Continuous Resistivity Profile Tracklines of Data Collected in 2005 in the Neuse River, North Carolina

Metadata:

• Identification_Information
• Data_Quality_Information
• Spatial_Data_Organization_Information
• Spatial_Reference_Information
• Entity_and_Attribute_Information
• Distribution_Information
• Metadata_Reference_Information

Identification_Information:

Citation:

Citation_Information:

Originator: John F. Bratton

Originator: VeeAnn A. Cross

Publication_Date: 2005

Title:

Continuous Resistivity Profile Tracklines of Data Collected in 2005 in the Neuse River, North Carolina

Geospatial_Data_Presentation_Form: vector digital data

Online_Linkage:

<http://pubs.usgs.gov/of/2005/1306/data/navigation/restracklines_05.zip>

Larger_Work_Citation:

Citation_Information:

Originator: VeeAnn A. Cross

Originator: John F. Bratton

Originator: Emile Bergeron

Originator: Jeff K. Meunier

Originator: John Crusius

Originator: Dirk Koopmans

Publication_Date: 2005

Title:

Continuous Resistivity Profiling Data from the Upper Neuse River Estuary, North Carolina, 2004-2005

Series_Information:

Series_Name: Open-File Report

Issue_Identification: 2005-1306

Publication_Information:

Publication_Place: Woods Hole Science Center, Woods Hole, MA

Publisher: U.S. Geological Survey, Coastal and Marine Geology Program

Online_Linkage: <http://pubs.usgs.gov/of/2005/1306>

Description:

Abstract:

The Neuse River Estuary in North Carolina is a broad, V-shaped water body located on the southwestern end of Pamlico Sound. This estuary suffers from severe eutrophication for which several water quality models have recently been developed to aid in the management of nutrient loading to the estuary. In an effort to help constrain model estimates of the fraction of nutrients delivered by direct ground-water discharge, continuous resistivity profile (CRP) measurements were made during the spring of 2004 and 2005. CRP is used to measure electrical resistivity of sediments, a property that is sensitive to difference in salinity of submarine ground water. The 2004 and 2005 surveys used floating resistivity streamers of 100 m and 50 m respectively. The depth penetration of the streamers is approximately 20% of the streamer length which translates to approximately 20-25 m with the 100 m streamer and 12-14 m with the 50 m streamer. These data were processed using AGI's EarthImager 2D software. CRP data enables the mapping of the extent and depth of the fresher ground water within the estuary.

Purpose:

This shapefile is provided to show the tracklines were continuous resistivity profile data were collected.

Time_Period_of_Content:

Time_Period_Information:

Range_of_Dates/Times:

Beginning_Date: 20050503

Ending_Date: 20050505

Currentness_Reference: ground condition

Status:

Progress: Complete

Maintenance_and_Update_Frequency: None planned

Spatial_Domain:

Bounding_Coordinates:

West_Bounding_Coordinate: -77.033752

East_Bounding_Coordinate: -76.812000

North_Bounding_Coordinate: 35.124350

South_Bounding_Coordinate: 34.936783

Keywords:

Theme:

Theme_Keyword_Thesaurus: General

Theme_Keyword: CMGP

Theme_Keyword: Coastal and Marine Geology Program

Theme_Keyword: Continuous Resistivity Profiling

Theme_Keyword: CRP

Theme_Keyword: marine resistivity

Theme_Keyword: navigation

Theme_Keyword: OF 2005-1306

Theme_Keyword: Open-File Report

Theme_Keyword: polyline

Theme_Keyword: shapefile

Theme_Keyword: U.S. Geological Survey

Theme_Keyword: USGS

Theme_Keyword: Woods Hole Science Center

Theme_Keyword: trackline

Place:

Place_Keyword_Thesaurus: General

Place_Keyword: Neuse River

Place_Keyword: North America

Place_Keyword: North Carolina

Place_Keyword: Pamlico Sound

Place_Keyword: United States

Access_Constraints: None.

Use_Constraints:

The U.S. Geological Survey must be referenced as the originator of the dataset in any future products or research derived from these data.

Point_of_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: 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

Native_Data_Set_Environment:

Microsoft Windows XP Version 5.1 (Build 2600) Service Pack 2; ESRI ArcCatalog 9.0.0.535

Data_Quality_Information:

Lineage:

Source_Information:

Source_Contribution:

These data were acquired with an AGI SuperSting Marine system that is described at the website: www.agiusa.com/marinesystem.shtml. The particular system used for this acquisition was an 11 electrode array with electrodes spaced 5 meters apart. The potential electrodes are made of graphite, with the remaining electrodes 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 potentials 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 *.gps file. The STG file contains the resistivity data, while the GPS file contains the navigation information. During the 2005 survey, we had large time periods where no navigation was recorded. A duplicate navigation value was recorded in the GPS file. The lines affected by this problem were L2F1, L3F1, L5F1, and L6F1.

