Skip to main content
U.S. Forest Service
Caring for the land and serving people

United States Department of Agriculture

Forest Health News 2018

ASSESSING DEFOLIATION EVENTS Using Satellite Imagery

By Daniel Ryerson and Tom Mellin, USDA FS


April 2018

Satellite Imagery

Satellite imagery shows the extent and severity of defoliation from Douglas-fir tussock moth. Photo by: Daniel Ryerson and Tom Mellin.

High-resolution commercial satellite imagery is a highly useful resource for detecting and monitoring forest health issues. Using the USGS CIDR (CRSSP Imagery-Derived requirements) tool we have been able to obtain commercial remote sensing imagery for areas of high interest at no additional cost to the agency. The CRSSP (Commercial Remote Sensing Space Policy) enables agencies to acquire commercial satellite imagery that other agencies have already obtained or for acquisition requests to be made for particular areas of interest.

On the Sandia Mountains of the Cibola National Forest, an ongoing outbreak of Douglas-fir tussock is occurring in a high-use recreation area and highly visible to the public. A request was made through the CIDR tool for imagery during the peak defoliation period. WorldView-3 imagery (1.3 m multispectral, 0.3 m panchromatic resolution) was successfully obtained. This high-resolution imagery allowed for careful examination of the outbreak activity (yellow outline) and comparison to the aerial detection survey mapping (green outline). Additionally this imagery clearly shows the extent and severity of the defoliation for sharing with local managers.

For more information contact: Daniel Ryerson, Forest Health Specialist, New Mexico Zone, dryerson@fs.fed.us, 505-842-3285 Tom Mellin, Regional Remote Sensing Coordinator, tmellin@fs.fed.us, 505-842-3845.