Department of Commerce (DOC), National Oceanic and Atmospheric Administration (NOAA), National Ocean Service (NOS), Office for Coastal Management (OCM)
20041223
Connecticut Coastal Airborne ADS40 Digital Imagery Acquisition and Natural Color and Color Infrared Orthophoto Production collected in September 2004
raster digital data
Charleston, SC
NOAA's Ocean Service, Office for Coastal Management (OCM)
https://coast.noaa.gov/digitalcoast
The NOAA Office for Coastal Management purchased digital ADS40 imagery and digital elevation models of the Connecticut coastline in 2004. The Coastal Connecticut project area is comprised of approximately 930 square miles. A total of 244 orthos (122 natural color and 122 color infrared) were produced to cover this area. Aerial imagery was collected in panchromatic, Red, Green, Blue and Near Infrared which yielded a natural color and false color infrared version of the completed digital orthophotography. In addition to producing the digital ortho imagery a first surface (reflective surface) elevation data set was produced. Imagery was collected at an approximate altitude of 15,750 feet above mean terrain.
These data were created to support a research investigation to identify and map invasive Phragmites australis. The data are part of the US government provided resources for a grant to the University of Connecticut. A secondary purpose was to provide a sample dataset to examine the applicability of digital aerial imagery for general purpose coastal management.
The bounding coordinates provided within the Spatial Domain section represent a rectangle covering the total area in which the project is located. The actual project boundary located within this area is comprised of areas delimited by areas along the coast of the state of Connecticut. The Coastal Connecticut project area is comprised of approximately 930 square miles. A total of 244 orthos (122 natural color and 122 color infrared) were produced to cover this area. Aerial imagery was collected in panchromatic, Red, Green, Blue and Near Infrared which yielded a natural color and false color infrared version of the completed digital orthophotography. In addition to producing the digital ortho imagery a first surface (reflective surface) elevation data set was produced. Imagery was collected at an approximate altitude of 15,750 feet above mean terrain. The ADS40 digital camera system used in this project incorporates the latest in sensor technology, optics, electronics, data transfer, and storage. The ADS40 imagery is generated from seven parallel sensor lines in the focal plane of a single lens system, three panchromatic (forward, nadir, backward), red, green, and blue lines placed next to each other, and one infrared. Each panchromatic channel consists of two lines, each with 12,000 pixels, staggered (shifted with respect to each other) by 0.5 pixels. The viewing angles and characteristics of the sensor are as follows - - Focal length 62.5mm - Pixel size 6.5mm - PAN 2 arrays 12,000 pixels each - R,G,B and NIR,R,G 12,000 pixels - Backward to nadir stereo angle -14.1 degrees - Near infrared to nadir stereo angle -2.05 degrees - Dynamic Range of CCD - 12-bits for all arrays. For this dataset, the natural color and color infrared orthoimages were produced at 0.50-meter pixel resolution. Each digital orthorectified quarter quad provides imagery for a nominal 3.75 by 3.75 minute area corresponding to the USGS quarter quad boundaries. The projected coordinate system is UTM (Zone 18) with a NAD83 datum. The naming convention is based on the National Grid. Deliverables include - - 24-Bit Natural Color in GeoTIFF format - 24-Bit False Color Infrared in GeoTIFF format - Reflective surface digital elevation data set in .flt format. An orthoimage is remotely sensed image data in which displacement of features in the image caused by terrain relief and sensor orientation have been mathematically removed. Orthoimagery combines the image characteristics of a photograph with the geometric qualities of a map. This task consists of two primary components, ADS40 digital image acquisition and natural color and color infrared digital orthophoto production. In addition to the orthophotos a reflective surface digital elevation data set covering the project area was produced.
20040920
20040922
ground condition
As needed
-073.811097
-071.755583
+41.658672
+40.911606
ISO 19115 Topic Category
imageryBaseMapsEarthCover
None
Remotely Sensed Imagery/Photos
Land Cover Analysis
Change Detection Analysis
Digital Orthophotography
Aerial Photography
ADS40
Digital Orthophoto Quarter Quad (DOQQ)
Color Infrared DOQQ
Natural Color DOQQ
Geographic Names Information System
Connecticut
CT
US
None
None
EarthData International, Inc.
