Identification_Information: Citation: Citation_Information: Originator: VeeAnn A. Cross Publication_Date: 2014 Title: JD105GPS_BESTDEPTH.SHP: Point shapefile of navigation and best depth values at ship positions during continuous resistivity profiling data collection in the Indian River Bay, Delaware, on April 15, 2010, on U.S. Geological Survey Field Activity 2010-006-FA (Geographic, WGS 84) Edition: 1 Geospatial_Data_Presentation_Form: vector digital data Series_Information: Series_Name: Open-File Report Issue_Identification: 2011-1039 Publication_Information: Publication_Place: Woods Hole Coastal and Marine Science Center, Woods Hole, MA Publisher: U.S. Geological Survey, Coastal and Marine Geology Program Online_Linkage: http://pubs.usgs.gov/of/2011/1039/data/navigation/resistivity/jd105gps_bestdepth.zip Online_Linkage: http://pubs.usgs.gov/of/2011/1039/html/ofr2011-1039-catalog.html Larger_Work_Citation: Citation_Information: Originator: V.A. Cross Originator: J.F. Bratton Originator: H.A. Michael Originator: K.D. Kroeger Originator: A. Green Originator: E. Bergeron Publication_Date: 2014 Title: Continuous Resistivity Profiling and Seismic-Reflection Data Collected in April 2010 from Indian River Bay, Delaware Edition: 1 Series_Information: Series_Name: Open-File Report Issue_Identification: 2011-1039 Publication_Information: Publication_Place: Reston, VA Publisher: U.S. Geological Survey Online_Linkage: http://pubs.usgs.gov/of/2011/1039/ Online_Linkage: http://dx.doi.org/10.3133/ofr20111039 Description: Abstract: A geophysical survey to delineate the fresh-saline groundwater interface and associated sub-bottom sedimentary structures beneath Indian River Bay, Delaware, was carried out in April 2010. This included surveying at higher spatial resolution in the vicinity of a study site at Holts Landing, where intensive onshore and offshore studies were subsequently completed. The total length of continuous resistivity profiling (CRP) survey lines was 145 kilometers (km), with 36 km of chirp seismic lines surveyed around the perimeter of the bay. Medium-resolution CRP surveying was performed using a 50-meter streamer in a bay-wide grid. Results of the surveying and data inversion showed the presence of many buried paleochannels beneath Indian River Bay that generally extended perpendicular from the shoreline in areas of modern tributaries, tidal creeks, and marshes. An especially wide and deep paleochannel system was imaged in the southeastern part of the bay near White Creek. Many paleochannels also had high-resistivity anomalies corresponding to low-salinity groundwater plumes associated with them, likely due to the presence of fine-grained estuarine mud and peats in the channel fills that act as submarine confining units. Where present, these units allow plumes of low-salinity groundwater that was recharged onshore to move beyond the shoreline, creating a complex fresh-saline groundwater interface in the subsurface. The properties of this interface are important considerations in construction of accurate coastal groundwater flow models. These models are required to help predict how nutrient-rich groundwater, recharged in agricultural watersheds such as this one, makes its way into coastal bays and impacts surface water quality and estuarine ecosystems. For more information on the survey conducted for this project, see http://woodshole.er.usgs.gov/operations/ia/public_ds_info.php?fa=2010-006-FA. Purpose: This point shapefile has several purposes. First, this shapefile provides the ship's XY position during the collection of continuous resistivity profile data in the Indian River Bay on April 15, 2010. Additionally, attributes in this shapefile account for extensive processing to derive acceptable depth values (not tide corrected) at each CRP data acquisition point. These depths improve the processing of the CRP data. This shapefile also acts as an archive of this dataset. Time_Period_of_Content: Time_Period_Information: Single_Date/Time: Calendar_Date: 20100415 Currentness_Reference: ground condition Status: Progress: Complete Maintenance_and_Update_Frequency: None planned Spatial_Domain: Bounding_Coordinates: West_Bounding_Coordinate: -75.190433 East_Bounding_Coordinate: -75.076000 North_Bounding_Coordinate: 38.620000 South_Bounding_Coordinate: 38.576217 Keywords: Theme: Theme_Keyword_Thesaurus: General Theme_Keyword: U.S. Geological Survey Theme_Keyword: USGS Theme_Keyword: Coastal and Marine Geology Program Theme_Keyword: CMGP Theme_Keyword: Woods Hole Coastal and Marine Science Center Theme_Keyword: WHCMSC Theme_Keyword: Field Activity Number 2010-006-FA Theme_Keyword: Info Bank ID K-6-10-DL Theme_Keyword: navigation Theme_Keyword: bathymetry Theme_Keyword: R/V Knob Theme_Keyword: Lowrance GPS Theme_Keyword: HYPACK Theme_Keyword: point shapefile Theme_Keyword: Open-file Report 2011-1039 Theme: Theme_Keyword_Thesaurus: ISO 19115 Topic Category Theme_Keyword: elevation Theme_Keyword: location Theme_Keyword: oceans Theme_Keyword: oceans and estuaries Theme_Keyword: oceans and coastal Place: Place_Keyword_Thesaurus: General Place_Keyword: North America Place_Keyword: North Atlantic Ocean Place_Keyword: United States Place_Keyword: Delaware Place_Keyword: Indian River Bay Place_Keyword: Indian River Inlet Place_Keyword: Holts Landing Place_Keyword: Piney Neck Place_Keyword: Sussex County Place_Keyword: Rosedale Beach Access_Constraints: None. Use_Constraints: Not to be used for navigation. 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. 