Cross, VeeAnn A. , 2011, GPS Navigation Supplemented with Existing Bathymetry Data During Fathometer Lapses from USGS Cruise 07005 from May 15 to May 16, 2007, in the Corsica River Estuary, Maryland: Open-File Report 2010-1094, 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/2010/1094/data/resistivity/raw_resis/fixedbathy/fixbathyraw.zip>
- <https://pubs.usgs.gov/of/2010/1094/html/catalog.html>
Cross, VeeAnn A. , Bratton, John F. , Worley, Charles R. , Crusius, John, and Kroeger, Kevin D. , 2011, Continuous resistivity profiling data from the Corsica River Estuary, Maryland: Open-File Report 2010-1094, U.S. Geological Survey, Coastal and Marine Geology Program, Woods Hole Coastal and Marine Science Center, Woods Hole, MA.Online Links:
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The purpose of these GPS files is to provide navigation with bathymetry to aid in the continuous resistivity profile (CRP) data processing. During original data acquisition, there were periods of time when no fathometer data was available. These files incorporate best available bathymetry data at the location of the navigation fix.
Person who carried out this activity:
(508) 548-8700 x2251 (voice)
(508) 457-2310 (FAX)
vatnipp@usgs.gov
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{
printf("$SDDPT,%0.1f,0.0*56\n",$1)
}
The program is run with the following command line:
awk -f awkfmtdepth L12F1_bathy.txt > L12F1.sddpt
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BEGIN {
FS = ","
}
{
FS = ","
if ($1=="$GPRMC")
{
print $0
}
}
This script was run with the command line:
awk -f awk_justgprmc2 L12F1.gps > L12F1.gprmcThe awk script used to extract the SDMTW data was awk_justsdmtw:
BEGIN {
FS = ","
}
{
FS = ","
if ($1=="$SDMTW")
{
print $0
}
}
This script was run with the command line:
awk -f awk_justsdmtw L12F1.gps > L12F1.sdmtw
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diff2 = depth_m + estdepth pos_est = estdepth * -1The equation for the pred_val attribute varied depending on the line of data.
for L24 the equation was pred_val = estdepth + 0.2 L25, pred_val = estdepth + 0.3 L26, pred_val = estdepth + 0.4 L27, pred_val = estdepth + 0.5 L28, pred_val - estdepth + 0.6Based on the other information in the file, the assumption was that the tide was rising.
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L24F2 output to L24F2_bathy.txt L25F1 output to L25F1_bathy.txt L26F1 output to L26F1_bathy.txt L27F1_part1 output to L27F1_part1_bathy.txt L27F1_part2 output to L27F1_part2_bathy.txt L28F1 output to L28F1_bathy.txt
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{
printf("$SDDPT,%0.1f,0.0*56\n",$1)
}
The program is run with the following command line:
awk -f awkfmtdepth inputfile > outputfile
Data sources used in this process:
Data sources produced in this process:
BEGIN {
FS = ","
}
{
FS = ","
if ($1=="$GPRMC")
{
print $0
}
}
This script was run with the command line:
awk -f awk_justgprmc2 inputfile > outputfile
Data sources used in this process:
Data sources produced in this process:
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The navigation system used was a Lowrance 480M with an LGC-2000 Global Positioning System (GPS) antenna. The antenna was located at the anchor point for the resistivity streamer, which is also directly above the fathometer transducer mount point. The GPS system is published to be accurate to within 10 meters.
The vertical accuracy of these files is a function of several factors. First of all is the accuracy of the original bathymetry dataset from which the depth values were extracted. And second is the offset applied to this bathymetry value to essentially add in the tidal component. Specific tide values were not acquired, but rather the grid bathymetry values were compared to actual valid fathometer reading to estimate and offset. These factors combine to detract from the vertical accuracy, making it probably more than 1 meter.
These files represent the attempt to fill in all bathymetry gaps in the original GPP/fathometer data acquisition. The lines needing the supplmental data are L12F1, L24F1, L24F2, L25F1, L26F1, L27F1, and L28F1.
Each file went through the same process steps in the attempt to supplment the missing fathometer data. Some of the files had sparse bathymetry data, while others had no fathometer data at all.
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 x2251 (voice)
(508) 457-2310 (FAX)
vatnipp@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 navigation data from May 15, 2007 and May 16, 2007 that required additional processing to derive depth values. Additionally, the WinZip file contains the associated metadata files. in format WinZip (version 9.0) Size: 0.048 MB |
|---|---|
| Network links: |
<https://pubs.usgs.gov/of/2010/1094/html/catalog.html> <https://pubs.usgs.gov/of/2010/1094/data/resistivity/raw_resis/fixedbathy/fixbathyraw.zip> |
| 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. The navigation are presented in their NMEA string format.
(508) 548-8700 x2251 (voice)
(508) 457-2310 (FAX)
vatnipp@usgs.gov