H11044N_MB10M_UTM18.TIF: Color GeoTIFF Image of the 10-m
Interpolated Bathymetric Grid of the Northern Part of National Oceanic
and Atmospheric Administration (NOAA) Survey H11044 off Milford,
Connecticut (UTM Zone 18, WGS84)
Originator: National Oceanic and Atmospheric
Administration
Originator: U.S. Geological Survey
Publication_Date: 2008
Title:
H11044N_MB10M_UTM18.TIF: Color GeoTIFF Image of the
10-m Interpolated Bathymetric Grid of the Northern Part of National
Oceanic and Atmospheric Administration (NOAA) Survey H11044 off
Milford, Connecticut (UTM Zone 18, WGS84)
During 2001 the NOAA Ship RUDE completed charting survey
H11044 that covered a roughly 293 km2 area of the sea floor in
north-central Long Island Sound, off Milford Connecticut. Although 100
percent coverage was achieved with sidescan sonar for charting
purposes, only reconnaissance (spaced line) bathymetry was acquired
with shallow-water multibeam and single-beam systems. Therefore,
further processing was conducted at the USGS's Woods Hole Science
Center to provide bathymetric datasets with more continuous coverage.
This project produced grids and GeoTIFF imagery of the combined and
interpolated shallow-water multibeam and single-beam bathymetry
generated from the northern part of this data set. Anthropogenic
wastes, toxic chemicals, and changes in land-use patterns resulting
from residential, commercial, and recreational development have
stressed the environment of the Sound, causing degradation and
potential loss of benthic habitats. Detailed maps of the sea floor are
needed to help evaluate the extent of adverse impacts and to help
manage resources wisely in the future. Therefore, in a continuing
effort to better understand Long Island Sound, we have interpolated and
gridded shallow-water multibeam and single-beam bathymetric data within
specific areas of special interest.
Purpose:
To release a color GeoTIFF image of the 10-m interpolated
grid of the shallow-water multibeam and single-beam bathymetry
generated from the northern part of NOAA survey H11044 off Milford,
Connecticut in UTM Zone 18, WGS84.
Time_Period_of_Content:
Time_Period_Information:
Range_of_Dates/Times:
Beginning_Date: 20010507
Ending_Date: 20011113
Currentness_Reference: ground condition
Status:
Progress: Complete
Maintenance_and_Update_Frequency: None planned
Spatial_Domain:
Bounding_Coordinates:
West_Bounding_Coordinate: -73.128976
East_Bounding_Coordinate: -72.933695
North_Bounding_Coordinate: 41.248977
South_Bounding_Coordinate: 41.127854
Keywords:
Theme:
Theme_Keyword_Thesaurus: General
Theme_Keyword: U.S. Geological Survey
Theme_Keyword: USGS
Theme_Keyword: Woods Hole Science Center
Theme_Keyword: shallow-water multibeam
bathymetry
Theme_Keyword: bathymetry
Theme_Keyword: Coastal and Marine Geology
Program
Theme_Keyword: CMGP
Theme_Keyword: WHSC
Theme_Keyword: Reson 8125
Theme_Keyword: NOAA survey H11044
Theme_Keyword: H11044
Theme_Keyword: National Oceanic and
Atmospheric Administration
Theme_Keyword: NOAA
Theme_Keyword: GeoTIFF
Theme_Keyword: Open-File Report 2008-1146
Theme_Keyword: Color
Theme_Keyword: OFR 2008-1146
Theme_Keyword: single-beam bathymetry
Theme_Keyword: interpolated bathymetry
Theme_Keyword: Odom Echotrac DF-3200
Theme:
Theme_Keyword_Thesaurus: ISO 19115 Topic
Category
Theme_Keyword: oceans and estuaries
Theme_Keyword: oceans and coastal
Theme_Keyword: elevation
Theme_Keyword: oceans
Place:
Place_Keyword_Thesaurus: General
Place_Keyword: Connecticut
Place_Keyword: Long Island Sound
Place_Keyword: U.S. East Coast
Place_Keyword: United States
Place_Keyword: North America
Place_Keyword: Atlantic Ocean
Place_Keyword: Milford
Place_Keyword: Charles Island
Place_Keyword: Stratford Point
Access_Constraints: None
Use_Constraints:
Data are not to be used for navigation purposes.
