For more than 80 years, archeologists have used aerial images to study archeological sites, but traditional methods of acquiring these images have been limited in their uses.
This spring, NCPTT is funding a study using powered parachutes (PPC) as an alternate way to gather aerial photos of archeological sites.
The study's director, Dr. Tommy Hailey of the Northwestern State University Cultural Research Office in Natchitoches, Louisiana, will be the first to take to the air to assess the suitability of the powered parachute as an archeological aerial reconnaissance vehicle.
Current technologies such as tethered inflatable balloons and radio-controlled aircraft are limited by the length of rope tethers or the range of the radio transmitter. Satellites and high-altitude aircraft are not restricted geographically, but high altitudes and forward movement of the aircraft or satellite can produce blurred images or insufficient resolution to identify many archeological features or sites. In addition, the cost of renting aircraft or hiring professional surveyors to conduct aerial reconnaissance is beyond the financial means of many projects.
The PPC offers the potential to overcome these limitations as a cost-effective means of acquiring large-scale, high-resolution aerial images, combined with unlimited geographic mobility. It is inexpensive to operate, costing only about $5.75 per hour for fuel and oil. It can fly at altitudes from ten to 3,000 meters at speeds of 28-30 miles per hour, providing the low altitude and low velocity necessary for large-scale, high resolution images. In addition, it can operate two to three hours on one tank of fuel, affording the geographic mobility needed to survey large areas for previously undiscovered sites.
During the course of the project, the stability of the PPC as a camera platform will be a major consideration. Effects of the design characteristics of the aircraft, wind, and turbulence on data acquisition will be evaluated by performing visual and computer analyses of aerial images for clarity and consistency.
Two types of archaeological aerial reconnaissance will be conducted: the investigation of known sites and the survey of a larger area for previously undiscovered sites.
Known sites to be included in the project - the eighteenth century Spanish presidio of Nuestra Senora del Pilar de los Adaes, and Fort Jesup, a major nineteenth-century American frontier post - are subjects of ongoing archeological investigations, including geophysical survey and excavation. These investigators will provide a comparative database to assist in the evaluation of the results of the project.
The larger survey area, in the Cane River National Heritage Area to the south of Natchitoches, was selected primarily because, as an area largely under cultivation, it offers an ideal setting for locating archeological resources from the air. Images will be acquired with digital still photography, digital videography, and thermal imaging in order to evaluate the efficiency of the PPC in acquiring data in a number of different formats currently in use by archeologists. Flights will be made throughout the year so that effects of changing seasonal vegetation on locating archeological sites and defining prehistoric and historic site signatures will be possible.
The potential importance of the PPC to the archeological and historic preservation communities is obvious, but the value of this project transcends archeological applications, to include almost any area of research that requires aerial reconnaissance. Foresters, geomorphologists, geographers, cultural anthropologists, geologists, and agricultural scientists have and do make use of remote sensing data, and all of these disciplines could benefit from this technology.
With the success of this project, a new research technique of great value to a wide range of disciplines and applicable in virtually any geographic setting will have been opened up to the scientific community. It is conceivable that, in years to come, any scientist planning fieldwork will consider benefits of, and will incorporate into his or her research design, a program of aerial reconnaissance using a powered parachute.