Page C. Valentine
Tanya S. Unger
Jessica L. Baker
2005
sunillum.tif: Sun-illuminated topographic imagery of the seafloor in the Stellwagen Bank National Marine Sanctuary region.
1.0
remote-sensing image
Scientific Investigations Map2840
Woods Hole Science Center, Woods Hole, MA
U.S. Geological Survey, Coastal and Marine Geology Program
http://pubs.usgs.gov/sim/2005/2840/data/sunillum/sunillum.zip
Page C. Valentine
2005
Sea floor image maps showing topography, sun-illuminated topography, backscatter intensity, ruggedness, slope, and the distribution of boulder ridges and bedrock outcrops in the Stellwagen Bank National Marine Sanctuary region off Boston, Massachusetts
1.0
Scientific Investigations Map
2840
Woods Hole Science Center, Woods Hole, MA
U.S. Geological Survey, Coastal and Marine Geology Program
scale 1:60,000, 6 maps, 12 sheets
http://pubs.usgs.gov/sim/2005/2840/
sunillum.tif
The sun-illuminated topographic imagery of the Stellwagen Bank National Marine Sanctuary region off Boston, Massachusetts covers an area of approximately 1100 square nautical miles. The Stellwagen Bank NMS Mapping Project is designed to provide detailed maps of the Stellwagen Bank region's environments and habitats and the first complete multibeam topographic and sea floor characterization maps of a significant region of the shallow EEZ. Data were collected on four cruises over a two year period from the fall of 1994 to the fall of 1996. The surveys were conducted aboard the Canadian Hydrographic Service vessel Frederick G. Creed, a SWATH (Small Waterplane Twin Hull) ship that surveys at speeds of up to 16 knots.
Development of interpretive seabed maps, sea floor imagery, and a GIS database that are accessible to scientists, policymakers, managers, and the general public.
en
1994
1998
ground condition
As needed
-70.6
-70.0333
42.8
42.0833
-23598.54000023581.4600003850013.7200003930613.720000
General
Geographic Information Systems
GIS
U.S. Geological Survey
USGS
Coastal and Marine Geology Program
CMGP
Woods Hole Science Center
WHSC
Frederick G. Creed
Swath Bathymetry
topographic data
sea floor topography
bathymetry
sun-illuminated imagery
gray scale image
GeoTIFF image
General
Massachusetts
MA
Stellwagen Bank National Marine Sanctuary
SBNMS
Shallow EEZ
EEZ
Gulf of Maine
Atlantic Ocean
Boston
oceans and estuariesimageryBaseMapsEarthCoverISO 19115 Topic Categoryelevation
none
Public domain data from the U.S. Government are freely redistributable with proper metadata and source attribution. Please recognize the U.S. Geological Survey (USGS) as the source of this information.
Not to be used for navigational purposes.
Page C. Valentine
U.S. Geological Survey
Research Geologist
mailing and physical address
U.S. Geological Survey
384 Woods Hole Rd.
Woods Hole
MA
02543-1598
USA
(508) 548-8700 x2239
(508) 457-2310
pvalentine@usgs.gov
Page C. Valentine
Tammie J. Middleton
Sarah J. Fuller
2001
Sea floor maps showing topography, sun-illuminated topography, and backscatter intensity of the Stellwagen Bank National Marine Sanctuary region off Boston, Massachusetts
1.01
Open-File Report
00-410
http://pubs.usgs.gov/of/of00-410/
Woods Hole Science Center, Woods Hole, MAU.S. Geological Survey, Coastal and Marine Geology Program
Page C. Valentine
Tanya S. Unger
Jessica L. Baker
2003
Sun-illuminated sea floor topography of the Stellwagen Bank National Marine Sanctuary off Boston, Massachusetts
1.0
map
Geologic Investigations Map
I-2676-B
Woods Hole Science Center, Woods Hole, MAU.S. Geological Survey, Coastal and Marine Geology Program
Microsoft Windows XP Version 5.1 (Build 2600) Service Pack 2; ESRI ArcCatalog 9.0.0.535Raster Datasethttp://pubs.usgs.gov/sim/2005/2840/data/sunillum/sunillum-thumb.gifGIFThumbnail image showing overview of the sun-illuminated topographic imager of the seafloor in the Stellwagen Bank National Marine Sanctuary region.http://pubs.usgs.gov/sim/2005/2840/data/sunillum/sunillum-browse.gifGIFImage showing overview of the sun-illuminated topographic imager of the seafloor in the Stellwagen Bank National Marine Sanctuary region.
