USDA-FSA-APFO20171122USDA-FSA-APFO Digital Ortho MosaicSalt Lake City, UtahUSDA_FSA_APFO Aerial Photography Field OfficeThis data set contains imagery from the National
Agriculture Imagery Program (NAIP). The 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 NAIP provides two main products: 1 meter
or 60cm GSD ortho imagery rectified within +/- 4
meters to true ground. The tiling format of NAIP imagery is
based on a 3.75' x 3.75' quarter quadrangle with a 300
pixel buffer on all four sides. The NAIP imagery is
formatted to the UTM coordinate system using the North
American Datum of 1983 (NAD83). The NAIP imagery may
contain as much as 10% cloud cover per tile. This file
was generated by compressing NAIP imagery that covers
the county extent. Two types of compression may be
used for NAIP imagery: MrSID and JPEG 2000. The target
value for the compression ratio is 15:1 for the 1 meter
imagery and 60:1 for the 60cm imagery.The NAIP imagery is typically 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 and 60cm GSD product provides an
ortho image base for Common Land Unit boundaries and other
data sets. The 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. The NAIP is
also used for disaster response often providing the most
current pre-event imagery.20171122Photography Source Image Dates.Irregular-90.965560-90.27656345.07827044.361541NonefarmingDigital Ortho Rectified ImageMosaicQuarter QuadrangleOrtho RectificationCompressionMrSIDJPEG 2000NAIPComplianceAerial ComplianceGeographic Names Information SystemClark CO., WI FSAFIPS 55019ClarkWisconsinThere are no limitations for access.None, The USDA-FSA Aerial Photography Field Office asks to
be credited in derived products.
If defects are found in the NAIP imagery during the 1 year
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.USDA-FSA Aerial Photography Field Officemailing and physical address2222 West 2300 SouthSalt Lake CityUtah84119-2020USA801-844-2922801-956-3653apfo.sales@slc.usda.govNoneNoneNoneNAIP 3.75 Quarter Quadrangles mosaicked into a County format
using data compression software. The target values for the
compression ratio are 15:1 for the 1 meter imagery and 60:1
for the 60 centimeter imagery.NAIP 3.75 minute tile file names are based
on the USGS quadrangle naming convention.NoneNAIP SpecificationsN/A 2d onlyUSDA-FSA Aerial Photography Field Office20171122Clark CO., WI FSA12000External Media Types20171122Majority Aerial Photography DateMrSID Compressed ImageMosaicked County ImageFlight planning was performed in Leica MissionPro over a
buffered boundary covering DOQQ extents provided by the
USDA. A 500m reduced resolution DEM file was used to
determine ground heights. A targeted flight altitude of
approximately 16,000 feet above ground level for
acquisition with sidelap of 27% was used for flight
planning parameters. Five Cessna Conquests and a Cessna
414 were utilized for acquisition, the seamline
shapefile clarifies which aircraft were used for a given
area. All aircraft were equipped with Leica ADS100
systems for data capture. The Leica ADS100 pushbroom
sensor has been calibrated by the manufacturer as well
as validated against a local calibration range.
The calibration includes measuring the radiometric and
geometric properties of the camera. These data are
used in the Post Processing Software
to eliminate the radiometric and geometric distortion.
All aerial imagery was collected with associated GPS/IMU
data. ADS collection requires high quality IMU data for
processing and was critical for early access hosting of
digital data to the web for USDA interim access and
review. After post processing was complete, all
imagery was triangulated using Leica XPro in which
the airborne GPS data was constrained to expected limits.
To validate the accuracy of the block adjustment derived
from GPS/IMU, sensor parameters and conjugate point
measurements, photo identifiable ground control points
were field surveyed within each State. These points were
surveyed using GPS techniques to produce coordinates
that are accurate to +/- 0.25 meters RMSE in XYZ.
