Cape Cod Bay: continuous bathymetry and topography terrain model of the Massachusetts coastal zone and continental shelf, (32-bit GeoTIFF, UTM 19 NAD 83, NAVD 88 vertical datum).

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Frequently anticipated questions:

What does this data set describe?

Title:
Cape Cod Bay: continuous bathymetry and topography terrain model of the Massachusetts coastal zone and continental shelf, (32-bit GeoTIFF, UTM 19 NAD 83, NAVD 88 vertical datum).
Abstract:
Integrated terrain models covering 16,357 square kilometers of the Massachusetts coastal zone and offshore waters were built to provide a continuous elevation and bathymetry terrain model for ocean planning purposes. The area is divided into the following four geographical areas to reduce file size and facilitate publishing: Massachusetts Bay from the Massachusetts-New Hampshire border south to Provincetown and Scituate and east to Stellwagen Bank; Cape Cod Bay from Provincetown to Scituate and south to Hyannis; Buzzards Bay from the Cape Cod Canal southwest to the State border including the Elizabeth Islands and extending north to Fall River and Mount Hope Bay; and Nantucket and Vineyard Sounds, from Hyannis south to the border of the Massachusetts Coastal zone approximately 8 kilometers south of Nantucket. A Triangulated Irregular Network was created from public-domain bathymetric and LiDAR data using the ArcGIS terrain-model framework and then interpolated into a 32-bit GeoTiff of 10 meter resolution. The grids for each of the four geographical areas are referenced to the Universal Transverse Mercator, Zone 19, North American Datum of 1983 coordinate system, and the North American Vertical Datum of 1988. A polygon shapefile recording the source datasets accompanies each of the four grids.
Supplemental_Information:
This raster data set should be used with the “CapeCodBay_Source.shp” polygon shapefile that delineates the spatial extent of each source dataset used to produce the raster. The collection date, and spatial resolution of the source data are variable and should be considered when using this raster for analysis at fine scales. The attribute table of the “CapeCodBay_Source.shp” provides details about the collection date, and web address of the source data.
  1. How might this data set be cited?
    U.S. Geological Survey, 2018, Cape Cod Bay: continuous bathymetry and topography terrain model of the Massachusetts coastal zone and continental shelf, (32-bit GeoTIFF, UTM 19 NAD 83, NAVD 88 vertical datum).: data release DOI:10.5066/F72806T7, U.S. Geological Survey, Coastal and Marine Geology Program, Woods Hole Coastal and Marine Science Center, Woods Hole, Massachusetts.

    Online Links:

    This is part of the following larger work.

    Andrews, Brian D., Baldwin, Wayne E., Sampson, Daniel W., and Schwab, William C., 2018, Continuous bathymetry and elevation models of the Massachusetts coastal zone and continental shelf: data release DOI:10.5066/F72806T7, U.S. Geological Survey, Reston, Virginia.

    Online Links:

    Other_Citation_Details:
    Suggested citation: Andrews, B.D., Baldwin, W.E., Sampson, D.W., and Schwab, W.C., 2018, Continuous bathymetry and elevation models of the Massachusetts coastal zone and continental shelf: U.S. Geological Survey data release, https://doi.org/10.5066/F72806T7.
  2. What geographic area does the data set cover?
    West_Bounding_Coordinate: -70.838962
    East_Bounding_Coordinate: -69.752209
    North_Bounding_Coordinate: 42.134525
    South_Bounding_Coordinate: 41.677850
  3. What does it look like?
    https://www.sciencebase.gov/catalog/file/get/5a4649fce4b0d05ee8c0548b?name=CapeCodBay_10m.jpg (JPEG)
    Preview image of the terrain model of Cape Cod Bay, Massachusetts. File is located in the compressed zip file.
  4. Does the data set describe conditions during a particular time period?
    Beginning_Date: 1933
    Ending_Date: 2016Currentness_Reference:
    ground condition at the time of original survey. This data set is composed of data collected by different organizations at different times.
  5. What is the general form of this data set?
    Geospatial_Data_Presentation_Form: remote-sensing image
  6. How does the data set represent geographic features?
    1. How are geographic features stored in the data set?
      This is a Raster data set. It contains the following raster data types:
      • Dimensions 4952 x 8941 x 1, type Grid Cell
    2. What coordinate system is used to represent geographic features?
      Grid_Coordinate_System_Name: Universal Transverse Mercator
      Universal_Transverse_Mercator:
      UTM_Zone_Number: 19
      Transverse_Mercator:
      Scale_Factor_at_Central_Meridian: 0.999600
      Longitude_of_Central_Meridian: -69.000000
      Latitude_of_Projection_Origin: 0.000000
      False_Easting: 500000.000000
      False_Northing: 0.000000
      Planar coordinates are encoded using row and column
      Abscissae (x-coordinates) are specified to the nearest 10.000000
      Ordinates (y-coordinates) are specified to the nearest 10.000000
      Planar coordinates are specified in meters
      The horizontal datum used is D_NAD_1983_2011.
      The ellipsoid used is Geodetic Reference System 80.
      The semi-major axis of the ellipsoid used is 6378137.000000.
      The flattening of the ellipsoid used is 1/298.257222101.
      Vertical_Coordinate_System_Definition:
      Altitude_System_Definition:
      Altitude_Datum_Name: North_American_Vertical_Datum_1988
      Altitude_Resolution: 1.0
      Altitude_Distance_Units: Meter
      Altitude_Encoding_Method:
      Explicit elevation coordinate included with horizontal coordinates
  7. How does the data set describe geographic features?
    Entity_and_Attribute_Overview:
    Elevation values in Esri 32-bit GeoTIFF format. Data values represent elevations above, and depths below the North American Vertical Datum of 1988 (NAVD 88).
    Entity_and_Attribute_Detail_Citation: Esri

