A selection process was performed by two USGS scientist to determine the valid data values acquired by the sensor. This selection process was largely subjective.
All YSI values deemed to be valid that have associated navigation fixes from April 13, 2010 are contained in this data file.
Process_Step:
Process_Description:
The YSI 600XLM was mounted just behind the fathometer transducer on the starboard side of the boat. This placed the instrument almost directly below the navigation antenna. On the first three days of data collection (April 12-14) this mount location was 17.6 m forward of the first electrode in the continuous resistivity profiling streamer array. On the fourth day (April 15), the GPS/YSI package was moved 1.6 meters toward the stern. Although data collection was continuous, recording a reading every minute, the values are fairly inconsistent. This inconsistency is possibly due to the YSI cavitating at speed, or too much air in the sensor cavity from fast moving water.
Process_Date: 2010
Process_Step:
Process_Description:
First, the raw YSI data were separated by day of acquisition into separate worksheets in Microsoft Excel 2003. Then a new column was added to reflect UTC time by adding 4 hours to the YSI time (local time). This process step, along with all subsequent process steps, was performed by the same person: VeeAnn A. Cross.
Process_Date: 201005
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:
The GPS HYPACK navigation for each day of data collection is already in a comma-delimited text file from other processing (see metadata for the various jd***bestdepth shapefiles available at
https://pubs.usgs.gov/of/2011/1039/html/ofr2011-1039-catalog.html. These files simply need to be reformatted for use with the YSI data so that the Excel command VLOOKUP can be used with the lookup column being time. The idea is to carry over the latitude and longitude values from the GPS file when the YSI time is the same as the GPS time. HYPACK software usually recorded a navigation fix every second. There were times when HYPACK was off, and that will be discussed later. VLOOKUP has two methods of operation: one when the match is exact, and the other is approximate match. For some reason, using the exact match did not work well. Times that were exact matches still produced NA values. Therefore, the approximate match method was used. The approximate match method find the largest value less than or equal to the match value. Manual editing was done in Excel to remove the latitude longitude values that carried over from HYPACK navigation gaps.
Process_Date: 201006
Process_Step:
Process_Description:
Once the VLOOKUP and editing were complete, the values were copied to a new worksheet to be exported from Excel. In order to determine valid YSI values, John Bratton wanted to not only look at the values in the spreadsheet, but also look at the spatial distribution of the data point and their values. The worksheet was exported from Excel as a comma-delimited text file and added to ArcMap 9.2 as an event theme by Tools - AddXY data, projection as geographic, WGS84. The event theme was then converted to a shapefile by right mouse click - data - export. A shapefile for each day of data collection was generated.
Process_Date: 201006
Source_Produced_Citation_Abbreviation: apr13_ysi_withnav.shp
Source_Produced_Citation_Abbreviation: apr14_ysi_withnav.shp
Source_Produced_Citation_Abbreviation: apr15_ysi_withnav.shp
Process_Step:
Process_Description:
Based on the spatial distribution of the YSI data values, and visual inspection of the data files in the Excel spreadsheet, John Bratton made a final worksheet containing the YSI values he considered valid. Once these values were selected, new shapefiles were generated containing only the accepted YSI values. This meant a repeat of the VLOOKUP procedures marrying the HYPACK navigation fixes with the valid YSI values, export from Excel, added as an event theme to ArcMap, and then exported as a shapefile for April 13, 14, and 15.
Source_Used_Citation_Abbreviation: apr13_ysi_withnav.shp
Source_Used_Citation_Abbreviation: apr14_ysi_withnav.shp
Source_Used_Citation_Abbreviation: apr15_ysi_withnav.shp
Source_Used_Citation_Abbreviation: Excel spreadsheet
Process_Date: 201007
Source_Produced_Citation_Abbreviation: cull_4_13_exp.shp
Source_Produced_Citation_Abbreviation: cull_4_14_exp.shp
Source_Produced_Citation_Abbreviation: cull_4_15_exp.shp
Process_Step:
Process_Description:
The filtered (culled) YSI shapefiles do not have the measurements in the units I need. So within ArcMap 9.2, using VAC Extras, version 2.1 (an extension written by VeeAnn Cross in Woods Hole), the resistivity values in ohm-m were calculated. VACExtras - Resistivity - Calc Resistivity. The calculation requires a temperature field in degrees Celsius and a salinity field - both of which are present in the YSI culled shapefile. The results are put in a new attribute called resval.
Source_Used_Citation_Abbreviation: cull_4_13_exp.shp
Source_Used_Citation_Abbreviation: cull_4_14_exp.shp
Source_Used_Citation_Abbreviation: cull_4_15_exp.shp
Process_Date: 201007
Source_Produced_Citation_Abbreviation: cull_4_13_exp.shp
Source_Produced_Citation_Abbreviation: cull_4_14_exp.shp
Source_Produced_Citation_Abbreviation: cull_4_15_exp.shp
Process_Step:
Process_Description:
In ArcMap 9.2 outlier points (those YSI points with locations plotting outside the study are) were deleted. These outliers were a result of no corresponding GPS coordinates, leading to latitude and longitude values of 0. The shapefiles were renamed to reflect these edits.
Source_Used_Citation_Abbreviation: cull_4_13_exp.shp
Source_Used_Citation_Abbreviation: cull_4_14_exp.shp
Source_Used_Citation_Abbreviation: cull_4_15_exp.shp
Process_Date: 201106
Source_Produced_Citation_Abbreviation: ysi_4_13_cln.shp
Source_Produced_Citation_Abbreviation: ysi_4_14_cln.shp
Source_Produced_Citation_Abbreviation: ysi_4_15_cln.shp
Process_Step:
Process_Description:
In ArcMap 9.2 the individual YSI shapefiles were merged into a single shapefile using ArcToolbox - Data Management Tools - General -Merge. Because the individual shapefiles all have the same attributes, nothing needed to be done to the field mapping. The output shapefile was ysi_Merge.shp.
Source_Used_Citation_Abbreviation: ysi_4_13_cln.shp
Source_Used_Citation_Abbreviation: ysi_4_14_cln.shp
Source_Used_Citation_Abbreviation: ysi_4_15_cln.shp
Process_Date: 201106
Source_Produced_Citation_Abbreviation: ysi_Merge.shp
Process_Step:
Process_Description:
Edits to the metadata were made to fix any errors that MP v 2.9.36 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.). Attempted to modify http to https where appropriate. Moved the minimal source information provided to make it the first process step. 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: 20171002
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: 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:
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