David C. Twichell
VeeAnn A. Cross
2003
Enhanced TIFF Sidescan-Sonar Mosaic of Boulder Basin - Lake Mead, Nevada: Geographic Coordinates
remote-sensing image
Open-File Report
03-320
Woods Hole Coastal and Marine Science Center, Woods Hole, MA
U.S. Geological Survey, Coastal and Marine Geology Program
https://doi.org/10.3133/ofr03320
http://pubs.usgs.gov/of/2003/of03-320/htmldocs/datacatalog.htm
http://pubs.usgs.gov/of/2003/of03-320/data/sscanimgs/geographic/enhanced/
http://pubs.usgs.gov/of/2003/of03-320/data/sscanimgs/geographic/enhanced/bbasinenh_g.tif
http://pubs.usgs.gov/of/2003/of03-320/data/sscanimgs/geographic/enhanced/bbasinenh_g.tfw
http://pubs.usgs.gov/of/2009/1150/gis/sidescan/bbasinenh_g.zip
David C. Twichell
VeeAnn A. Cross
Stephen D. Belew
2003
Mapping the floor of Lake Mead (Nevada and Arizona): Preliminary discussion and GIS data release
Open-File Report
03-320
Reston, VA
U.S. Geological Survey
http://pubs.usgs.gov/of/2003/of03-320/
Lake Mead is a large interstate reservoir located in the Mojave Desert of southeastern Nevada and northwestern Arizona. It was impounded in 1935 by the construction of Hoover Dam and is one of a series of multi-purpose reservoirs on the Colorado River. The lake extends 183 km from the mouth of the Grand Canyon to Black Canyon, the site of Hoover Dam, and provides water for residential, commercial, industrial, recreational, and other non-agricultural users in communities across the southwestern United States. Extensive research has been conducted on Lake Mead, but a majority of the studies have involved determining levels of anthropogenic contaminants such as synthetic organic compounds, heavy metals and dissolved ions, furans/dioxins, and nutrient loading in lake water, sediment, and biota (Preissler, et al., 1998; Bevans et al, 1996; Bevans et al., 1998; Covay and Leiker, 1998; LaBounty and Horn, 1997; Paulson, 1981). By contrast, little work has focused on the sediments in the lake and the processes of deposition (Gould, 1951). To address these questions, sidescan-sonar imagery and high-resolution seismic-reflection profiles were collected throughout Lake Mead by the USGS in cooperation with researchers from University of Nevada Las Vegas (UNLV). These data allow a detailed mapping of the surficial geology and the distribution and thickness of sediment that has accumulated in the lake since the completion of Hoover Dam. Results indicate that the accumulation of post-impoundment sediment is primarily restricted to former river and stream beds that are now submerged below the lake while the margins of the lake appear to be devoid of post-impoundment sediment. The sediment cover along the original Colorado River bed is continuous and is typically greater than 10 m thick through much of its length. Sediment thickness in some areas exceeds 35 m while the smaller tributary valleys typically are filled with less than 4 m of sediment. Away from the river beds that are now covered with post-impoundment sediment, pre-impoundment alluvial deposits and rock outcrops are still exposed on the lake floor.
This sidescan-sonar imagery is used to map the morphology of the lake floor and determine the extent of sediment distribution on the lake floor.
This previously published dataset is provided as a courtesy in Open-File Report 1150 "Surficial Geology of the Floor of Lake Mead (Arizona and Nevada) as Defined by Sidescan-sonar Imagery, Lake Floor Topography and Post-impoundment Sediment Thickness", available online: http://pubs.usgs.gov/of/2009/1150/. Improvements have been made to this metadata file even though the originally published data have not been modified.
19990514
19990525
ground condition
None planned
-114.863735
-114.584436
36.156649
36.013028
USGS Metadata Identifier
USGS:9e00399c-692f-4f58-8dd9-e07933f5b51e
None
CMGP
Coastal and Marine Geology Program
images
mosaic
OFR03-320
Open-File Report
reservoir
sidescan
sidescan sonar
TIFF
U.S. Geological Survey
USGS
Woods Hole Field Center
ISO 19115 Topic Category
geoscientificInformation
imageryBaseMapsEarthCover
inlandWaters
USGS Thesaurus
lakebed acoustic reflectivity
image mosaics
sidescan sonar
geophysics
geospatial datasets
None
Arizona
Black Canyon
Boulder Basin
Hoover Dam
Lake Mead
Las Vegas
Las Vegas Bay
Mojave Desert
Nevada
United States
North America
NONE
The U.S. Geological Survey must be referenced as the originator of the dataset in any future products or research derived from these data.
