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Gibbs, Ann E. , 2009, A106AK_PhotoLocations: USGS Digital Data Series DS-436, U.S. Geological Survey, Santa Cruz, CA.Online Links:
This is a Point data set. It contains the following vector data types (SDTS terminology):
Horizontal positions are specified in geographic coordinates, that is, latitude and longitude. Latitudes are given to the nearest 0.000001. Longitudes are given to the nearest 0.000001. Latitude and longitude values are specified in Decimal degrees.
The horizontal datum used is D_WGS_1984.
The ellipsoid used is WGS_1984.
The semi-major axis of the ellipsoid used is 6378137.000000.
The flattening of the ellipsoid used is 1/298.257224.
Sequential, unique whole numbers that are automatically generated.
Coordinates defining the ArcGIS features.
| Range of values | |
|---|---|
| Minimum: | -157.538019 |
| Maximum: | -140.909008 |
| Units: | Decimal degrees; Western Hemisphere values are negative. |
| Range of values | |
|---|---|
| Minimum: | 69.631448 |
| Maximum: | 71.389706 |
| Units: | Decimal degrees; Northern Hemisphere values are positive. |
| Range of values | |
|---|---|
| Minimum: | 13.500 |
| Maximum: | 255.700 |
| Units: | Decimal meters above mean sea level. |
| Range of values | |
|---|---|
| Minimum: | 38936.934109 |
| Maximum: | 38939.067604 |
| Units: | Decimal serial number of days since January 1, 1900. |
Names are in the form "DSC0iiii" or "IMG_iiii" where "iiii" is an image counter.
Names are in the form "A106AK_ddAUG06_photos\A106AK_IMG_iiii.jpg" or "A106AK_ddAUG06_photos\A106AK_DSC0iiii.jpg" where "dd" is the day of month and "iiii" is an image counter.
U.S. Geological Survey
831-427-4740 (voice)
agibbs@usgs.gov
To provide an easily accessible overview of the coastal morphology and character of the north Alaska coast.
In general, photographs were taken using the largest field of view. However, the photographer could also zoom the lens to collect more detailed photos of features of interest. Because of variable aircraft altitude and distance from the shoreline, along with variable shooting parameters, the photographs do not show a consistent image width.
A Garmin GPSmap 76CS (WAAS enabled) handheld global positioning system (GPS) unit recorded the position of the aircraft every 5 to 10 seconds. All the imagery was georeferenced to the aircraft position at the time the photo was taken, annotated with position and time information, resampled (to 2000 x 1333 pixels), and compressed (to 90% original .jpg quality) using software and hardware developed by Red Hen Systems (<http://redhensystems.com>).
U.S. Geological Survey, Coastal and Marine Geology Program, 2007, National Assessment of Shoreline Change Project.Online Links:
Accuracy of data set attribute information was deduced to be good based both on visual examination of photographic image and of flight line location and on their agreement with observer's field knowledge.
Positional information reflects the position of the aircraft and was collected using a handheld, WAAS enabled GSP unit, recording at between 6 and 10 Hz.
DGPS (WAAS) accuracy for position is less than 3 meters. (From Garmin GPSMAP 76C/76CS Specifications, M01-10108-00, Rev0304, <https://buy.garmin.com/shop/store/assets/pdfs/specs/gpsmap76c_76cs_spec.pdf>).
The aircraft typically flew at about 500 feet elevation and approximately 1000 feet offshore.
Barometric altimeter features 10 feet accuracy with proper calibration with a resolution of 1 foot. (From Garmin GPSMAP 76C/76CS Specifications, M01-10108-00, Rev0304, <https://buy.garmin.com/shop/store/assets/pdfs/specs/gpsmap76c_76cs_spec.pdf>).
Some gaps in photography exist due to fog banks or rain, and only partial coverage of the river delta areas were collected. Total coverage is estimated at well over 80%.
Because of variable aircraft altitude and distance from the shoreline, along with variable shooting prarmeters, the photgraphs do not show a consistant image width.
Are there legal restrictions on access or use of the data?
- Access_Constraints:
- Information presented on this site is considered public information and may be distributed or copied.
- Use_Constraints:
- Use of appropriate byline/photo/image credit is requested; Suggested credit: Photo by Bruce Richmond/Ann Gibbs, USGS (or U.S. Geological Survey, depending on audience).
This information is not intended for navigational purposes.
Any use of trade, product, or firm names is for descriptive purposes only and does not imply endorsement by the U.S. Government.
Some USGS information accessed through this means may be preliminary in nature and presented without the approval of the Director of the USGS. This information is provided with the understanding that it is not guaranteed to be correct or complete and conclusions drawn from such information are the responsibility of the user.
831-427-4740 (voice)
agibbs@usgs.gov
Digital Data Series DS-436
Information presented on this site is considered public information and may be distributed or copied. Use of appropriate byline/photo/image credit is requested; Suggested credit: Photo by Bruce Richmond, USGS (or U.S. Geological Survey, depending on audience).
This information is not intended for navigational purposes.
Any use of trade, product, or firm names is for descriptive purposes only and does not imply endorsement by the U.S. Government.
Some USGS information accessed through this means may be preliminary in nature and presented without the approval of the Director of the USGS. This information is provided with the understanding that it is not guaranteed to be correct or complete and conclusions drawn from such information are the responsibility of the user.
| Data format: | ARCE Size: 0.082 |
|---|---|
| Network links: |
USGS Publication Warehouse <http://pubs.er.usgs.gov/usgspubs/index.jsp?view=adv> |
831-427-4740 (voice)
agibbs@usgs.gov
