BATHY_05M: Bathymetric data, stored as elevations relative to IGLD85, collected by the U.S. Geological Survey within the St. Clair River between Michigan and Ontario, Canada, 2008 (ESRI GRID)

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Metadata:


Identification_Information:
Citation:
Citation_Information:
Originator: U.S. Geological Survey
Publication_Date: 2010
Title:
BATHY_05M: Bathymetric data, stored as elevations relative to IGLD85, collected by the U.S. Geological Survey within the St. Clair River between Michigan and Ontario, Canada, 2008 (ESRI GRID)
Edition: 1.0
Geospatial_Data_Presentation_Form: raster digital data
Series_Information:
Series_Name: Open-File Report
Issue_Identification: 2010-1035
Publication_Information:
Publication_Place: Woods Hole Coastal and Marine Science Center, Woods Hole, MA
Publisher: U.S. Geological Survey
Online_Linkage:
<http://pubs.er.usgs.gov/of/2010/1035/gis_catalog/bathymetry/bathy_05m/bathy_05m.zip>
Online_Linkage: <https://pubs.usgs.gov/of/2010/1035/html/gis.html>
Larger_Work_Citation:
Citation_Information:
Originator: Jane F. Denny
Originator: David S. Foster
Originator: Charles R. Worley
Originator: Barry J.Irwin
Publication_Date: 2010
Title:
Geophysical data collected from the St. Clair River between Michigan and Ontario, Canada, 2008-016-FA
Edition: 1.0
Geospatial_Data_Presentation_Form: online
Series_Information:
Series_Name: Open-File Report
Issue_Identification: 2010-1035
Publication_Information:
Publication_Place: Woods Hole Coastal and Marine Science Center
Publisher: U.S. Geological Survey
Online_Linkage: <https://pubs.usgs.gov/of/2010/1035/>
Description:
Abstract:
In 2008, the U.S. Geological Survey (USGS), Woods Hole Coastal and Marine Science Center (WHCMSC), in cooperation with the U.S. Army Corps of Engineers conducted a geophysical and sampling survey of the riverbed of the Upper St. Clair River between Port Huron, MI, and Sarnia, Ontario, Canada. The objectives were to define the Quaternary geologic framework of the St. Clair River to evaluate the relationship between morphologic change of the riverbed and underlying stratigraphy. This report presents the geophysical and sample data collected from the St. Clair River, May 29-June 6, 2008 as part of the International Upper Great Lakes Study, a 5-year project funded by the International Joint Commission of the United States and Canada to examine whether physical changes in the St. Clair River are affecting water levels within the upper Great Lakes, to assess regulation plans for outflows from Lake Superior, and to examine the potential effect of climate change on the Great Lakes water levels ( <http://www.iugls.org>). This document makes available the data that were used in a separate report, U.S. Geological Survey Open-File Report 2009-1137, which detailed the interpretations of the Quaternary geologic framework of the region. This report includes a description of the suite of high-resolution acoustic and sediment-sampling systems that were used to map the morphology, surficial sediment distribution, and underlying geology of the Upper St. Clair River during USGS field activity 2008-016-FA . Video and photographs of the riverbed were also collected and are included in this data release. Future analyses will be focused on substrate erosion and its effects on river-channel morphology and geometry. Ultimately, the International Upper Great Lakes Study will attempt to determine where physical changes in the St. Clair River affect water flow and, subsequently, water levels in the Upper Great Lakes.
