Executive Summary
The power parachute vehicle in flight.
New Philadelphia, Illinois was the first town platted and legally registered by an African American in the United States. Founded by Frank McWorter, a former slave, in 1836, this town grew as a demographically integrated community through the late nineteenth century. New Philadelphia was platted in a grid pattern with 42 acres of space, divided into 20 blocks, 144 lots, alleyways, and several streets. The town population reached a peak of approximately 160 people, 29 households, and merchant and crafts operations listed in the 1865 federal census. New Philadelphia was bypassed by a new railroad in 1869 and the population declined steadily thereafter. By 1885, the status of the community as a town was eliminated and large tracts of the land were put into agricultural use. Today, no structures from the town remain above ground, and the town site is covered by prairie grasses and agricultural fields.
A preliminary sample and excerpt of data results from the 2008 thermal survey, with potential anomalies highlighted
The National Center for Preservation Technology and Training (NCPTT) awarded funding of $14,800 to test the usefulness of low-altitude aerial surveys employing high resolution thermal imaging at New Philadelphia. This method was employed at the town site in 2008 for a new and specific purpose: determining whether this technology can detect the grid pattern of an historic town site buried beneath 1-2 feet of agricultural fields and prairie grasses. The success of this technique will provide an extremely useful resource for applications on numerous similar sites throughout the nation.
Dr. Tommy Hailey of Northwestern State University in Natchitoches, Louisiana, and Mr. Bryan Haley of the University of Mississippi, have pioneered the techniques used in combination in this survey, and they collected and processed the survey data utilizing a powered parachute ultralight aircraft and a high resolution thermal camera. The data sets were geo-referenced and integrated using spatial mapping programs, such as Geographic Information Systems software, and the creation of mosaic imaging representations. The survey results were then examined in relation to a geo-referenced version of the 1836 town plan and other comparative data. Dr. Christopher Fennell of the University of Illinois at Urbana-Champaign served as principal investigator and provided overall coordination of the project. Overall, the survey technique proved successful for identifying probable sub-surface locations of buried foundation remains within the 42-acre town site.
A map of electromagnetic, ground-based geophysics surveys conducted at New Philadelphia.
The chief difference between aerial photography and aerial survey is that whereas the former can include obliques and photographic reconnaissance, aerial survey is a very precise operation involving photogrammetry.