Hrebienok 1975 KH-9 Image Subset.
Subset of the RETROCHANGE High Tatras 1975 KH-9 Satellite Image
Mosaic, version 1.0. RETROCHANGE project.
https://gis.tuzvo.sk/retrochange


CONTACT AND PROJECT
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Technical University in Zvolen
T. G. Masaryka 24, 960 01 Zvolen, Slovakia

RETROCHANGE - Retrospective Analysis of Forest and Landscape
Changes from Historical Satellite Imagery
https://gis.tuzvo.sk/retrochange
