Raw and Modified Raw Continuous Resistivity Profile Data Collected in the Potomac River/Chesapeake Bay on Sept. 7, 2006

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Metadata:


Identification_Information:
Citation:
Citation_Information:
Originator: John F. Bratton
Originator: VeeAnn A. Cross
Publication_Date: 2010
Title:
Raw and Modified Raw Continuous Resistivity Profile Data Collected in the Potomac River/Chesapeake Bay on Sept. 7, 2006
Series_Information:
Series_Name: Open-File Report
Issue_Identification: 2009-1151
Publication_Information:
Publication_Place: Woods Hole Coastal and Marine Science Center, Woods Hole, MA
Publisher: U.S. Geological Survey, Coastal and Marine Geology Program
Online_Linkage:
<https://pubs.usgs.gov/of/2009/1151/data/resistivity/raw_resis/sept7_raw.zip>
Online_Linkage: <https://pubs.usgs.gov/of/2009/1151/html/catalog.html>
Larger_Work_Citation:
Citation_Information:
Originator: VeeAnn A. Cross
Originator: David S. Foster
Originator: John F. Bratton
Publication_Date: 2010
Title:
Continuous Resistivity Profiling and Seismic-Reflection Data Collected in 2006 from the Potomac River Estuary, Virginia and Maryland
Series_Information:
Series_Name: Open-File Report
Issue_Identification: 2009-1151
Publication_Information:
Publication_Place: Woods Hole Coastal and Marine Science Center, Woods Hole, MA
Publisher: U.S. Geological Survey, Coastal and Marine Geology Program
Online_Linkage: <https://pubs.usgs.gov/of/2009/1151/>
Description:
Abstract:
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.
Purpose:
The purpose of this dataset is to provide the raw resistivity data collected on this date by the AGI SuperSting system. In addition, these data are provided in a format ready for processing. In some cases, small edits had to be made to the original raw files to make them suitable for processing. Both the raw and modified raw files are included. And finally, this dataset acts as a data archive.
Time_Period_of_Content:
Time_Period_Information:
Single_Date/Time:
Calendar_Date: 20060907
Currentness_Reference: ground condition
Status:
Progress: Complete
Maintenance_and_Update_Frequency: None planned
Spatial_Domain:
Bounding_Coordinates:
West_Bounding_Coordinate: -76.751217
East_Bounding_Coordinate: -76.453150
North_Bounding_Coordinate: 38.228350
South_Bounding_Coordinate: 38.077633
Keywords:
Theme:
Theme_Keyword_Thesaurus: General
Theme_Keyword: U.S. Geological Survey
Theme_Keyword: USGS
Theme_Keyword: Coastal and Marine Geology Program
Theme_Keyword: CMGP
Theme_Keyword: Woods Hole Coastal and Marine Science Center
Theme_Keyword: WHCMSC
Theme_Keyword: Field Activity Serial Number 06018
Theme_Keyword: Info Bank ID K-1-06-CH
Theme_Keyword: navigation
Theme_Keyword: bathymetry
Theme_Keyword: Continuous Resistivity Profiling
Theme_Keyword: CRP
Theme_Keyword: R/V Kerhin
Theme_Keyword: Lowrance GPS
Theme_Keyword: AGI SuperSting
Theme_Keyword: raw data
Theme_Keyword: groundwater
Theme_Keyword: submarine groundwater
Theme:
Theme_Keyword_Thesaurus: ISO 19115 Topic Category
Theme_Keyword: elevation
Theme_Keyword: inlandWaters
Theme_Keyword: location
Theme_Keyword: oceans
Theme_Keyword: oceans and estuaries
Theme_Keyword: oceans and coastal
Theme_Keyword: geoscientificInformation
Place:
Place_Keyword_Thesaurus: General
Place_Keyword: North America
Place_Keyword: North Atlantic
Place_Keyword: United States
Place_Keyword: Virginia
Place_Keyword: Potomac River Estuary
Place_Keyword: Chesapeake Bay
Place_Keyword: Dennis Point Marina
Place_Keyword: Solomons, Maryland
Place_Keyword: Maryland
Place_Keyword: Patuxent River
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.
Point_of_Contact:
Contact_Information:
Contact_Person_Primary:
Contact_Person: John F. Bratton
Contact_Organization: U.S. Geological Survey
Contact_Address:
Address_Type: mailing and physical address
Address: Woods Hole Coastal and Marine Science Center
Address: 384 Woods Hole Rd.
City: Woods Hole
State_or_Province: MA
Postal_Code: 02543-1598
Contact_Voice_Telephone: (508) 548-8700 x2254
Contact_Facsimile_Telephone: (508) 457-2310
Contact_Electronic_Mail_Address: jbratton@usgs.gov
Native_Data_Set_Environment:
Microsoft Windows XP Version 5.1 (Build 2600) Service Pack 3; ESRI ArcCatalog 9.2.6.1500

