PROGRESS ON APPLICATION OF AIRBORNE RADAR AND GIS TO SAN CLEMENTE ISLAND ARCHAEOLOGY

We report on progress in application remote sensing data, principally AirSAR airborne radar, and GIS to cultural resource management. The DoD and DoE are legally required to locate and care for cultural resources on lands they control. Much is unsurveyed and current methods are slow and expensive. Presently over 19 million acres of DoD land alone are unsurveyed. In the western US surveys cost $30-$35 per acre, far more in the heavily vegetated eastern US. Evaluation and mitigation are required before site disturbance. Delays and significant schedule impact can occur should archaeological sites inadvertently be discovered. We evaluate JPL AIRSAR multiparameter radar imagery and TOPSAR high resolution digital elevation data (http://airsar.jpl.nasa.gov/) as a tool for archaeological research. The radar imagery is collected at three wavelengths (~68cm, ~24cm, and ~5.6cm) and full polarization diversity. Resolution is up to 1m. TOPSAR topographic data is achieved in an interferometric mode. TOPSAR digital elevation models (DEMs) have vertical resolutions as high as 1.5 m. These attributes are unique to AIRSAR. San Clemente Island, offshore southern California is used as an initial study site. Analysis of AIRSAR and TOPSAR data of San Clemente Island is underway. The high resolution TOPSAR DEM is extremely useful. Meter scale accuracy allows insight into water resources. Work to date on the radar imagery has shown that many sites are bright in radar images. The images thus act as target finders in identifying locations for field investigation. The response relates to native Americans collecting rocks surrounding habitation sites and using them for shelter foundations. Habitation sites also become preferential environments for vegetation. Present work includes trying to discriminate the vegetation types based on radar signatures. We are also incorporating other remote sensing data into the analysis including hyperspectral (AVIRIS and Hyperion), ASTER, and ALI. In summary, the remote sensing data shows promise of being a significant aid in the evaluation of cultural resources when incorporated into a GIS.