Declassified Satellite Imagery Acquired Near Barrow Alaska
The Office of Polar Programs (OPP) at the National Science Foundation (NSF) has facilitated access to declassified Military imagery of the Barrow region. Three composite mosaics have been made available to us so far. These are scenes from August 1988 (brw0888* series), June 1989 (brw0689* series) and August 1995 (brw0895* series).
These images fill in significant gaps in the air photo time series compiled for the region. Images cover a vast expanse of the Barrow region that has not been covered by air photo coverage since 1964. The only other satellite coverage that exists for this expanse of coastal plain tundra in the region is low-resolution satellite imagery (greater than 10m pixels) so they are a valuable remote sensing resource for the region.
There are, however, some limitations of the imagery that may prevent its widespread use in terrestrial ecosystem research:
- Most of the scenes appear to have a pixel resolution of 2 meters. This is a lower resolution of most air photos and the most recent publicly available satellite image (such as IKONOS which has 1m panchromatic).
- There is some significant cloud cover over several images, which may limit its use for point specific uses.
- There is significant spectral distortion of the imagery along the coastline adjacent to sea ice. It would appear that this is the result of previous image processing and, although this may be corrected, it would be time consuming and tedious. This may limit the application of this imagery for use in coastal erosion studies. It will also limit the application of this imagery to automated classification procedures, which could have otherwise been used for texture analysis etc.
The imagery has been orthorectified to approximately 100m. Although we have a collection of Ground Control Points (GCPs) recorded for the Barrow region that will enhance more accurate orthorectification, this will be time consuming.