David C. Twichell
U.S. Geological Survey
Oceanographer
mailing and physical address
384 Woods Hole Rd.
Woods Hole
MA
02543-1598
(508) 548-8700 x2266
(508) 457-2310
dtwichell@usgs.gov
Microsoft Windows XP Version 5.1 (Build 2600) Service Pack 3; ESRI ArcCatalog 9.2.6.1500
H.E. Bevans
S.L. Goodbred
J.F. Miesner
S.A. Watkins
T.S. Gross
N.D. Denslow
T. Choeb
1996
Synthetic organic compounds and carp endocrinology and histology, Las Vegas Wash and Las Vegas and Callville bays of Lake Mead Nevada
Water-Resources Investigations
96-4266
Reston, VA
U.S. Geological Survey
H.E. Bevans
M.S. Lico
S.J. Lawrence
1998
Water quality in the Las Vegas Valley area and the Carson and Truckee River basins, Nevada and California, 1992-1996
Circular
1170
Reston, VA
U.S. Geological Survey
K.J. Couvay
T.J. Leiker
1998
Synthetic organic compounds in water and bottom sediment from streams, detention basins, and sewage-treatment plant outfalls in Las Vegas Valley, Nevada, 1997
Open-File Report
98-633
Reston, VA
U.S. Geological Survey
H.R. Gould
1951
Some quantitative aspects of Lake Mead turbidity currents
SEPM Special Publication
No. 2
Tulsa, OK
Society of Economic Paleontologists and Mineralogists
J.F. LaBounty
M.J. Horn
1997
The influence of drainage from the Las Vegas Valley on the limnology of Boulder Basin, Lake Mead, Arizona-Nevada
Journal of Lake and Reservoir Management
v. 13
L.J. Paulson
1981
Nutrient management with hydroelectric dams on the Colorado River
Technical Report
#8
Department of Biological Sciences, University of Nevada, Las Vegas, Nevada
Lake Mead Limnological Research Center
A.M. Preissler
G.A. Roach
K.A. Thomas
J.W. Wilson
1998
Water resources data, Nevada, water year 1998
Water Resources Data Nevada
NV-98-1
Reston, VA
U.S. Geological Survey
All these data were collected with the same sidescan-sonar towfish. The majority of the data comprising this mosaic was acquired at a 1500m total swath width. In some small areas, data gaps were filled with data collected at a 750m total swath width. However, in each case, the data were resampled to a 2 m pixel size.
All imagery necessary to map the lake floor was used.
The ship was navigated with P-CODE GPS. The towfish was deployed at approximately the same depth each day, with little variation during the course of the survey. Therefore range to fish values are assumed consistent and accurate.
Sidescan sonar imagery was collected using a Datasonics SIS-1000 sidescan sonar system and logged to a Triton QMIPS data logging computer.
Unknown
The digital sidescan data were then processed and mapped to provide proper geographic locations of features identified in the imagery. The processing steps included subsampling the raw sidescan data using a median filtering routine to suppress speckle noise and reduce file size, and correct for slant-range distortion, signal attenuation, and dropped sonar lines using XSonar (Danforth et al., 1991). After these processing steps, the imagery was mapped into its proper geographic location using techniques summarized by Paskevich (1996). Individual sidescan swaths were mapped with each pixel geographically positioned at a resolution of 2 m/pixel.
Due to the difficult nature of working in a lake environment, XSonar was modified by Danforth to incorporate the ability to exclude portions of the imagery from the beam angle correction routine. This enabled the stark contrast between highly reflection rock outcrops and fine-grained sediment deposits to be preserved. This enhancement was not available in 1999 when the data were collected, so the data were reprocessed in 2001. Processing the data up to this point was done be VeeAnn Cross.
Danforth, W.W., O'Brien, T.F., and Schwab, W.C., 1991, USGS image processing system: near real-time mosaicking of high-resolution sidescan-sonar data: Sea Technology, Jan., 1991, p. 54-59.
Paskevich, V.F., 1996, MAPIT: An improved method for mapping digital sidescan sonar data using the Woods Hole Image Processing System (WHIPS) software: U.S. Geological Survey Open-File Report 96-281, 73p.
Unknown
Non-overlapping swaths were then brought into the remote sensing software package PCI. The techniques for generating the composite digital sidescan mosaic are summarized by Paskevich (1992). Processing of the data from this point on was done by David C. Twichell.
Paskevich, V.F., 1992, Digital mapping of sidescan sonar data with the Woods Hole Image Processing System software: U.S. Geological Survey Open-File Report 92-536, 87p.
Unknown
Because of the close relationship of the imagery to the topography of the lake, a shaded-relief image generated from the DEM with the 10m contours burned into it was imported to PCI and the sidescan-sonar image strips were georeferenced to it. Misalignments based on the ground control points that were selected between the sidescan-sonar imagery and the DEM after georeferencing were less than 20m in all areas of the lake except a small section of Black Canyon and part of Boulder Canyon.
Unknown
The mosaic then had a linear stretch applied to the data to reduce the valid data range from 0-255 to 0-254. When mapped on a white background, the background can be made transparent in the GIS without affecting the data.
