VeeAnn A. Cross
2018
Point shapefile of navigation, water depth, and water temperature at ship positions during continuous resistivity profiling data collection in Greenwich Bay, Rhode Island, May 14 and 15, 2009, on U.S. Geological Survey Field Activity 2009-021-FA (Geographic, WGS84)
1.0
vector digital data
data release
DOI:10.5066/F7DR2TSX
Woods Hole Coastal and Marine Science Center, Woods Hole, MA
U.S. Geological Survey, Coastal and Marine Geology Program
https://doi.org/10.5066/F7DR2TSX
John F. Bratton
VeeAnn A. Cross
2015
Continuous Resistivity Profiling Data and Associated Data from Greenwich Bay, Rhode Island collected in 2009, U.S. Geological Survey Field Activity 2009-021-FA
1.0
data release
DOI:10.5066/F7DR2TSX
Reston, VA
U.S. Geological Survey
Suggested citation: Bratton, J.F., and Cross, V.A., 2018, Continuous resistivity profiling data and associated data from Greenwich Bay, Rhode Island collected in 2009, U.S. Geological Survey Field Activity 2009-021-FA: U.S. Geological Survey data release, https://doi.org/10.5066/F7DR2TSX.
https://doi.org/10.5066/F7DR2TSX
https://cmgds.marine.usgs.gov/data/field-activity-data/2009-021-FA/
As part of a larger investigation to understand groundwater-surface water interactions in Greenwich Bay, Rhode Island, a geophysical survey was conducted from a small research boat on 14-15 May 2009. The specific research objective was to gain an improved understanding of the role of direct groundwater discharge in delivery of excess nitrogen to the bay, which may have contributed to the development of low-oxygen conditions in waters of the bay and associated fish kills. Data collected in this survey included digital navigation information, continuous resistivity profiling (CRP) data, and point salinity measurements. The CRP method is a survey and data processing approach that is sensitive to differences in electrical properties of surface water and underlying porewater in sediments that have contrasting salinities. During the survey, Greenwich Bay salinity was approximately 27 ppm, so surface water would be expected to have low electrical resistivity (high conductivity), and any areas of active groundwater discharge from less salty aquifer sources would yield relatively higher resistivity values. This survey is identified as field activity 09021 (also referenced as 2009-021-FA) by the U.S. Geological Survey, Woods Hole, Massachusetts, and additional information is available from: https://cmgds.marine.usgs.gov/fan_info.php?fan=2009-021-FA.
This point shapefile provides the boat's XY position, water depth, and water temperature during the collection of continuous resistivity profile data in Greenwich Bay, Rhode Island in May 2009. This shapefile also acts as an archive of this dataset.
20090414
20090515
ground condition
None planned
-71.452350
-71.369483
41.696383
41.651083
None
U.S. Geological Survey
USGS
Coastal and Marine Geology Program
CMGP
Woods Hole Coastal and Marine Science Center
WHCMSC
Field Activity Number 2009-021-FA
Info Bank ID B-21-09-RI
navigation
bathymetry
water temperature
continuous resistivity profiling
CRP
Lowrance GPS
ISO 19115 Topic Category
elevation
location
geoscientificInformation
USGS Thesaurus
navigational data
marine geophysics
None
North America
United States
Rhode Island
Greenwich Bay
Narragansett Bay
Warwick, RI
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.
VeeAnn A. Cross
U.S. Geological Survey
Marine Geologist
mailing and physical address
384 Woods Hole Rd.
Woods Hole
MA
02543-1598
(508) 548-8700 x2251
(508) 457-2310
vatnipp@usgs.gov
https://cmgds.marine.usgs.gov/data/field-activity-data/2009-021-FA/data/geophysics/navigation/2009_021_FA_res_pntnav.jpg
Browse graphic of the point navigation locations.
JPEG
Microsoft Windows Vista Version 6.1 (Build 7601) Service Pack 1; ESRI ArcCatalog 9.3.1.4095
Each file was looked at individually, but the files as a collection were handled in the same manner.
These points represent all the navigation for the CRP lines that are processed. There were no lines 1-4 as there were battery problems during data collection. Line 18 had to be split into three separate parts to be processed due to gaps in the navigation.
The navigation system used was a Lowrance 480M with an LGC-2000 Global Positioning System (GPS) antenna. The antenna was located 1.5 meters forward of the resistivity streamer tow point and directly above the fathometer transducer. The GPS is assumed to be accurate to within 10 meters.