Purpose:
This grid represents approximately 100 kilometers of swath bathymetric data collected within the Upper St. Clair River, May 29 - June 4, 2008. These data are used to define the morphology of the riverbed.
Time_Period_of_Content:
Time_Period_Information:
Range_of_Dates/Times:
Beginning_Date: 20080529
Ending_Date: 20080601
Currentness_Reference: ground condition
Status:
Progress: Complete
Maintenance_and_Update_Frequency: None planned
Spatial_Domain:
Bounding_Coordinates:
West_Bounding_Coordinate: -82.429028
East_Bounding_Coordinate: -82.400587
North_Bounding_Coordinate: 43.015839
South_Bounding_Coordinate: 42.955703
Keywords:
Theme:
Theme_Keyword_Thesaurus: General
Theme_Keyword: U.S. Geological Survey
Theme_Keyword: USGS
Theme_Keyword: Woods Hole Coastal and Marine Science Center
Theme_Keyword: WHCMSC
Theme_Keyword: Coastal and Marine Geology Program
Theme_Keyword: CMGP
Theme_Keyword: bathymetry
Theme_Keyword: swath bathymetry
Theme_Keyword: interferometry
Theme_Keyword: SEA SWATHplus 234 kHz
Theme_Keyword: sea-floor morphology
Theme_Keyword: WHCMSC field activity serial number 08016 (2008-016-FA)
Theme_Keyword: ESRI Grid
Theme_Keyword: USGS R/V Rafael
Theme:
Theme_Keyword_Thesaurus: ISO 19115 Topic Category
Theme_Keyword: elevation
Theme_Keyword: geoscientificInformation
Theme_Keyword: imageryBaseMapsEarthCover
Theme_Keyword: inlandWaters
Place:
Place_Keyword_Thesaurus: General
Place_Keyword: North America
Place_Keyword: United States
Place_Keyword: Michigan
Place_Keyword: Great Lakes
Place_Keyword: Upper Great Lakes
Place_Keyword: Lake Huron
Place_Keyword: St. Clair River
Place_Keyword: Upper St. Clair River
Place_Keyword: Canada
Place_Keyword: Ontario
Access_Constraints: None
Use_Constraints:
These data are NOT to be used for navigation. Public domain data from the U.S. Government are freely redistributable with proper metadata and source attribution. Please recognize the U.S. Geological Survey as the originator of the dataset.
Point_of_Contact:
Contact_Information:
Contact_Person_Primary:
Contact_Person: Jane F. Denny
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
Country: USA
Contact_Voice_Telephone: 508-548-8700 x2311
Contact_Facsimile_Telephone: 508-457-2310
Contact_Electronic_Mail_Address: jdenny@usgs.gov
Browse_Graphic:
Browse_Graphic_File_Name:
<https://pubs.usgs.gov/of/2010/1035/gis_catalog/bathymetry/bathy_05m/bathy_05m_sm.jpg>
Browse_Graphic_File_Description: Thumbnail image of the color-coded swath bathymetry
Browse_Graphic_File_Type: JPEG
Native_Data_Set_Environment:
Microsoft Windows XP Version 5.1 (Build 2600) Service Pack 3; ESRI ArcCatalog 9.2.6.1500
Cross_Reference:
Citation_Information:
Originator: David S. Foster
Originator: Jane F. Denny
Publication_Date: 2009
Title:
Quaternary Geologic Framework of the St. Clair River between Michigan and Ontario, Canada
Edition: 1.0
Geospatial_Data_Presentation_Form: on-line document
Series_Information:
Series_Name: Open-File Report
Issue_Identification: 2009-1137
Publication_Information:
Publication_Place: Woods Hole Coastal and Marine Science Center, Woods Hole, MA
Publisher: U.S. Geological Survey, Coastal and Marine Geology Program
Online_Linkage: <https://pubs.usgs.gov/of/2009/2009/1137/>