Data_Quality_Information:
Logical_Consistency_Report: All the data files were checked and handled in the same manner.
Completeness_Report:
These files represent all the raw resistivity files used to process resistivity profile data on this date. In cases where corrections had to be made to the Global Positioning System (GPS) navigation files and/or the raw resistivity files (STG), both the original and corrected files are included.
Positional_Accuracy:
Horizontal_Positional_Accuracy:
Horizontal_Positional_Accuracy_Report:
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.
Vertical_Positional_Accuracy:
Vertical_Positional_Accuracy_Report:
On this day most of the bathymetric values were collected by the Lowrance fathometer. This fathometer was mounted mid-ship on the starboard side of the boat. The Lowrance manufacturer indicates the speed of sound used by the system to convert to depths is 4800 feet/second. The ship's fathometer was hull mounted approximately mid-ship, relatively close to the navigation antenna. All values are assumed to be accurate to within 1 meter.
Lineage:
Source_Information:
Source_Contribution:
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.
Process_Step:
Process_Description:
The data were transferred from the logging computer via AGISSAdmin software version 1.03.09. The data files available for this day are L7F1, L8F1, F9L1, F10L1, L10F2, L11F1, L12F1, L13F1, L14F1, L15F1, L16F1, L17F1, L18F1, and L19F1. These files were then transferred via a thumb drive to the processing computer.
Process_Date: 2006
Process_Step:
Process_Description:
The first step is to check the navigation recorded in the *.gps file for each line of acquisition. I extracted the $GPRMC line from the CRP GPS files using an AWK script. (* refers to the line name, which for this day are L7F1, L8F1, F9L1, F10L1, L10F2, L11F1, L12F1, L13F1, L14F1, L15F1, L16F1, L17F1, L18F1, and L19F1).
AWK script awkit_tmp:
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, %s\n",declon, declat, hr, min, sec, date, ARGV[2])
	}
}
This AWK script was initialized by "doawk" - shell script run under CYGWIN (UNIX like environment that runs under Windows):
files=`ls *.gps | cut -d. -f1`
for file in $files
do
awk -f awkhold $file.gps $file >> resnav_jd250.txt
done
Source_Used_Citation_Abbreviation: *.gps
Process_Date: 2006
Source_Produced_Citation_Abbreviation: resjustnav_jd250.txt
Process_Step:
Process_Description:
This text file (resjustnav_jd250.txt) was loaded as an event them into ArcView 3.3. Displaying these points allowed me to flag the sections of bad navigation.
Source_Used_Citation_Abbreviation: resjustnav_jd250.txt
Process_Date: 2006
Process_Step:
Process_Description:
An ANSI text file containing the ship's navigation and fathometer information was transferred from the ship's system using a thumb drive.
Source_Used_Citation_Abbreviation: usgs090706.nav
Process_Date: 2006
Process_Step:
Process_Description:
The ship's text navigation file was reformatted using an AWK script into a comma-delimited ANSI text file suitable for loading in the GIS.
AWK script "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)
}
Source_Used_Citation_Abbreviation: usgs090706.nav
Process_Date: 2006
Source_Produced_Citation_Abbreviation: shippnts_jd250.txt
Process_Step:
Process_Description:
I was than able to extract each segment of reformatted ship's navigation that corresponded to the time gaps within my resistivity navigation.
Source_Used_Citation_Abbreviation: shippnts_jd250.txt
Process_Date: 2006
Source_Produced_Citation_Abbreviation: l7f1_gap1.txt
Source_Produced_Citation_Abbreviation: l7f1_gap2.txt
Source_Produced_Citation_Abbreviation: l8f1_gap1.txt
Source_Produced_Citation_Abbreviation: l8f1_gap2.txt
Process_Step:
Process_Description:
When the navigation glitched for the Lowrance, records were sent to the GPS file, but the times and fixes were bogus. Chuck Worley discovered the glitches were a result of a bad wire associated with the navigation cable. These bogus records start by recording a time of 000001 with the second record showing a time of 000006. Based on the navigation in the rest of the file which has fixes roughly every five seconds, I'm assuming that although the times themselves are bogus, the time interval in seconds is accurately represented. Based on this, I manually went through the ship's navigation segments and manually removed the records I don't need - keeping only those ship fixes that were closest in time to the fixes I believed I needed. Of course the times in the ship's navigation don't match exactly with the times I need from the Lowrance system as the ship's navigation records a fix every 3 or 4 seconds. But simply keeping the closest ship fix in time all fixes were within 1 second relative to the resistivity navigation fix I needed. The resulting files are *trim.txt (where the * refers to the initial gap files from the ship navigation).
