Historical digital elevation models (DEMs) and orthoimage mosaics for North American Glacier Aerial Photography (NAGAP) program, version 1.0

This data archive contains digital elevation models (DEMs) and orthoimages generated from scanned historical aerial photographs from the North American Glacier Aerial Photography program available from the NSF Arctic Data Center (ADC, arcticdata.io). 

The scanned images were preprocessed using the Historical Image Pre-Processing v0.1 software. Photogrammetric processing was performed with the Historical Structure from Motion v0.1 software. 

All DEM and orthoimage products are provided in the UTM Zone 10N (EPSG:32610) projected coordinate system. Elevation values are in meters above the WGS84 ellipsoid. 

See manuscript and supplement for processing details and further dataset description.

This release contains data products for two study sites in Washington state, USA:

Mount Baker
1970-09-09
1970-09-29
1974-08-10
1977-09-27
1979-10-06
1987-08-21
1990-09-05
1991-09-09
1992-09-15
1992-09-18

South Cascade
1967-09-21
1970-09-29
1974-08-10
1977-10-03
1979-08-20
1979-10-06
1984-08-14
1986-09-05
1987-08-21
1990-09-05
1991-09-09
1992-07-28
1992-09-15
1992-09-18
1992-10-06
1994-09-06
1996-09-10
1997-09-23

The 00_thumbnails.jpg provides a quicklook overview at both sites.

The DEM and ortho file names are structured as follows:
hsfm_NAGAP_[site-name]_[date]_[type].tif

For example:
hsfm_NAGAP_south-cascade_19670921_ortho.tif

Where:
[site-name] = Either mount-baker or south-cascade
[date] = Image acquisition date in YYYYMMDD format
[type] = File type

For each DEM and ortho pair, we provide the following:
_1m_dem.tif = Digital elevation model posted at 1 m resolution 
_ortho.tif = Orthoimage mosaic posted at the median image ground sample distance, rounded up to the nearest second decimal place.
_metadata.tar.gz = Metadata tarball containing:
    _ortho_footprints.geojson = Orthoimage mosaic footprint polygons provided in GeoJSON format (EPSG:4326)
    _dem_footprints.geojson = DEM footprint polygons provided in GeoJSON format (EPSG:4326)
    _cameras.csv = Image file names, positions, and orientations