Data_Quality_Information:
Logical_Consistency_Report:
All bathymetric data were collected during USGS cruise 08016 using a SWATHplus 234-kHz swath bathymetric system and an Octopus F180R Attitude and Positioning System. Quality control was conducted during processing of the data. Any spurious data or artifacts were removed or minimized.
Completeness_Report:
Lines 1 - 65 of swath bathymetric data were processed and used to generate the final bathymetric grid. Gaps present in this data set fall within shallow water areas where the swath width of the bathymetric system decreased to less than the 75-m survey trackline spacing. Data gaps at the beginning of survey lines 1 and 2 are due to deletion of poor quality data at the beginning of the line; the bathymetric system was not tracking bottom (i.e. the riverbed). Data gaps along the northeastern and southeastern edge of the survey are due to insufficient bottom coverage with the SWATHplus system.
Positional_Accuracy:
Horizontal_Positional_Accuracy:
Horizontal_Positional_Accuracy_Report:
Differential Global Positioning System (DGPS) navigation data were acquired with the forward, or primary, Octopus F180R Attitude and Positioning system DGPS antenna and transmitted via a network connection to the SWATHplus data collection software. The F180R Attitude and Positioning system uses 2 L1 antennas for position and heading and an Inertial Measurement Unit (IMU) for motion sensing. The F180R IMU is mounted on the rigid sidemount used to deploy the SWATHplus bathymetric system, and is located directly above the SWATHplus transducers. The F180R antennas are mounted on a rigid horizontal pole, 3 meters above the F180R IMU, offset in a forward/aft configuration (see 'source contribution' for a full description of the F180R). DGPS accuracy is 1 to 3 meters, depending on the distance from a US Coast Guard coastal repeater station (<http://www.navcen.uscg.gov/>).
Vertical_Positional_Accuracy:
Vertical_Positional_Accuracy_Report:
DGPS navigation was used to record horizontal and vertical position (x,y,z) of bathymetric soundings during data acquisition aboard the USGS R/V Rafael. An additional DGPS antenna, connected to an Ashtech Z-Xtreme receiver, was attached at the center of the rigid horizontal pole used to mount the Octopus F180R Attitude and Positioning system antennas. Real Time Kinematic GPS (RTK-GPS) corrections were applied to the Ashtech Z-Xtreme navigation data during post-processing in order to provide sub-meter vertical accuracy for bathymetric soundings. Fort Gratiot, MI, a Continuously Operating Reference Station (CORS) (<http://www.ngs.noaa.gov/CORS/>), was used as the reference station for the RTK-GPS corrections. A rover RTK-GPS station was established at the tidal benchmark at the U.S. Coast Guard Base at Port Huron in order to determine the offset between North American Vertical Datum of 1988 (NAVD 88) (vertical datum referenced at the CORS site) and the International Great Lakes Datum 1985 (IGLD 85) referenced at the tidal benchmark. The following offsets were applied to the shipboard DGPS data during post-processing: vertical offset between NAVD 88 and IGLD 85, the measured distance between the DGPS antenna and SWATHplus transducer, and the depth of the transducer below the water line. The resulting values were applied to the bathymetric soundings during processing to provide a measure of depth relative to IGLD 85.
Lineage:
Source_Information:
Source_Citation:
Citation_Information:
Originator: U.S. Geological Survey
Type_of_Source_Media: disc
Source_Time_Period_of_Content:
Time_Period_Information:
Range_of_Dates/Times:
Beginning_Date: 20080529
Ending_Date: 20080602
Source_Currentness_Reference: ground condition
Source_Contribution:
Swath-bathymetric and acoustic-backscatter data were acquired with a SEA, Ltd., SWATHplus interferometric sonar operating at a 234-kHz frequency (<http://www.sea.co.uk/swathplus.aspx?nav=products>). The SWATHplus transducer was mounted at the bow of the USGS R/V Rafael. Bathymetric data were acquired over variable swath widths ranging from 10 to 100 m, in water depths of about 1 to 25 m. A total of 109 km of swath bathymetric data were collected.