Who produced the data set?

  1. Who are the originators of the data set? (may include formal authors, digital compilers, and editors)
  2. Who also contributed to the data set?
    Please recognize the U.S. Geological Survey (USGS) as the source of this information.
  3. To whom should users address questions about the data?
    Brian Andrews
    U.S. Geological Survey
    Geographer
    384 Woods Hole Rd.
    Woods Hole, MA
    USA

    508-548-8700 x2348 (voice)
    508-457-2310 (FAX)
    bandrews@usgs.gov

Why was the data set created?

Provide a continuous surface starting in the offshore waters and working inshore to the shoreward extent of the Massachusetts Coastal Zone that will be used as a regional planning framework. This model, used in conjunction with the related source dataset shapefile will also 1) Provide an inventory of the most recent elevation and bathymetry datasets within the Massachusetts Coastal Zone and offshore water, and 2) Identify areas of the offshore waters that are only covered by historical lead line soundings and should be updated using new survey methods.

How was the data set created?

  1. From what previous works were the data drawn?
  2. How were the data generated, processed, and modified?
    Date: Jul-2016 (process 1 of 8)
    PROCESSING STEP 1: CREATE FEATURE DATASET
    A feature dataset (CCBay_Terrain) was created within an ArcGIS (v. 10.3.1) file geodatabase to manage and store points and boundary polyon used to create the continuous surface. Create an empty polygon feature class that will be used as a "soft clip" boundary for the terrain model. The feature dataset and all data within it, use the Universal Transverse Mercator (UTM) Zone 19, NAD 83 coordinate system. The vertical datum for the feature dataset is the North American Vertical Datum of 1988 (NAVD 88), meters. All output files described in Steps 2-5 below were imported and stored within the "CCBay_Terrain" feature dataset. This process step and all subsequent process step were performed by the same person-Brian Andrews. Person who carried out this activity:
    Brian Andrews
    U.S. Geological Survey
    Geographer
    384 Woods Hole Rd
    Woods Hole, MA
    USA

