Bratton, John F. , and Cross, VeeAnn A. , 2010, Raw and Modified Raw Continuous Resistivity Profile Data Collected in the Potomac River/Chesapeake Bay on Sept. 7, 2006: Open-File Report 2009-1151, U.S. Geological Survey, Coastal and Marine Geology Program, Woods Hole Coastal and Marine Science Center, Woods Hole, MA.This is part of the following larger work.Online Links:
- <https://pubs.usgs.gov/of/2009/1151/data/resistivity/raw_resis/sept7_raw.zip>
- <https://pubs.usgs.gov/of/2009/1151/html/catalog.html>
Cross, VeeAnn A. , Foster, David S. , and Bratton, John F. , 2010, Continuous Resistivity Profiling and Seismic-Reflection Data Collected in 2006 from the Potomac River Estuary, Virginia and Maryland: Open-File Report 2009-1151, U.S. Geological Survey, Coastal and Marine Geology Program, Woods Hole Coastal and Marine Science Center, Woods Hole, MA.Online Links:
This is a Point data set.
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 Degrees and decimal minutes.
The horizontal datum used is North American Datum of 1983.
The ellipsoid used is Geodetic Reference System 80.
The semi-major axis of the ellipsoid used is 6378137.000000.
The flattening of the ellipsoid used is 1/298.257222.
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(508) 457-2310 (FAX)
jbratton@usgs.gov
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.
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
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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)
}
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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") }
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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.
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.
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.
All the data files were checked and handled in the same manner.
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.
(508) 548-8700 x2254 (voice)
(508) 457-2310 (FAX)
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.
| Data format: | The WinZip file contains all the raw CRP data from Sept. 7, 2006 as well as the associated metadata files. in format WinZip (version 9.0) Size: 1.4 MB |
|---|---|
| Network links: |
<https://pubs.usgs.gov/of/2009/1151/data/resistivity/raw_resis/sept7_raw.zip> <https://pubs.usgs.gov/of/2009/1151/html/catalog.html> |
| Media you can order: |
DVD-ROM
(Density 4.75
GBytes)
(format UDF)
|
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.
(508) 548-8700 x2251 (voice)
(508) 457-2310 (FAX)
vatnipp@usgs.gov