SWATHplus acquisition software (version 3.05.90) was used to digitally log the bathymetric data at a rate of 30 pings/second and 3,072 samples per swath (ping) in the SWATHplus SXR format. Data collection parameters are saved into a SWATHplus session file in SEA's SXS format. These files can be later used for data replay.

An Octopus F180R Attitude and Positioning system (see: <http://www.codaoctopus.com/motion/f180/index.asp>) recorded ship motion (heave, pitch, roll, and yaw). These data were transmitted via network connection to the SWATHplus data collection software. The Octopus F180R Inertial Measurement Unit (IMU) was mounted directly above the SWATHplus transducers, to minimize lever arm offsets that can lead to positioning errors. The F180R uses two L1 antennas for position and heading accuracy. The antennas are mounted on a rigid horizontal pole, 3 meters above the F180R IMU, with a horizontal separation of 1 meter and are offset from the IMU in a forward/aft configuration. The forward offset of the primary antenna from the IMU is 0.5 meters, with no port/starboard offset.

Eight sound-velocity profiles were acquired during survey operations at roughly 4-hr intervals using an Applied Microsystems SV Plus V2 Velocimeter (Applied Microsystems, 2008).

Process_Step:
Process_Description:
SWATHplus Configuration

Offsets of the SWATHplus transducers and DGPS navigation antenna from the Octopus F180R Attitude and Positioning System Inertial Measurement Unit (IMU), which is the designated common reference point (CRP), were verified as entered correctly into the SWATHplus session file for the survey. Offsets forward, below, and to the right (starboard) of the CRP are considered positive:

Primary navigation antenna to IMU: Height offset: -3 meters, Forward offset: 0 meters, Starboard offset: 0 meters

Draft of the MRU below water line: 0.63 meters.

Offset of SWATHplus transducer 1 (port side) from the CRP: Height offset: 0.158 meters Forward offset: -0.019 meters Starboard offset: -0.11 meters

Offset of SWATHplus transducer 2 (starboard side) from the CRP: Height offset: 0.158 meters Forward offset: -0.019 meters Starboard offset: 0.11 meters

Software: SWATHplus 3.05.19.0

Process_Date: 2009
Process_Contact:
Contact_Information:
Contact_Person_Primary:
Contact_Person: Jane Denny
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
Country: USA
Contact_Voice_Telephone: 508-548-8700 x 2311
Contact_Facsimile_Telephone: 508-457-2310
Contact_Electronic_Mail_Address: jdenny@usgs.gov
Process_Step:
Process_Description:
Sound Velocity Profiles

Data from eight sound velocity profiles were incorporated into the SWATHplus session file. The velocity data is stored in Microsoft Office Excel 2003 SP3 commas-separated values (csv) format, and the location and time, as well as the velocity information, were extracted from the csv file and entered into the sound velocity profile dialog in SWATHplus. Sound velocity information closest in time to the bathymetric data collected are utilized by the SWATHplus program to correct for variations in sound velocity through the water column, minimizing ray bending effects that can produce erroneous depth soundings.

Software: SWATHplus 3.05.19.0

Process_Date: 2009
Process_Contact:
Contact_Information:
Contact_Person_Primary:
Contact_Person: Jane Denny
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
Contact_Voice_Telephone: (508) 548-8700x2311
Contact_Facsimile_Telephone: 508-457-2310
Contact_Electronic_Mail_Address: jdenny@usgs.gov
Process_Step:
Process_Description:
Bathymetric Filters

Various filters were set in the SWATHplus software in order to refine the depth of the seafloor across the swath for each ping based on the phase and amplitude of the returning sonar signal. Only the filters listed below were set, all others were turned off. Filter settings:

Low amp: 100; Range: Max amplitude 1 meter, min amplitude 0 meters; Phase Confidence: 70 percent; Angle Proximity: 25 sample window, range 0.11, threshold 9 samples, Minimum elevation -120 degrees; Box: Minimum Depth 0 meters, Minimum Horizontal Range 1 meter; Median sample window size 5; Along track 1: Max depth difference 10 meters, window size 5, learn rate 0.6 Along track 2: Max depth difference 5 meters, window size 1, learn rate 0.9; Mean output processed pixel size: 0.2 meters.

