VeeAnn A. Cross 2010 vector digital data Open-File Report 2009-1151 Woods Hole Coastal and Marine Science Center, Woods Hole, MA U.S. Geological Survey, Coastal and Marine Geology Program https://doi.org/10.3133/ofr20091151 http://pubs.usgs.gov/of/2009/1151/data/navigation/resistivity/resgpspnts_jd249.zip http://pubs.usgs.gov/of/2009/1151/html/catalog.html VeeAnn A. Cross David S. Foster John F. Bratton 2010 Open-File Report 2009-1151 Reston, VA U.S. Geological Survey http://pubs.usgs.gov/of/2009/1151/ In order to test hypotheses about groundwater flow under and into Chesapeake Bay, geophysical surveys were conducted by U.S. Geological Survey (USGS) scientists on Chesapeake Bay and the Potomac River Estuary in September 2006. Chesapeake Bay resource managers are concerned about nutrients that are entering the estuary via submarine groundwater discharge, which are contributing to eutrophication. The USGS has performed many related studies in recent years to provide managers with information necessary to make informed decisions about this issue. The research carried out as part of the study described here was designed to help refine nutrient budgets for Chesapeake Bay by characterizing submarine groundwater flow and discharge of groundwater beneath part of the mainstem and a major tributary, the Potomac River Estuary. The purpose of this point shapefile is to provide the ship's position and bathymetric values during the collection of continuous resistivity profile data. 20060906 ground condition Complete None planned -76.454833 -76.310367 38.295767 37.946450 USGS Metadata Identifier USGS:0b53d382-6ad6-41e4-9fd8-b57f830d11b3 None U.S. Geological Survey USGS Coastal and Marine Geology Program CMGP Woods Hole Coastal and Marine Science Center WHCMSC Field Activity Serial Number 06018 navigation bathymetry point shapefile Continuous Resistivity Profiling CRP R/V Kerhin Lowrance GPS Info Bank ID K-1-06-CH ISO 19115 Topic Category elevation inlandWaters location oceans USGS Thesaurus navigational data bathymetry water temperature marine geophysics geospatial datasets None North America North Atlantic United States Virginia Potomac River Estuary Chesapeake Bay Dennis Point Marina Solomons, Maryland Maryland Patuxent River None. 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. John F. Bratton U.S. Geological Survey mailing and physical address

Woods Hole Coastal and Marine Science Center

384 Woods Hole Rd.

Woods Hole MA 02543-1598 (508) 548-8700 x2254 (508) 457-2310 jbratton@usgs.gov http://pubs.usgs.gov/of/2009/1151/data/navigation/resistivity/resgpspnts_jd249.gif Thumbnail image showing the location of resistivity navigation points collected Sept. 6, 2006. The coastline is included for spatial reference. GIF Microsoft Windows XP Version 5.1 (Build 2600) Service Pack 3; ESRI ArcCatalog 9.2.6.1500 No duplicate points are present. The navigational fixes and depth values were checked for valid values. Invalid data points were deleted. No other checks were performed. There is a navigational fix and fathometer reading for every reading of resistivity data. No temperature data was recorded on this day. The primary navigation system used was a Lowrance 480M with an LGC-2000 Global Positioning System (GPS) antenna. The antenna was located 7.9 meters forward of the anchor point for the resistivity streamer, and approximately 3 meters forward of the fathometer transducer. These offsets were not entered into the GPS system. Additionally, because of navigation and fathometers issues, periodically the ship's navigation system was used to supplement these data. The ship had a Differential GPS (DGPS) system with the antenna placed in the same location as the Lowrance antenna. The fathometer was located (hull-mounted) roughly directly below the antenna, so no horizontal offset. Because of the mixture of systems, the accuracy is on the order of 20 meters. All the bathymetric values from this day were collected by the ship's fathometer. This fathometer was hull mounted approximately midship, relatively close to the navigation antenna. The values are assumed to be accurate to within 1 meter. U.S. Geological Survey Unpublished material hard disk 20060906 ground condition raw crp data 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. The particular system used for this acquisition was a 100-m streamer with an 11 electrode array with electrodes spaced 10 meters apart. 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. 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 which was not working on Julian Day 249. Lowrance indicates the speed of sound used by the system is 4800 feet/second. On the first day of data collection (Julian Day 249, Sept. 6, 2006) the Lowrance transducer was side-mounted mid-ship on the port side of the boat. The remainder of the cruise the transducer was side-mounted mid-ship of the starboard side of the boat. 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. The data files were transferred from the acquisition computer via a USB thumb drive. The first step is to check the navigation recorded in the *.gps file for each line of acquisition. Although the navigation fixes themselves appear to be okay, the fathometer data is not. To verify this, I extracted the $GPRMC line from the CRP GPS files using an AWK script. (* refers to the line name, which for this day are l1f1, l2f1, l3f1, l4f1, l5f1 and l6f1) >awkpullgprmc: >BEGIN { >FS = "," >} >{ >FS = "," >if ($1=="$GPRMC") >{ >print $0 >} >endif >} *.gps 2006 *.gprmc VeeAnn A. Cross U.S. Geological Survey Marine Geologist mailing and physical address

