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Publication_Date: Unpublished material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: 20050503
Ending_Date: 20050505
Source_Currentness_Reference: ground condition
Source_Citation_Abbreviation: raw crp data
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
Process_Date: Unknown
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
Process_Date: Unknown
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
Process_Date: Unknown
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_Date: Unknown
Process_Step:
Process_Description: The joined shapefile table was then exported to a text file.
Process_Date: Unknown
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
Process_Date: Unknown
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_Date: Unknown
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_Date: Unknown
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_Date: Unknown
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_Date: Unknown
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_Date: Unknown
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_Date: Unknown
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_Date: Unknown
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_Date: Unknown
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_Date: Unknown
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_Date: Unknown
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_Date: Unknown
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_Date: Unknown
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.
Process_Date: Unknown
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 process steps without process dates had the date set to unknown. The distribution liability, format and network resource had to be added. 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: 20161101
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