Software: SWATHplus 3.05.19.0

Process_Date: 2009
Process_Contact:
Contact_Information:
Contact_Person_Primary:
Contact_Person: Jane Denny
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
Contact_Voice_Telephone: (508) 548-8700x2311
Contact_Facsimile_Telephone: 508-457-2310
Contact_Electronic_Mail_Address: jdenny@usgs.gov
Process_Step:
Process_Description:
Patch Test

Patch test, used to asses roll offset, lines were replayed through the SWATHplus software after the velocity profiles (for that day) and filters were set and saved in the SWATHplus session file. Processed data files were saved in the SWATHplus sxp format.

The patch test processed sxp files (p1 through p8.sxp) were imported into the SWATHplus Grid Processor program and run 2 times through the calibration tool to determine any static offsets for roll. Results: Port roll offset = +0.254 degrees, Stbd roll offset = -1.037 degrees. These offsets were then entered into the SWATHplus session file.

Software: SWATHplus Grid Processor 3.05.19.0

Process_Date: 2009
Process_Contact:
Contact_Information:
Contact_Person_Primary:
Contact_Person: Jane Denny
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
Contact_Voice_Telephone: (508) 548-8700x2311
Contact_Facsimile_Telephone: 508-457-2310
Contact_Electronic_Mail_Address: jdenny@usgs.gov
Process_Step:
Process_Description:
Post-Processed Navigation (RTK corrections applied to DGPS data):

The Ashtech Z-Xtreme receiver collected position (x,y) and elevation (z) data of the DGPS antenna during survey operations (see: Source Contribution for antenna configuration). DGPS position data (xyz) were recorded with HYPACK Hydrographic Survey Software (<http://www.hypack.com/>). Real-Time Kinematic (RTK) corrections based on vertical position data from the Fort Gratiot, Michigan National Geodetic Survey Continuously Operating Reference Stations (CORS) were applied to the recorded antenna heights (z) during post-processing using NovAtels Waypoint GrafNav post-processing high-precision package, a static kinematic/baseline processor (<http://www.novatel.com/>). A rover RTK-GPS station was established at the tidal benchmark at the U.S. Coast Guard Base at Port Huron in order to determine the offset between North American Vertical Datum of 1988 (NAVD 88) (vertical datum referenced at the CORS site) and the International Great Lakes Datum 1985 (IGLD 85) referenced at the tidal benchmark.

An offset was applied to the RTK-corrected antenna heights to convert the reference heights to the local chart datum, International Great Lakes Datum 1985 (IGLD85). Additional offsets were applied to translate the height of the antenna to the waterline. The resulting data file contained date, time (every second) and height of waterline relative to IGLD85.

(Navigation data are stored in American Standard Code for Information Interchange (ASCII) files. Offsets were applied using GNUs Not Unix (GNU) gawk 3.1.5 programming language).

NovAtel GrafNav 8.1.0; GNU gawk 3.1.5; HYPACK 8.2.3.7

Process_Date: 2009
Process_Contact:
Contact_Information:
Contact_Person_Primary:
Contact_Person: Jane Denny
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
Contact_Voice_Telephone: (508) 548-8700x2311
Contact_Facsimile_Telephone: 508-457-2310
Contact_Electronic_Mail_Address: jdenny@usgs.gov
Process_Step:
Process_Description:
The date, time (every second) and height of waterline relative to IGLD85 were imported to The MathWorks MATLAB technical computing software (version 7.4.0 (R2007a)). A median filter (medfilt1) using a 361 boxcar (approximately a 6 minute filter) was applied to smooth the chatter present in the elevation data. The filtered elevations were then exported from MATLAB. A GNU gawk script was used to downsample the output file from every second to every minute:

BEGIN { latmin = 0.0}{min= substr($1,4,2); if(lastmin !=min) {printf("%s %s %.2f\n", $1, $2, $3)} lastmin=min;}

The filtered elevations at one-minute time intervals were then entered into SEA, LTD SWATHplus software as a Tide in the following format: HR:MN DD/MM/YYYY XXX.XX, where HR=hour, MN=minute, DD=day, MM= month, YYYY=year, XXX.XX=tide.

