National High Altitude Photography and National Aerial Photography Program

Table of Contents

Background

The National High Altitude Photography (NHAP) program was initiated in 1980 and coordinated by the U.S. Geological Survey (USGS) to acquire aerial photography of the 48 conterminous states every five years. This interagency program was designed to eliminate duplicate efforts in various government programs and to maximize the use of government funds to build a uniform archive for multiple uses. In 1987 the program name was changed to the National Aerial Photography Program (NAPP) in recognition of modifications in the user requirements and flight specifications.

NHAP photography were acquired at 40,000 feet above mean terrain and flight lines were centered on the 1:24,000-scale USGS map series. Two different camera systems were used; a 6 inch focal length lens was used to acquire black-and-white film at an approximate scale of 1:80,000 and an 8.25 inch lens was used to acquire color-infrared film at an approximate scale of 1:58,000. A duel port camera system was used to acquire simultaneous coverage.

NAPP photography are acquired at 20,000 feet above mean terrain with a 6 inch focal length lens. The flight lines are quarter quad-centered on the 1:24,000-scale USGS maps. NAPP photographs have an approximate scale of 1:40,000, and are flown in black-and-white or color infrared, depending on state or federal requirements.

Examples of NAPP Photography

IMAGE Color Image of Boston Harbor (253 kb)

IMAGE B&W Image of Boston Harbor (180 kb)

Extent of Coverage

While it was the intent of both the NHAP and NAPP programs to acquire complete coverage of the conterminous United States every five years, that has varied somewhat due to budgetary constraints. Nevertheless, these programs do provide nearly complete coverage of the entire United States on a fairly regular basis. The next cycle of NAPP coverage is planned for 1997 - 2003.

Flight season, film type, and coverage requirements are negotiated each year based upon available funds from the contributing federal and state agencies and the operational requirements of those agencies. (A list of contributing federal agencies is included in the Appendix.)

IMAGE NAPP Seven Year Acquisition Plan 1997 - 2003 (70 kb)

IMAGE NAPP Second Cycle 1992 - 1996 (28 kb)

IMAGE NAPP First Cycle 1987 - 1991 (28.3 kb)

Data Characteristics

The NAPP/NHAP archive contains over 10,000 rolls of cartographic quality aerial photography acquired since 1980. On the average, 700 new rolls are acquired each year based upon a pre-determined flight schedule and season. All photographs are cloud free, and only contract-acceptable photographs are indexed to the map line plots. The photographic frames are maintained as original and working master archives by two support facilities, the EROS Data Center and the U.S. Department of Agriculture's Aerial Photographic Field Office (APFO).

All photographs are manually assessed to ensure that they meet the photographic, cartographic, coverage accuracy, and quality standards of each contract. Commercial flight contractors must meet a stringent list of acceptance criteria and provide proof of camera certification in order to fulfill contract requirements.

Spatial Resolution

The NAPP/NHAP film can be used to resolve objects as small as one to two meters in size. The photography can be manipulated to a variety of non-standard enlargements to generate products of desired scales.

NAPP and NHAP Black-and-White Scenes

Boulder, Colorado (NAPP 9/24/88) (25.5 kb)

Boston, Massachusetts (NHAP 4/17/85) (28.9 kb)

Charleston, South Carolina (NAPP 2/12/89) (23 kb)

Chicago, Illinois (NAPP 4/12/88) (28 kb)

Houston, Texas (NAPP 3/8/89) (26.1 kb)

Republic City, Nebraska (NHAP 5/24/81) (24.5 kb)

San Francisco, California (NHAP 8/16/82) (23.7 kb)

Smithfield, Utah (NAPP 7/24/87) (25.7 kb)

Three Mile Island, Pennsylvania (NAPP 9/04/87) (22.6 kb)

Washington, D.C. (NAPP 4/5/88) (37.1 kb)

Data Organization

The NAPP/NHAP photography are indexed using map line plots available on microfiche and supported by a data base that is maintained by the managing centers. User inquiries are answered through the use of these map plots. NAPP photography are indexed on 1:100,000-scale USGS maps while the NHAP frames are indexed on 1:250,000-scale USGS map sheets.

Data Availability

Procedures for Obtaining Data

To place orders and to obtain additional information regarding technical details and pricing schedules, contact one of the offices listed below:

Customer Services, EROS Data Center
Earth Science Information Centers (ESICs)
USDA Aerial Photography Field Office

Online requests for these data can be placed via the USGS Global Land Information System (GLIS) interactive query system. The GLIS system contains metadata and online samples of Earth science data. With GLIS, you may review metadata, determine product availability, and place online requests for products. The Federal Geospatial Data Content (FGDC) Metadata Standard documentation is available for the NAPP data set.

