| Section 1 | Overview | |||
| Originator | U.S. Department of Agriculture (USDA), Farm Service Agency (FSA), Aerial Photography Field Office (APFO) | |||
| Title | National Agricultural Imagery Program (NAIP), Minnesota, 2013, Digital Orthorectified Images (DOQ) | |||
| Abstract | This data set contains 4-band natural color and false color infrared imagery from the National Agricultural Imagery Program (NAIP). NAIP acquires digital ortho imagery during the agricultural growing seasons in the continental U.S. A primary goal of the NAIP program is to enable availability of ortho imagery within one year of acquisition.
The source files are 1 meter ground sample distance (GSD) ortho imagery rectified to a horizontal accuracy of within +/- 6 meters of reference digital ortho quarter quads (DOQQ's) from the National Digital Ortho Program (NDOP) or from NAIP. The tiling format of NAIP imagery is based on a 3.75' x 3.75' quarter quadrangle with a 300 meter buffer on all four sides. NAIP imagery is formatted to the UTM coordinate system using NAD83. NAIP imagery may contain as much as 10% cloud cover per tile. The natural color county mosaic files downloadable from the USDA NRCS Geospatial Data Gateway were generated by compressing NAIP imagery that cover the county extent. MrSID compression was used. Target values for the compression ratio are (15:1). (Note: The Minnesota Geospatial Information Office (MnGeo) has created this metadata record to describe the entire NAIP 2013 dataset, using information from Farm Service Agency metadata. Each natural color county file available from the USDA NRCS Geospatial Data Gateway is accompanied by the original FSA metadata for that county.) | |||
| Purpose | NAIP imagery is available for distribution within 60 days of the end of a flying season and is intended to provide current information of agricultural conditions in support of USDA farm programs. For USDA Farm Service Agency, the 1 meter GSD product provides an ortho image base for Common Land Unit boundaries and other data sets. The 1 meter NAIP imagery is generally acquired in projects covering full states in cooperation with state government and other federal agencies who use the imagery for a variety of purposes including land use planning and natural resource assessment. NAIP is also used for disaster response often providing the most current pre-event imagery. | |||
| Time Period of Content Date | 2013 | |||
| Currentness Reference | Summer and Fall 2013. See the IDATE attribute in the accompanying seamline shapefile for each county to find out the date(s) that the source imagery was acquired. | |||
| Progress | Complete | |||
| Maintenance and Update Frequency | Irregular | |||
| Spatial Extent of Data | Minnesota | |||
| Bounding Coordinates | -97.5 -89.00 49.5 43.0 | |||
| Place Keywords | Minnesota, MN | |||
| Theme Keywords | imageryBaseMapsEarthCover, Digital Orthorectified Image, Digital Orthophoto Quad, Ortho, Orthophoto, DOQ, NAIP, Compliance, Air Photo, Air Photography, Aerial Photo, Aerial Photography | |||
| Theme Keyword Thesaurus | ISO 19115 Topic Category | |||
| Access Constraints | None | |||
| Use Constraints | The Aerial Photography Field Office asks to be credited in derived products.