MATLAB 7.4.0 (R2007a)

Process_Date: 2009
Process_Contact:
Contact_Information:
Contact_Person_Primary:
Contact_Person: Jane Denny
Contact_Organization: U.S. Geological Survey
Contact_Position: Geologist
Contact_Address:
Address_Type: mailing and physical address
Address: 384 Woods Hole Rd.
City: Woods Hole
State_or_Province: MA
Postal_Code: 02543-1598
Contact_Voice_Telephone: (508) 548-8700x2311
Contact_Facsimile_Telephone: 508-457-2310
Contact_Electronic_Mail_Address: jdenny@usgs.gov
Process_Step:
Process_Description:
Raw SXR bathymetry data were replayed line by line through the SEA SWATHplus software to generate processed SWATHplus sxp files. The following information was stored within the SWATHplus session files and applied to the raw bathymetric soundings: eight sound velocity profiles, TIDE (RTK-corrected water level heights relative to IGLD85), roll offsets calculated during pre-survey patch test, draft of the transducer below the water line, and the measured angles and relative positions of the swath bathymetric transducers. The SWATHplus software applies the pitch, roll, heave, and heading data supplied by the F180R IMU, to compensate depth solutions across the swath for any ship motion.

Software: SWATHplus 3.05.19.0

Process_Date: 2009
Process_Contact:
Contact_Information:
Contact_Person_Primary:
Contact_Person: Jane Denny
Contact_Organization: U.S. Geological Survey
Contact_Position: Geologist
Contact_Address:
Address_Type: mailing and physical address
Address: 384 Woods Hole Rd.
City: Woods Hole
State_or_Province: MA
Postal_Code: 02543-1598
Contact_Voice_Telephone: (508) 548-8700x2311
Contact_Facsimile_Telephone: 5084572310
Contact_Electronic_Mail_Address: jdenny@usgs.gov
Process_Step:
Process_Description:
All the processed SWATHplus sxp files were imported into CARIS HIPS/SIPS Hydrographic Data Processing System software (www.caris.com) using the CARIS HIPS Conversion Wizard (specifying the SWATHplus format, RawData (sxp files), a CARIS HIPS project, vessel, and julian day, ground coordinates [UTM zone 17N WGS84] and speed of sound of 1450 meters/second as measured at the SWATHplus transducer face). The conversion wizard converts depth, navigation, and motion data recorded in the sxp files into an internal CARIS HIPS format.

The SXP files were then edited using the following filters: across track distance 7 times nadir depth (reduces the swath width to seven times the water depth in order to reduce noise in the outer range), across track angle of 2 degrees (calculates the slope of each beam in degrees to the prior and post beams within the same swath. If slopes exceed the specified value and are of opposite sign the beam is rejected), Missing neighbors: port and starboard, forward and aft, and any 2 of 4 (filters the soundings if neighboring soundings to the port and starboard, forward and aft, or if two of the four neighboring beams are missing) (<http://www.caris.com>). Individual files were further edited with the SWATH EDITOR where remaining outliers were manually removed.

Field sheets were then created with UTM zone 17N, WGS84 projection and used to organize the processed bathymetric data and generate A Bathymetry Associated with Statistical Error (BASE) surfaces. Three BASE surfaces were created at the following resolutions: 0.5, 2.0 and 5.0 meters and the swath angle Surface Type (default). The maximum footprint size in the BASE surface that a sounding was utilized was set to 9 pixels, and the include status for soundings were set to accepted, examined, and outstanding.

Each of the BASE surfaces was interpolated in CARIS HIPS. The interpolation is only applied to areas of no data, and helped to fill in small gaps in the surface. Parameters used for the interpolation were: Matrix size 5X5 pixels, minimum number of neighboring pixels required for interpolation was 6.

