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William F. Manley, Leanne R. Lestak, and Eric G. ParrishINSTAAR, University of Colorado
High-Resolution Orthorectified Imagery for Three Target Areas in Lake Clark National Park
and Preserve (LACL), Southwest Alaska
Introduction
This powerpoint presentation is a visual overview of high-resolution orthorectified imagery that is now available for the coastal and nearshore areas of three target areas within Lake Clark National Park and Preserve (LACL): Glacier Spit, Silver Salmon, and Tuxedni Bay.
The imagery was completed as part of a pilot study by the University of Colorado in collaboration with the Southwest Alaska Network Inventory and Monitoring Program. Beyond analysis of coastal change, the imagery will be of interest to land managers, scientists, and others for observation and study of natural features and ecosystems.
Orthorectified Aerial Photography
1993
2004-2006 IKONOS(available separately)
ca. 1950
1978
Goals
The three, co-registered “timeslices” of imagery complement recent IKONOS acquisitions, and greatly improve the resolution, accuracy, and temporal extent of the previously georectified LACL coastal atlas. The imagery will be helpful for a broad range of studies, and to detect change in:
• cultural resources and archeological sites
• ecosystem components such as coastal zones, wetlands, geology, soils, lake & stream hydrology, and vegetation assemblages
• marine, terrestrial, and freshwater habitats for a variety of animals
The imagery assists the goals of the Southwest Alaska Network for inventory and monitoring of natural resources.
Study Area
• coastal LACL
• three target areas with importance for resource management and other I&M studies
1954-1957
• 5 frames• Black and White• 1:43,000• 60 cm resolution• 15.5 m accuracy
1978
• 3 frames• Color IR• 1:65,000• 1.0 m resolution• 17.3 m accuracy
1993
• 8 frames• Black and White• 1:24,000• 30 cm resolution• 7.2 m accuracy• low tide (~MLLW)
Glacier Spit1957
tidal channel dynamics
beach accretion
wetland changes
forest expansion
Glacier Spit1978
tidal channel dynamics
beach accretion
wetland changes
forest expansion
Glacier Spit1993
tidal channel dynamics
beach accretion
wetland changes
forest expansion
Glacier Spit2004 (IKONOS)
tidal channel dynamics
forest expansion
beach accretion
wetland changes
Silver Salmon1957
coastalerosion
forest expansion
wetland changes
tidal channeldynamics
Silver Salmon1978
coastalerosion
forest expansion
wetland changes
tidal channeldynamics
Silver Salmon1993
coastalerosion
forest expansion
wetland changes
tidal channeldynamics
Silver Salmon2004 (IKONOS)
tidal channeldynamics forest expansion
coastalerosion
wetland changes
Tuxedni Bay1954
intertidal flat
Tuxedni Bay1978
expansion of wetland vegetation after uplift of 1964 earthquake
Tuxedni Bay1993
wetland
changes
Tuxedni Bay2006 (IKONOS)
wetland
changes
Tuxedni Bay1978(Perspective views are also possible)
Methods Each frame fully orthorectified to the IKONOS reference imagery. Procedure after extensive testing:
• ERDAS Imagine, with:• air photo camera models• IKONOS stereo Digital Terrain Model• available camera calibration information• image-to-image control points spread across frame
Horizontal accuracy for each frame then quantified with independent check points. Errors can be reduced further for small areas.
• 30 cm resolution• 3.4 m accuracy
• 2 m resolution• 260 m accuracy
Comparison at Glacier Spit
Previously Georectified Coastal Atlas This Data Release
Available to the Public:
• readme file• orthoimagery for 1993, 1978, and ca. 1950• index map layers• FGDC metadata• on 2 DVD’s
Contact:Southwest Alaska Network Data ManagerNational Park ServiceSouthwest Alaska Inventory and Monitoring Program240 West 5th AvenueAnchorage, AK [email protected]
Questions?:
Southwest Alaska Network Data ManagerNational Park ServiceSouthwest Alaska Network Inventory and Monitoring Program240 West 5th AvenueAnchorage, AK [email protected]
William Manley, PhDInstitute of Arctic and Alpine Research (INSTAAR)University of Colorado1560 30th StreetBoulder, CO [email protected]
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