Harold Rempel
Director of Program Management
mailing and physical
7320 Executive Way
Frederick
MD
21704
USA
301-948-8550
301-963-2064
hrempel@earthdata.com
9:00am - 4:00pm
NOAA Office for Coastal Management
Leica ADS40 Digital Camera System X Digital Image Processing Software Z/I Imaging Orthopro 4.0 Windows NT/2000 Systems
The digital imagery for each acquisition sortie is differentially rectified to produce orthophotography for the Red, Green, and Blue and near infrared channels at a resolution of 0.50-meter per pixel. The Orthophoto mosaics are inspected for accuracy issues that fall in the following categories Aerotriangulation related - DSM related Accuracy issues will be investigated through review an correction of the DSM or triangulation adjustment. Once the imagery has passed quality control review, final radiometric adjustments are performed to create a uniform overall appearance
Compliance with the accuracy standard was ensured by the placement of photo identifiable ground control points and the collection of airborne GPS data. Using several tools that are part of the ISTAR workflow, a digital surface model (DSM) was correlated at a post spacing of 2 meters depending on terrain and land cover. The ISTAR correlation algorithm computes the X,Y,Z value for each DSM post utilizing every stereo angle that is available. A series of DSM files were created for each acquisition block, one for each stereo look angle. A mosaic was then created from the separate DSM files where the best vertical value for each posting was selected from all look angles compared against the aerotriangulation adjustment which is incorporated into the mosaic. Company X then edited the surface to the level required to support the orthophoto production. An RMS value was calculated based on the imagery utilized in the production of the tile by comparing the aerotriangulated X and Y coordinates. This value represents an estimate of the accuracy of the horizontal coordinate measurements in the tile expressed in meters.
Compliance with the accuracy standard was ensured by the placement of photo identifiable ground control points and the collection of airborne GPS data.
Accuracy assessment determined by evaluating the horizontal accuracy obtained during the aerotriangulation process for each lift.
CheckDEM is a program designed to compare a list of controls against DEM file(s) and therefore to check the accuracy of the DEM file(s). For each control point, first, the program selects all the DEM points that fall into a given radius from the position of the control point. Second, the program calculates a weighted average of the DEM points to interpolate an elevation at the position of the control point. And last, the program computes the difference between the elevation of the control point and the interpolated elevation. After all the control points have been checked, the program computes several statistics on the differences between controls and interpolated DEM elevations. The statistics include RMSE, Standard Deviation, Minimum Difference, Maximum Difference, and Mean Difference. In the output report, the program prints out elevation differences for every control points and the statistics. Raw elevation measurements have been determined to be vertically accurate to within 0.328 meters.
Terrasurv Inc.
20041223
Ground Control Survey of Coastal Connecticut
model
1800
digital
20040927
20040928
ground condition
GPS Ground Control
Terrasurv Inc. established ground control to support the aerotriangulation process. A total of 16 points were surveyed to support the AT process.
Company X
20041223
Coastal Connecticut Digital Surface Model
model
1800
digital
20041223
publication date
Digital Surface Model
Used to provide ground elevations for the orthorectification process.
EarthData International Inc
20041223
ADS40 Digital Imagery
Remote sensing image
1800
digital
20040920
20040922
ground condition
Imagery
The digital imagery mission was composed of a total of 2 lifts. Imagery was obtained at an altitude of 15,750 feet above mean terrain. The mission was flown with a Leica ADS40 digital camera with ABGPS and IMU. Imagery was acquired on the following dates - Lift Date 26404B 09/20/2004 26604A 09/22/2004.
