National Geodetic Survey's Airport Aerial Photography

The National Geodetic Survey (NGS), formerly part of the U.S. Coast and Geodetic Survey, has been performing Aeronautical surveys since the 1920's. NGS, in accordance with a series of interagency agreements with the Federal Aviation Administration (FAA), provides airport geodetic control, runway, navigational aid, obstruction and other aeronautical data that is critical to the operation of the National Airspace System (NAS). The FAA uses the data to develop instrument approach and departure procedures, determine maximum takeoff weights, update aeronautical publications, and airport planning and engineering studies.Most of this data is source information obtained using field and photogrammetric survey methods. NGS acquires aerial photography of most commercial and many general aviation airports in the United States to support several types of aeronautical surveys, including Airport Obstruction Chart (AOC), Operational Evolution Plan (OEP), and Congressional (CGR) and, until recently, Area Navigation Approach (ANA). The high resolution photographs are used to perform a photogrammetric analysis of the Obstruction Identification Surface (OIS), determine areas obstructing the OIS, delineate aircraft movement areas and associated airport features, and are useful when performing ground surveys. Over 1,000 airports have been flown and photographs for these locations are currently available through the NGS photo library.

The National Geodetic Survey (NGS) provides position, height, and orientation information needed for safe navigation of the National Airspace System (NAS). These surveys provide critical information about runway, aids to navigation, obstructions and airport features. The Federal Aviation Administration uses the data to establish airport approach and departure procedures, determine maximum takeoff weights, update aeronautical publications, and airport planning and construction studies.

1293

Photo reproductions (prints, film positives, and negatives) are custom processed and cannot be returned for credit or refund. This includes customer-misordered reproductions.

Digital copies of photographs can be scanned at varying resolutions (100 dpi to 1200 dpi).; Please describe the area of interest by latitude and longitude, a detailed description or sketch, or by the photograph number.;

None

These photographs were obtained for use by NGS during the course of its development of potential final products to fulfill its statutory mission. Although NGS is making these photographs available to others who may find the photographs of value, NGS does not warrant, endorse, or recommend the use of these photographs for any given purpose. NGS is providing these photographs "as is," and NGS disclaims any and all warranties, whether expressed or implied, including (without limitation) any implied warranties of merchantability or fitness for a particular purpose. In no event will NGS be liable to you or any third party for any direct, indirect, incidental, consequential, special or exemplary damages or lost profits resulting from any use or misuse of these data.

The primary aerial photographic product is a 9x9 inch print which is usually exposed at a 1:30,000 scale, varying slightly due to shrinkage or expansion of the paper due to atmospheric conditions, slight variations in the altitude of the plane during flying, tip and tilt of the airplane, camera optics, and the effects of ground relief.Over the years, the image resolution capabilities and spectral quality of aerial films have advanced, and so have camera systems, photogrammetric instruments, and processes. These photographs are of metric quality for mapping purposes. The most current photogrammetric processing techniques need to be used. Documenting the process used to minimize the effects due to scale variations and optical distortions allows the user of the data obtained from photographs to determine its accuracy.

The photographs adequately represented ground truth at the time they were obtained. These photographs have not been processed to reduce the errors inherent in the photogrammetric technique.

These photographs are being presented "as is". They have undergone no processing to reduce the errors that are inherent in the photogrammetric techniques. These photographs should be assumed to have errors due to scale variation and optical distortions.