2013 Rio Puerto Nuevo, Puerto Rico ADS40 4-Band Imagery

Imagery acquired with airborne sensors contain camera and terrain related distortions which make the images unsuitable for geospatial analysis as positions within the image may be significantly inaccurate. A digital orthophoto is a georeferenced image prepared from aerial imagery, or other remotely-sensed data in which the displacement within the image due to sensor orientation and terrain relief has been removed. Orthophotos combine the image characteristics of an image with the geometric qualities of a map. Orthoimages show ground features such as roads, buildings, and streams in their proper positions, without the distortion characteristic of unrectified aerial imagery. Digital Orthoimages produced and used within the Forest Service are developed from imagery acquired through various national and regional image acquisition programs. The resulting orthoimages, also known as orthomaps, can be directly applied in remote sensing, GIS and mapping applications. They serve a variety of purposes, from interim maps to field Standards for Digital Orthophotos references for earth science investigations and analysis. Because of the orthographic property, an orthoimage can be used like a map for measurement of distances, angles, and areas with scale being constant everywhere. Also they can be used as map layers in GIS or other computer based manipulation, overlaying, and analysis. An orthoimage differs from a map in a manner of depiction of detail; On the map only selected detail is shown by conventional symbols, whereas on an orthoimage all details appear just as in original aerial imagery.

Original contact information:

Contact Org: U.S. Army Corps of Engineers, Jacksonville District, Geomatics Section

Phone: 904-232-2214

Email: ted.n.schall@usace.army.mil

The purpose of the project is to provide the United States Army Corps of Engineers with updated digital orthographic aerial imagery covering the Rio Puerto Nuevo basin of the greater San Juan, Puerto Rico metropolitan area. The Corps regularly uses digital orthographic imagery to support regulatory, land management and acquisition, planning, engineering and habitat restoration projects. The data may also become available to local, state and other federal agencies for their specific management and analysis needs.

11950

The data design specifications for this product includes several directed to insure its quality, consistency, and usability. These specifications address some of the technical issues associated with orthoimage production: 1) the tops of buildings and other structures elevated above the surface of the ground 'tilt' away from the center point of the source imagery and from their own bases as a result of perspective and their height which is not compensated for in digital elevation models of the ground surface and 2) individual orthoimages may be assembled from several source aerial images. The data is referenced and adjusted to the NAD83(2011) datum. At the time of publication, this realization of NAD83 had not been included by ESRI in the ArcGIS datum library. Therefore, the GeoTIFF header datum reference was assigned as NAD83(NSRS2007). At such time that ESRI includes NAD83(2011) in the ArcGIS datum library, the images' GeoTIFF datum reference should updated to reflect this.

8-bit pixels per band, 0-255, 4-band RGBiR

None

Users must assume responsibility to determine the appropriate use of these data. DATA SHOULD NOT BE USED FOR LEGALLY BINDING APPLICATIONS.

None

Acknowledgment of the United States Army Corps of Engineers would be appreciated for products derived from these data.

Microsoft Windows 7 Version 6.1 (Build 7601) Service Pack 1; ESRI ArcGIS 10.1.3035

Tested 0.12 meters horizontal accuracy at the 95% confidence level; Quantitative Value: 0.12 meters, Test that produced the value: Horizontal position accuracy for the set digital orthoimages was determined by measuring the locations of 12 well defined points within the images and comparing their locations to field positions as determined by GPS survey methods. This comparison resulted in the following accuracy statistics: Radial RMSE (RMSEr) = 0.07m, Radial Standard Deviation (Sr) = 0.03m, National Standard for Spatial Data Accuracy (Accuracy) = 0.12m

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Cloud Cover: 0

These data cover approximately 70 square miles of the Rio Puerto Nuevo basin and the greater San Juan metropolitan area. These specifications address some of the technical issues associated with orthoimage production: 1) the tops of buildings and other structures elevated above the surface of the ground 'tilt' away from the center point of the source imagery and from their own bases as a result of perspective and their height which is not compensated for in digital elevation models of the ground surface and 2) individual orthoimages may be assembled from several source aerial images.

These specifications address some of the technical issues associated with orthoimage production: 1) the tops of buildings and other structures elevated above the surface of the ground 'tilt' away from the center point of the source imagery and from their own bases as a result of perspective and their height which is not compensated for in digital elevation models of the ground surface and 2) individual orthoimages may be assembled from several source aerial images.