READMEs for arctic dem add-on

qgreenland/addons-readme.txt

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+32-meter resolution ArcticDEM (digital elevation model): The Polar Geospatial
+Center has provided a custom Greenland 32-m resolution ArcticDEM for added
+detail. Two download packages are provided for the v4.1 ArcitcDEM:
+
+* arcticdem_v4.1_32m_greenland_dem_only.zip: A ~4.1GB package containing only
+  the 32-m resolution DEM.
+
+* arcticdem_v4.1_32m_greenland_dem_full.zip: A ~9.5GB package containing the
+  32-m resolution DEM and ancillary datasets (e.g., a "count" dataset giving the
+  number of contributing DEMs for each pixel).
+
+Download one of these add-on packages and place it in a suitable location in your
+filesystem. Unzip the package and then follow the directions in the 'README.txt'
+file included.

qgreenland/arctic-dem-dem-only-readme.txt

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+-------------------
+Getting Started:
+-------------------
+
+This package consists of many small raster images (tiles) which together make up
+a larger 32m resolution Arctic DEM mosaic of Greenland. To add this data to
+QGIS, navigate in the **Menu Bar** to **Layer -> Add Layer -> Add Raster Layer**
+and browse to and select the included .vrt file as the layer source. This .vrt
+file references all of the individual tiles in the `tiles/` subdirectory, and
+allows them all to be loaded as a single mosaiced raster layer in QGIS. More
+information about VRTs can be found here:
+https://gdal.org/drivers/raster/vrt.html.
+
+
+-------------------
+Building Overviews:
+-------------------
+
+Because this dataset is large and consists of many smaller files, performance of
+the layer after initially loading it into QGIS may be slow. We recommend that
+users build raster overviews for this data, which will increase the rendering
+speed when zooming in/out with the 32m Arctic DEM enabled.
+
+To build overviews in QGIS, navigate in the Menu Bar to `Raster -> Miscellaneous
+-> Build Overviews (Pyramids)` . Select the 32m Arctic DEM as the input layer,
+and then click `Run` (leave the rest of the parameters as their defaults). This
+process will take several minutes and produce a new `.ovr` file in the data
+directory. The new `.ovr` file is expected to be ~5.5GB in size, and there is no
+need to interact with this new file.
+
+
+-------------------
+Styling this data:
+-------------------
+
+For information on changing the symbology of raster layers in QGIS, see:
+
+* QGIS lesson on changing raster symbology:
+  https://docs.qgis.org/3.28/en/docs/training_manual/rasters/changing_symbology.html
+
+* QGIS documentation on raster symbology properties:
+  https://docs.qgis.org/3.28/en/docs/user_manual/working_with_raster/raster_properties.html#symbology-properties
+
+
+-------------------
+Citing this data:
+-------------------
+
+The ArcticDEM dataset should be cited as follows
+Porter, C., Howat, I., Noh, M.J., Husby, E., Khuvis, S., Danish, E., Tomko, K.,
+Gardiner, J., Negrete, A., Yadav, B., Klassen, J., Kelleher, C., Cloutier, M.,
+Bakker, J., Enos, J., Arnold, G., Bauer, G., and Morin, P., 2023, "ArcticDEM
+- Mosaics, Version 4.1", https://doi.org/10.7910/DVN/3VDC4W

qgreenland/arctic-dem-full-package-readme.txt

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+-------------------
+Getting Started:
+-------------------
+
+This package contains the 32m Arctic DEM and ancillary data:
+
+* arcticdem_v4.1_32m_dem_greenland.vrt: 32-bit floating point elevation
+  raster. This is the primary DEM tile datafile.
+
+* arcticdem_v4.1_32m_browse_greenland.vrt: 32m DEM hillshade.
+
+* arcticdem_v4.1_32m_datamask_greenland.vrt: Raster indicating DEM pixels with
+  heights purely sourced from SETSM output (1) versus those that have been
+  filled/merged with another dataset or mask out as NoData in quality control
+  steps (0).
+
+* arcticdem_v4.1_32m_count_greenland.vrt: Number of contributing DEMs.
+
+* arcticdem_v4.1_32m_mad_greenland.vrt: Median absolute deviation of
+  contributing DEMs.
+
+* arcticdem_v4.1_32m_maxdate_greenland.vrt: Latest date of contributing DEMs in
+  days since Jan 1, 2000.
+
+* arcticdem_v4.1_32m_mindate_greenland.vrt: Earliest date of contributing DEMs
+  in days since Jan 1, 2000.
+
+Many small raster images (tiles) make up each of these layers to make a mosaic
+of Greenland. To add this data to QGIS, navigate in the **Menu Bar** to **Layer
+-> Add Layer -> Add Raster Layer** and browse to and select one of the included
+.vrt files as the layer source. This .vrt file references all of the individual
+tiles in the layer's associated `tiles/` subdirectory, and allows them all to be
+loaded as a single mosaiced raster layer in QGIS. More information about VRTs
+can be found here: https://gdal.org/drivers/raster/vrt.html.
+
+
+-------------------
+Building Overviews:
+-------------------
+
+Because each layer is large and consists of many smaller files, performance of
+each layer after initially loading it into QGIS may be slow. We recommend that
+users build raster overviews for each layer, which will increase the rendering
+speed when zooming in/out.
+
+To build overviews for a layer in QGIS, navigate in the **Menu Bar** to **Raster
+-> Miscellaneous -> Build Overviews (Pyramids)** . Select the layer as the input
+layer, and then click `Run` (leave the rest of the parameters as their
+defaults). This process will take several minutes and produce a new `.ovr` file
+in the data directory. The new `.ovr` file is expected to be several GB in size,
+and there is no need to interact with this new file.
+
+
+-------------------
+Styling this data:
+-------------------
+
+For information on changing the symbology of raster layers in QGIS, see:
+
+* QGIS lesson on changing raster symbology:
+  https://docs.qgis.org/3.28/en/docs/training_manual/rasters/changing_symbology.html
+
+* QGIS documentation on raster symbology properties:
+  https://docs.qgis.org/3.28/en/docs/user_manual/working_with_raster/raster_properties.html#symbology-properties
+
+
+-------------------
+Citing this data:
+-------------------
+
+The ArcticDEM dataset should be cited as follows
+Porter, C., Howat, I., Noh, M.J., Husby, E., Khuvis, S., Danish, E., Tomko, K.,
+Gardiner, J., Negrete, A., Yadav, B., Klassen, J., Kelleher, C., Cloutier, M.,
+Bakker, J., Enos, J., Arnold, G., Bauer, G., and Morin, P., 2023, "ArcticDEM
+- Mosaics, Version 4.1", https://doi.org/10.7910/DVN/3VDC4W