Remote Sensing: A Sampling Tool to Inventory and Monitor Natural Resources

Remote sensing is sometimes thought of as a tool for reconnaissance, mapping or photo interpretation. However, it can also be used as a sampling tool to either directly sample a forest attribute (using aerial photography or high-resolution satellite imagery), or to stratify the landscape for additional field or higher-resolution photo sampling. Although remote sensing was frequently used by the USDA Forest Service several decades ago for this purpose, today it is largely overlooked. Nevertheless, declining budgets and advances in remote sensing technologies make this application of remote sensing perhaps even more valuable today than it was 50 years ago. Studies have documented that a combination of field and photo estimates can increase sampling efficiency by more than an order of magnitude compared to using field data alone. Sampling based on aerial photographs or high-resolution satellite imagery can reduce the time required for field surveys by more than half. In recent years, the Forest Service Remote Sensing Applications Center has continued to implement sampling projects that incorporate remote sensing. These projects include augmenting FIA field sampled data, assessing conifer mortality, and estimating riparian area. The technical methods developed for these projects and sample designs are applicable to a wide range of forest and rangeland information needs.