Hudson River Estuary Bathymetric Contours

Metadata also available as


Marine Sciences Research Center, State University of New York at Stony Brook
Publication_Date: 2007
Title: Hudson River Estuary Bathymetric Contours
Geospatial_Data_Presentation_Form: vector digital data
Series_Name: Hudson River Estuary Program
Issue_Identification: Benthic Mapping Project
Publication_Place: Albany, NY
Publisher: New York State Department of Environmental Conservation
This data set consists of contoured bathymetry. Multibeam bathymetry data was collected with a Simrad EM 3000 system and referenced to NAVD 1988.
These data were collected as part of the Hudson River Benthic Mapping Project. Purpose of the Hudson River Benthic Mapping Project of the New York State DEC is to create a comprehensive map of the bottom of the Hudson River Estuary, its sediment distribution and habitat for species of interest. Several observational datasets including water depth (bathymetry), backscatter, subbottom profiles, sediment samples, and sediment profile imagery were collected to describe the physical environment of the estuary floor.
- Bell, R.E., R.D. Flood, S. Carbotte, W.B.F. Ryan, C. McHugh, M. Cormier, R. Versteeg, H. Bokuniewicz, V.L. Ferrini, J. Thissen, J.W. Ladd, E. A. Blair, 2006, Benthic habitat mapping in the Hudson River Estuary, in J. Levinton and J. Waldman(editors), The Hudson River Estuary, Cambridge Univ Press., pp 51-64.
- Carbotte, S.M., R.E. Bell, W.B.F. Ryan, C. McHugh, A. Slagle, F.O. Nitsche , J. Rubenstone, 2004, Environmental change and oyster colonization within the Hudson River estuary linked to Holocene climate, Geo-Marine Letters, 24, 212-224.
- McHugh, C.M.G., Pekar, S.F., Christie-Blick, N., Ryan, W.B.F., Carbotte, S., Bell, R., 2004. Spatial variations in a condensed interval between estuarine and open marine settings: Holocene Hudson River Estuary and adjacent continental shelf, Geology, 32 (2): 169-172.
- Nitsche, F.O., Bell, R., Carbotte, S.M., Ryan, W.B.F., Flood, R., 2004. Process-related classification of acoustic data from the Hudson River Estuary, Marine Geology, 209(1-4): 131-145.
- Nitsche, F.O. R. Bell, S.M. Carbotte, W.B.F. Ryan, A. Slagle, S. Chillrud, T. Kenna, R. Flood, V. Ferrini, R. Cerrato, C. McHugh, D. Strayer, 2005, Integrative acoustic mapping reveals Hudson River sediment processes and habitats, EOS 86(24), pp
- Nitsche, F.O., S. Carbotte, W.B.F. Ryan and R. Bell, 2005, A seabed classification approach based on multiple acoustic sensors in the Hudson River Estuary, in D.M. FitzGerald and J. Knight (editors) High Resolution Morphodynamics and Sedimentary Evolution of Estuaries: Springer, pp 33-55..
- Nitsche, F.O., W.B.F. Ryan, S.M. Carbotte, R.E. Bell, A. Slagle, C. Bertinado, R. Flood, T. Kenna, C. McHugh, 2007, Regional patterns and local variations of sediment distribution in the Hudson River Estuary, Estuarine, Coastal and Shelf Science, 71, 259-277.
- Pekar, S.F., McHugh, C.M.G., Christie-Blick, N., Jones, M., Carbotte, S.M., Bell, R.E., Lynch-Stieglitz, J., 2004, Estuarine processes and their stratigraphic record: paleosalinity and sedimentation changes in the Hudson Estuary (North America), Marine Geology, 209(1-4): 113-129.