Woods Hole Coastal and Marine Science Center

384 Woods Hole Rd.

Woods Hole MA 02543-1598 (508) 548-8700 x2251 (508) 457-2310 vatnipp@usgs.gov Used an AWK script to reformat the GPRMC navigation to a comma-delimited ANSI text navigation file suitable for loading in the GIS. (* refers to the line name, which for this day are l1f1, l2f1, l3f1, l4f1, l5f1 and l6f1). The text editor VI was used to add the necessary header line to each file. >awk_justgprmc: >BEGIN { >FS="," >} >{ >FS= "," >ARGC = 2 >if ($1=="$GPRMC") { >gpstime = $2 >hr = substr($2,1,2) >min = substr($2,3,2) >sec = substr($2,5,2) >latdeg = substr($4,1,2) >latmin = substr($4,3,6) >londeg = substr($6,2,2) >lonmin = substr($6,4,6) >declat = latdeg + (latmin/60) >declon = (londeg + (lonmin/60)) * -1 >date = $10 >day = substr($10,1,2) >month = substr($10,3,2) >year = substr($10,5,2) >printf("%8.6f, %8.6f, %s:%s:%s, %s\n",declon, declat, hr, min, sec, date) >} >} *.gprmc 2006 *gprmc.txt VeeAnn A. Cross U.S. Geological Survey Marine Geologist mailing and physical address

Woods Hole Coastal and Marine Science Center

384 Woods Hole Rd.

Woods Hole MA 02543-1598 (508) 548-8700 x2251 (508) 457-2310 vatnipp@usgs.gov Using ArcView 3.3 this comma-delimited ANSI text file was loaded as an event theme. This event theme was then saved as a shapefile using Theme - Convert to shapefile. (* refers to the line name, which for this day are l1f1, l2f1, l3f1, l4f1, l5f1 and l6f1) *gprmc.txt 2006 *.shp VeeAnn A. Cross U.S. Geological Survey Marine Geologist mailing and physical address

Woods Hole Coastal and Marine Science Center

384 Woods Hole Rd.

Woods Hole MA 02543-1598 (508) 548-8700 x2251 (508) 457-2310 vatnipp@usgs.gov An ANSI text file containing the ship's navigation and fathometer information was transferred from the ship's system using a thumb drive. 2006 usgs090606.nav VeeAnn A. Cross U.S. Geological Survey Marine Geologist mailing and physical address

Woods Hole Coastal and Marine Science Center

384 Woods Hole Rd.

Woods Hole MA 02543-1598 (508) 548-8700 x2251 (508) 457-2310 vatnipp@usgs.gov This text file was reformatted using an AWK script into a comma-delimited ANSI text file suitable for loading in the GIS. >awknav: >{ >shipdate = $1 >gpstime = $2 >latdeg = substr($5,1,2) >latdecmin = $6 >declat = latdeg + (latdecmin/60) >londeg = substr($7,1,3) >londecmin = $8 >declon = -1 * (londeg + (londecmin/60)) >depmeters = $10 >printf("%s, %s, %9.6f, %9.6f, %s\n",shipdate, gpstime, declat, declon, depmeters) >} usgs090606.nav 2006 shippnts_249.txt VeeAnn A. Cross U.S. Geological Survey Marine Geologist mailing and physical address