    508-548-8700 x2348 (voice)
    508-457-2310 (FAX)
    bandrews@usgs.gov
    Data sources produced in this process:
    • CCBay_Terrain (Feature DataSet)
    • CCBay_TerBnd (Polygon feature class)
    Date: Jul-2016 (process 2 of 8)
    PROCESSING STEP 2: LiDAR
    Download and process LiDAR datasets using the common methods detailed below. First, the tile index in polygon shapefile format (tileindex.shp) available at the "Data URL" below was downloaded for each survey to manage the numerous LiDAR data files for each survey. The tileIndex shapefile was opened in GlobalMapper (v. 17.2.2) and all files that overlapped the terrain boundaries were downloaded using the "URL" attribute within the tileindex.shp which contains the URL (with file name) to each LiDAR file.
    All data were downloaded in laz format using the Geographic Coordinate System NAD 83, reviewed for point classification range, and final class codes of "Ground" or "valid bathymetric points" were used (described below in Data Source entry) to create a bare earth model. LAZ point files were converted to a grid in GlobalMapper using the Binning (Average Value) method with the "Elevation Grid "No Data" Distance Criteria" set to zero so no interpolation occurred over "no data" values such as building footprints or other non-bare earth features. The Universal Transverse Mercator, (UTM) Zone 19, NAD83, and the North American Vertical Datum of 1988 (NAVD 88) coordinate systems were specified for the Global Mapper project.
    The gridded data were exported from GlobalMapper as a 32-bit floating point GeoTIFF with resolutions of 5 or 10 meters depending on the area covered by the data set. For example, the 2013 USACE LiDAR survey of the Menemsha Harbor and Pond (an area on the western coast of Martha’s Vineyard depicted in “Ntkt_VS_10m.tif) was exported at 5-meter resolution to capture the detail of the relatively small area. Datasets covering larger areas (e.g. USACE 2007 Cape and Islands survey) were exported at 10-meter resolutions to provide adequate feature detail while facilitating computation of the terrain model. The resolution of each input raster dataset is identified in parentheses in the "output multipoint file" section below. Polygon outlines were created for each of the input LiDAR grids (listed below) and used to mask older or lower quality data in areas of overlap. The polygons are published in this data release in the "CapeCodBay_Source" shapefile. See metadata of that layer for more information on the logic of the clipping operations. After addressing areas of overlap (if required), each input grid was exported to an ArcGIS Multipoint feature class for input to the terrain model. 
    The surveys used as sources for this and subsequent processing steps are documented below using the following format:
Data Source: Title of published dataset as listed in metadata.
Data URL: Web address to metadata.
Download Date: Date data were downloaded.
ASPRS Class used:(This only pertains to LiDAR data) LiDAR data are published using point classifications according to
standards established in the American Society of Photogrammetry and Remote Sensing (ASPRS).
Class number and description used for this grid are described.
Output Multipoint File: The name of the multipoint file used as input to the terrain model. 
The resolution in meters of the GeoTIFF used to create the multipoint file is in parentheses.
Note: File size for historical NOAA singlebeam x,y, z data were small enough that they used simple point feature classes instead
of multipoint feature classes. In addition, these historical data are published as x,y,z only (not gridded), so there is no
cell resolution associated with them as other input datasets.

Data Source: 2007 US Army Corps of Engineers (USACE) Topo/Bathy LiDAR: Maine, Massachusetts, and Rhode Island
Data URL:https://coast.noaa.gov/htdata/lidar1_z/geoid12a/data/116/2005-2007_NE_Topobathy_metadata.html
Download Date:201604
ASPRS Class Used: class=11 water.
Output Multipoint File:ACOE2007_SShore_10m_MP_navd88 (10 m)
					
Data Source:2010 US Army Corps of Engineers (USACE) Joint Airborne LiDAR Bathymetry Technical Center of eXpertise (JALBTCX) Topobathy >LiDAR: Northeast (MA,ME, NH, RI)
Data URL: https://coast.noaa.gov/htdata/lidar1_z/geoid12a/data/1174/2010_USACE_NE_metadata.html
Download Date:201604
ASPRS Class Used:11=NOAA OCM Bathymetry
Output Multipoint File:ACOE2010_CCBay_10m_MP_navd88 (10 m),
Note: Elevation and bathymetry point clouds were published separately and only the bathymetry files were used to >create this terrain model.	

Data Source:2011 U.S. Geological Survey Topographic LiDAR: LiDAR for the North East
Data URL: https://coast.noaa.gov/htdata/lidar1_z/geoid12a/data/2524/ne2011_usgs_lftne_metadata.html
Download Date:201611
ASPRS Class Used:2=Ground
Output File:USGS2011_CCBay_MP_navd88 (10 M)

Data Source: 2013-2014 U.S. Geological Survey CMGP LiDAR: Post Sandy (MA, NH, RI)
Data URL: https://coast.noaa.gov/htdata/lidar1_z/geoid12b/data/4914/2013_2014_usgs_post_sandy_ma_nh_ri_metadata.html
Download date: 201604
ASPRS Class used: 2=Ground
Output Multipoint File:USGS13_10m_MP_navd88(10 m)

Data Source:2013 USACE NAE Topobathy LiDAR: Massachusetts.
Data URL:https://coast.noaa.gov/htdata/lidar1_z/geoid12b/data/4933/ma2013_usace_nae_massachusetts_m4933_metadata.html
Download Date:201604
ASPRS Class Used: 1= unclassified, 2=Ground, 29=valid bathymetric points.
Output Multipoint File:ACOE2013Snwch_10m_MP_navd88 (10 m)
Note: Data extent covered portions Sandwich Town Beach.