- Slagle, et al., 2006, Late-stage estuary infilling controlled by limited accommodation space in the Hudson River. Marine Geology, Volume 232, Issues 3-4, Pages 181-202.
- Strayer, D.L., M.M. Malcolm, R.E. Bell, S.M. Carbotte, F.O. Nitsche, 2006, Using geophysical information to define benthic habitats in a large river, Freshwater Biology 51, 25?38
-Area A1 survey dates: 5/11/1999-5/14/1999
-Area A2 survey dates:11/17/1998-12/04/1998
-Area A3 survey dates: 11/24/1998-12/03/1998
-Area A3 survey dates: 5/17/1999 - 5/19/1999
-Area A4 survey dates: 5/19/1999 - 5/21/1999
-Harbor survey dates: 7/16/2002 - 7/19/2002 and 9/24/2002 - 9/29/2002
-Area B0 survey dates: 6/01/2003 - 6/05/2003 and 6/24/2003 - 6/28/2003
-Area B1 survey dates: 6/01/2003 - 6/05/2003 and 6/24/2003 - 6/28/2003
-Area B2 survey dates: 6/11/2001 - 6/22/2001
-Area B3 survey dates: 6/22/2001 - 6/29/2001
-Area B4 survey dates: 10/22/2001 - 11/08/2001
-Area B5 survey dates: 5/21/2003 - 5/31/2003
-Area B6 survey dates: 5/21/2003 - 5/31/2003
-Area B7 survey dates: 10/30/2001 - 11/07/2001
-Area B8 survey dates: 5/17/2003 - 5/20/2003
-Area B9 survey dates: 5/17/2003 - 5/20/2003
Beginning_Date: 1998
Ending_Date: 2003
Currentness_Reference: publication date
Progress: Complete
Maintenance_and_Update_Frequency: None planned
West_Bounding_Coordinate: -74.075
East_Bounding_Coordinate: -73.685
North_Bounding_Coordinate: 42.753
South_Bounding_Coordinate: 40.600
Theme_Keyword_Thesaurus: None
Theme_Keyword: Hudson River
Theme_Keyword: bathymetry
Theme_Keyword: depth
Theme_Keyword: estuary
Access_Constraints: None
none; Roger Flood, Marine Sciences Research Center, State University of New York at Stony Brook, requests to be acknowledged as the originator of the data in future products or derivative research.
Contact_Person: John Ladd
Contact_Organization: Hudson River National Estuarine Research Reserve, NYS DEC
Address_Type: mailing and physical address
Address: Norrie Point Environmental Center
Address: PO Box 315
City: Staatsburg
State_or_Province: New York
Postal_Code: 12580
Country: USA
Contact_Voice_Telephone: 845-889-4745
Roger Flood, Marine Sciences Research Center, State University of New York at Stony Brook
Originator: Roger Flood
Marine Sciences Research Center, State University of New York at Stony Brook
Publication_Date: 2007
Title: Hudson River Estuary Bathymetry 10-meter Grid
Series_Name: Hudson River Estuary Program
Issue_Identification: Benthic Mapping Project
Publication_Place: Albany, NY
Publisher: NYS DEC
Originator: Lamont-Doherty Earth Observatory of Columbia University
Publication_Date: 2005
Title: Hudson River Estuary Benthic Survey Index
Series_Name: Hudson River Estuary Program
Issue_Identification: Benthic Mapping Project
Publication_Place: Albany, NY
Publisher: NYS Dept Environmental Conservation
Originator: Lamont-Doherty Earth Observatory, Columbia University
Publication_Date: 2004
Title: Hudson River Estuary Shoreline
Series_Name: Hudson River Estuary Program
Issue_Identification: Benthic Mapping Project
Publication_Place: Albany, NY
Publisher: NYS DEC

