USGS Data Series 932: Geospatial Compilation and Digital Map of Center-Pivot Irrigated Areas in the Mid-Atlantic Region, United States

Table 1. Dates and sources of aerial imagery used for digitizing crop circles.

[See figure 1 for State locations. NAIP, National Agricultural Imagery Program; USDA, U.S. Department of Agriculture; APFO, Aerial Photography Field Office]

State	Year of imagery (NAIP)
Delaware	NAIP not used. Obtained vector shapefile from the University of Delaware.
Maryland	2011—USDA–APFO
New Jersey	2010—USDA–APFO
New York	2011—USDA–APFO
North Carolina	2012—USDA–APFO
Pennsylvania	2010—USDA–APFO
Virginia	2012—USDA–APFO

Prepared in cooperation with the University of Delaware Agricultural Extension

Geospatial Compilation and Digital Map of Center-Pivot Irrigated Areas in the Mid-Atlantic Region, United States

By Jason S. Finkelstein and Mark R. Nardi

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