Navigation, bathymetry, and water temperature points of ship position during continuous resistivity profile data collection in Northport Harbor on Long Island, New York in May, 2008 (RESGPSPNTS_NORTHPORT.SHP)

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Frequently anticipated questions:


What does this data set describe?

Title:
Navigation, bathymetry, and water temperature points of ship position during continuous resistivity profile data collection in Northport Harbor on Long Island, New York in May, 2008 (RESGPSPNTS_NORTHPORT.SHP)
Abstract:
An investigation of coastal groundwater systems was performed along the North Shore of Long Island, New York during May 2008 to constrain nutrient delivery to Northport Harbor and Manhasset Bay by delineating locations of likely groundwater discharge. The embayments are bounded by steep moraines and are underlain by thick fine-grained sediments deposited in proglacial lakes during the last ice age. Beach sand and gravel overlie the glacial deposits along the coast. The continuous resistivity profiling (CRP) surveys that were conducted indicate the existence of low-salinity groundwater in shore-parallel bands, typically 25 to 50 meters wide, along the shorelines of both bays. Piezometer sampling and seepage meter deployments in intertidal and subtidal areas of the two bays confirmed the presence and discharge of brackish and low-salinity groundwater. The large tidal ranges (up to 3 meters), and the steep onshore topography and hydraulic gradients are important variables controlling coastal groundwater discharge in these areas. For more information on the survey involved in this project, see https://cmgds.marine.usgs.gov/fan_info.php?fan=2008-007-FA.
  1. How might this data set be cited?
    Bratton, John F., and Cross, VeeAnn A., 2011, Navigation, bathymetry, and water temperature points of ship position during continuous resistivity profile data collection in Northport Harbor on Long Island, New York in May, 2008 (RESGPSPNTS_NORTHPORT.SHP): Open-File Report 2011-1041, U.S. Geological Survey, Coastal and Marine Geology Program, Woods Hole Coastal and Marine Science Center, Woods Hole, MA.

    Online Links:

    This is part of the following larger work.

    Cross, V.A., Bratton, J.F., Crusius, J., Kroeger, K.D., and Worley, C.R., 2011, Continuous Resistivity Profiling Data from Northport Harbor and Manhasset Bay, Long Island, New York: Open-File Report 2011-1041, U.S. Geological Survey, Reston, VA.

    Online Links:

    Other_Citation_Details: CD-ROM
  2. What geographic area does the data set cover?
    West_Bounding_Coordinate: -73.367117
    East_Bounding_Coordinate: -73.353100
    North_Bounding_Coordinate: 40.911567
    South_Bounding_Coordinate: 40.888367
  3. What does it look like?
    https://pubs.usgs.gov/of/2011/1041/data/navigation/resgpspnts_northport.gif (GIF)
    Thumbnail GIF image showing the location of resistivity navigation points collected in Northport Harbor. The coastline with piers is included for spatial reference.
  4. Does the data set describe conditions during a particular time period?
    Beginning_Date: 12-May-2008
    Ending_Date: 14-May-2008
    Currentness_Reference:
    ground condition
  5. What is the general form of this data set?
    Geospatial_Data_Presentation_Form: vector digital data
  6. How does the data set represent geographic features?
    1. How are geographic features stored in the data set?
      This is a Vector data set. It contains the following vector data types (SDTS terminology):
      • Entity point (2378)
    2. What coordinate system is used to represent geographic features?
      Horizontal positions are specified in geographic coordinates, that is, latitude and longitude. Latitudes are given to the nearest 0.000001. Longitudes are given to the nearest 0.000001. Latitude and longitude values are specified in Decimal degrees. The horizontal datum used is D_WGS_1984.
      The ellipsoid used is WGS_1984.
      The semi-major axis of the ellipsoid used is 6378137.000000.
      The flattening of the ellipsoid used is 1/298.257224.
      Vertical_Coordinate_System_Definition:
      Depth_System_Definition:
      Depth_Datum_Name: Local surface
      Depth_Resolution: 0.1
      Depth_Distance_Units: meters
      Depth_Encoding_Method: Attribute values
  7. How does the data set describe geographic features?
    resgpspnts_northport
    ESRI point shapefile (Source: ESRI)
    FID
    Internal feature number. (Source: ESRI) Sequential unique whole numbers that are automatically generated.
    Shape
    Feature geometry. (Source: ESRI) Coordinates defining the features.
    gpstime
    GPS time in the format HHMMSS. GPS time is +4 from local time during the survey. (Source: U.S. Geological Survey) Although the value is represented as a number, the number as a whole doesn't have a particular meaning. Only when the individual parts for hours, minutes, and seconds are broken out does the number have meaning.
    longitude
    Longitude coordinate of the point in decimal degrees, WGS84. (Source: U.S. Geological Survey)
    Range of values
    Minimum:-73.367117
    Maximum:-73.3531
    Units:decimal degrees
    latitude
    Latitude coordinate of the point in decimal degrees, WGS84. (Source: U.S. Geological Survey)
    Range of values
    Minimum:40.888367
    Maximum:40.911567
    Units:decimal degrees
    depth_m
    Depth of the water below the fathometer in meters recorded by the ship's fathometer/navigation system. Datum is local surface (no tides taken into account). A value of -9999 indicates no data. (Source: U.S. Geological Survey)
    Range of values
    Minimum:0.2
    Maximum:5.9
    Units:meters
    temp_c
    Water temperature in degrees Celsius as recorded at the Lowrance fathometer transducer. (Source: U.S. Geological Survey)
    Range of values
    Minimum:12.8
    Maximum:17.9
    Units:degrees Celsius
    line
    The alphanumeric name corresponding to the prefix of the GPS filename. This name reflects the name assigned to the line of data acquisition. (Source: U.S. Geological Survey) Character set.
    location
    A general text description of the area of surveying. (Source: U.S. Geological Survey) Character set.
    streamer
    Indication of the streamer used to collect the resistivity data along the trackline. (Source: U.S. Geological Survey) Character set. Two streamers were used during the survey - a 15 meter and 50 meter. This field allows quick identification of each.
    jday
    This number represents the Julian day of data collection based on the GPS day. Julian day is the integer number representing the interval of time in days since January 1 of the year. (Source: U.S. Geological Survey)
    Range of values
    Minimum:133
    Maximum:135
    Units:day
    col_date
    The gregorian date corresponding to the Julian day of data collection in the format MM/DD/YY. (Source: U.S. Geological Survey) Character set.

