Datasets / ORTHOIMAGERY, Calvert County, MD


ORTHOIMAGERY, Calvert County, MD

Published By Federal Emergency Management Agency, Department of Homeland Security

Issued about 9 years ago

US
beta

Summary

Type of release
ongoing release of a series of related datasets

Data Licence
Not Applicable

Content Licence
Creative Commons CCZero

Verification
automatically awarded

Description

This data set contains imagery from the National Agricultural Imagery Program (NAIP). NAIP acquires digital ortho imagery during the agricultural growing seasons in the continental U.S.. A primary goal of the NAIP program is to enable availabilty of ortho imagery within a year of acquisition. NAIP provides two main products: 1 meter ground sample distance (GSD) ortho imagery rectified to a horizontal accuracy of within +/- 5 meters of reference digital ortho quarter quads (DOQQS) from the National Digital Ortho Program (NDOP); and, 2 meter GSD ortho imagery rectified to within +/- 10 meters of reference DOQQs. The tiling format of NAIP imagery is based on a 3.75' x 3.75' quarter quadrangle with a 300 meter buffer on all four sides. NAIP quarter quads are rectified to the UTM coordinate system NAD83 and cast into a single predetermined UTM zone. NAIP imagery can obtain as much as 10% cloud cover per tile. This file was generated by compressing NAIP digital quarter quadrangle image tiles either natural color positive or color infrared positive source imagery into a single mosaic. The mosaic may cover all or portions of an individual county. MrSid software compression, with mosaic option, was used to create the final product. Target values for the compression ratio are (15:1) and the maximum N-levels are used. All digital products and the underlying source images were produced through the National Agriculture Imagery Program (NAIP). The primary purpose of the mosaicked digital ortho quarter quads is to support USDA Field Service Centers located in counties throughout the United States.