Public domain data are freely redistributable with proper
metadata and source attribution. Please recognize the National Oceanic
and Atmospheric Administration (NOAA) and U.S. Geological Survey (USGS)
as the originators of this information.
All collected data from the northern part of NOAA survey
H11044 were processed and used to produce this dataset.
Positional_Accuracy:
Horizontal_Positional_Accuracy:
Horizontal_Positional_Accuracy_Report:
Navigation was by differential GPS
Vertical_Positional_Accuracy:
Vertical_Positional_Accuracy_Report:
The vertical resolution of the shallow-water
multibeam data is approximately 0.5% of the water depth.
Lineage:
Source_Information:
Source_Citation:
Citation_Information:
Type_of_Source_Media: DVD-ROM
Source_Time_Period_of_Content:
Time_Period_Information:
Range_of_Dates/Times:
Beginning_Date: 20010507
Ending_Date: 20011113
Source_Currentness_Reference: ground
condition
Source_Contribution:
Original processed shallow-water multibeam and
single-beam bathymetric data.
Process_Step:
Process_Description:
The multibeam data were acquired in XTF (extended
Triton data format) and recorded digitally through an ISIS data
acquisition system. A Reson SeaBat 9003 echosounder was used to acquire
the shallow-water multibeam bathymetric data and an Odom Echotrac
DF-3200 dual-frequency echosounder was used to acquire the single-beam
bathymetry from the NOAA ship Rude. An Odom Echotrac DF-3200
dual-frequency echosounder hull-mounted on a 23' launch deployed from
the NOAA ship Rude was used to acquire sounding data in the shallower
areas. These data were processed using CARIS HIPS (Hydrographic Image
Processing System) software for quality control, and to incorporate
sound velocity and tidal corrections. Sound velocity corrections were
derived using frequent SEACAT CTD (conductivity-temperature-depth)
profiles. Typically, a CTD cast was conducted every four to six hours
of multibeam acquisition. Tidal zone corrections were calculated from
data acquired at tidal gauges at Bridgeport and NewHaven, Connecticut,
and at Kings Point, New York. The vertical resolution of the
shallow-water multibeam data is approximately 0.5% of the water depth.
The data were gridded to 1.5-m resolution and exported in text (.txt)
format. Vertical datum is mean lower low water; X and Y units are
decimal degrees.
The PROJ v4.5 cartographic projections library was
used to project the data to UTM zone 18 [proj +proj=utm +zone=18
+ellps=WGS84 -r -s -f %0.2f h11044_1_5mddeg_xyz.txt >
UTM_H11044_1_5m.xyz].
A series of GMT v4.0 (the Generic Mapping Tools) are
run during this process including Minmax to determine the data bounds
and to help identify anomalous values [minmax UTM_H11044_1_5m.xyz]. An
AWK script was run to filter the dataset and prepare it to be processed
thru the GMT block median routine [awk '{if($3>0 && $3<22
$1>4555000) printf "%6.2f\t%7.2f\t%3.2f\n",$2,$1,$3*-1}'
UTM_H11044_1_5m.xyz > sda_44.end].
Based on visual inspection of the removed data points (both their
location and their elevation relation to the surrounding data points)
the values above 22 were indeed anomalous.