All data samples were taken using DGPS positioning with a horizontal accuracy is +/- 1 m.
The real time quality control for the multibeam system includes operator monitoring of the navigation and the ping returns. The surveying is stopped when the broadcast differential GPS correction is unavailable. The real time quality control also permits the operators to monitor for bad pings. Survey lines with excessive bad pings were resurveyed. After the acquisition of the multibeam data several major steps are required to produce the final digital terrain maps. The first step is the editing of the navigation and the ping files for erroneous values. There are manual and automatic stages to both these editing tasks. The navigation plots are reviewed in detail to identify any positioning errors. The automatic navigation editing process identifies times when the number of satellites was insufficient, the HDOP (the Horizontal Dilution of Precision) was excessive, or there was no differential correction. Pings which fail the navigation criteria are masked from the final data product if the time interval with poor navigation was too long (greater than about 30 seconds). For shorter time intervals, navigation was linearly interpolated between good fixes. The manual component of the ping editing involved viewing the depth data from approximately 80 pings at a time (about 8,000 to 9,000 depth determinations are viewed at one time). The operator reviews both the depth and the backscatter data simultaneously. Outliers in depth data sets were flagged as bad data and not used in the final map. For a typical screen of data, from 5 to 50 pings are flagged as bad (less than 1%). We discovered that excessive ping editing could remove sharp narrow features such as shipwrecks in Area 2, Newburgh Bay. We carefully reviewed our ping editing to ensure we had not removed any feature of the riverbed due to excessive editing, and pings incorrectly flagged as bad were restored.
The data cover the whole Hudson River Estuary from Verrazano Bridge to Troy in areas deeper than 4 meters.
A multibeam system operates by transmitting a sound beam perpendicular to the ship track, and then processing the returned sonar data to determine a number of depths across the ship track. The EM 3000 operated in a single-head mode forms up to 120 echosounder beams, each nominally 1.5º wide and spaced 0.9º apart. These beams are transmitted in a swath width that is four times the water depth. The maximum ping rate is 20 times a second, decreasing to 13 times a second as water depth increases to 10 m. In water depths of 10 m and at a speed of 8 kts, the bathymetric and backscatter data has an along-track and across track spacing of as little as 30 cm. The manufacture's specified accuracy of each depth measurement is 0.05 -0.10 m. This resolution is sufficient to map medium to large-scale bed forms and other features with dimensions of about 1 meter. In addition to the beam forming instrumentation the EM-3000 requires accurate navigation and orientation data to produce high quality bathymetric measurement. The POS/MV attitude sensor uses three accelerometers and three gyroscopes to correct the multibeam data for heading, roll, pitch and heave. A differential GPS system (supplemented by inertial navigation; also part of the POS/MV system) determines position to within 1 meter. The real time differential corrections were provided by Omnistar. Other system components include: a separate display to guide the boat along precise survey lines; a CTD for determining the sound velocity profile; a tide gauge for determining local sea-level changes during a survey; Sun and SGI computers (with 36? wide and page-size printers) for logging, storing, processing and displaying the data; and multibeam processing software. Near-final survey products can be generated within a short time after the survey is completed, and our products generally meet hydrographic mapping standards. The multibeam survey was designed to optimize the ship time while fulfilling the goal of 100% coverage of the river in water depths greater than 5 m (15'). Swath width depends on water depth, thus ship tracks need to be closer together in shallower water and farther apart in deeper water. The mapping strategy was therefore to follow the river contours rather than to run parallel ship tracks. The navigation display on the bridge provides the ship's captain with real time guidance on the portion of the river which has been successfully surveyed and the regions which need to be traversed so that the ship could be directed to an unsurveyed area. CTD casts were conducted about every 90 minutes. The CTD profiles were converted to sound velocity profiles and integrated into the data acquisition to provide correction for ray bending and thus precise depth determinations.
Process_Date: 1999-2003 (See Supplemental Information)
After the post-acquisition editing described above in the Logical_Consistency_Report, the next stage of processing was to produce bathymetric and backscatter maps using the depth measurements, with depth measurements being corrected for predicted tidal data. The goal of this step was to identify any remaining anomalies in the data set. The final major step in the processing is to correct the depth data for the actual tidal fluctuations during the survey. Predicted tides in the Hudson are good to better than 1 meter, but to reach the target of 30 cm, actual tidal measurements are necessary. In general, we operated two tide gauges in the area where the multibeam surveying was occurring. Water elevations at the ship location were determined by calculating a river slope from the gauge data and then calculating a water elevation for the ship position. If data from only one gauge was available a model of river slope vs. tide phase, determined when two gauges were deployed, was used to determine water level for each survey. During data gaps in the LDEO/MSRC instruments we used the USGS tide gauges. The improved tide model, incorporating the observed tide, reduced the error in the multibeam maps to ~10 cm. Depths are reported relative to NAVD88. Thus water depths shown are about ~1 m greater than depths reported relative to MLLW (mean lower low water) displayed on nautical charts.
Process_Date: 2007
After these corrections, the depth data was gridded at an appropriate interval (usually 1 m) to create a digital terrain map (DTM). This DTM was averaged to a 10-meter spacing before being contoured at 1 m to show regional bathymetric patterns.
Process_Date: 2007