Source_Used_Citation_Abbreviation: l7f1_gap1.txt
Source_Used_Citation_Abbreviation: l7f1_gap2.txt
Source_Used_Citation_Abbreviation: l8f1_gap1.txt
Source_Used_Citation_Abbreviation: l8f1_gap2.txt
Process_Date: 2006
Source_Produced_Citation_Abbreviation: l7f1_gap1trim.txt
Source_Produced_Citation_Abbreviation: l7f1_gap2trim.txt
Source_Produced_Citation_Abbreviation: l8f1_gap1trim.txt
Source_Produced_Citation_Abbreviation: l8f1_gap2trim.txt
Process_Step:
Process_Description:
I use an AWK script to reformat the "trimmed" ship's navigation and write the output in the $GPRMC, $SDDPT and $SDMTW strings that the resistivity system will need. The ship system doesn't have temperature, so I used a constant value of 24.3 based on the existing temperature information from the Lowrance system. The new files are *.gps (where * refers to the trim prefix file name)
AWK script awknewgps:
BEGIN {
FS=","
}
{
FS=","
alltime=$2
hr=substr($2,1,2)
min=substr($2,4,2)
sec=substr($2,7,2)
month=substr($1,1,2)
day=substr($1,4,2)
yr=substr($1,9,2)
depth=$5
declon=$4 * -1
londeg=int(declon)
lonmin=(declon-londeg)*60
declat=$3
latdeg=int(declat)
latmin=(declat-latdeg)*60 >printf("$GPRMC,%s%s%s,A,%02d%06.3f,N,%03d%06.3f,W,000.0,0,%s%s%s,0,W*73\n",hr,min,sec,latdeg,latmin,londeg,lonmin,day,month,yr)
printf("$SDDPT,%s,0.0*56\n",depth)
printf("$SDMTW,24.3,C*01\n") }
Source_Used_Citation_Abbreviation: l7f1_gap1trim.txt
Source_Used_Citation_Abbreviation: l7f1_gap2trim.txt
Source_Used_Citation_Abbreviation: l8f1_gap1trim.txt
Source_Used_Citation_Abbreviation: l8f1_gap2trim.txt
Process_Date: 2006
Source_Produced_Citation_Abbreviation: l7f1_gap1trim.gps
Source_Produced_Citation_Abbreviation: l7f1_gap2trim.gps
Source_Produced_Citation_Abbreviation: l8f1_gap1trim.gps
Source_Produced_Citation_Abbreviation: l8f1_gap2trim.gps
Process_Step:
Process_Description:
I then used VI text editor to insert these properly formatted files into the necessary sections of the resistivity navigation files that had "holidays". I also noticed that each navigation stop/start on the Lowrance system incremented the date stamp by a day. As a precaution, I copied l7f1_mod.gps to l7f1_mod2.gps before fixing this date error. Once I was confident I was fixing it correctly, in line 8 I didn't take the intermediate step.
Source_Used_Citation_Abbreviation: l7f1_gap1trim.gps
Source_Used_Citation_Abbreviation: l7f1_gap2trim.gps
Source_Used_Citation_Abbreviation: l8f1_gap1trim.gps
Source_Used_Citation_Abbreviation: l8f1_gap2trim.gps
Process_Date: 2006
Source_Produced_Citation_Abbreviation: l7f1_mod2.gps
Source_Produced_Citation_Abbreviation: l8f1_mod.gps
Process_Step:
Process_Description:
The STG files that accompany these GPS files also had to be modified. As noted, each glitch in the navigation system caused the date to increment and the times to reset to 000000. I used VI to edit the dates and times in the STG files to correspond to the date and times in the GPS files.
Source_Used_Citation_Abbreviation: L7F1.stg
Source_Used_Citation_Abbreviation: L8F1.stg
Process_Date: 2006
Source_Produced_Citation_Abbreviation: L7F1_mod.stg
Source_Produced_Citation_Abbreviation: L8F1_mod.stg
Process_Step:
Process_Description:
Two other lines had navigation gaps. These gaps were the actual absence of any information, so these lines had to be split to enable the resistivity software to process the data. Simply used Microsoft WordPad to delete the one portion of the original navigation and save the file under a new name.
Source_Used_Citation_Abbreviation: L10F2.gps
Source_Used_Citation_Abbreviation: L13F1.gps
Process_Date: 2006
Source_Produced_Citation_Abbreviation: L10F2_part1.gps
Source_Produced_Citation_Abbreviation: L10F2_part2.gps
Source_Produced_Citation_Abbreviation: L13F1_part2.gps
Source_Produced_Citation_Abbreviation: L13F1_part2.gps
Process_Step:
Process_Description:
To account for the navigation gaps, the STG files of l10f2 and l13f1 also had to be split. This was done in the same manner as splitting the GPS files, where the file was brought into WordPad, the unwanted section deleted, and the file saved under a new name.
Source_Used_Citation_Abbreviation: L10F2.stg
Source_Used_Citation_Abbreviation: L13F1.stg
Process_Date: 2006
Source_Produced_Citation_Abbreviation: L10F2_part1.stg
Source_Produced_Citation_Abbreviation: L10F2_part2.stg
Source_Produced_Citation_Abbreviation: L13F1_part2.stg
Source_Produced_Citation_Abbreviation: L13F1_part2.stg