The ship's position was determined with an accuracy of 10 m or better using a Magnavox 4200 geographic positioning system (GPS) receiver in conjunction with differential GPS corrections transmitted by U.S. Coast Guard radio beacons. At the start of each day, casts were made to record the sound velocity profile of the water column in the area to be surveyed. Sound velocity information was updated during the day whenever the survey moved from one area to another. Tidal corrections based on NOAA's Boston tide gauge were used to reference depth data to mean lower low water. Sounding rates depend on water depth but vary from 2 to 4 per second in water depths less than 100 meters. Horizontal spatial resolution at these sounding rates is on the order of 10% of the water depth at 16 knots; however, vertical resolution is approximately 1% or better in the same depth range.
The bathymetric data are displayed in real time on the Sun workstation using software designed and written by the Ocean Mapping Group, University of New Brunswick. This display allows data gaps to be identified during the survey and also gives a measure of the data quality.
Sounding rates depend on water depth but vary from 2 to 4 per second in water depths less than 100 meters. Horizontal spatial resolution at these sounding rates is on the order of 10% of the water depth at 16 knots; however, vertical resolution is approximately 1% or better in the same depth range.
Sounding rates depend on water depth but vary from 2 to 4 per second in water depths less than 100 meters. Horizontal spatial resolution at these sounding rates is on the order of 10% of the water depth at 16 knots; however, vertical resolution is approximately 1% or better in the same depth range.
The navigation and topographic data were both edited using SwathEd, a suite of multibeam software editing and display tools developed by Dr. John Hughes Clarke of the Ocean Mapping Group, University of New Brunswick (UNB).. Tidal corrections were obtained from NOAA's Boston Tide Gauge (Station 8443970) and merged into the data set using UNB's tidal routines. The topographic information was converted into an ASCII text file containing lat, long, and depth fields, using a script created by Bill Danforth at the U.S. Geological Survey. The ASCII file was brought into Arc/Info, and a grid was generated and processed using ESRI's Arc/Info version 7.0.4 software. A point coverage containing depth values was created using the routine point-generate.
The grid was created based on the depth values for each of the points using the command pointgrid. The grid was filtered with a 9 by 9 focalmedian filter. Contours were generated using latticecontour. All editing and edgematching was done by hand using arcedit. The shaded relief images shown here were created using a light source that is 45 degrees above the horizon from an azimuth of 350 degrees. The vertical exaggeration in the images is four times. In effect, topographic relief is enhanced by illuminating the sea floor from a position 10 degrees west of north so that shadows are cast on the southern flanks of seabed features. Some features in the images are artifacts of data collection. They are especially noticeable where the seabed is smooth and include small highs and lows and unnatural-looking features and patterns that are oriented parallel or perpendicular to survey tracklines.
Raster
Pixel
8060
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1
10.00000010.0000008Upper LeftFALSENone1pixel codesTRUETIFF
Mercator
41.65
-70.3167
0
0
row and column
10.000000
10.000000
meters
North American Datum of 1983
Geodetic Reference System 80
Sun-illuminated topographic imagery combines contoured topography and sun-illuminated topographic imagery. The image shown here uses a sun elevation angle of 45 degrees above the horizon from an azimuth of 350 degrees and a vertical exaggeration of four times. In effect, topographic relief is enhanced by having the sun illuminate the sea floor from a position 10 degrees west of north so that shadows are cast on the southern flanks of seabed features. Unnatural-looking stripes and patterns oriented parallel or perpendicular to survey track lines are artifacts of data collection. Blank areas represent places where no data exists. The topographic imagery is identical to that shown on Sheet 3 of this report.
Page C. Valentine
U.S. Geological Survey
Research Geologist
mailing and physical address
U.S. Geological Survey
384 Woods Hole Rd.
Woods Hole
MA
02543-1598
USA
(508) 548-8700 x2239
(508) 457-2310
pvalentine@usgs.gov
Downloadable Data
Although these data have been used by the U.S. Geological Survey, U.S. Department of the Interior, no warranty expressed or implied is made by the U.S. Geological Survey as to the accuracy of the data.
Any use of trade, product, or firm names is for descriptive purposes only and does not imply endorsement by the U.S. Government.
TIFF
0.000
0.000GeoTIFFA zip archive containing the GeoTIFF image, associated world file, and metadata.zip
DVD-ROM
UDF
4.75Gbytes
http://pubs.usgs.gov/sim/2005/2840/data/sunillum/sunillum.zip
None
This image is available as a GEOTIFF image with an accompanying world file. To utilize this data, the user must have an image viewer, image processing or GIS software package capable of importing a GeoTIFF image.
20050823
U.S. Geological Survey
Page C. Valentine
Research Geologist
mailing and physical address
U.S. Geological Survey
384 Woods Hole Rd.
Woods Hole
MA
02543
USA
(508) 548-8700 x2239
(508) 457-2310
pvalentine@usgs.gov
FGDC Content Standards for Digital Geospatial Metadata
FGDC-STD-001-1998
local time
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