Software: CARIS HIPS/SIPS 6.1

Process_Date: 2009
Process_Contact:
Contact_Information:
Contact_Person_Primary:
Contact_Person: Jane F. Denny
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: 02536
Country: USA
Contact_Voice_Telephone: 508-548-8700 x 2311
Contact_Facsimile_Telephone: 508-457-2310
Contact_Electronic_Mail_Address: jdenny@usgs.gov
Process_Step:
Process_Description:
Interactive Visualization Systems (IVS) Data Magician software (version 6.7.0k) was used to import the CARIS BASE surfaces. These data were imported as Gridded Data in the CARIS Base Surface File Type. The CARIS Base Surfaces were converted and saved in IVS dtm and geo format.

The 0.5 m bathymetric grid contained data gaps at nadir. The filters used within the SWATHplus software eliminated noisy data near nadir, resulting in data gaps of less than 5 meters at nadir. To fill these data gaps, the IVS command dtmmerge from within the Fledermaus Commander was used to merge the high-resolution 0.5 meter grid with the lower resolution 2.0 grid.

Dtmmerge in file1_highres.dtm file2_lowres.dtm out output.dtm cellsize 0.5

By default, the lower resolution grid is used to fill data gaps present within the higher resolution grid, with the output grid reflecting the high-resolution input grid: 0.5 meters.

After merging the 0.5- and 2.0-meter grids, several data gaps remained in areas where adjacent tracklines did not provide complete coverage of the riverbed. Dtmmerge was run again using the output from the first pass (merging the 0.5 and 2 meters grids) and the 5-m resolution grid in order to minimize data gaps between lines.

The final grid, bathy_05m, was exported from IVS Data Magician as an Arcview Grid (ESRI ASCII grid) (bathy_05m_m.asc).

Software: IVS DMagic 6.7.0

Process_Date: 2009
Process_Contact:
Contact_Information:
Contact_Person_Primary:
Contact_Person: Jane F. Denny
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: 02536
Country: USA
Contact_Voice_Telephone: 508-548-8700 x 2311
Contact_Facsimile_Telephone: 508-457-2310
Contact_Electronic_Mail_Address: jdenny@usgs.gov
Process_Step:
Process_Description:
The ESRI ASCII grid (bathy_05m_m.asc) was then imported to ArcGIS 9.2 using the ASCII to Raster Tool within ArcToolbox - Conversion Tools - To Raster.

The projection of the grids was then defined as UTM, zone 17N, WGS84, using Arc Toolbox, Data Management Tools, Projections and Transformations, Define Projection.

In order to reduce spurious bathymetric points along the perimeter of the bathymetric grid, the border of the grid was digitized and saved as a polygon shapefile (border.shp). The Spatial Analyst Tool Extraction Extract by Mask was then used to clip the bathymetric grid (bathy_05m_m) based on the digitized border (border.shp), thus eliminating spurious points at the edges of the bathymetric grid. The output clipped grid was stored as bathy_05m.

Software: ESRI ArcGIS 9.2

Process_Date: 2009
Process_Contact:
Contact_Information:
Contact_Person_Primary:
Contact_Person: Jane F. Denny
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: 02536
Country: USA
Contact_Voice_Telephone: 508-548-8700 x 2311
Contact_Facsimile_Telephone: 508-457-2310
Contact_Electronic_Mail_Address: jdenny@usgs.gov
Process_Step:
Process_Description:
The bathymetric grid was converted from RASTER to ASCII using ArcGIS 9.2, ArcToolbox, Conversion Tools, From Raster, Raster to ASCII.

ArcGIS 9.2

Process_Date: 2010
Process_Contact:
Contact_Information:
Contact_Person_Primary:
Contact_Person: Jane Denny
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
Country: USA
Contact_Voice_Telephone: 508-548-8700 x 2311
Contact_Facsimile_Telephone: 508-457-2310
Contact_Electronic_Mail_Address: jdenny@usgs.gov

Spatial_Data_Organization_Information:
Direct_Spatial_Reference_Method: Raster
Raster_Object_Information:
Raster_Object_Type: Grid Cell
Row_Count: 13285
Column_Count: 4415
Vertical_Count: 1