Spatial_Data_Organization_Information:
Direct_Spatial_Reference_Method: Point

Spatial_Reference_Information:
Horizontal_Coordinate_System_Definition:
Geographic:
Latitude_Resolution: 0.000001
Longitude_Resolution: 0.000001
Geographic_Coordinate_Units: Degrees and decimal minutes
Geodetic_Model:
Horizontal_Datum_Name: North American Datum of 1983
Ellipsoid_Name: Geodetic Reference System 80
Semi-major_Axis: 6378137.000000
Denominator_of_Flattening_Ratio: 298.257222
Vertical_Coordinate_System_Definition:
Depth_System_Definition:
Depth_Datum_Name: Local surface
Depth_Resolution: 0.1
Depth_Distance_Units: meters
Depth_Encoding_Method: Explicit depth coordinate included with horizontal coordinates

Distribution_Information:
Distributor:
Contact_Information:
Contact_Person_Primary:
Contact_Person: John F. Bratton
Contact_Organization: U.S. Geological Survey
Contact_Address:
Address_Type: mailing and physical address
Address: Woods Hole Coastal and Marine Science Center
Address: 384 Woods Hole Rd.
City: Woods Hole
State_or_Province: MA
Postal_Code: 02543-1598
Contact_Voice_Telephone: (508) 548-8700 x2254
Contact_Facsimile_Telephone: (508) 457-2310
Contact_Electronic_Mail_Address: jbratton@usgs.gov
Resource_Description: Downloadable Data
Distribution_Liability:
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.
Standard_Order_Process:
Digital_Form:
Digital_Transfer_Information:
Format_Name: WinZip
Format_Version_Number: 9.0
Format_Information_Content:
The WinZip file contains all the raw CRP data from Sept. 7, 2006 as well as the associated metadata files.
Transfer_Size: 1.4 MB
Digital_Transfer_Option:
Online_Option:
Computer_Contact_Information:
Network_Address:
Network_Resource_Name:
<https://pubs.usgs.gov/of/2009/1151/data/resistivity/raw_resis/sept7_raw.zip>
Network_Resource_Name: <https://pubs.usgs.gov/of/2009/1151/html/catalog.html>
Offline_Option:
Offline_Media: DVD-ROM
Recording_Capacity:
Recording_Density: 4.75
Recording_Density_Units: GBytes
Recording_Format: UDF
Fees: None.
Technical_Prerequisites:
The data are provided in a WinZip compressed file. The user must have software capable of uncompressing the archive. In addition, the raw data are available in a format compatible with AGI Geosciences Marine Log Manager software. The user must have software capable of reading the AGI format in order to process these data.

Metadata_Reference_Information:
Metadata_Date: 20100325
Metadata_Contact:
Contact_Information:
Contact_Person_Primary:
Contact_Person: VeeAnn A. Cross
Contact_Organization: U.S. Geological Survey
Contact_Position: Marine Geologist
Contact_Address:
Address_Type: mailing and physical address
Address: Woods Hole Coastal and Marine Science Center
Address: 384 Woods Hole Rd.
City: Woods Hole
State_or_Province: MA
Postal_Code: 02543-1598
Contact_Voice_Telephone: (508) 548-8700 x2251
Contact_Facsimile_Telephone: (508) 457-2310
Contact_Electronic_Mail_Address: vatnipp@usgs.gov
Metadata_Standard_Name: FGDC Content Standards for Digital Geospatial Metadata
Metadata_Standard_Version: FGDC-STD-001-1998
Metadata_Time_Convention: local time
Metadata_Extensions:
Online_Linkage: <http://www.esri.com/metadata/esriprof80.html>
Profile_Name: ESRI Metadata Profile

Generated by mp version 2.9.6 on Thu Mar 25 13:43:16 2010