Products and Services

NAPP and NHAP coverage are available as standard photographic products. These products include the following:

NAPP Black-and-White (B&W) and Color-Infrared (CIR) Products

Standard Approximate Approximate Photographic Prod. B&W Scale CIR Scale 9-by-9 inch print 1:40,000 1:40,000 9-by-9 film neg. 1:40,000 1:40,000 9-by-9 film pos. 1:40,000 1:40,000 1:24,000-scale print 1:24,000 1:24,000 18-by-18 inch print 1:20,000 1:20,000 36-by-36 inch print 1:10,000 1:10,000

NHAP Black-and-White (B&W) and Color-Infrared (CIR) Products

Standard Approximate Approximate Photographic Prod. B&W Scale CIR Scale 9-by-9 inch print 1:80,000 1:58,000 9-by-9 film neg. 1:80,000 1:58,000 9-by-9 film pos. 1:80,000 1:58,000 18-by-18 inch print 1:40,000 1:29,000 1:24,000-scale print 1:24,000 1:24,000 36-by-36 inch print 1:20,000 1:14,400

Custom products are also available upon request for non-standard enlargements.

Applications and Related Data Sets

The NAPP archive is an invaluable source of high quality, cloud free, quad-based photography for the conterminous U.S. The photography can be integrated into Geographic Information Systems (GIS) as base images through high resolution scanners or they can be used to manually interpret land use, land cover, and feature changes when compared to other photography or satellite imagery acquired from earlier or later time periods.

References

U.S. Geological Survey, 1997, Aerial photography frequently asked questions (FAQs): Sioux Falls, South Dakota, EROS Data Center, electronic version, http://edc.usgs.gov/glis/hyper/news/aerialfaq.html

U.S. Geological Survey, 1992, The National Aerial Photography Program (NAPP), factsheet: Reston, Virginia, U.S. Geological Survey, 1 p.

U.S. Geological Survey, 1992, NHAP and NAPP photographic enlargements, factsheet: Reston, Virginia, U.S. Geological Survey, 1 p.

U.S. Geological Survey, 1991, The National Aerial Photography Program (NAPP), [brochure]: Reston, Virginia, U.S. Geological Survey, 2 p. [fold out]

Appendix

Federal Contributors

The following Federal agencies have contributed funds to NHAP/NAPP:

U.S. Department of Agriculture (USDA)

U.S. Department of Interior (DOI)

Tennessee Valley Authority (TVA)

Black-and-White Film Specifications

The black-and-white film emulsion shall be sensitive to red, green, and blue wave lengths (electromagnetic spectrum), and shall have an extended red sensitivity to approximately 720 to 750 nanometers. The film shall be exposed and processed to obtain a minimum density (D-min) of not less than 0.30 density units above base plus fog and a maximum (D-max) not in excess of 1.50 units above base plus fog. The aim point for density range is 1.0 density units for the average frame.

Color-Infrared Film Specifications

All color-infrared film shall be exposed and processed to the manufacturer's specifications. The CIR emulsion shall be sensitive to the visible and near infrared spectrum from 400 to 900 nanometers (electromagnetic spectrum).

Contract-Acceptable Flight Specifications

Flight specifications for the NHAP/NAPP program require that all photographs meet certain standards regardless of the geographic area involved. The sun angle is thirty percent or higher to reduce potential shadow effects on the ground. Cloud cover must be absent, and atmospheric haze must be minimal. Even seasonal factors such as the presence of snow on the ground, flooding, or the amount of foliage are considered prior to accepting the photography. The center point of each photograph must also fall within a 1,000 foot radius of a pre-determined position within the north-south flight lines. Camera tilt shall not exceed four degrees, nor average more than two degrees, in any ten mile section of a flight, nor average more than one degree for the entire flight contract.

Quarter Quad-Centered

The NAPP photographs are acquired over pre-determined exposure points within a 7.5 minute quadrangle map. The principal points of exposure divide the quad into quarter sections. Each section involves a 3.75 minute sub-quadrangle. The NAPP flight lines run north-south down the middle of these quarter-quads.

    |------ * ------|------ * ------|
    |       .       |       .       | \
    |       .       |       .       |  \
 .  |       *       |       *       |   \
/|\ |       .       |       .       |    \
 |  |       .       |       .       |     \
 N  |------ * ------------- * ------|      \ 7.5 minute
    |       .       |       .       |      / Quadrangle
    |       .       |       .       |     /  
    |       *       |       *       |    / * = pre-determined
    |       .       |       .       |   /      exposures
    |       .       |       .       |  /    
    |------ * ------|------ * ------| /    . = flight line
                                                 trace

Map Line Plots

The NAPP/NHAP photographs are indexed by using 1:100,000 or 1:250,000-scale USGS series maps. The center points, roll, and frame number of all accepted photographs are plotted on the maps. The maps are further annotated with project names, roll numbers and roll acquisition dates in the map margin. The resulting map line plot is then microfilmed and sleeved into microfiche jackets. The microfiche are duplicated and sent out to distribution sites and information offices as subscription catalogs. The microfiched map line plots are also sent out to answer coverage inquiries or paper blow-back copies are made upon request.