If defects are found in the NAIP imagery during the warranty period such as horizontal offsets, replacement imagery may be provided. Imagery containing defects that require the acquisition of new imagery, such as excessive cloud cover, specular reflectance, etc., will not be replaced within a NAIP project year. Redistribution conditions: In obtaining this data from MnGeo, it is understood that you and/or your organization have the right to use it for any purpose. If you modify it, you are encouraged to apply responsible best practices by documenting those changes in a metadata record. If you transmit or provide the data to another user, it is your responsibility to provide appropriate content, limitation, warranty and liability information as you see fit. | |||
| Contact Person Information | ,
USDA-FSA-APFO Aerial Photography Field Office 2222 West 2300 South Salt Lake City, UT 84119 Phone: 801-844-2922 Fax: 801-956-3653 Email: apfo.sales@slc.usda.gov | |||
| Browse Graphic | None available | |||
| Associated Data Sets | A shapefile, with its associated metadata, is included with the compressed county mosaic datasets downloadable from the USDA NRCS Geospatial Data Gateway. It shows seamline polygons delineating the boundary between DOQQ imagery used in the creation of the county NAIP file and attributes such as the source date of the imagery. All the seamline shapefiles for Minnesota's 87 counties may also be downloaded in one zipfile from MnGeo's website. For more information, see: http://www.mngeo.state.mn.us/chouse/metadata/naip13_date.html
For information on other air photos available for Minnesota, including other years of NAIP imagery, see http://www.mngeo.state.mn.us/chouse/airphoto/index.html | |||
| Section 2 | Data Quality | |||
| Attribute Accuracy | NAIP imagery may contain as much as 10% cloud cover per tile. | |||
| Logical Consistency | N/A | |||
| Completeness | No report. | |||
| Horizontal Positional Accuracy | FSA Digital Orthophoto Specs. The quarter-quad files are 1 meter ground sample distance (GSD) ortho imagery rectified to a horizontal accuracy of within 6 meters of absolute ground control ("true ground") rather than reference imagery. | |||
| Vertical Positional Accuracy | N/A | |||
| Lineage | Digital imagery was collected at a nominal GSD of 1.0m using seven Cessna 441 aircrafts flying at an average flight height of 9052m above ground level (AGL). All aircraft flew with Leica Geosystem's ADS80/SH82 digital sensors with firmware 3.20 or newer. Each sensor collected 11 image bands. PanF27A, PanF02A and PanB14A panchromatic bands with a spectral range of 465-676nm. RedN00a and RedB16a with a spectral range of 604-664nm. GrnN00a and GrnB16a with a spectral range of 533-587nm. BluN00a and BluB16a with a spectral range of 420-492nm and Near-infrared bands NirN00a and NirB16a with a spectral range of 833-920nm. The CCD (charge-coupled device) arrays have a pixel size of 6.5 microns in a 12000x1 format. Both the CCD's and the A/D convertors have a dynamic range of 12bits. The data is stored in 16bit format. The ADS is a push-broom sensor and the ground footprint of the imagery at NAIP scale is 12km wide by the length flightline. The maximum flightline length is limited to approximately 240km. The factory calibrations and IMU (Internal Measurement Unit) alignments for each sensor (Serial Numbers: 1321, 1413, 1420, 30012, 30017, 30022, 30034, and 30110) were tested and verified by in-situ test flights before the start of the project. The Leica ADS Flight Planning and Evaluation Software (FPES) is used to develop the flight acquisition plans.
Flight acquisition sub blocks are designed first to define the GNSS (Global Navigation Satellite System) base station logistics, and to break the project up into manageable acquisition units. The flight acquisition sub blocks are designed based on the specified acquisition season, native UTM zone of the DOQQs, flight line length limitations (to ensure sufficient performance of the IMU solution) as well as air traffic restrictions in the area. Once the sub blocks have been delineated they are brought into FPES for flight line design. The design parameters used in FPES will be 30% lateral overlap and 1.0m resolution. The flight lines have been designed with a north/south orientation. The design takes into account the latitude of the state, which affects line spacing due to convergence as well as the terrain. SRTM elevation data is used in the FPES design to ensure the 1m GSD is achieved over all types of