The first thing to outline is a definition of NAIP. NAIP - The National Agriculture Imagery Program is designed to collect aerial imagery during active agriculture season and deliver them to U.S. Department of Agriculture's Farm Service Agency (FSA). NAIP acquirement process is conducted by Aerial Photography Field Office (APFO) in Salt Lake City, Utah. According to available funding and FSA acquirement cycle, NAIP remote sensing research is to be contracted every year.
It all started in 2003 with a 5-year cycle, then in 2009 it became a 3-year cycle. First imagery was acquired with film cameras, but 2008 became a transition year to digital sensors. The program results into orthoimagery of 1-meter ground sample resolution, with a horizontal accuracy to match within six meters of photo-identifiable ground control points.
NAIP imagery products can be obtained as digital ortho quarter quad tiles (DOQQs) or as compressed county mosaics (CCM). The area for DOQQs corresponds to the USGS topographic quadrangles. A separate image tile is a 3.75-minute longitude by 3.75-minute latitude quarter quadrangle with a 300-meter buffer on four sides. To generate CCMs, DOQQ image tiles are compressed in one mosaic. All the obtained tile images and the mosaic are rectified in the UTM coordinate system, NAD 83, and submitted in a single predetermined UTM zone.
Before 2007 the default spectral resolution was RGB (red, green, blue), but since then there has been an imagery delivered with four bands of data: natural color (RGB) and near infrared color. The images are orthorectified so they combine aerial photograph characteristics and the georeferenced maps qualities.
Image Sample:A full NAIP scene; location: Major County, Oklahoma State, USA, 2017
How to obtain imagery:
CCMs can be get 45 days after the end of the program through USDA Geospatial Data Gateway. Imagery can be downloaded for free as ½, 1, or 2 meter CCMs, depending on the original spatial resolution. It corresponds to file sizes less than 8 GB, in case the size exсeeds, they can be obtained through APFO (Aerial Photography Field Office) Customer Service Section.
DOQQs are delivered to APFO within 30 days after the end of an acquisition period. The natural color format imagery can be get from the public web service, and the four band DOQQs are to be purchased, on drives or hard copies.
Purchase of CCMs and DOQQs can be done through an order on APFO website. NAIP DOQQs might also be added into a GIS project and viewed with APFO’s ArcGIS service, by WMS (Web Mapping Services) users only.
The initial goal objective of the NAIP program appears to be an acquisition of digital orthophotography to be used by governmental agencies or public users. The results can be helpful for:
agriculture: federal farm programs support, certification, acreage reporting, draught or flooded areas determination, land classification or irrigation zones definition and schedule, for forest management decision-making, farm modeling, soil science, yield analysis.
external programs: Activities of Conservation Reserve Program (CRP) and Common Land Unit (CLU)
generic purposes: education, public health and safety, environmental change detection, 3d modeling, hydrology, real estate or land sales, engineering and landscape architecture applications development, infrastructure maintaining, wildlife predictions.
From 2019 fiscal year FSA is going to consider a program change, offering to switch from a public domain program to a Commercial off-the-shelf (COTS) licensing model.