This Working Group for Orthophotography Planning is responsible for developing plans and seeking sources of funding to assist counties and state agencies in acquiring high resolution imagery. High-resolution color orthophotography (half-foot or one-foot pixel resolution) is used extensively by local and state government agencies. It is flown during the winter months to achieve better ground visibility (leaf-off conditions). The Working Group develops procedures for the distribution of this aerial imagery within a network of state government agencies.
The current Chair is Gary Thompson (919.733.3836).
Statewide Imagery Project
In 2010, the NC 911 board funded the acquisition and delivery of high resolution orthoimagery for all 100 counties. The exciting outcome of this project is that consistent high resolution imagery is now available for the entire state for the first time ever. The data are now available through the NC OneMap Geospatial Portal. Funding is now available to continue the program with acquisition of one-fourth of the state in 2012 as the beginning of the next four-year phase.
Business Plan for Orthoimagery in North Carolina
The Working Group for Orthophotography Planning released the North Carolina Orthoimagery Business Plan to support the coordinated acquisition in future years of a seamless statewide imagery dataset of standardized quality, resolution, age, and format. The GICC reviewed the plan at its November 10, 2010 meeting.
Using Color Infrared Imagery. In 2011 the Working Group for Orthophotography Planning produced a guide for understanding, interpreting and benefitting from color infrared imagery. The paper provides technical insight into CIR imagery and the many useful appliations that it serves.
NAD 27 to NAD 83 Conversion. In 1986 the National Geodetic Survey officially adopted a redefined horizontal control network for North America. The North America Datum for 1983 (NAD 83) replaced the earlier version (NAD 27). In North Carolina, the State Legislature later updated the general statute on the State’s Official Survey Base, to be based on NAD 83. The Working Group for Orthophotography Planning recently prepared an issue paper, adopted by the SMAC, with background and guidelines for converting and referencing mapping and photogrammetry products and the resulting coordinate-based Parcel Identification Number (PIN) determinations from NAD 27 to NAD 83.
New Technical Specifications for NC Orthophotos. The “Technical Specifications for Base, Cadastral and Digital Mapping (Orthophotos),” developed by the North Carolina Land Records Management Program, has been revised and adopted as the official standard for digital orthophotography. The Geographic Information Coordinating Council adopted the revised standard on August 12, 2009, and the Office of the Secretary of State declared it the official standard for all county and municipal mapping projects on October 1, 2009.
The US Department of Agriculture also flies color orthophotography (one-meter pixel resolution) to capture crop and agricultural conditions in the summer. North Carolina partnered with USDA for a 2008 summer flight by the National Agriculture Imagery Program (NAIP). Compressed images, by county mosaic, are now available from the NC Department of Agriculture and Consumer Services. Contact Dan Madding. To understand “best practices” for the NAIP program image processing, consult this document.
Large-format digital camera technology is rapidly replacing the large-scale aerial imagery previously captured by aerial film collection. The current North Carolina Land Record Specifications were created for and are related to aerial film collection of orthophotography. A White Paper prepared by the Orthophotography Planning Work Group and presented to the Geographic Information Coordinating Council in August 2008 presents the differences between film and digital collection of that photography. Read more. To see the photographic differences from the two types of cameras, click here.
To learn more about modern photogrammetry, here are two PowerPoints prepared by the NC Department of Transportation: Photogrammetry Workshop: Basics of Modern Photogrammetry (Oct 2007), and the 2008 Review Officers Workshop.
History of Cost Share Programs for Orthophotography
Review the History of cost share programs for acquiring orthophotography in North Carolina.