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0.3 meter orthoimage, rectified photograph, rectified image, orthophoto, natural color orthophoto, orthoimage, image map
This data depicts geographic features on the surface of the earth. It was created to provide easily accessible geospatial data which is readily available to enhance the capability of Federal, State, and local emergency responders, as well as plan for homeland security efforts. This data also supports The National Map.
This data set consists of 0.3-meter pixel resolution (approximately 1-foot), natural color orthoimages covering the urban area footprint. 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. The design accuracy is estimated not to exceed 3-meter diagonal RMSE (2.12m RMSE in X or Y). Each orthoimage provides imagery over a 1500-meter by 1500-meter block on the ground. There is no image overlap between adjacent files. The projected coordinate system is UTM with a NAD83 datum. The naming convention is based on the U. S. National Grid (USNG), taking the coordinates of the SW corner of the orthoimage. Task Order Number G09PD01896. USGS Contract Number 07CRCN0014. Nominal Acquisition Altitude (AGL) was 9600'. The geoid used to reduce satellite derived elevations to orthometric heights was Geoid 03. GPS coordinates are referenced to NAD83 Universal Transverse Mercator Zone 19. The maximum differential baseline length is 69373.00 meters. The mean baseline length is 25668.18 meters. Camera sensors calibration reports are included in the project report. Calibration flights are flown regularly.
Photo Science, Inc. in combination with JWSewall.
None. However, users should be aware that temporal changes may have occurred since this data set was collected and that some parts of this data may no longer represent actual surface conditions. Users should not use this data for critical applications without a full awareness of it's limitations. Acknowledgment of the U.S. Geological Survey would be appreciated for products derived from these data.
Extent
There is no extent for this item.
| Maximum (zoomed in) | 1:5,000 |
| Minimum (zoomed out) | 1:150,000,000 |
Monday through Friday
Monday through Friday
None. However, users should be aware that temporal changes may have occurred since this data set was collected and that some parts of this data may no longer represent actual surface conditions. Users should not use this data for critical applications without a full awareness of it's limitations. Acknowledgment of the U.S. Geological Survey would be appreciated for products derived from these data.
Monday through Friday
Monday through Friday
This data set consists of 0.3-meter pixel resolution (approximately 1-foot), natural color orthoimages covering the urban area footprint. 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. The design accuracy is estimated not to exceed 3-meter diagonal RMSE (2.12m RMSE in X or Y). Each orthoimage provides imagery over a 1500-meter by 1500-meter block on the ground. There is no image overlap between adjacent files. The projected coordinate system is UTM with a NAD83 datum. The naming convention is based on the U. S. National Grid (USNG), taking the coordinates of the SW corner of the orthoimage. Task Order Number G09PD01896. USGS Contract Number 07CRCN0014. Nominal Acquisition Altitude (AGL) was 9600'. The geoid used to reduce satellite derived elevations to orthometric heights was Geoid 03. GPS coordinates are referenced to NAD83 Universal Transverse Mercator Zone 19. The maximum differential baseline length is 69373.00 meters. The mean baseline length is 25668.18 meters. Camera sensors calibration reports are included in the project report. Calibration flights are flown regularly.
This data depicts geographic features on the surface of the earth. It was created to provide easily accessible geospatial data which is readily available to enhance the capability of Federal, State, and local emergency responders, as well as plan for homeland security efforts. This data also supports The National Map.
ground condition
None
None. However, users should be aware that temporal changes may have occurred since this data set was collected and that some parts of this data may no longer represent actual surface conditions. Users should not use this data for critical applications without a full awareness of it's limitations.
Acknowledgment of the U.S. Geological Survey would be appreciated for products derived from these data.
Photo Science, Inc. in combination with JWSewall.
Radiometry is verified by visual inspection of the digital orthophoto. Slight systematic radiometric differences may exist between adjacent orthoimage files; these are due primarily to differences in source image capture dates and sun angles along flight lines. These differences can be observed in an image's general lightness or darkness when it is compared to adjacent orthoimage file coverages. Tonal balancing may be performed over a group of images during the mosaicking process which may serve to lighten or darken adjacent images for better color tone matching.
All GeoTIFF tagged data and image file sizes are validated using commercial GIS software to ensure proper loading before being archived. This validation procedure ensures correct physical format and field values for tagged elements. Seamlines and tile edges are visually inspected. Seamline mismatches are not corrected unless the overall displacement exceeds one meter.
Orthoimages are visually inspected for completeness to ensure that no gaps or image misplacements exist within and between adjacent images. These images are derived by mosaicking multiple images to ensure complete coverage. Source imagery is cloud free. Photography was flown during leaf-off in deciduous vegetation regions. Coastal areas and international boundary regions may have areas without images (void areas) in parts of the coverage. These void areas have a radiometric value of either zero (black) or 128 (uniform gray).
Ground Control Points of known and visible points were collected and measured.
Radial RMSE
Digital Elevation Models (DEMs) used were National Elevation Dataset (NEDs).
The DEMs are used as-is and were not modified.
Remotely sensed imagery
Scanned film files were orthorectified in order to create the orthophoto tiles.
External Orientation data was used to rectify scanned images.
Ground control points were used to test accuracy of orthoimagery
AIRPHOTOs were scanned to create SCANS. SCANS were orthorectified with EO data in order to create rectified frames. Seamlines were manually drawn to combine rectified frames for final mosaic tiles. GCP were used to check the tiles RMSE.
Dataset copied.
Natural color orthoimagery is organized in three color bands or channels which represent the red, green, and blue (RGB) portions of the spectrum. Each image pixel is assigned a triplet of numeric values, one for each color band. Numeric values range from 0 to 255. Areas where data is incomplete due to lack of full image coverage are represented with the numeric value of 0.
U.S. Department of the Interior, U.S. Geological Survey, 1996, Standards for Digital Orthophotos: Reston, VA.
Users must assume responsibility to determine the usability of this data for their purposes.
The Maine Office of GIS and the GeoLibrary Board provide web mapping services to distribute aerial photos and other digital data. A WMS is not a web application which you can see in a web browser; rather, it requires you to add the service to a GIS software application.
http://www.maine.gov/geolib/wms.htm
The above is the contact information for EROS Data Center in Sioux Falls, SD. This is the digital data storage and distribution center for the USGS. Metadata information can also be obtained through online services using The National Map Viewer, at http:/nationalmap.usgs.gov or EarthExplorer, at http://earthexplorer.usgs.gov.