Data Source:W00313
Data URL: https://www.ngdc.noaa.gov/nos/W00001-W02000/W00313.html
Download Date:201702
Output Multipoint File:W00313_10m_MP_navd88 (10 m)
Note: These data were published in bag format at 5 meter resolution. Bag file was aggregated up to 10 meters.
    Date: Nov-2016 (process 3 of 8)
    PROCESSING STEP 3: U.S. GEOLOGICAL SURVEY SWATH BATHYMETRY
    Swath bathymetry data from three published USGS Open-File Reports were used to compile this grid. Bathymetry data were downloaded from individual publications and processed using the common methods detailed below. Data were published using the UTM 19 WGS 84 horizontal datum, and a tidal datum of Mean Lower Low Water (MLLW). These data were transformed to UTM 19 NAD 83 horizontal datum and the North American Vertical Datum 1988 using VDatum Tool (v 3.6) developed by NOAA National Geodetic Survey https://vdatum.noaa.gov/. Polygon outlines were created for each of the input grids (listed below) and used to mask older or lower quality data in areas of overlap. The polygons are published in this data release in the "CapeCodBay_Source" shapefile. See metadata of that layer for more information on the logic of the clipping operations. After addressing areas of overlap (if required), the input grids were exported to ArcGIS Multipoint feature classes for input to the terrain model. 
    
Data Source:USGS CMGP 2010-1006: 5 meter ArcRaster grid (gaps filled) of bathymetry acquired using a SEA Ltd. SWATHplus
interferometric sonar offshore of Massachusetts within northern Cape Cod Bay (ESRI BINARY GRID, UTM Zone 19N).
Data URL: https://pubs.usgs.gov/of/2010/1006/GIS/raster/bathymetry/ccb_bath_f.html
Download Date:201702
Output Multipoint File: ccbf_5m_MP_navd88 (5 m)

Data Source:dh_bathy5m:Bathymetric data collected by the U.S. Geological Survey and the National Oceanic and Atmospheric Administration
offshore of Massachusetts between Duxbury and Hull (Esri BINARY Grid)
Data URL: https://pubs.usgs.gov/of/2009/1072/GIS/raster/bathy/dh_bathy5m.html
Download Date:2016
Output Multipoint File:USGS_2009_1072_5m_MP_navd88 (5 m)
		
Data Source:CAPENORTH/SOUTH_GEO4M_XYZ.TXT: ASCII formatted file of the 4-m bathymetry from the northern and southern half of USGS survey 98015 of 
the Sea Floor off Eastern Cape Cod (Geographic).
Data URL: https://pubs.usgs.gov/of/2005/1048/data/bathymetry/grid/capenorth_geo4m_xyz.htm
Data URL: https://pubs.usgs.gov/of/2005/1048/data/bathymetry/grid/capesouth_geo4m_xyz.htm 
Download Date:2016
Output Multipoint File:USGS_Creed_4m_MP_navd88 (4 m)	
Note: Note: x,y,z file from both north and south areas was reprojected to UTM Zone 19 with the output cell size set to 5 meters, then exported as an ascii text for conversion in VDatum.
    Date: Apr-2017 (process 4 of 8)
    PROCESSING STEP 4: ARMY CORPS OF ENGINEERS MULTIBEAM BATHYMETRY
    Multibeam bathymetry data were accessed from the Massachusetts Navigation Projects web page of the U.S. Army Corps of Engineers, New England District.http://www.nae.usace.army.mil/Missions/Navigation/Massachusetts-Projects/. Data were collected using the MA state plane (ft) NAD 83 coordinate system and a vertical datum of Mean Lower Low Water (MLLW). X,Y,Z data were converted to the UTM 19 NAD 83 coordinate system and the North American Vertical Datum of 1988 (NAVD 88) vertical datum using VDatum Tool (v 3.6). Polygon outlines were created for each of the input point files (listed below) and used to mask older or lower quality data in areas of overlap. The polygons are published in this data release in the "CapeCodBay_Source" shapefile. See metadata of that layer for more information on the logic of the clipping operations. After addressing areas of overlap (if required), the underlying soundings were exported to ArcGIS Multipoint feature classes for input to the terrain model. 
    Data Source: ACOE_KinHbr.csv
Data URL: http://www.nae.usace.army.mil/Portals/74/docs/Navigation/MA/KIN/KIN.html
Collection Date: 20091210
Collection Method: Multibeam
Download Date:201612
Output file: ACOE_KinHbr_navd88.
NOTE: Although data were collected using multibeam sonar, the x,y,z file was binned by the ACOE based on shallowest depth with a 3 x 3 (foot) filter.
Data were further binned using a 40 foot radius to provide a scale dependent plot of the data at 1:200 map scale. 
In general, there are 5-10 meters between adjacent soundings.