All bathymetry values were acquired by the 200 kHz Lowrance fathometer. The fathometer was mounted on the starboard side of the University of Rhode Island pontoon boat, 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. No tide corrections were performed.
John F. Bratton
2015
Raw CRP data
disk
20090513
20090515
ground condition
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. Two streamer systems were used during this field activity - a 50-m streamer and a 100-m streamer. The 50-m streamer has an 11 electrode array with electrodes spaced 5 meters apart. The 100-m streamer has an 11 electrode array with electrodes spaced 10 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 1/4 the streamer length. So for the 50-m streamer, maximum depth is about 12.5 meters while the 100-m streamer maximum depth is about 25 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 antenna and fathometer transducer were mounted on the starboard side of the boat. The streamer tow point was on the port side aft. The layback offset between the navigation antenna and the first electrode was 16.5 meters. This layback offset was not accounted for during data acquisition, so was entered during processing of the data. The approximately 2.5 m lateral offset between the streamer tow point and the navigation antenna is not accounted for. The Lowrance transducer also contains a temperature sensor that records temperature in degrees Celsius. For depth measurements, Lowrance indicates the speed of sound used by the system is 4800 feet/second, but depths are recorded in meters. 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.
The data were transferred from the logging computer using AGISSAdmin software version 1.3.4.198. These files were then emailed from the field to the USGS office in Woods Hole in a single zip file. The data files included in this release 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 water 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. The field collection and data transfer were done by Chuck Worley of the USGS.
Raw CRP data
200905
U.S. Geological Survey
Charles Worley
Marine Geologist
mailing address
384 Woods Hole Rd.
Woods Hole
MA
02543-1598
(508) 548-8700 x2250
(508) 457-2313
cworley@usgs.gov
First, the navigation in the GPS files was checked. One file - L18F1 - had several navigation gaps. This file was split into 3 parts effectively eliminating the navigation gaps. The gaps would cause problems in processing of the data. Additionally, the navigation in the GPS files were inspected visually. This was done by quickly parsing the GPS text files into comma-delimited text files with a header line, and then viewing the files in ArcMap 9.2. The AWK scripts used to parse the navigation was awkhold. The scripts used for data collection on May 14, 2009 are as follows.
>
awkhold:
>
>BEGIN {
>FS = ","
>}
>{
>FS = ","
>ARGC = 2
>depth = -9999
>temp = -9999
>if (NR==1)
> {
> #printf("utctime, longitude, latitude, depth_m, temp_c, line\n")
> }
>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 file was executed by a shell script to effectively batch process all the files in a single folder with the extension gps. The batch processing script was called dohold.
>
dohold:
>
>files=`ls *.gps | cut -d. -f1`
>for file in $files
>do
> awk -f awkhold $file.gps $file >> may14_09_gps.txt
>done
>
Under Cygwin, all of the hold files were concatenated into a single comma-delimited text file and a header line added to the file. The header line added to the text file was: gpstime, longitude, latitude, depth_m, temp_c, line. Using ArcMap 9.2 - Tools - Add XY Data, the comma-delimited text file was added as an event theme to ArcMap. No erroneous points were detected.
>
This processing step and all subsequent processing steps were performed by the same person - VeeAnn A. Cross.
Raw CRP data
200905
Modified (because the navigation was modified) Raw CRP data
may14_09_gpssplits.csv
may15_09_gps.csv
VeeAnn A. Cross
U.S. Geological Survey
Marine Geologist
mailing and physical address
384 Woods Hole Rd.
Woods Hole
MA
02543-1598
(508) 548-8700 x2251
(508) 457-2310
vatnipp@usgs.gov
The text editor VI was used under Cygwin to add the following header line to the resulting text file:
>gpstime, longitude, latitude, depth_m, temp_c, line
>
This text file was then imported to ArcMap 9.2 using Tools -AddXY Data. The X field is longitude, Y field is latitude, and the coordinate system as defined as WGS84. This "Event Theme" was converted to a shapefile by right-mouse clicking on the layer - Data - Export Data.
may14_09_gpssplits.csv
may15_09_gps.csv
200905
may14_09_gps_spl_pnts.shp
may15_09_gpspnts.shp
Several additional attributes were added to the shapefile and populated in ArcMap 9.3.1. The attributes added were gpsdate, jul_date, streamer. For the May 14th data, these attributes were populated with 20090514, 134, 50-m. This reflects the data of data collection, the Julian day of data collection, and the streamer length of data collection. For the May 15th data, these attributes were populated with 20090515, 135, 100-m.