Source Imagery - ADS40 Digital Camera Imagery. Control - Airborne GPS/IMU supplemented with photo identifiable field control Aerotriangulation - X software package Elevation Model - X software package Radiometric Balancing - X software package and COTS Software (PhotoShop). Orthorectification - X software package. Mosaic - X software package and Z/I Imaging OrthoPro software package. The following section describes the X digital image production sequence. This is a mature, stable workflow and incorporates all production components into an integrated series of tools to accomplish photogrammetric mensuration, aerotriangulation, elevation model development, ortho production and finishing. Production processes are fully documented in accordance with ISO9001 mandates. The following is a step-by-step description of the X workflow to develop digital orthophoto quarter quads to. Step 1 The unprocessed ADS40 data and accompanying GPS and IMU data for one or more sorties was downloaded from the portable hard disks and checked to verify that no files were corrupted and that all data could be downloaded. Digital aerial imagery that was used for this project includes the Red, Green, Blue, Near Infrared channels as well as the S1 pan, S2 pan and nadir green channels. Sample segments of the imagery were inspected in an uncorrected state to verify the integrity of each data sortie. Step 2 The GPS/IMU parameters for each sortie were optimized using the ground control points and the error calibration map. The horizontal and vertical positions of all ground control points in the block were observed in each channel (R,G,B, IR, R, G, S1 Pan, S2 Pan). Step 3 Aerotriangulation was accomplished using the CLB tool that is a component of the X process. The ground control, GPS and IMU information were ingested and tie points between strips were identified. Normally, only 3 tie points are needed between adjacent flight lines. Step 4 CLB produces a bundle adjustment for each data sortie. The results of the adjustment were verified through the development of a sub-sampled panchromatic mosaic for the data sortie. The mosaic was corrected using the aerotriangulation points only. This mosaic was inspected by the photogrammetric technician to identify any gross errors in the adjustment as well as the identification of any voids or image quality problems. Step 5 Using several tools that are part of the ISTAR workflow, a digital surface model (DSM) is correlated at a post spacing of 2 meters depending on terrain and land cover. The ISTAR correlation algorithm computes the X,Y,Z value for each DSM post utilizing every stereo angle that is available. A series of DSM files are created for acquisition block, one for each stereo look angle. A mosaic is then created from the separate DSM files where the best vertical value for each posting is selected from all look angles compared against the aerotriangulation adjustment which is incorporated into the mosaic. Company X will then edit the surface to the level required to support the orthophoto production. Step 6 The digital imagery for each acquisition sortie was differentially rectified to produce digital orthophoto mosaics in natural color and false color infrared renditions at a resolution of 0.50-meter per pixel. The orthophoto mosaics were inspected for accuracy issues that fall in the following categories - - Aerotriangulation related - DSM related Accuracy issues were investigated through review and correction of the DEM or triangulation adjustment. Once the imagery passed quality control review, final radiometric adjustments were performed to create a uniform overall appearance. The final DOQQ tiles were organized for nominal 3.75 by 3.75 minute areas corresponding to the USGS quarter quad boundaries and were clipped out with the specified overage of a minimum of 30 meters beyond the quarter quad boundaries. Imagery was output in the following formats - 24-bit natural color GeoTIFF images 24-bit false color infrared GeoTIFF images Step 7 The completed digital orthophotos were checked for image quality. Minor artifacts were corrected using Adobe Photoshop in an interactive editing session. Digital files were assigned final names based on the National Grid. Step 8 Project level metadata describing the orthophoto production process was developed to support the task.
20041223
Universal Transverse Mercator
18
0.999600
-075.000000
+00.000000
500000.0
0.000000
row and column
0.500000
0.500000
meters
North American Datum of 1983
Geodetic Reference System 80
6378137
298.257222101
Leica ADS40 sensors Push-broom Cameras SP14 50 centimeter pixel resolution Color and color IR
Not Applicable
NOAA Office for Coastal Management
mailing and physical
2234 South Hobson Avenue
Charleston
SC
29405-2413
843-740-1202
coastal.info@noaa.gov
Downloadable Data
Users must assume responsibility to determine the usability of these data.
20151218
20151218
NOAA Office for Coastal Management
mailing and physical
2234 South Hobson Avenue
Charleston
SC
29405-2413
843-740-1202
coastal.info@noaa.gov
FGDC Content Standard for Digital Geospatial Metadata
FGDC-STD-001-1998