Data Source: Duxbury Harbor, Massachusetts, Condition Survey. 
Data URL: http://www.nae.usace.army.mil/Portals/74/docs/Navigation/MA/DUX/DUX63.txt
Collection Date: 201601
Collection Method: Multibeam
Download Date: 201701
Output file: ACOE_DUX63_navd88.
NOTE: Although data were collected using multibeam sonar, the x,y,z file was binned by the ACOE based on
shallowest depth with a 3 x 3 (foot) filter. Data were further binned using a 40 foot radius to provide a scale
dependent plot of the data at 1:200 map scale. In general, there are 5-10 meters between adjacent soundings.

Data Source: Plymouth Harbor, Plymouth, Massachusetts, Condition Survey. 
Data URL:http:http://www.nae.usace.army.mil/Portals/74/docs/Navigation/MA/PLY/PLY507.txt
Collection Date: 201602
Collection Method: Multibeam
Download Date: 201702
Output file: ACOE_Ply16_navd88.
NOTE: Although data were collected using multibeam sonar, the x,y,z file was binned by the USACE based on shallowest depth with a
3 x 3 (foot) filter. Data were further binned using a 40 foot radius to provide a scale dependent plot of the data at 1:200 map
scale. In general, there are 5-10 meters between adjacent soundings.

Data Source: USACE CCC:CCCanal_SPFtNAD83_MLLW.csv
Data URL: Data were acccessed by e-mail request to Chief, Navigation Section, USACE, New England District, 696 Virginia Rd., Concord, MA 01742. 
Collection Date: 2011
Collection Method: Multibeam
Download Date: 201610
Output file: ACOE2011CCCanal_navd88.
NOTE: Although data were collected using multibeam sonar, the x,y,z file was binned by the USACE based on shallowest 
depth with a 3 x 3 (foot) filter. Data were further binned using a 40 foot radius to provide a scale dependent plot of
the data at 1:200 map scale. In general, there are 10-15 meters between adjacent soundings.
    Date: Sep-2016 (process 5 of 8)
    PROCESSING STEP 5:NOAA BATHYMETRY
    Data were downloaded from NOAA National Center for Environmental Information (NCEI)and processed as described below. Most NOAA multibeam data accessed for this grid are published using the UTM Zone 19, NAD 83 coordinate system and the Mean Lower Low Water (MLLW) tidal datum. Most historical sounding data (fathometer, singlebeam) data accessed for this grid are published in x,y,z format using a Geographic coordinate system (lat,lon) in the NAD 83 horizontal datum and a mean low water (MLW) or mean lower low water (MLLW) tidal datum. Data were transformed into the UTM, Zone 19 NAD 83 coordinate system (if required), and the NAVD 88 vertical datum using VDatum Tool (v 3.6). A point feature class ("SurveyName"_navd88) was created for each survey along with an associated boundary polygon ("SurveyName"_Mask) encompassing the soundings. The boundary polygons were clipped to remove soundings in areas that overlapped with newer multibeam or bathymetric LiDAR data. During the clipping operation a 50 to a 100 meter buffer was applied to create space between the older sparse echosounder data, and the newer higher resolution data. This 50 to 100-meter distance between the different data densities, creates a gradual transition in the terrain model and improves the quality of the final 10-meter grid by smoothing transitions between datasets. 
    
Data Source:W00037
Data URL: https://www.ngdc.noaa.gov/nos/W00001-W02000/W00037.html
Collection Date: 2003
Collection Method:Multibeam
Download Date:201702
Output file:W00037_10m_MP_navd88 (10 m)
Note: Survey data delivered in 2 different bag files of 5, and 10 meters resolution based on depth. Combined the two bag files into one GeoTIFF at 10-meter resolution for input to terrain model.