Who produced the data set?

  1. Who are the originators of the data set? (may include formal authors, digital compilers, and editors)
    • John F. Bratton
    • VeeAnn A. Cross
  2. Who also contributed to the data set?
  3. To whom should users address questions about the data?
    VeeAnn A. Cross
    U.S. Geological Survey
    Marine Geologist
    Woods Hole Coastal and Marine Science Center
    Woods Hole, MA

    (508) 548-8700 x2251 (voice)
    (508) 457-2310 (FAX)
    vatnipp@usgs.gov

Why was the data set created?

The purpose of this point shapefile is to provide the ship's position, bathymetric values, and water temperature during the collection of continuous resistivity profile data in Northport Harbor on northern Long Island, New York from May 12 to May 14, 2008.

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: 2008 (process 1 of 11)
    The continuous resistivity profile (CRP) system used on this cruise was an AGI SuperSting marine system described at the website: www.agiusa.com/marinesystem.shtml. Two different streamers were used for data collection - not simultaneously. One streamer was a 50-m streamer with an 11 electrode array with electrodes spaced 5 meters apart. The other streamer was a 15-m streamer with an 11 electrode array with electrodes spaced 1.5 meters apart. In both cases, the source electrodes are graphite, while the receiver electrodes are stainless steel. A dipole-dipole configuration was used for the data collection in which two fixed current electrodes are assigned with the measurement of voltage potential between electrode pairs in the remaining electrodes. The maximum depth below the water surface the streamer can reach is approximately ¼ the streamer length. So for the 50-m streamer, maximum depth is about 12.5 meters, while the 15 meter streamer can reach about 3.75 meters. Each line of data acquisition records several files. The two files necessary for processing are the *.stg and the *.gps file. The STG file contains the resistivity data, while the GPS file contains the navigation information. The navigation system used in concert with the CRP system is a Lowrance LMS-480M with an LGC-2000 GPS antenna and a 200 kHz fathometer transducer. The transducer also contains a temperature sensor. Lowrance indicates the speed of sound used by the system is 4800 feet/second. Both the temperature and depth information are recorded in the logged GPS file. The CRP system images the subsurface electrical properties of an estuarine, riverine or lacustrine environment. Resistivity differences can be attributed to subsurface geology (conductive vs less conductive layers) and hydrogeologic conditions with fresh water exhibiting high resistivity and saline conditions showing low resistivity.
    Date: May-2008 (process 2 of 11)
    The data were transferred from the logging computer via AGISSAdmin software version 1.3.2.165. These files were then transferred via a thumb drive to the processing computer. The files included in this publication are the *.crs, *.cmd, *.gps, and *.stg. The two files essential for processing are the GPS and STG files. The GPS file contains the navigation, and in the case of the Lowrance system also includes water depth and temperature. The STG file contains the resistivity measurements from each of the electrodes. The CRS file contains the contact resistance readings. The CMD file contains the parameters for data collection. These last two files aren't necessary for data processing, but can be useful in terms of troubleshooting. Due to a large navigation gap, L38F1 had to be split into two parts with the new filename prefix for the GPS and STG files being L38F1_part1 and L38F1_part2. This process step, along with all subsequent process steps, was performed by the same person: VeeAnn A. Cross. Person who carried out this activity:
    VeeAnn A. Cross
    U.S. Geological Survey
    Marine Geologist
    Woods Hole Coastal and Marine Science Center
    Woods Hole, MA