Woods Hole Coastal and Marine Science Center

384 Woods Hole Rd.

Woods Hole MA 02543-1598 (508) 548-8700 x2251 (508) 457-2310 vatnipp@usgs.gov The ANSI text file was loaded into ArcView 3.3 as an event theme and then saved as a shapefile using Theme - convert to shapefile. shippnts_249.txt 2006 shippnts_249.shp VeeAnn A. Cross U.S. Geological Survey Marine Geologist mailing and physical address

Woods Hole Coastal and Marine Science Center

384 Woods Hole Rd.

Woods Hole MA 02543-1598 (508) 548-8700 x2251 (508) 457-2310 vatnipp@usgs.gov Within ArcView 3.3 I used the spatial join capabilities to join the ship navigation and fathometer information to each line of resistivity navigation. This is accomplished by opening both attribute tables in ArcView. Then make the source table active (the table that I want to join to the other table). In this case, that's the attribute table for shippnts_249.shp. Within this table, click the Shape field's name. Then make the other attribute table active (*.shp where * represents the line name such as l1f1). Select the Shape field's name. Then from the table menu, choose "Join". This essentially finds the closest positional point in shippnts_249.shp and joins it to the *.shp attribute table. (* refers to the line name, which for this day are l1f1, l2f1, l3f1, l4f1, l5f1 and l6f1) *.shp shippnts_249.shp 2006 VeeAnn A. Cross U.S. Geological Survey Marine Geologist mailing and physical address

Woods Hole Coastal and Marine Science Center

384 Woods Hole Rd.

Woods Hole MA 02543-1598 (508) 548-8700 x2251 (508) 457-2310 vatnipp@usgs.gov The only information I need from this joined table is the bathymetry information. So using the table properties, I turn off (uncheck the visible option) everything but the depth values. Once this is done, I use File - Export to export the table to a delimited text file. (* refers to the line name, which for this day are l1f1, l2f1, l3f1, l4f1, l5f1 and l6f1) *.shp 2006 *_shipbathy.txt VeeAnn A. Cross U.S. Geological Survey Marine Geologist mailing and physical address

Woods Hole Coastal and Marine Science Center

384 Woods Hole Rd.

Woods Hole MA 02543-1598 (508) 548-8700 x2251 (508) 457-2310 vatnipp@usgs.gov I then ran an AWK script which would take the each line of the bathymetry information and convert it to the $SDDPT format that a GPS system would record. (* refers to the line name, which for this day are l1f1, l2f1, l3f1, l4f1, l5f1 and l6f1). The $SDDPT refers to the water depth relative to the transducer, in meters. The sentence is of the format "$SDDPT, DATA_METERS, OFFSET_METERS, MAXIMUM_METERS*hh<0D><0A> where the portion after the * is a checksum value. I manually defined everything except the actual depth values, since those are the only values I'll use. >awk_sddpt: >{ >depthval = $1 >printf("$SDDPT,%s,0.0*65\n",depthval) >} *_shipbathy.txt 2006 *.sddpt VeeAnn A. Cross U.S. Geological Survey Marine Geologist mailing and physical address