Spatial_Reference_Information:
Horizontal_Coordinate_System_Definition:
Planar:
Grid_Coordinate_System:
Grid_Coordinate_System_Name: Universal Transverse Mercator
Universal_Transverse_Mercator:
UTM_Zone_Number: 17
Transverse_Mercator:
Scale_Factor_at_Central_Meridian: 0.999600
Longitude_of_Central_Meridian: -81.000000
Latitude_of_Projection_Origin: 0.000000
False_Easting: 500000.000000
False_Northing: 0.000000
Planar_Coordinate_Information:
Planar_Coordinate_Encoding_Method: row and column
Coordinate_Representation:
Abscissa_Resolution: 0.500021
Ordinate_Resolution: 0.500021
Planar_Distance_Units: meters
Geodetic_Model:
Horizontal_Datum_Name: D_WGS_1984
Ellipsoid_Name: WGS_1984
Semi-major_Axis: 6378137.000000
Denominator_of_Flattening_Ratio: 298.257224
Vertical_Coordinate_System_Definition:
Altitude_System_Definition:
Altitude_Datum_Name: International Great Lakes Datum (IGLD) 1985
Altitude_Resolution: 0.5
Altitude_Distance_Units: meters
Altitude_Encoding_Method: Explicit depth coordinate included with horizontal coordinates

Distribution_Information:
Distributor:
Contact_Information:
Contact_Person_Primary:
Contact_Person: Jane Denny
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
Country: USA
Contact_Voice_Telephone: 508-548-8700 x2311
Contact_Facsimile_Telephone: 508-457-2310
Contact_Electronic_Mail_Address: jdenny@usgs.gov
Resource_Description: Downloadable Data
Distribution_Liability:
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.

Standard_Order_Process:
Digital_Form:
Digital_Transfer_Information:
Format_Name: WinZip
Format_Version_Number: 9.0
Format_Information_Content:
WinZip file containing ASCII raster grid, ESRI binary grid and metadata for bathymetric data collected during USGS cruise 08016.
File_Decompression_Technique: Use WinZip or pkUnzip
Transfer_Size: 233.904
Digital_Transfer_Option:
Online_Option:
Computer_Contact_Information:
Network_Address:
Network_Resource_Name:
htp://pubs.usgs.gov/of/2010/1035/gis_catalog/bathymetry/bathy_05m.zip
Access_Instructions: Data can be downloaded via the World Wide Web (WWW)
Fees: none
Technical_Prerequisites:
The grid contained in the bathy_05m.zip file is available as an ESRI Binary grid and an ASCII grid with an ESRI header. However, the folder structure within bathy_05m.zip is critical to proper use of the ESRI binary grid.

To utilize these data, the user must have a GIS software package capable of reading ESRI Binary grids or ASCII grids with ESRI headers, or be able to manipulate an ASCII matrix with a geospatial header. The ASCII raster files can be easily converted to ESRI grid format in either ArcView with Spatial Analyst extension (Import Data Source: ASCII Raster) or ArcGIS with Spatial Analyst extension (ASCII to Raster). The user should select floating point grid (as opposed to integer grid) when converting the bathymetry data.


Metadata_Reference_Information:
Metadata_Date: 20110125
Metadata_Contact:
Contact_Information:
Contact_Organization_Primary:
Contact_Organization: U.S. Geological Survey
Contact_Person: Jane F. Denny
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: 02536
Country: USA
Contact_Voice_Telephone: 508-548-8700 x2311
Contact_Facsimile_Telephone: 508-457-2310
Contact_Electronic_Mail_Address: jdenny@usgs.gov
Metadata_Standard_Name: FGDC Content Standards for Digital Geospatial Metadata
Metadata_Standard_Version: FGDC-STD-001-1998
Metadata_Time_Convention: local time
Metadata_Access_Constraints: none
Metadata_Use_Constraints: none
Metadata_Extensions:
Online_Linkage: <http://www.esri.com/metadata/esriprof80.html>
Profile_Name: ESRI Metadata Profile

Generated by mp version 2.8.25 on Tue Jan 25 16:41:59 2011