GMT v4.0 programs were used to create a 10-m
interpolated GMT grid of the bathymetry. Interpolation was achieved
during GMT processing by running the data through a block median filter
[blockmedian sda_44.end -R656854.36/674854.36/4555000.52/4570000.52/
-I10/10 -V -bod > sda_44.blockmed], a surface generating algorithm
[surface sda_44.blockmed -R656854.36/674854.36/4555000.52/4570000.52/
-Gsda_big44.grd -C0.1 -I10/10 -T1.0 -V -bid], and the grid cut program
[grdcut sda_big44.grd -R656854.36/673134.36/4555000.52/4568110.52/
-Gsda_cut44.grd]. Processing parameters were set to default unless
otherwise noted in the scripts.
The GDAL v1.3.2 (Geospatial Data Abstraction Library)
commandline utility gdal_translate was used to convert the GMT grid
into a 32bit GeoTIFF with proper bounds and projection information
[gdal_translate -sds -a_ullr 656849.36 4554995.52 673139.36 4568115.52
-a_srs EPSG:32618 sda_cut44.grd sda_44_new2.tif].
The GeoTIFF created in GMT/GDAL was then clipped by a
shapefile of the survey extent using ESRI ArcGIS ArcToolbox v9.2
(Spatial Analyst, Extraction, Extract by Mask).
Imported the bathymetry grid into IVS
Fledermaus-DMagic v6.5.1 and created the hillshade file
"h11044_10mutm.shade" with azimuth 45 deg and vertical scale 8x. Opened
the shade file in IVS Fledermaus-ImageViewer v6.5.1-ImageViewer v6.5.1,
and exported it as a GeoTIFF with a world file with an upper left
origin.
There are no attributes associated with the GeoTiff
image. Pixel values convey RGB values of individual cells.
Distribution_Information:
Distributor:
Contact_Information:
Contact_Organization_Primary:
Contact_Organization: U.S. Geological
Survey
Contact_Person: Larry Poppe
Contact_Position: Geologist
Contact_Address:
Address_Type: mailing and physical
address
Address: 384 Woods Hole Road
City: Woods Hole
State_or_Province: MA
Postal_Code: 02543-1598
Country: USA
Contact_Voice_Telephone: (508) 548-8700 x2314
Contact_Facsimile_Telephone: (508) 457-2310
Contact_Electronic_Mail_Address:
lpoppe@usgs.gov
Resource_Description: Downloadable Data
Distribution_Liability:
Neither the U.S. Government, the Department of the Interior,
the USGS, NOAA, Connecticut Department of Environmental Protection, 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.
Any use of trade, product, or firm names is for descriptive purposes
only and does not imply endorsement by the U.S. Government.
Standard_Order_Process:
Digital_Form:
Digital_Transfer_Information:
Format_Name: TIFF
Format_Specification: GEOTIFF
Format_Information_Content:
One file (h11044n_mb10m_utm18.zip) containing the
GeoTIFF, world file, browse graphic and metadata.
Access_Instructions: Data are
downloadable via the World Wide Web (WWW).
Offline_Option:
Offline_Media: DVD-ROM
Recording_Capacity:
Recording_Density: 4.75
Recording_Density_Units: Gbytes
Recording_Format: UDF
Fees: None
Technical_Prerequisites:
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.
Available_Time_Period:
Time_Period_Information:
Single_Date/Time:
Calendar_Date: 2008
Metadata_Reference_Information:
Metadata_Date: 20080930
Metadata_Contact:
Contact_Information:
Contact_Person_Primary:
Contact_Person: Larry Poppe
Contact_Organization: U.S. Geological
Survey
Contact_Position: Geologist
Contact_Address:
Address_Type: mailing and physical
address
Address: 384 Woods Hole Road
City: Woods Hole
State_or_Province: MA
Postal_Code: 02543-1598
Country: USA
Contact_Voice_Telephone: (508) 548-8700 x2314
Contact_Facsimile_Telephone: (508) 457-2310
Contact_Electronic_Mail_Address:
lpoppe@usgs.gov
Metadata_Standard_Name: FGDC Content Standards for
Digital Geospatial Metadata