Woods Hole Coastal and Marine Science Center

384 Woods Hole Rd.

Woods Hole MA 02543-1598 (508) 548-8700 x2251 (508) 457-2310 vatnipp@usgs.gov For every line in the extracted GPRMC data, I now have a separate files with the same number of lines containing bathymetry information in the $SDDPT format. Using CYGWIN (a UNIX like environment that runs under Windows) I use the "paste" command to join the two files using a newline character as the delimiter between the two files. Essentially what this does is generate a file with a line of GPRMC data, then SDDPT and so for and so on. The syntax with the paste command I used for the resistivity navigation is: paste -d '\n' filename1 filename2 > output where filename1 is the GPRMC text file, filename2 is the bathymetry text file, and the output is the repaired GPS navigation file. (* refers to the line name, which for this day are l1f1, l2f1, l3f1, l4f1, l5f1 and l6f1) *.gprmc *.sddpt 2006 *fix.gps VeeAnn A. Cross U.S. Geological Survey Marine Geologist mailing and physical address

Woods Hole Coastal and Marine Science Center

384 Woods Hole Rd.

Woods Hole MA 02543-1598 (508) 548-8700 x2251 (508) 457-2310 vatnipp@usgs.gov I then ran an AWK script on the resulting GPS files to generate a single comma-delimited text file with the information of interest. I then used VI to add the appropriated header line. >AWK script awkit: >BEGIN { >FS="," >} >{ >FS= "," >ARGC = 2 >if ($1=="$GPRMC") { >gpstime = $2 >hr = substr($2,1,2) >min = substr($2,3,2) >sec = substr($2,5,2) >latdeg = substr($4,1,2) >latmin = substr($4,3,6) >londeg = substr($6,2,2) >lonmin = substr($6,4,6) >declat = latdeg + (latmin/60) >declon = (londeg + (lonmin/60)) * -1 >date = $10 >day = substr($10,1,2) >month = substr($10,3,2) >year = substr($10,5,2) >} >else if ($1=="$SDDPT") { >depth = $2 >printf("%8.6f, %8.6f, %s:%s:%s, %s, %s, %s\n",declon, declat, hr, min, sec, date, depth, ARGV[2]) >} >} > The running of the script was initiated with a simple executable shell script under CYGWIN (a Unix like environment that runs under Windows >"doawk": >files=`ls *.gps | cut -d. -f1` >for file in $files >do >awk -f awkit $file.gps $file >> resnav_jd249.txt >done l1f1fix.gps l2f1fix.gps l3f1fix.gps l4f1fix.gps l5f1fix.gps l6f1fix.gps 2006 resnav_jd249.txt VeeAnn A. Cross U.S. Geological Survey Marine Geologist mailing and physical address

Woods Hole Coastal and Marine Science Center

384 Woods Hole Rd.

Woods Hole MA 02543-1598 (508) 548-8700 x2251 (508) 457-2310 vatnipp@usgs.gov 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, NAD83. Because of the format of the "gpstime" field, the default for ArcMap is to import this as a date/time field. Because I wanted this field to remain a text field, I edited the schema.ini file in the folder with the text file to define each attributes definition. I also made sure the DATE field imported as a text attribute to preserve the leading zero. I then used the data export (right-mouse click on the event theme, Data - Export Data) to save the event theme as a shapefile. >schema.ini: >[resnav_jd249.txt] >Format=CSVDelimited >ColNameHeader=True >Col1=longitude Double >Col2=latitude Double >Col3=gpstime Text Width 8 >Col4=gpsdate Text Width 10 >Col5=depth_m float >Col6=linename Text Width 11 resnav_jd249.txt 2009 resgpspnts_jd249.shp VeeAnn A. Cross U.S. Geological Survey Marine Geologist mailing and physical address

Woods Hole Coastal and Marine Science Center

384 Woods Hole Rd.

Woods Hole MA 02543-1598 (508) 548-8700 x2251 (508) 457-2310 vatnipp@usgs.gov Using ArcMap 9.2 added the attributes "gps_src' and "bathy_src" so that I could differentiate the source of each navigation fix and bathymetry value. On this particular day, all the navigational fixes came from the Lowrance system, while the bathymetry values came from the ship's gps/fathometer system. resgpspnts_jd249.shp 2009 resgpspnts_jd249.shp VeeAnn A. Cross U.S. Geological Survey Marine Geologist mailing and physical address

