A remote sensing stategy for measuring logging road system length from small-format aerial photography

Small format aerial photographs (SFAPJ can be acquired at a relatively low cost to obtain quantitative data for natural resource applications. A remote sensing strategy was developed for measuring logging road system length from SFAP. Aerial photography, digital image processing, and fieldwork procedures are described in sufficient detail fornatural resource managers to acquire their own SFAP with only basic skills and equipment. An alternative field-based strategy was developed and used to evaluate time, costs, and relative accuracy of the remote sensing strategy. The field-based strategy was assumed to consistently produce more accurate measurements of road system length than did the remote sensing strategy. The remote sensing strategy was less expensive than the field-based strategy because logging road system length can be measured in a shorter amount of time. Error for the remote sensing strategy has an average of 11 percent and can be expected to range from 8 to 14 percent. Accuracy is limited by use of uncontrolled mosaics, lens distortion, tilt displacement, topographic displacement, and scale variation. [ABSTRACT FROM AUTHOR]