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:
The source of the bathymetric values was dependant on the day of collection. On Sept. 6, 2006 (Julian day 249) all the bathymetric values were collected by the ship's fathometer. This fathometer was hull mounted approximately mid-ship, relatively close to the navigation antenna. The values are assumed to be accurate to within 1 meter. On Sept. 7, 2006 (Julian day 250) 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. On Sept. 8, 2006 (Julian day 251) the bathymetric values were collected by the Lowrance fathometer.
Source_Information:
Source_Citation:
Citation_Information:
Originator: U.S. Geological Survey
Publication_Date: Unpublished material
Title: Raw CRP Data
Type_of_Source_Media: hard disk
Source_Time_Period_of_Content:
Time_Period_Information:
Range_of_Dates/Times:
Beginning_Date: 20060906
Ending_Date: 20060908
Source_Currentness_Reference: ground condition
Source_Citation_Abbreviation: *.dep and *.xyz
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:
One of the resulting files from processing resistivity data with AGI's EarthImager software is an XYZ file. This XYZ file has three columns of information: distance along line (meters), resistivity reading depth (meters), resistivity value (ohm-m). One of the resulting files from linearization of the raw STG resistivity data is a DEP file. The DEP file has four columns of information: distance along line (meters), water depth (meters), latitude, longitude. This DEP file is dependant on the presence of bathymetry data in the originally recorded GPS file, or the addition of bathymetry information to that GPS file. This DEP file is used in the EarthImager processing and is carried over to the processing output. The Matlab script justbelowsed.m combines these two data files such that the output is only the resistivity values that fall at or below the sediment water interface. This script was written by the USGS in Woods Hole. In order to have a value at the sediment water interface, the software usually has to interpolate values. The version of Matlab used for these data was Matlab 7.5.0.342 (R2007b). An example of the script usage in Matlab is: justbelowsed('F10L1_lin_AllInvRes.xyz','F10L1_lin_wres.dep'). The output is: F10L1_lin_AllInvRes_jbsed.xyz. This resulting XYZ file has 5 columns of information: distance along line (meters); depth below water surface (meters); depth below sediment/water interface (meters); resistivity value (ohm-m); log(10) resistivity value. This process step and all subsequent process steps were performed by the same person - VeeAnn A. Cross.
Source_Used_Citation_Abbreviation: *.dep
Source_Used_Citation_Abbreviation: *.xyz
Process_Date: 2009
Source_Produced_Citation_Abbreviation: *_jbsed.xyz
Process_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
Process_Step:
Process_Description:
Using ArcMap 9.2 and VACExtras v 2.05 (extension developed by the USGS in Woods Hole) these XYZ files are converted to shapefiles. The tool in VACExtras to do this is "convert resistivity to shapefile". This tool requires the data frame be in a UTM projection, the active layer in the data frame needs to be a polyline shapefile with one record selected (the polyline navigation file) and the user is prompted for the file from justbelowsed.m. The program uses the distance along value to find an actual latitude and longitude. The software assumes the datum of the data layer and the data frame projection are the same. The conversion of the Easting and Northing locations to latitudes and longitudes is done by the tool. The result is a point shapefile with 11 columns of information. The Id attribute is automatically generated upon creation of a shapefile, the LINENAME attribue is the line name as indicated within the polyline shapefile that the program prompts the user for, dist is the distance along attribute carried over from the Matlab file, the attributes of location information (latitude, longitude, utmx, utmy) are calculated by the tool, the attributes depth, dep_b_sed, resvalue, and reslogval are carried over from the Matlab file. The Entity and Attribute section further describes these attribues and their units.
Source_Used_Citation_Abbreviation: resgpslns_jd249.shp
Source_Used_Citation_Abbreviation: resgpslns_jd250.shp
Source_Used_Citation_Abbreviation: resgpslns_jd251.shp
Source_Used_Citation_Abbreviation: all the *jbsed.xyz files
Process_Date: 2009
Source_Produced_Citation_Abbreviation: all the point shapefiles for each individual line
Process_Step:
Process_Description:
With all the individual point shapefiles in ArcMap 9.2, ArcToolbox - Data management Tools - General - Merge was used to combine the individual files into a single shapefile. The input was all the individual point shapefiles, with the output being mrg2006_allxyz.shp.
Source_Used_Citation_Abbreviation: all the individual point shapefiles.
Process_Date: 2009
Source_Produced_Citation_Abbreviation: mrg2006_allxyz.shp
Process_Step:
Process_Description:
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.
Process_Date: 20161019
Process_Contact:
Contact_Information:
Contact_Organization_Primary:
Contact_Organization: U.S. Geological Survey
Contact_Person: VeeAnn A. Cross
Contact_Position: Marine Geologist
Contact_Address:
Address_Type: Mailing and Physical
Address: 384 Woods Hole Road
City: Woods Hole
State_or_Province: MA
Postal_Code: 02543
Contact_Voice_Telephone: 508-548-8700 x2251
Contact_Facsimile_Telephone: 508-457-2310
Contact_Electronic_Mail_Address: vatnipp@usgs.gov
Process_Step:
Process_Description: USGS Thesaurus keywords added to the keyword section.
Process_Date: 20180720
Process_Contact:
Contact_Information:
Contact_Organization_Primary:
Contact_Organization: U.S. Geological Survey
Contact_Person: VeeAnn A. Cross
Contact_Position: Marine Geologist
Contact_Address:
Address_Type: Mailing and Physical
Address: 384 Woods Hole Road
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
Process_Step:
Process_Description: Crossref DOI link was added as the first link in the metadata.
Process_Date: 20191118
Process_Contact:
Contact_Information:
Contact_Organization_Primary:
Contact_Organization: U.S. Geological Survey
Contact_Person: VeeAnn A. Cross
Contact_Position: Marine Geologist
Contact_Address:
Address_Type: Mailing and Physical
Address: 384 Woods Hole Road
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
Process_Step:
Process_Description:
Added keywords section with USGS persistent identifier as theme keyword.
Process_Date: 20200908
Process_Contact:
Contact_Information:
Contact_Organization_Primary:
Contact_Organization: U.S. Geological Survey
Contact_Person: VeeAnn A. Cross
Contact_Position: Marine Geologist
Contact_Address:
Address_Type: Mailing and Physical
Address: 384 Woods Hole Road
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