Data Source:W00038
Data URL:https://www.ngdc.noaa.gov/nos/W00001-W02000/W00038.html
Collection Date: 2003
Collection Method:Multibeam
Download Date:201702
Output file:W00038_10m_MP_navd88 (10 m)
Note: Survey data delivered in 2 different bag files of 5, and 10 meters resolution based on depth. 
Combined the two bag files into one GeoTIFF at 10 meter resolution for input to terrain model.

Data Source:W00194
Data URL:https://www.ngdc.noaa.gov/nos/W00001-W02000/W00194.html
Collection Date: 2005
Collection Method:Multibeam
Download Date:201701
Output file:W00194_8M_navd88 (8 m)
Note: Survey data delivered in 3 different bag files of 2, 4, and 8 meters resolution based on depth. Combined the three bag files into one GeoTIFF at 8 meter 
resolution for input to terrain model.

Data Source:H11636
Data URL:https://www.ngdc.noaa.gov/nos/H10001-H12000/H11636.html
Collection Date: 2007
Collection Method:Multibeam
Download Date:201701
Output file:H11636_2m_navd88 (2 m)
Note:Survey data delivered in 2 different bag files of 0.5, and 2 meters resolution based on depth. Combined the three bag files into one GeoTIFF at 2 meter 
resolution for input to terrain model.

Data Source:H11695
Data URL:https://www.ngdc.noaa.gov/nos/H10001-H12000/H11695.html
Collection Date: 2007
Collection Method:Multibeam
Download Date:201702
Output file:H11695_5m_MP_navd88 (5 m)
Note: Survey data delivered in 25 different bag files 0.7,1,2,and 3 meters resolution based on depth.
Combined into one GeoTIFF at 5 meter resolution for input to terrain model
				
LEAD LINE

Data Source: H05401
Data https://www.ngdc.noaa.gov/nos/H04001-H06000/H05401.html
Collection Date:1933
Collection Method:Hand lead line
Download Date:200906
Output file:H05401_navd88

Data Source: H05400
Data https://www.ngdc.noaa.gov/nos/H04001-H06000/H05400.html
Collection Date:1933
Collection Method:Hand lead line
Download Date:200912
Output file:H05400_navd88

Data Source: H05543
Data https://www.ngdc.noaa.gov/nos/H04001-H06000/H05543.html
Collection Date:1934
Collection Method:Hand lead line
Download Date:200906
Output file:H05543_navd88

Data Source: H05588
Data https://www.ngdc.noaa.gov/nos/H04001-H06000/H05588.html
Collection Date:1934
Collection Method:Hand lead line
Download Date:200906
Output file:H05588_navd88

FATHOMETER

Data Source: H06563
Data https://www.ngdc.noaa.gov/nos/H06001-H08000/H06563.html
Collection Date:1940
Collection Method:Fathometer
Download Date:200704
Output file:H06563_navd88

Data Source: H06562
Data https://www.ngdc.noaa.gov/nos/H06001-H08000/H06562.html
Collection Date:1940
Collection Method:Fathometer
Download Date:200912
Output file:H06562_navd88

Data Source: H08166
Data https://www.ngdc.noaa.gov/nos/H08001-H10000/H08166.html
Collection Date:1954
Collection Method:Fathometer
Download Date:200704
Output file:H08166_navd88

Data Source: H08165
Data https://www.ngdc.noaa.gov/nos/H08001-H10000/H08165.html
Collection Date:1954
Collection Method:Fathometer
Download Date:200704
Output file:H08165_navd88

Data Source: H08164
Data https://www.ngdc.noaa.gov/nos/H08001-H10000/H08164.html
Collection Date:1954
Collection Method:Fathometer
Download Date:200703
Output file:H08164_navd88

Data Source: H08348
Data https://www.ngdc.noaa.gov/nos/H08001-H10000/H08348.html
Collection Date:1955
Collection Method:Fathometer
Download Date:200906
Output file:H08348_navd88

Data Source: H09011
Data https://www.ngdc.noaa.gov/nos/H08001-H10000/H09011.html
Collection Date:1968
Collection Method:Fathometer
Download Date:200906
Output file:H09011_navd88

Data Source: H09233
Data https://www.ngdc.noaa.gov/nos/H08001-H10000/H09233.html
Collection Date:1971
Collection Method:Fathometer
Download Date:200906
Output file:H09233_navd88

Data Source: H09232
Data https://www.ngdc.noaa.gov/nos/H08001-H10000/H09232.html
Collection Date:1971
Collection Method:Fathometer
Download Date:200906
Output file:H09232_navd88

