National Agriculture Imagery Program (NAIP)

The National Agriculture Imagery Program (NAIP) is administered by the U.S. Department of Agriculture's Farm Service Agency (FSA) through the Aerial Photography Field Office (APFO) in Salt Lake City, Utah. NAIP acquires aerial imagery at a resolution of 1-meter ground sample distance (GSD) for the United States during the agricultural growing season, or leaf on conditions. The images are orthorectified which combines the image characteristics of an aerial photograph with the georeferenced qualities of a map.

NAIP projects are contracted each year based upon available funding and the FSA acquisition cycle. The program began with a 5-year cycle in 2003 then switched over to a 3-year cycle in 2009, with 2008 being a transition year.

Each individual image tile is based on a 3.75-minute longitude by 3.75-minute latitude quarter quadrangle plus a 300-meter buffer on all four sides. Tiles in the NAIP collection are natural color (red, green, and blue bands) or color near infra-red (red, green, blue, and near infrared bands) and may contain as much as 10 percent cloud cover per tile.

The U.S. Geological Survey (USGS) Earth Resources Observation and Science (EROS) Center distributes NAIP products in GeoTIFF and JPEG2000 format. The JPEG2000 format is a compressed file with embedded georeferencing information. The 10:1 lossy compression makes the file size smaller by reorganizing the data, but it also slightly degrades the imagery.

NAIP quarter quads are projected to the Universal Transverse Mercator (UTM) coordinate system and referenced to NAD83. Compressed data in the JPEG 2000 format acquired after 2013 are referenced to WGS84 and utilize the WGS 1984 Web Mercator Auxiliary Sphere projection.

APFO has stringent imagery compliance guidelines, and all deliverables are inspected using automated and visual methods to ensure accuracy and compliance with specifications. NAIP transitioned to an absolute accuracy specification beginning in 2006, which tied the imagery to ground control points rather than existing orthorectified imagery. Contracts mandate that all well-defined points tested shall fall within 6 meters of true ground at a 95% confidence level. Beginning in 2009, all states flown adhered to this specification.