201307
may14_09_gps_spl_pnts.shp
may15_09_gpspnts.shp
Using ArcMap 9.3.1, the individual points shapefiles were merged into a single shapefile. This was done using ArcToolbox - Data Management Tools - General - Merge.
may14_09_gps_spl_pnts.shp
may15_09_gpspnts.shp
2013
res_pntnav_mergenav.shp
Filename was changed to include the field activity number for publication purposes.
res_pntnav_mergenav.shp
2015
2009-021-FA_res_pntnav.shp
The point shapefile was exported to a CSV file. This was done in ArcGIS 10.3.1 using XToolsPro v. 12.0. Within XTools - Table operations - Export Table to File. Filename was set to 2009-021-FA_res_pntnav.csv, all fields except FID were selected for export, and the option of comma separated values was chosen. This process was performed in order to provide the data in an open data format.
20180412
Vector
Entity point
7788
0.000001
0.000001
Decimal degrees
D_WGS_1984
WGS_1984
6378137.000000
298.257224
2009-021-FA_res_pntnav
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.
gpstime
GPS time in the format HHMMSS. GPS time is +4 hours from local time during the survey.
U.S. Geological Survey
Although the value is represented as a number in a text defined field, 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.
U.S. Geological Survey
-71.45235
-71.369483
decimal degrees
latitude
Latitude coordinate of the point in decimal degrees, WGS84.
U.S. Geological Survey
41.651083
41.696383
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.
U.S. Geological Survey
0.4
22.4
meters
temp_c
Water temperature in degrees Celsius as recorded at the Lowrance fathometer transducer. A value of -9999 indicates no data.
U.S. Geological Survey
13.9
16.7
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 and incorporates modifiers to reflect modification of the GPS file if the GPS file was split into more than one part.
U.S. Geological Survey
Character set.
gpsdate
The date of data acquisition in the format YYYYMMDD.
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 month, day, and year are broken out does the number have meaning.
jul_date
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.
U.S. Geological Survey
134
135
day
streamer
The CRP streamer length used for data collection.
U.S. Geological Survey
Character set where 50-m indicates the 50-m streamer was used for data acquisition, and 100-m indicates the 100-m streamer was used for data acquisition.
The data in the shapefile is also available in a CSV format. The FID and Shape attributes are omitted from the CSV file, but all the other attributes (attribute lables are in the first row of the CSV file) and data are included in the CSV file.
U.S. Geological Survey
VeeAnn A. Cross
U.S. Geological Survey
Marine Geologist
mailing and physical address
384 Woods Hole Rd.
Woods Hole
MA
02543-1598
(508) 548-8700 x2251
(508) 457-2310
vatnipp@usgs.gov
The 2009-021-FA_res_pntnav.zip file contains the 2009-021-FA_res_pntnav point shapefile and its components, the data in CSV format (2009-021-FA_res_pntnav), a browse graphic (2009_021_FA_res_pntnav.jpg), as well as the FGDC CSDGM metadata in the following formats: XML, HTML, and text.
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 9.3.1
The zip file contains all the shapefile of the processed CRP navigation data from U.S. Geological Survey field activity 2009-021-FA, the data in CSV format, a browse graphic, and the associated metadata files.
1
https://cmgds.marine.usgs.gov/data/field-activity-data/2009-021-FA/data/geophysics/navigation/2009-021-FA_res_pntnav.zip
https://doi.org/10.5066/F7DR2TSX
The first link downloads the data directly, the second link is to the landing page of the data.
CSV
ArcGIS 10.3.1/XToolsPro 12.0
comma-separated values
The zip file contains all the shapefile of the processed CRP navigation data from U.S. Geological Survey field activity 2009-021-FA, the data in CSV format, a browse graphic, and the associated metadata files.
1
https://cmgds.marine.usgs.gov/data/field-activity-data/2009-021-FA/data/geophysics/navigation/2009-021-FA_res_pntnav.zip
https://doi.org/10.5066/F7DR2TSX
The first link downloads the data directly, the second link is to the landing page of the data.
None
The user must be capable of extracting the data from the zip file, and reading the shapefile format. This shapefile filename starts with a number and has dashes in it. This filename may not work with some geoprocessing or ArcPy scripts and may need to be renamed.
20180412
VeeAnn A. Cross
U.S. Geological Survey
Marine Geologist
mailing and physical address
384 Woods Hole Rd.
Woods Hole
MA
02543-1598
(508) 548-8700 x2251
(508) 457-2310
vatnipp@usgs.gov
FGDC Content Standards for Digital Geospatial Metadata
FGDC-STD-001-1998
local time