JD103HYPACK.SHP: Parsed HYPACK navigation from April 13, 2010 of U.S. Geological Survey Field Activity 2010-006-FA in Indian River Bay, Delaware (Geographic, WGS 84)

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Frequently-anticipated questions:


What does this data set describe?

Title:
JD103HYPACK.SHP: Parsed HYPACK navigation from April 13, 2010 of U.S. Geological Survey Field Activity 2010-006-FA in Indian River Bay, Delaware (Geographic, WGS 84)
Abstract:
A geophysical survey to delineate the fresh-saline groundwater interface and associated sub-bottom sedimentary structures beneath Indian River Bay, Delaware, was carried out in April 2010. This included surveying at higher spatial resolution in the vicinity of a study site at Holts Landing, where intensive onshore and offshore studies were subsequently completed. The total length of continuous resistivity profiling (CRP) survey lines was 145 kilometers (km), with 36 km of chirp seismic lines surveyed around the perimeter of the bay. Medium-resolution CRP surveying was performed using a 50-meter streamer in a bay-wide grid. Results of the surveying and data inversion showed the presence of many buried paleochannels beneath Indian River Bay that generally extended perpendicular from the shoreline in areas of modern tributaries, tidal creeks, and marshes. An especially wide and deep paleochannel system was imaged in the southeastern part of the bay near White Creek. Many paleochannels also had high-resistivity anomalies corresponding to low-salinity groundwater plumes associated with them, likely due to the presence of fine-grained estuarine mud and peats in the channel fills that act as submarine confining units. Where present, these units allow plumes of low-salinity groundwater that was recharged onshore to move beyond the shoreline, creating a complex fresh-saline groundwater interface in the subsurface. The properties of this interface are important considerations in construction of accurate coastal groundwater flow models. These models are required to help predict how nutrient-rich groundwater, recharged in agricultural watersheds such as this one, makes its way into coastal bays and impacts surface water quality and estuarine ecosystems. For more information on the survey conducted for this project, see <http://woodshole.er.usgs.gov/operations/ia/public_ds_info.php?fa=2010-006-FA>.
  1. How should this data set be cited?

    Cross, VeeAnn A. , 2014, JD103HYPACK.SHP: Parsed HYPACK navigation from April 13, 2010 of U.S. Geological Survey Field Activity 2010-006-FA in Indian River Bay, Delaware (Geographic, WGS 84): Open-File Report 2011-1039, 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., Michael, H.A., Kroeger, K.D., Green, A., and Bergeron, E., 2014, Continuous Resistivity Profiling and Seismic-Reflection Data Collected in April 2010 from Indian River Bay, Delaware: Open-File Report 2011-1039, U.S. Geological Survey, Reston, VA.

    Online Links:

  2. What geographic area does the data set cover?

    West_Bounding_Coordinate: -75.203600
    East_Bounding_Coordinate: -75.062150
    North_Bounding_Coordinate: 38.618983
    South_Bounding_Coordinate: 38.566450

  3. What does it look like?

    <http://pubs.usgs.gov/of/2011/1039/data/navigation/hypack/processed/jd103hypack.gif> (GIF)
    Thumbnail GIF image showing HYPACK navigation points collected April 13, 2010. The coastline is included for spatial reference.

  4. Does the data set describe conditions during a particular time period?

    Calendar_Date: 13-Apr-2010
    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 (26688)

    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?

    jd103hypack
    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 hours 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 position of the point (decimal degrees, WGS84) (Source: U.S. Geological Survey)

    Range of values
    Minimum:-75.2036
    Maximum:-75.06215
    Units:decimal degrees

    latitude
    Latitude position of the point (decimal degrees, WGS84) (Source: U.S. Geological Survey)

    Range of values
    Minimum:38.56645
    Maximum:38.618983
    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:24.2
    Units:meters

    gpsdate
    The date recorded in the GPS navigation in the format DDMMYY. Because of the time offset from local time, this date could actually be different than the local acquisition date. (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 day, month, and year are broken out does the number have meaning.

    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:103
    Maximum:103
    Units:days


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?

  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 02543-1598

    (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 parsed data from the raw HYPACK (VER 9.0.5.17) navigation files. The parsed data will contain latitudes, longitudes, and depth values. The depth values are particularly necessary to fill depth data gaps in the continuous resistivity profile GPS data.


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: Apr-2010 (process 1 of 5)
    All the ASCII HYPACK (VER 9.0.5.17) navigation files collected on April 13, 2010 were placed in their own folder on the computer. Each file has the following filename convention: LLL_TTTT.RAW where LLL is the line number and TTTT is the start time (UTC) of data collection in the format HHMM. In order to parse these files to extract navigation and depth information, two scripts were run under a Cygwin operating system. The first script "donav" is an executable script that cycles through all the *.raw files in the folder and calls another script to extract particular lines of information.
    donav:
    files=`ls *.RAW | cut -d. -f1`
    for file in $files
    do
    	awk -f awkit $file.RAW > $file.navdep
    done
    
    The AWK script "awkit" simply extracts any line of information in the HYPACK file that contains either the string "GPGGA" or "SDDBT" and writes this information to a new file with the extension navdep.
    awkit:
    {
    if ($0 ~ /GPGGA|SDDBT/) {
    	print $0
    	}
    }
    
