2016-2017 NOAA NGS 4band Orthoimagery: South Carolina Coast

This data set consists of 0.3-meter pixel resolution, 4-band orthoimages covering the project area. 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. Each orthoimage provides imagery over a 3,000-meter x 3,000-meter block on the ground. There is no image overlap between adjacent files.

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 storm water management and assessment.

Aerial imagery was acquired using a Zeiss/Intergraph Digital Frame camera (DMC IIe) with a flight design that included a total of 843 exposures in 34 flight lines. Aerial imagery was supplemented with the simultaneous acquisition of airborne GPS/IMU data, which captured the ground coordinate for the nadir point of each photograph. Aerial imagery was exposed at an altitude of 16,175' above mean terrain for 0.3 m imagery.

Users must assume responsibility to determine the usability of these data. These photographs were obtained for use by NGS during the course of its development of potential final products to fulfill its statutory mission. Although NGS is making these photographs available to others who may find the photographs of value, NGS does not warrant, endorse, or recommend the use of these photographs for any given purpose. NGS is providing these photographs "as is," and NGS disclaims any and all warranties, whether expressed or implied, including (without limitation) any implied warranties of merchantability or fitness for a particular purpose. In no event will NGS be liable to you or any third party for any direct, indirect, incidental, consequential, special, or exemplary damages or lost profits resulting from any use or misuse of these data. Any conclusions drawn from the analysis of this information are not the responsibility of NOAA, the National Geodetic Survey, the Office for Coastal Management, or its partners.

Imagery covers the areas along the coast

Data is available online for custom downloads

None

Users should be aware that temporal changes may have occurred since this data set was collected and 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 its limitations.

The project specifications require that horizontal be computed for orthoimagery files. The required accuracy is: 0.6 meters RMSEx and RMSEy, derived according to NSSDA. The RMSEx and RMSEy were tested with 62 of 79 checkpoints; 17 points were not used as they fell on obscured, damaged, or ambiguous locations. The checkpoints were distributed throughout the project area and were surveyed using GPS techniques. Values from the orthoimagery were measured for the x,y location of each check point. Horizontal positions interpolated from the orthoimagery were then compared to the horizontal values of the surveyed control points. Accuracy has been tested to meet 0.6 meters or better as defined by the National Standards for Spatial Data Accuracy (NSSDA).

Tested 0.305 meters RMSEx as defined by the National Standards for Spatial Data Accuracy (NSSDA). The RMSEx of the orthoimage was calculated using 62 checkpoints.

Tested 0.38 meters RMSEy as defined by the National Standards for Spatial Data Accuracy (NSSDA). The RMSEy of the orthoimage was calculated using 62 checkpoints.