terrain. The raw data was downloaded from the sensors after each flight using Leica XPro software. The imagery was then georeferenced using the 200Hz GPS/INS data creating an exterior orientation for each scan line (x/y/z/o/p/k). Technicians precisely measured tie points in 3 bands/looks (Back/Nadir/Forward) for each line using Leica Xpro software. The resulting point data and exterior orientation data were used to perform a full bundle adjustment with ORIMA software. Blunders were removed, and additional tie points measured in weak areas to ensure a robust solution. Once the point data was clean and point coverage was acceptable, photo-identifiable GPS-surveyed ground control points were introduced into the block adjustment. The bundle adjustment process produces revised exterior orientation data for the sensor with GPS/INS, datum, and sensor calibration errors modeled and removed. Using the revised exterior orientation from the bundle adjustment, orthorectified image strips were created with Xpro software and the April 2013 USGS 10m NED (National Elevation Dataset) DEM. The Xpro orthorectification software applies an atmospheric-BRDF radiometric correction to the imagery. This correction compensates for atmospheric absorption, solar illumination angle and bi-directional reflectance. The orthorectified strips were then overlaid with each other and the ground control to check accuracy. Once the accuracy of the orthorectified image strips were validated the strips were then imported into Inpho's OrthoVista 4.6 package which was used for the final radiometric balance, mosaic, and DOQQ sheet creation. The final DOQQ sheets, with a 300m buffer and a ground pixel resolution of 1m were then combined and compressed to create the county wide CCMs. | |||
| Section 3 | Spatial Data Organization (not used in this metadata) | |||
| Section 4 | Coordinate System | |||
| Horizontal Coordinate Scheme | Universal Transverse Mercator | |||
| UTM Zone Number | 15 | |||
| Horizontal Datum | NAD83 | |||
| Horizontal Units | meters | |||
| Cell Width | 1 | |||
| Cell Height | 1 | |||
| Section 5 | Attributes | |||
| Overview | Imagery has 32-bit pixels, 4 band color (RGBIR) represent brightness values 0 - 255. | |||
| Detailed Citation | None | |||
| Table Detail: | ||||
| Section 6 | Distribution | |||
| Publisher | U.S. Department of Agriculture | |||
| Publication Date | 10/30/2013 | |||
| Contact Person Information | Nancy Rader,
GIS Data Coordinator Minnesota Geospatial Information Office (MnGeo) 658 Cedar Street St. Paul, MN 55155 Phone: 651-201-2489 Email: gisinfo.mngeo@state.mn.us | |||
| Distributor's Data Set Identifier | NAIP 2013 | |||
| Distribution Liability | 1. FSA Liability Statement: In no event shall the creators, custodians, or distributors of this information be liable for any damages arising out of its use (or the inability to use it).
2. MnGeo's data disclaimer is online: http://www.mngeo.state.mn.us/chouse/disclaimer.html | |||
| Ordering Instructions | The imagery is available free online by clicking below after Online Linkage. This link will take you to a webpage that contains direct links to:
1. View the files seamlessly via a WMS service without having to download the files. They are available as two separate layers: a natural color version and a color infrared version. 2. Download each county file in MrSID format (natural color only, does not include color infrared Band 4) and accompanying seamline shapefile from the U.S. Dept. of Agriculture, Natural Resources Conservation Service's Geospatial Data Gateway site: http://datagateway.nrcs.usda.gov 3. To obtain just the seamline shapefiles (1 per county) that include the date that the photos were flown, see: http://www.mngeo.state.mn.us/chouse/metadata/naip13_date.html | |||
| Online Linkage | I AGREE to the notice in "Distribution Liability" above. Clicking to agree will either begin the download process, link to a service, or provide more instructions. See "Ordering Instructions" above for details. | |||
| Section 7 | Metadata Reference | |||
| Metadata Date | 10/24/2014 | |||
| Contact Person Information | Nancy Rader,
GIS Data Coordinator Minnesota Geospatial Information Office (MnGeo) 658 Cedar Street St. Paul, MN 55155 Phone: 651-201-2489 Email: gisinfo.mngeo@state.mn.us | |||
| Metadata Standard Name | Minnesota Geographic Metadata Guidelines | |||
| Metadata Standard Version | 1.2 | |||
| Metadata Standard Online Linkage | http://www.mngeo.state.mn.us/committee/standards/mgmg/metadata.htm | |||