    This process step and all subsequent process steps were 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 02543-1598

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

    Data sources used in this process:
    • *.RAW

    Data sources produced in this process:

    • *.navdep

    Date: Apr-2010 (process 2 of 5)
    With the particular lines of interest extracted from the original HYPACK files, additional scripts were run to extract the specific information of interest. The next two scripts run are doholdhypack and awkholdhypack. The doholdhypack is a shell script run under Cygwin which cycles through all the *.navdep files in the folder and calls the awkholdhypack AWK script to process the file, with the results output to *.holdhypack. Of note, if the SDBPT record does not contain a depth value, a value of -9999 is written to the output file - acting as a nodata value.
    doholdhypack:
    files=`ls *.navdep | cut -d. -f1`
    for file in $files
    do
    	awk -f awkholdhypack $file.navdep > $file.holdhypack
    done
    awkholdhypack:
    BEGIN {
    FS = ","
    }
    
    {
    FS = ","
    depth = -9999
    if ($1 ~ /GPGGA/)
    	{
    	utctime = $2
    	latdeg = substr($3,1,2)
    	latmin = substr($3,3,6)
    	declat = latdeg + (latmin/60)
    	londeg = substr($5,1,3)
    	lonmin = substr($5,4,6)
    	declon = -1 * (londeg + (lonmin/60))
    	if (NR==1) {
    		holddepth = -9999
    		}
    	else {
    		printf("%s, %9.6f, %9.6f, %5.1f\n", holdutctime, holddeclon, holddeclat, holddepth)
    	}
    	holdutctime = utctime
    	holdutcdate = utcdate
    	holddeclon = declon
    	holddeclat = declat
    	holddepth = -9999
    	}
    if ($1 ~ /SDDBT/)
    	{
    	if ($4 != "")
    		{
    		depthreal = $4
    		holddepth = depthreal
    		}
    	else
    		{
    		depthreal = -9999
    		holddepth = -9999
    		}
    	}
    }
    END {
    printf("%s, %9.6f, %9.6f, %5.1f\n", holdutctime, holddeclon, holddeclat, holddepth)
    }
    

    Data sources used in this process:

    • *.navdep

    Data sources produced in this process:

    • *.holdhypack

    Date: Apr-2010 (process 3 of 5)
    With each individual HYPACK file processed, I want to concatenate all the individual files on a given day into a single file. Because the file naming convention starts with the line number, and surveying wasn't done in numerical order of lines, I have to look at the order the files were acquired. The time is in the filename, but another additional file written during acquisition was a LOG file containing the order of the lines. By editing this file and converting it to a shell script, the individual files can be concatenated in chronological order. On April 13, 2010, the LOG file was RAW0413.LOG. This file, copied to a new file "catit", edited, converted to an executable file, and run under Cygwin successfully concatenated the files. catit:
    cat 201_1213.holdhypack \
    202_1414.holdhypack \
    203_1441.holdhypack \
    
    .204_1600.holdhypack > jd103hypack.csv

    Data sources used in this process:

    • *.holdhypack

    Data sources produced in this process:

    • jd103hypack.csv

    Date: Apr-2010 (process 4 of 5)
    Using VI editor, under Cygwin, the resulting CSV file was edited to add the header line "gpstime, longitude, latitude, depth_m". With this header line added, the CSV file can be imported to ArcMap 9.2 as an event theme using Tools - Add XY data and defining the projection as Geographic, WGS84. This event theme is then converted to a point shapefile by right mouse click - data - export and saving the shapefile as jd103hypack.shp.

    Data sources used in this process:

    • jd103hypack.csv

    Data sources produced in this process:

    • jd103hypack.shp

    Date: Apr-2010 (process 5 of 5)
    The table of this shapefile was edited in ArcMap 9.2 to add two additional attributes: gpsdate and jday.

    Data sources used in this process:

    • jd103hypack.shp

    Data sources produced in this process:

    • jd103hypack.shp

  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 directly above the fathometer transducer mount point. GPS data are assumed to be accurate within 10 meters on this survey.

  3. How accurate are the heights or depths?

    All bathymetry values were acquired by the 200 kHz Lowrance fathometer. The fathometer was mounted on the starboard side of the R/V Knob, directly below the GPS antenna. The Lowrance manufacturer indicates the speed of sound used by the system to calculate depth is 4800 feet/second. The depth values are not corrected for the approximately 0.2 m transducer draft. All depth values are assumed to be accurate to within 1 meter.

  4. Where are the gaps in the data? What is missing?

    This point shapefile represents every location fix and accompanying depth parsed from the raw HYPACK ASCII files.

  5. How consistent are the relationships among the observations, including topology?

    All of the HYPACK files were handled in the same manner.


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 02543-1598

    (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 zip file contains data available in ESRI point shapefile format. The user must have software capable of uncompressing the zip file and reading/displaying the shapefile.


Who wrote the metadata?

Dates:
Last modified: 30-Jun-2014
Metadata author:
VeeAnn A. Cross
U.S. Geological Survey
Marine Geologist
Woods Hole Coastal and Marine Science Center
Woods Hole, MA 02543-1598

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

Metadata standard:
FGDC Content Standards for Digital Geospatial Metadata (FGDC-STD-001-1998)
Metadata extensions used:


Generated by mp version 2.9.6 on Mon Jun 30 15:35:50 2014