Process_Step:

Process_Description:

The GPS files were processed using an AWK script to parse out the navigational information from the $GPRMC string and concatenated into a single file.

Source_Used_Citation_Abbreviation: *.gps

Source_Produced_Citation_Abbreviation: allgps.txt

Process_Step:

Process_Description:

This comma delimited text file was then imported as a table into ArcView 3.3, loaded as an event theme, and then converted to a shapefile.

Source_Used_Citation_Abbreviation: allgps.txt

Source_Produced_Citation_Abbreviation: allgps.shp

Process_Step:

Process_Description:

The allgps shapefile was copied to a new shapefile (tempall) and a field called record was added. This field was filled with the record number so that each point had a unique identifier.

Source_Used_Citation_Abbreviation: allgps.shp

Source_Produced_Citation_Abbreviation: tempall.shp

Process_Step:

Process_Description:

The extension pathfind.avx (Path, with Distance and Bearings, v. 3.2) was loaded into the ArcView project. Clicking on the pathfind button brings up a dialog. Select the shapefile (tempall) and the ID field and SERIES field. In this case, both are the "record" field in the shapefile. For the RESULTS table, I checked the option RESULTS table and Join results with Theme Attribute table. Select NO LINES for connection lines. ***Because I think in terms of meters, not decimal degrees for distance measure, I had set the View Properties to UTM, Zone 18, NAD83 projection.

Process_Step:

Process_Description: The joined shapefile table was then exported to a text file.

Source_Produced_Citation_Abbreviation: temp.txt

Process_Step:

Process_Description:

This exported text file was then reloaded as a table, added as an event theme, and converted to a shapefile. Three new fields are now in the shapefiles as a result of the pathfind extension: To_ID, Cent_Bear, Cent_Dist. (The record field is the fromID). The navigation problem, which manifests itself as the same fix for a long period of time is now readily obtainable. The Cent_Bear value becomes -999 and the Cent_Dist is 0.000.

Source_Used_Citation_Abbreviation: temp.txt

Source_Produced_Citation_Abbreviation: gps_fixing.shp

Process_Step:

Process_Description:

Three new fields are added to the shapefile: new_dist, new_bear, sum_dist. The new_dist field is for the value that I want to be between each navigation point, assuming the ship is traveling at a constant speed. This value is calculated by using the Cent_dist value that appears right after the 0 values, divided by the number of -999 azimuth values plus 1. That Cent_dist value records the large distance jump once the navigation started acquiring valid values. For example, if there are 9 values of -999, then I divide the large distance value by 10. This resulting value needs to be placed in the 2nd -999 row, through to one row after the lat -999 value (in the new_dist column).

Process_Step:

Process_Description:

The sum_dist field simply sums the distance covered by each new distance section. Select the records from a section for an individual line that needs this calculation. Use the calculate button (table must be in edit mode) and enter the equation: sum_dist = new_dist *([To_ID]-xxxx] where xxxx is the record field value of the first row in the selection.

Process_Step:

Process_Description:

To properly populate the new_bear field, I used the extension dist_az_tools. For each gap, I measured the azimuth between the last good point and the point where the gps started working again. This value was then placed into the appropriate section.

Process_Step:

Process_Description:

I decided to do the rest of the processing on the individual lines that need the repairs. I selected all the points from each line of interest and saved them as a new shapefile resulting in: templ2f1.shp, templ3f1.shp, templ5f1.shp, templ6f1.shp. **Because my distance and azimuth readings are based on the shapefile being projected, I exported the files as projected shapefiles.

Process_Step:

Process_Description:

The distance_azimuth tool now lets me create a new shapefile based on distances and azimuths. Run the tool for each new shapefile, select the second option (Input theme, using unique distances and azimuths). Next window, select the shapefile with the DISTANCE FIELD being sum_dist, and the AZIMUTH FIELD being new_bear. Select all the fields for the new shapefile. What the script does is take the point and move it to a new location based on the distance and azimuth as specified in those fields. The result is that only points that need moving have values other than zeros in the sum_dist and new_bear fields, therefore those are the only points that are actually moved. The new shapefiles were called: templ2f1_fix.shp, templ3f1_fix.shp, templ5f1_fix.shp, templ6f1_fix.shp

Process_Step:

Process_Description:

Because these shapefiles are projected, I needed to convert them back to geographic. I used ArcToolbox (9.0) to define their projection as UTM, Zone 18, NAD83, and then reprojected them to Geographic, NAD83. Resulting files were: templ2f1_fixgeog.shp, templ3f1_fixgeog.shp, templ5f1_fixgeog.shp, templ6f1_fixgeog.shp

Process_Step:

Process_Description:

These geographic shapefiles were loaded back into ArcView 3.3 and I used a modified form of the addxycoo.ave script to add back in the xy (latitude, longitude) fields. The modification to the script had it write 6 decimal places instead of 5.

