Data Management Plan

This data set contains polygons delineating the seamline

boundaries of imagery acquired as part of the

National Agriculture Imagery Program (NAIP), and used in

the creation of DOQQs and compressed county mosaics

(CCM). These seam polygons can be used as a

tool in determining the image source and date of each

portion of the DOQQ or the CCM. The NAIP acquires

4 band digital ortho imagery from airborne and/or space

based platforms during the agricultural growing seasons

in the U.S.. A primary goal of the NAIP program is to enable

availability of ortho imagery within sixty days of acquisition.

The NAIP provides 1 meter or 1/2 meter GSD ortho imagery rectified

within +/- 6 meters to true ground at a 95% confidence level.

The tiling format of NAIP imagery is based on a 3.75' x 3.75'

quarter quadrangle with a 300 (plus or minus 30) pixel buffer

on all four sides. The NAIP quarter quads are formatted to

the UTM coordinate system using the North American Datum

of 1983 (NAD83).

Process Steps:

• 2015-12-18 00:00:00 - The imagery was collected using the following digital sensors: Leica ADS-100 (Serial Number 10529) Leica ADS-100 (Serial Number 10547) Leica ADS-100 (Serial Number 10548) with Flight and Sensor Control Management System (FCMS) firmware 4.40 and Leica ADS-80SH82 (Serial Number 1301) Leica ADS-80SH81 (Serial Number 1318) with Flight and Sensor Control Management System (FCMS) firmware 3.38. Cameras are calibrated radiometrically and geometrically by the manufacturer and are all certified by the USGS. Collection was performed using a combination of the following twin-engine aircraft: Turbines flying at 16,500 ft above mean terrain (tail number: AC90 N910FC) (tail number: C402 N246MP) (tail number: PA31 N35AS) (tail number: PAY2 N400CM) With these flying heights, there is a 23% sidelap, giving the collected data nominal ground sampling distance of 0.40 meters at 16,500. Based-upon the CCD Array configuration present in the ADS digital sensor, imagery for each flight line is 12,000-pixels in width. Red, Green, Blue, Near-Infrared and Panchromatic image bands were collected. The ADS 100 has the following band specifications: Red 619-651 Green 525-585 Blue 435-495 Near Infrared 808-882 all values are in nanometers The ADS 80 has the following band specifications: Pan 465-676 Red 604-664 Green 533-587 Blue 420-492 Near Infrared 833-920 all values are in nanometers Collected data was downloaded to portable hard drives and shipped to the processing facility daily. Raw flight data was extracted from external data drives using XPro software. Airborne GPS / IMU data was post-processed using INYS, PosPac and/or TerraPos software and reviewed to ensure sufficient accuracy for project requirements. Using XPro software, planar rectified images were generated from the collected data for use in image quality review. The planar rectified images were generated at five meter resolution using a two standard deviation histogram stretch. Factors considered during this review included but were not limited to the presence of smoke and/or cloud cover, contrails, light conditions, sun glint and any sensor or hardware-related issues that potentially could result in faulty data. When necessary, image strips identified as not meeting image quality specifications were re-flown to obtain suitable imagery.
• 2015-12-18 00:00:00 - Aero triangulation blocks were defined primarily by order of acquisition and consisted of four to seventeen strips. Image tie points providing the observations for the least squares bundle adjustment were selected from the images using an auto correlation algorithm. Photogrammetric control points consisted of photo identifiable control points, collected using GPS field survey techniques. The control points were loaded in to a softcopy workstation and measured in the acquired image strips. A least squares bundle adjustment of image pass points, control points and the ABGPS was performed to develop an aero triangulation solution for each block using Pictovera software. Upon final bundle adjustment, the triangulated strips were ortho-rectified to the digital elevation model (DEM) The most recent USGS 10 meter DEMs were used in the rectification process. Positional accuracy was reviewed in the rectified imagery by visually verifying the horizontal positioning of the known photo-identifiable survey locations using ArcGIS software. The red, green, blue, and infrared bands were combined to generate a final ortho-rectified image strip. The ADS sensor collects twelve bit image data which requires radiometric adjustment for output in standard eight bit image channels. The ortho-rectified image strips were produced with the full 12 bit data range, allowing radiometric adjustment to 8 bit range to be performed on a strip by strip basis during the final mosaicking steps. The 12 bit data range was adjusted for display in standard eight bit image channels by defining a piecewise histogram stretch using OrthoVista Radiometrix software. A constant stretch was defined for each image collection period, and then strip by strip adjustments were made as needed to account for changes in sun angle and azimuth during the collection period. Strip adjustments were also made to match the strips histograms as closely as possible to APFO specified histogram metrics and color balance requirements. Automated balancing algorithms were applied to account for bi- directional reflectance as a final step before the conversion to 8 bit data range. The imagery was mosaicked using manual seam line generation in OrthoVista. APFO specified DOQQs were extracted from the final mosaic in GeoTIFF format. 4-Band DOQQs were produced and 3-Band RGB CCMs were created. DOQQs corresponding to an individual CCM were reviewed for overall color balance within the CCM. Local corrections were made where necessary to ensure uniformity within the CCM. In the case of DOQQs occurring in more than one CCM, a separate version of the image was generated and balanced for each CCM it occurred in. The color balanced DOQQs were then compressed to MrSID Generation 3 format at 15:1 compression ratio to create a composite CCM.