Unknown
Once the mosaics were completed, noise and areas of no data were trimmed from the fringes of the completed mosaic. The lake shoreline as defined by the U.S. Bureau of Reclamation was used to trim noise and nodata areas that fell beyond the limits of the lake.
Unknown
A root stretch was applied in PCI to the sidescan image to help enhance the features. The root stretch was from 15-220 with resulting values between 0 and 254. This was done so that the white background (255) could be made transparent in the GIS.
Unknown
The UTM projected image was the reprojected to Geographic coordinates using BlueMarble's Geographic Transformer software. Transform parameters used a resolution of 2m/pixel and a central latitude of 36N.
Unknown
Edits to the metadata were made to fix any errors that MP v 2.9.34 flagged. This is necessary to enable the metadata to be successfully harvested for various data catalogs. In some cases, this meant adding text "Information unavailable" or "Information unavailable from original metadata" for those required fields that were left blank. Other minor edits were probably performed (title, publisher, publication place, etc.). Added online link to the data in the distribution section. Both geographic and a planar coordinate system were present, the planar one was removed. The distribution format name was modified in an attempt to be more consistent with other metadata files of the same data format. The metadata date (but not the metadata creator) was edited to reflect the date of these changes. The metadata available from a harvester may supersede metadata bundled within a download file. Compare the metadata dates to determine which metadata file is most recent.
20161109
U.S. Geological Survey
VeeAnn A. Cross
Marine Geologist
Mailing and Physical
384 Woods Hole Road
Woods Hole
MA
02543
508-548-8700 x2251
508-457-2310
vatnipp@usgs.gov
USGS Thesaurus keywords added to the keyword section.
20180720
U.S. Geological Survey
VeeAnn A. Cross
Marine Geologist
Mailing and Physical
384 Woods Hole Road
Woods Hole
MA
02543-1598
508-548-8700 x2251
508-457-2310
vatnipp@usgs.gov
Crossref DOI link was added as the first link in the metadata.
20191118
U.S. Geological Survey
VeeAnn A. Cross
Marine Geologist
Mailing and Physical
384 Woods Hole Road
Woods Hole
MA
02543-1598
508-548-8700 x2251
508-457-2310
vatnipp@usgs.gov
Added keywords section with USGS persistent identifier as theme keyword.
20200908
U.S. Geological Survey
VeeAnn A. Cross
Marine Geologist
Mailing and Physical
384 Woods Hole Road
Woods Hole
MA
02543-1598
508-548-8700 x2251
508-457-2310
vatnipp@usgs.gov
Raster
Pixel
7968
12536
1
0.000018
0.000022
Decimal degrees
D_WGS_1984
WGS_1984
6378137.000000
298.257224
The pixel value represents the DN return value of the sidescan-sonar system. A high value (ie 254) indicates a highly reflective lake floor surface, while a low value (ie 0) indicates low reflectance.
U.S. Geological Survey
David C. Twichell
U.S. Geological Survey
Oceanographer
mailing and physical address
384 Woods Hole Rd.
Woods Hole
MA
02543-1598
(508) 548-8700 x2266
(508) 457-2310
dtwichell@usgs.gov
Downloadable Data
Neither the U.S. Government, the Department of the Interior, nor the USGS, nor any of their employees, contractors, or subcontractors, make any warranty, express or implied, nor assume any legal liability or responsibility for the accuracy, completeness, or usefulness of any information, apparatus, product, or process disclosed, nor represent that its use would not infringe on privately owned rights. The act of distribution shall not constitute any such warranty, and no responsibility is assumed by the USGS in the use of these data or related materials. Any use of trade, product, or firm names is for descriptive purposes only and does not imply endorsement by the U.S. Government.
GeoTIFF
BlueMarble Geographic Transformer
The WinZip (version 9.0) file contains the sidescan-sonar GeoTIFF image as well as the TIFF world file and FGDC metadata.
25.7
http://pubs.usgs.gov/of/2003/of03-320/data/sscanimgs/geographic/enhanced/bbasinenh_g.tif
http://pubs.usgs.gov/of/2003/of03-320/data/sscanimgs/geographic/enhanced/bbasinenh_g.tfw
http://pubs.usgs.gov/of/2009/1150/gis/sidescan/bbasinenh_g.zip
CD-ROM
650
MBytes
UDF
None.
The user must be capable of uncompressing the WinZip file. In addition, to view the TIFF image spatially, the user must have software that is capable of reading the GeoTIFF header information, or alternatively, read the TIFF world file spatial reference information.
20240318
VeeAnn A. Cross
U.S. Geological Survey
Marine Geologist
mailing and physical address
384 Woods Hole Rd.
Woods Hole
MA
02543-1598
(508) 548-8700 x2251
(508) 457-2310
whsc_data_contact@usgs.gov
The metadata contact email address is a generic address in the event the person is no longer with USGS. (updated on 20240318)
FGDC Content Standards for Digital Geospatial Metadata
FGDC-STD-001-1998
local time