Process_Step:

Process_Description:

I then "turned off" all the fields except the ones I needed: col_time, col_date, depth_m, temp, x-coord, y-coord and exported the table to a comma delimited text file. These files were: l2f1_gpsfix.txt, l3f1_gpsfix.txt, l5f1_gpsfix.txt, l6f1_gpsfix.txt

Process_Step:

Process_Description:

These fixed text files were concatenated into a single file: lines2_6navfix.txt and brought into ArcView as an event theme.

Process_Step:

Process_Description:

The original navigation text files that did not need navigational fixes were concatenated into restoflines.txt and brought into ArcView as an event theme.

Process_Step:

Process_Description:

The geoprocessing wizard was used to merge restoflines.txt event theme and lines2-6navfix.txt event theme into a single shapefile called merge_clnpnts.

Process_Step:

Process_Description:

An avenue script, navpnts2lines, was used to convert merge_clnpnts to a polyline shapefile with each line based on the unique identifier in the "Line" field.

Process_Step:

Process_Description:

In processing the resistivity data, several of the lines needed to be split into multiple parts. To reflect this in the trackline shapefile, ArcMap 9.0 was used to split the polylines based on distance along to reflect the same parts in the split resistivity files.

Spatial_Data_Organization_Information:

Direct_Spatial_Reference_Method: Vector

Point_and_Vector_Object_Information:

SDTS_Terms_Description:

SDTS_Point_and_Vector_Object_Type: String

Point_and_Vector_Object_Count: 19

Spatial_Reference_Information:

Horizontal_Coordinate_System_Definition:

Geographic:

Latitude_Resolution: 0.000000

Longitude_Resolution: 0.000000

Geographic_Coordinate_Units: Decimal degrees

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

Entity_and_Attribute_Information:

Detailed_Description:

Entity_Type:

Entity_Type_Label: restracklines_05

Attribute:

Attribute_Label: FID

Attribute_Definition: Internal feature number.

Attribute_Definition_Source: ESRI

Attribute_Domain_Values:

Unrepresentable_Domain:

Sequential unique whole numbers that are automatically generated.

Attribute:

Attribute_Label: Shape

Attribute_Definition: Feature geometry.

Attribute_Definition_Source: ESRI

Attribute_Domain_Values:

Unrepresentable_Domain: Coordinates defining the features.

Attribute:

Attribute_Label: ID

Attribute_Definition: Number corresponding to unique trackline, not polyline.

Attribute_Definition_Source: Software generated.

Attribute_Domain_Values:

Range_Domain:

Range_Domain_Minimum: 0

Range_Domain_Maximum: 10

Attribute:

Attribute_Label: LINENAME

Attribute_Definition:

String representing the prefix of the original resistivity line name.

Attribute_Definition_Source: Data processor.

Attribute_Domain_Values:

Unrepresentable_Domain: character set

Attribute:

Attribute_Label: COL_TIME

Attribute_Definition: The time at which data collection began, UTC time.

Attribute_Definition_Source: Software.

Attribute_Domain_Values:

Unrepresentable_Domain: time in hr:min:sec

Attribute:

Attribute_Label: COL_DATE

Attribute_Definition: Date of data acquisition.

Attribute_Definition_Source: Software.

Attribute_Domain_Values:

Unrepresentable_Domain: data in the format of DDMMYR

Attribute:

Attribute_Label: SPLITPART

Attribute_Definition:

Prefix filename assigned to the datafile if the STG file was split. This value is the same as Linename if no split occurred.

Attribute_Definition_Source: Data processor.

Attribute_Domain_Values:

Unrepresentable_Domain: character set

Attribute:

Attribute_Label: LENGTH

Attribute_Definition:

Length of the trackline in meters, based on the UTM, zone 18, NAD83 projection.

Attribute_Definition_Source: Software computed.

Attribute_Domain_Values:

Range_Domain:

Range_Domain_Minimum: 1231.614

Range_Domain_Maximum: 18532.95

Attribute_Units_of_Measure: meters

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: 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

Resource_Description: Downloadable Data

Standard_Order_Process:

Digital_Form:

Digital_Transfer_Information:

Transfer_Size: 0.168

Metadata_Reference_Information:

Metadata_Date: 20051101

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: 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