    (508) 548-8700 x2251 (voice)
    (508) 457-2310 (FAX)
    vatnipp@usgs.gov
    Date: May-2008 (process 3 of 11)
    An AWK script was used to extract the navigation, bathymetry, and temperature information recorded in each individual GPS data file for each day of data acqusition.
    AWK script "awkhold":
    BEGIN {
    FS = ","
    }
    {
    FS = ","
    ARGC = 2
    depth = -9999
    temp = -9999
    if ($1=="$GPRMC")
    	{
    	utctime = $2
    	latdeg = substr($4,1,2)
    	latmin = substr($4,3,6)
    	declat = latdeg + (latmin/60)
    	londeg = substr($6,1,3)
    	lonmin = substr($6,4,6)
    	declon = -1 * (londeg + (lonmin/60))
    	if (NR==1) {
    		holddepth = -9999
    		holdtemp = -9999
    		}
    	else {
    		printf("%s, %9.6f, %9.6f, %5.1f, %5.1f, %s\n", holdutctime, >holddeclon, holddeclat, holddepth, holdtemp, ARGV[2])
    	}
    	holdutctime = utctime
    	holddeclon = declon
    	holddeclat = declat
    	holddepth = -9999
    	holdtemp = -9999
    	}
    if ($1=="$SDDPT")
    	{
    	depthreal = $2
    	holddepth = depthreal
    	}
    if ($1=="$SDMTW")
    	{
    	tempreal = $2
    	holdtemp = tempreal
    	}
    }
    END {
    printf("%s, %9.6f, %9.6f, %5.1f, %5.1f, %s\n", holdutctime, holddeclon, >holddeclat, holddepth, holdtemp, ARGV[2])
    }
    
    This AWK script was initialized by "dogps" - shell script run under CYGWIN v. 1.5.1 (UNIX like environment that runs under Windows). This is the script used for the May 12 data collection:
    files=`ls *.gps | cut -d. -f1`
    for file in $files
    do
    	awk -f awkhold $file.gps $file >> day1gps.txt
    done
    
    The script not only parses the GPS navigation, but concatenates the results into a single file. This script was repeated for day 2 and day 3 (May 13 and May 14 respectively) with the output directed to day2gps.txt and day3gps.txt.
    Date: May-2008 (process 4 of 11)
    VI (v. 7.2) under CYGWIN was used to add the appropriate header line and the comma-delimited text file was imported to ArcMap 9.2: Tools - Add XY Data. The X field is longitude; Y field is latitude, and the Coordinate System was defined as Geographic, WGS84. This "Event Theme" was converted to a shapefile by right-mouse clicking on the layer - Data - Export Data. The resulting shapefiles were day1gps.shp, day2gps.shp and day3gps.shp.
    Date: May-2008 (process 5 of 11)
    Using ArcMap 9.2 the following attributes were added to the shapefiles: location, streamer, jday, and col_date.
    Date: 09-Nov-2010 (process 6 of 11)
    Using ArcMap 9.2 - ArcToolbox - Data Management Tools - General - Merge Input datasets: day1gps.shp day2gps.shp day3gps.shp
    Output: resgpspnts_northport.shp
    In the field mapping section I renamed depth to depth_m and tempc to temp_c
    I had the following definition query set up in day1gps: "line" <> '7' Although I processed the GPS file, the navigation was bad and the data unusable.
    I had the following definition query set up in day2gps: "line" <> 'L8F2' AND "line" <> 'L9F1' AND "line" <> 'L9F2' Those points had bad longitude values and needed to be excluded.
    Date: 16-Oct-2017 (process 7 of 11)
    Edits to the metadata were made to fix any errors that MP v 2.9.36 flagged. This is necessary to enable the metadata to be successfully harvested for various data catalogs. In some cases, this meant adding text "Information unavailable" or "Information unavailable from original metadata" for those required fields that were left blank. Other minor edits were probably performed (title, publisher, publication place, etc.). Attempted to modify http to https where appropriate. Reordered the links in the identification section to have a landing page link as the first link. Updated the link to the field activity. Moved the minimal source information provided to make it the first process step. The distribution format name was modified in an attempt to be more consistent with other metadata files of the same data format. The metadata date (but not the metadata creator) was edited to reflect the date of these changes. The metadata available from a harvester may supersede metadata bundled within a download file. Compare the metadata dates to determine which metadata file is most recent. Person who carried out this activity:
    U.S. Geological Survey
    Attn: VeeAnn A. Cross
    Marine Geologist
    384 Woods Hole Road
    Woods Hole, MA