Woods Hole Coastal and Marine Science Center

384 Woods Hole Rd.

Woods Hole MA 02543-1598 (508) 548-8700 x2251 (508) 457-2310 vatnipp@usgs.gov Edits to the metadata were made to fix any errors that MP v 2.9.34 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.). The source information was incomplete and had to be modified to meet the standard. 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. 20161020 U.S. Geological Survey VeeAnn A. Cross Marine Geologist Mailing and Physical

384 Woods Hole Road

Woods Hole MA 02543 508-548-8700 x2251 508-457-2310 vatnipp@usgs.gov USGS Thesaurus keywords added to the keyword section. 20180720 U.S. Geological Survey VeeAnn A. Cross Marine Geologist Mailing and Physical

384 Woods Hole Road

Woods Hole MA 02543-1598 508-548-8700 x2251 508-457-2310 vatnipp@usgs.gov Crossref DOI link was added as the first link in the metadata. 20191118 U.S. Geological Survey VeeAnn A. Cross Marine Geologist Mailing and Physical

384 Woods Hole Road

Woods Hole MA 02543-1598 508-548-8700 x2251 508-457-2310 vatnipp@usgs.gov Added keywords section with USGS persistent identifier as theme keyword. 20200908 U.S. Geological Survey VeeAnn A. Cross Marine Geologist Mailing and Physical

384 Woods Hole Road

Woods Hole MA 02543-1598 508-548-8700 x2251 508-457-2310 vatnipp@usgs.gov Vector Entity point 6141 0.000001 0.000001 Decimal degrees North American Datum of 1983 Geodetic Reference System 80 6378137.000000 298.257222 Local surface 0.1 meters Explicit depth coordinate included with horizontal coordinates resgpspnts_jd249 ESRI point shapefile ESRI FID Internal feature number. ESRI Sequential unique whole numbers that are automatically generated. Shape Feature geometry. ESRI Coordinates defining the features. longitude Longitude coordinate of the point in decimal degrees, NAD83. U.S. Geological Survey -76.454833 -76.310367 decimal degrees latitude Latitude coordinate of the point in decimal degrees, NAD83. U.S. Geological Survey 37.94645 38.295767 decimal degrees gpstime GPS time in the format HH:MM:SS. GPS time is +4 hours from local time during the survey. U.S. Geological Survey Character set. 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. U.S. Geological Survey Character set. depth_m Depth of the water below the fathometer in meters recorded by the ship's fathometer/navigation system. U.S. Geological Survey 1.7 21.200001 meters linename The alphanumeric name corresponding to the prefix of the GPS filename. This name reflects the name assigned to the line of data acquisition and incorporates modifiers to reflect modification of the GPS file. U.S. Geological Survey Character set. gps_src The system from which the navigation point was derived. On this day those values came from the Lowrance system. U.S. Geological Survey Character set. bathy_src The system from which the bathymetric value was acquired. On this day, all bathymetry came from the ship navigation/fathometer system. U.S. Geological Survey Character set. John F. Bratton U.S. Geological Survey mailing and physical address

Woods Hole Coastal and Marine Science Center

384 Woods Hole Rd.

Woods Hole MA 02543-1598 (508) 548-8700 x2254 (508) 457-2310 jbratton@usgs.gov Downloadable Data 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. Shapefile ArcGIS 9.2 This WinZip (version 9.0) file contains the point shapefile as well as the associated metadata files. 0.197 http://pubs.usgs.gov/of/2009/1151/data/navigation/resistivity/resgpspnts_jd249.zip http://pubs.usgs.gov/of/2009/1151/html/catalog.html DVD-ROM 4.75 GBytes UDF None. 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. 20240318 VeeAnn A. Cross U.S. Geological Survey Marine Geologist mailing and physical address

Woods Hole Coastal and Marine Science Center

384 Woods Hole Rd.

Woods Hole MA 02543-1598 (508) 548-8700 x2251 (508) 457-2310 whsc_data_contact@usgs.gov The metadata contact email address is a generic address in the event the person is no longer with USGS. (updated on 20240318) FGDC Content Standards for Digital Geospatial Metadata FGDC-STD-001-1998 local time