The GPS surveying techniques utilized assured that the
coordinates are derived in the required project datum
and relative to an approved
National Reference System. If the block does not fit the
control points within specifications the pass and tie
points were reviewed for blunders and weak areas. If,
after these corrections were made, the block still
does not fit the control well the GPS and IMU processing
were reviewed. Once the block has proper statistics and
fits the control to specifications, the final bundle
adjustment was made. As AT points are frequently on
man-made and other vertical features not included in
the DEM, these ortho points can only be used to
indicate regions of error by the clusters of points
that predict excessive horizontal displacement.
The final adjustments assure a high quality relative
adjustment and a high quality absolute adjustment
limited to the airborne GPS data accuracy. This process
assures the final absolute accuracy of all geopositioned
imagery. Both signalized and photo identified
ground control were used to QC and control the IMU/GPS
based aerial triangulation bundle block solution. Surdex
Grouping Tool provides real-time updates
of the USDA APFO Image Metrics. The image technician
adjusts image correction parameters to bring the
radiometric characteristics of large groups of images
within the Image Metrics ranges. For each
project area the highest resolution DEM or LiDAR was
obtained and utilized for rectification of captured
imagery. A visual inspection of the final DEM using
color cycled classification by elevation and a shaded
relief was performed to check for gaps, corruption
and gross errors. The predicted horizontal error for
each point was added as an attribute in the SURDEX
enterprise database. An operator reviews ortho seams
in areas these predicted errors indicate horizontal
error in excess of the contract specifications.
Any imagery errors introduced by source DEM required
patching from an alternate perspective or strip of
photography. Processing hardware used included various
brands of survey grade GPS receivers, various brands
and models of computers, calibrated monitors and
various brands of monitor calibration colorimeters.
Leica XPro was used for post
processing of ADS pushbroom data, triangulation and
orthorectification. SURDEX software was used to color
correct and remove bidirectional reflectance,
vignetting and other illumination trends.
USDA APFO Image Metrics are measured and
images corrected to conform to the Image Metrics using
SURDEX software. GPS/IMU data was reduced to projected
coordinates in the appropriate UTM zone using
Inertial Explorer software from Novatel. Aerial
Triangulation and orthorectification was performed
using Leica XPro. SURDEX software was used to
adjust for minor radiometric variation between adjacent
images. SURDEX software was used to calculate the
optimal seam path, check seam topology and
create master tiles. SURDEX ortho software generates
occlusion/smear polygons used during seam review
of steep terrain. SURDEX software was used to
visually inspect master tiles for seam and image
defects. SURDEX software was used to project and
cut final DOQQ image files from masters.
SURDEX software was used to create CCM
metadata. Lizardtech GeoExpress version 9.1.0.3981
was used to create the CCM image file. SURDEX software
was used to perform final formatting, QC and naming
of the DOQQ. USGS metadata parser software was used
to validate the metadata.
Various versions of Microsoft Windows were used in all
phases of production. Grouping Tool was used again
after DOQQ and CCM production to provide a
quality assurance check. Individual DOQQ and CCM may
not meet the USDA APFO Image Metrics ranges
due to land cover. The goal is to have the state as a
whole meet the Image Metrics. All products are reviewed
by independent personnel prior to delivery.
The delivery is checked for omissions, commissions,
naming, formatting, specification compliance and data integrity.20171122Clark CO, WisconsinRasterPixelUniversal Transverse Mercator150.9996-93.00.05000000.0row and column1.01.0metersNorth American Datum of 1983Geodetic Reference System 806378137298.25724-bit pixels, 3 band color(RGB) values 0 - 255NoneSupervisor Customer Services SectionUSDA-FSA Aerial Photography Field Officemailing and physical address2222 West 2300 SouthSalt Lake CityUtah84119-2020USA801-844-2922801-956-3653apfo.sales@slc.usda.govNoneIn 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).Compressed County MosaicNatural ColorNoneDVD-RISO 9660USB Hard DiskNTFSFireWire Hard DiskNTFSFlash driveFat32 or NTFSContact the Aerial Photography Field Office
for more information20171122USDA-FSA Aerial Photography Field Officemailing and physical address2222 West 2300 SouthSalt Lake CityUtah84119-2020USA801-844-2900Content Standard for Digital Geospatial MetadataFGDC-STD-001-1998