Data Source: H09226
Data https://www.ngdc.noaa.gov/nos/H08001-H10000/H09226.html
Collection Date:1971
Collection Method:Fathometer
Download Date:200906
Output file:H09226_navd88

Data Source: H09225
Data https://www.ngdc.noaa.gov/nos/H08001-H10000/H09225.html
Collection Date:1971
Collection Method:Fathometer
Download Date:200906
Output file:H09225_navd88

Data Source: F00550
Data https://www.ngdc.noaa.gov/nos/F00001-F02000/F00550.html
Collection Date:2007
Collection Method:Fathometer
Download Date:201702
Output file:F00550_navd88
    Date: Nov-2017 (process 6 of 8)
    PROCESSING STEP 6: APPEND POLYGON SURVEYMASK BOUNDARIES TO TERRAINBND.
    A polygon boundary was created as a "soft clip" during the terrain building process by appending all the "SurveyName"_Mask polygons to the "CCBayTerBnd" feature class created in STEP 1 above. The CCBayTerBnd feature class was reviewed and edited as needed to fill gaps between adjacent mask polygons, or fill no data holes within the LiDAR data produced from using only ground or valid bathymetry points in the input LiDAR laz files. Gaps within, and between, bathymetric mask polygons were filled if the adjacent data supported interpolating across the no data gap. For example, the gaps between adjacent lines from NOAA Survey H12642 at the entrance to New Bedford Harbor were filled in because A) the gaps between adjacent lines were small (30-40 meters), and B) The adjacent data was new high resolution multibeam data. Gaps remain onshore in lakes, ponds, or small steams where terrestrial LiDAR did not penetrate. Gaps remain in the bathymetry in areas not covered by the VDatum boundary. Data sources produced in this process:
    • CCBayTerBnd
    Date: Oct-2017 (process 7 of 8)
    PROCESSING STEP 7: CREATE TERRAIN.
    An ArcGIS (v. 10.3.1) Terrain (CCBayTer) was created within the CCBayTerrain feature dataset created in step 1 using the context menu in ArcCatalog (v. 10.3.1) and the following parameters: average point spacing = 10 meters, pyramid type = Z Tolerance. One Terrain pyramid level of Tolerance 1 was used as a thinning routine to facilitate faster redraw times when working with the Terrain (TIN). During the build process the "CCBayTerBnd" created in Step 6 was used as a "soft clip" to delineate the data boundaries. Data sources produced in this process:
    • CCBayTer
    Date: Oct-2017 (process 8 of 8)
    PROCESSING STEP 8: CONVERT TERRAIN TO RASTER.
    The terrain (CCBayTer) was converted to a 32-bit GeoTIFF (CCBay_10m.tif) using the "Convert Terrain to Raster" tool in ArcGIS (v. 10.3.1), specifying the Natural Neighbors method and a cell size of 10 meters. During the conversion process a pyramid level of zero was selected so that all the points were used to create the raster. Data sources used in this process:
    • CCBayTer
    Data sources produced in this process:
    • CCBay_10m.tif
  3. What similar or related data should the user be aware of?

How reliable are the data; what problems remain in the data set?

