Optical remote sensing for forest area estimation

The air photo dot-count method is now widely and successfully used for esti mating;operational forest area in the USDA forest Inventory and Analysis (F IA) program. Possible alternatives that would provide for more frequent upd ates, spectral change detection, and maps of forest area include the AVHRR calibration-center technique and various Landsat Thematic Mapper classifica tion algorithms. Should a switch from proven technology be advised, our gen eral recommendation is to conduct several pilot studies that would focus on developing or refining tools and methodologies to allow objective, repeata ble, and accurate forest area estimation using multi-spectral earth resourc e satellite data.