    508-548-8700 x2251 (voice)
    508-457-2310 (FAX)
    vatnipp@usgs.gov
    Date: 30-Jan-2018 (process 8 of 11)
    An error was fixed in one of the originator names. Person who carried out this activity:
    U.S. Geological Survey
    Attn: VeeAnn A. Cross
    Marine Geologist
    384 Woods Hole Road
    Woods Hole, MA

    508-548-8700 x2251 (voice)
    508-457-2310 (FAX)
    vatnipp@usgs.gov
    Date: 20-Jul-2018 (process 9 of 11)
    USGS Thesaurus keywords added to the keyword section. Person who carried out this activity:
    U.S. Geological Survey
    Attn: VeeAnn A. Cross
    Marine Geologist
    384 Woods Hole Road
    Woods Hole, MA

    508-548-8700 x2251 (voice)
    508-457-2310 (FAX)
    vatnipp@usgs.gov
    Date: 18-Nov-2019 (process 10 of 11)
    Crossref DOI link was added as the first link in the metadata. Person who carried out this activity:
    U.S. Geological Survey
    Attn: VeeAnn A. Cross
    Marine Geologist
    384 Woods Hole Road
    Woods Hole, MA

    508-548-8700 x2251 (voice)
    508-457-2310 (FAX)
    vatnipp@usgs.gov
    Date: 08-Sep-2020 (process 11 of 11)
    Added keywords section with USGS persistent identifier as theme keyword. Person who carried out this activity:
    U.S. Geological Survey
    Attn: VeeAnn A. Cross
    Marine Geologist
    384 Woods Hole Road
    Woods Hole, MA

    508-548-8700 x2251 (voice)
    508-457-2310 (FAX)
    vatnipp@usgs.gov
  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 navigation system used was a Lowrance 480M with an LGC-2000 Global Positioning System (GPS) antenna. The antenna was located at the anchor point for the resistivity streamer, which is also directly above the fathometer transducer mount point. The GPS system is published to be accurate to within 10 meters.
  3. How accurate are the heights or depths?
    All bathymetry values were collected by the 200 kHz Lowrance fathometer. The fathometer was mounted starboard side aft, directly below the GPS antenna and the resistivity streamer tow point. The transducer was approximately 0.30 meters below the sea surface, and this draft was not corrected for. The Lowrance manufacturer indicates the speed of sound used by the system to convert to depths is 4800 feet/second (1463 meters/second). All values are assumed to be accurate to within 1 meter.
  4. Where are the gaps in the data? What is missing?
    All GPS files acquired as part of the CRP data collection were processed to generate this point shapefile.
  5. How consistent are the relationships among the observations, including topology?
    No duplicate points are present. The navigational fixes were checked for valid values. Invalid data points were deleted. No other checks were performed. The "line" attribute reflects the linename assigned in the field. In general, the format is LXFX, which would refer to line number, file number (in the case that more than one file was collected on a single line). There are exceptions to this naming convention, and are usually a result of typos when entering the linename.

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 The 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.
  1. Who distributes the data set? (Distributor 1 of 1)
    VeeAnn A. Cross
    U.S. Geological Survey
    Marine Geologist
    Woods Hole Coastal and Marine Science Center
    Woods Hole, MA

    (508) 548-8700 x2251 (voice)
    (508) 457-2310 (FAX)
    vatnipp@usgs.gov
  2. What's the catalog number I need to order this data set? Downloadable Data
  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?
    This WinZip file contains data available in ESRI point shapefile format. The user must have software capable of uncompressing the WinZip file and reading/displaying the shapefile.

Who wrote the metadata?

Dates:
Last modified: 18-Mar-2024
Metadata author:
VeeAnn A. Cross
U.S. Geological Survey
Marine Geologist
Woods Hole Coastal and Marine Science Center
Woods Hole, MA

(508) 548-8700 x2251 (voice)
(508) 457-2310 (FAX)
whsc_data_contact@usgs.gov
Contact_Instructions:
The metadata contact email address is a generic address in the event the person is no longer with USGS. (updated on 20240318)
Metadata standard:
FGDC Content Standards for Digital Geospatial Metadata (FGDC-STD-001-1998)

This page is <https://cmgds.marine.usgs.gov/catalog/whcmsc/open_file_report/ofr2011-1041/resgpspnts_northportmeta.faq.html>
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