  1. How well have the observations been checked?
  2. How accurate are the geographic locations?
    The horizontal accuracy of the source multibeam bathymetry (NOAA/NOS) is reported at +/- 3 meters. The horizontal accuracy of the swath bathymetry (USGS) is conservatively estimated to be +/- 10 meters. The LiDAR data were collected to meet the +/- 3-meter accuracy specification. Horizontal accuracy for lead-line and fathometer soundings are not documented. The horizontal accuracy of this composite topographic and bathymetric grid is assumed to be within 20 meters, as additional errors could have been introduced during resampling, vertical and horizontal reprojections, and interpolation. See USGS Open File Reports and NOAA survey descriptive reports using the "PubLink" in the "CapeCodBay_Source.shp" shapefile for individual survey positioning methods.
  3. How accurate are the heights or depths?
    The vertical accuracy of the source multibeam bathymetry collected by NOAA/NOS is reported at +/- 30 to 50 cm. The vertical accuracy of the swath bathymetry collected by USGS is estimated to be +/- 10 to 60 cm. The LiDAR data were collected to meet the +/- 30-cm accuracy specification. This composite topographic and bathymetric grid is assumed to be vertically accurate to within 1-meter, as additional errors could have been introduced during resampling, vertical and horizontal reprojections, and interpolation. The vertical accuracy for NOAA lead-line and single-beam sonar soundings are not documented. NOAA survey methods and processing of sounding data are in descriptive reports.
  4. Where are the gaps in the data? What is missing?
    In general, newer data of higher resolution supersedes older data of lower resolution where one or more surveys overlap. As a result, the grid does not include all data collected during all surveys if newer data exists for the same area(s). The terrain model extends sufficiently landward to seamlessly overlap other publicly available terrestrial LiDAR datasets.
    Data gaps in this grid exist for two general reasons: 1) LiDAR does not penetrate inland lakes and ponds, and 2) although bathymetry data may exist in small estuaries they could not be transformed to NAVD 88 because the current VDatum (v.3.6) boundary file does not cover that area.
  5. How consistent are the relationships among the observations, including topology?
    This grid was created using a 10-meter cell resolution to reflect the finest cell resolution supported by input data of the lowest spatial resolution (historical NOS fathometer data). The boundaries of all four GeoTIFFs published in this data release are designed to overlap with adjacent grids to create a seamless surface if mosaicked together. In the areas where the GeoTIFFs overlap, the values in the overlap areas may not be the same in both terrain models. This variability can be explained by one of two reasons, or a combination of both:
    1) The cell values of the raster output from the terrain model depend on the origin and extent of the bounding polygon for each original TIN (triangulated irregular network). In the areas of overlap, the cells are not necessarily coincident; therefore the input data used to assign the value to that cell are not necessarily the same.
    2) A different source dataset was used as input in the generation of the terrain model for adjacent GeoTIFFs. General guidelines were established for the selection of the source elevation data, but for such a large area and complicated series of possible input datasets, the same source dataset may not have been chosen as input for adjacent terrain models in areas of overlap.
    Vertical differences between adjacent data sets exist in some places for two general reasons: 1) Some areas are highly dynamic over times scales that are short relative to the frequency of data acquisition. For example, around Monomoy Island (an area near Chatham, MA on the southern extent of Outer Cape Cod that is depicted in “NTK_VS_10m.tif”), where strong currents and high sediment transport rates drive continual morphologic change, high resolution LiDAR data collected along the near shore do not agree well with older soundings collected in adjacent deeper water. The boundary between data collected in different years will reflect this change in depth between adjacent datasets.
    2) Differences in vertical referencing methods also cause disagreement between overlapping data. Most of the multibeam data used in this terrain model were collected and referenced to mean lower low water (MLLW) using either regional tide zone models (NOAA), or real-time kinematic tides (USGS). Although both methods for referencing data to a tidal datum are valid, small differences of 10-70 centimeters exist were these data overlap. All bathymetry referenced to tidal datums were converted to NAVD 88 vertical datum as described in Processing Step 3 and 4 below.

How can someone get a copy of the data set?

Are there legal restrictions on access or use of the data?
Access_Constraints: None.
Use_Constraints:
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 (USGS) as the source of this information. Users are advised to read the data set's metadata thoroughly to understand appropriate use and data limitations.
  1. Who distributes the data set? (Distributor 1 of 1)
    U.S. Geological Survey-ScienceBase
    Denver Federal Center, Building 810, Mail Stop 302
    Denver, CO
    USA

    1-888-275-8747 (voice)
    sciencebase@usgs.gov
  2. What's the catalog number I need to order this data set? CCBay_10m.tif: file contains the 32-bit GeoTIFF (CCBay_10m.tif), TIFF world file (CCBay_10m.tfw), CCBay_10m.jpg browse graphic, and the associated FGDC CSDGM metadata in XML, HTML, FAQ, and text formats.
  3. What legal disclaimers am I supposed to read?
    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.
  4. How can I download or order the data?
  5. What hardware or software do I need in order to use the data set?
    To utilize this data, the user must have software capable of reading a 32-bit GeoTIFF.

Who wrote the metadata?

Dates:
Last modified: 29-Jan-2018
Metadata author:
Brian Andrews
U.S. Geological Survey, Northeast Region
Geographer
384 Woods Hole Road
Woods Hole, MA

508-548-8700 ext. 2348 (voice)
bandrews@usgs.gov
Metadata standard:
FGDC Content Standard for Digital Geospatial Metadata (FGDC-STD-001-1998)
Generated by mp version 2.9.44 on Mon Jan 29 10:10:22 2018