Direct_Spatial_Reference_Method: Vector
SDTS_Point_and_Vector_Object_Type: string

Grid_Coordinate_System_Name: Universal Transverse Mercator
UTM_Zone_Number: 18
Scale_Factor_at_Central_Meridian: 0.999600
Longitude_of_Central_Meridian: -75.000000
Latitude_of_Projection_Origin: 0.000000
False_Easting: 500000.000000
False_Northing: 0.000000
Planar_Coordinate_Encoding_Method: coordinate pair
Abscissa_Resolution: 10
Ordinate_Resolution: 10
Planar_Distance_Units: meters
Horizontal_Datum_Name: North American Datum of 1983
Ellipsoid_Name: Geodetic Reference System 80
Semi-major_Axis: 6378137.000000
Denominator_of_Flattening_Ratio: 298.257222
Altitude_Datum_Name: North American Vertical Datum 1988
Altitude_Resolution: 0.05
Altitude_Distance_Units: meters
Altitude_Encoding_Method: attribute values

Entity_Type_Label: bathymetry
bathymetry derived from multibeam sonar surveys in the Hudson River Estuary
Marine Sciences Research Center, State University of New York at Stony Brook

Resource_Description: Downloadable Data
Address: 625 Broadway
Address_Type: mailing and physical address
Address: 3rd Floor
City: Albany
State_or_Province: NY
Postal_Code: 12233-2750
Country: USA
Contact_Organization: New York State Department of Environmental Conservation
Contact_Person: Division of Information Services, GIS Unit
Contact_Voice_Telephone: (518) 402-9860
Contact_Facsimile_Telephone: (518) 402-9031
New York State Department of Environmental Conservation provides these geographic data "as is." New York State Department of Environmental Conservation makes no guarantee or warranty concerning the accuracy of information contained in the geographic data. New York State DEC further makes no warranty, either expressed or implied, regarding the condition of the product or its fitness for any particular purpose. The burden for determining fitness for use lies entirely with the user. Although these data have been processed successfully on a computer system at New York State Department of Environmental Conservation, no warranty expressed or implied is made regarding the accuracy or utility of the data on any other system or for general or scientific purposes, nor shall the act of distribution constitute any such warranty. This disclaimer applies both to individual use of the data and aggregate use with other data. It is strongly recommended that careful attention be paid to the contents of the metadata file associated with these data. New York State Department of Environmental Conservation shall not be held liable for improper or incorrect use of the data described and/or contained herein.

Metadata_Date: 20080101
Marine Sciences Research Center, State University of New York at Stony Brook
Contact_Person: Dr. Roger Flood
Address_Type: Endeavor 157
City: Stony Brook
State_or_Province: NY
Postal_Code: 11794-5000
Contact_Voice_Telephone: (631) 632-6971
Metadata_Standard_Name: FGDC Content Standards for Digital Geospatial Metadata
Metadata_Standard_Version: FGDC-STD-001-1998
Metadata_Time_Convention: local time
Online_Linkage: <>
Profile_Name: ESRI Metadata Profile

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