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: 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 Browse_Graphic: Browse_Graphic_File_Name: http://pubs.usgs.gov/of/2011/1039/data/navigation/resistivity/jd105gps_bestdepth.gif Browse_Graphic_File_Description: Thumbnail GIF image showing the location of resistivity navigation points collected April 15, 2010. The coastline is included for spatial reference. Browse_Graphic_File_Type: GIF Native_Data_Set_Environment: Microsoft Windows Vista Version 6.1 (Build 7601) Service Pack 1; ESRI ArcCatalog 9.3.1.4095 Data_Quality_Information: Logical_Consistency_Report: All of the files were handled in the same manner. Completeness_Report: This point shapefile represents every valid GPS point collected by the Lowrance navigation system recorded by the resistivity acquisition software. Positional_Accuracy: Horizontal_Positional_Accuracy: Horizontal_Positional_Accuracy_Report: The navigation system used was a Lowrance 480M with an LGC-2000 Global Positioning System (GPS) antenna. The antenna was located directly above the fathometer transducer mount point, and approximately 2 meters starboard of the mount point of the towed continuous resistivity profile streamer. GPS data are assumed to be accurate within 10 meters on this survey. Vertical_Positional_Accuracy: Vertical_Positional_Accuracy_Report: All collected bathymetry values were collected by the 200 kHz Lowrance fathometer. The fathometer was mounted starboard side, directly below the GPS antenna. The Lowrance manufacturer indicates the speed of sound used by the system to convert to depths is 4800 feet/second. The depth values are not corrected for the approximately 0.2 m transducer draft. All values are assumed to be accurate to within 1 meter. Some of the depths recorded as attributes are extracted from a gridded surface and are assumed to be accurate within 1 meter. Lineage: Source_Information: 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 50-m streamer with an 11 electrode array with electrodes spaced 5 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. The maximum depth below the water surface the streamer can reach is approximately 1/4 the streamer length. So for the 50-m streamer, maximum depth is about 12.5 meters. 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 antenna and fathometer transducer were mounted on the starboard side of the boat. The streamer tow point was on the port side aft. The layback offset between the navigation antenna and the first electrode was 17.6 meters on April 13 and 14. On April 15 the antenna and transducer were moved 1.6 m aft changing the layback offset to 16 m. This layback offset is accounted for by the acquisition system. The approximately 2 m lateral offset is not accounted for. The Lowrance transducer also contains a temperature sensor. Lowrance indicates the speed of sound used by the system is 4800 feet/second. Both the temperature and depth information are recorded in the logged GPS file. There are instances where no depth or temperature information is recorded due to an equipment problem. 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: The data were transferred from the logging computer via AGISSAdmin software version 1.3.2.165. These files were then transferred via email to the processing computer. The files included in this publication are the *.crs, *.cmd, *.gps, and *.stg. The two files essential for processing are the GPS and STG files. The GPS file contains the navigation, and in the case of the Lowrance system also includes water depth and temperature. The STG file contains the resistivity measurements from each of the electrodes. The CRS file contains the contact resistance readings. The CMD file contains the parameters for data collection. These last two files aren't necessary for data processing, but can be useful in terms of troubleshooting. This process step, along with all subsequent process steps, was performed by the same person: VeeAnn A. Cross. Process_Date: 201003 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: An AWK script was used to extract the navigation, bathymetry, and temperature information recorded in each individual GPS data file for each day of data acquisition. AWK script "awkhold": >BEGIN { >FS = "," >} >{ >FS = "," >ARGC = 2 >depth = -9999 >temp = -9999 >if ($1=="$GPRMC") > { > utctime = $2 > utcdate = $10 > latdeg = substr($4,1,2) > latmin = substr($4,3,6) > declat = latdeg + (latmin/60) > londeg = substr($6,1,3) > lonmin = substr($6,4,6) > declon = -1 * (londeg + (lonmin/60)) > if (NR==1) { > holddepth = -9999 > holdtemp = -9999 > } > else { > printf("%s, %s, %9.6f, %9.6f, %5.1f, %5.1f, %s\n", holdutctime, holdutcdate, holddeclon, holddeclat, holddepth, holdtemp, ARGV[2]) > } > holdutctime = utctime > holdutcdate = utcdate > holddeclon = declon > holddeclat = declat > holddepth = -9999 > holdtemp = -9999 > } >if ($1=="$SDDPT") > { > depthreal = $2 > holddepth = depthreal > } >if ($1=="$SDMTW") > { > tempreal = $2 > holdtemp = tempreal > } >} >END { >printf("%s, %s, %9.6f, %9.6f, %5.1f, %5.1f, %s\n", holdutctime, holdutcdate, holddeclon, holddeclat, holddepth, holdtemp, ARGV[2]) >} This AWK script was initialized by "dohold" - shell script run under CYGWIN (UNIX like environment that runs under Windows). This shell script reads all the files in a folder with the extension "gps" and processes them. This is the script used for the April 13 data collection: >files=`ls *.gps | cut -d. -f1 | tr "[A-Z"] ["a-z"]` >for file in $files >do > awk -f awkhold $file.gps $file > $file.holds >done Source_Used_Citation_Abbreviation: *.gps Process_Date: 201004 Source_Produced_Citation_Abbreviation: *.holds Process_Step: Process_Description: Each of the resulting *.holds files were concatenated together using a shell script running under Cygwin. The shell script is as follows: >cat l20f2.holds \ >l21f1.holds \ >l22f1.holds \ >l23f1.holds \ >l24f1.holds \ >l25f1.holds \ >l26f1.holds \ >l26f2.holds \ >l27f1.holds \ >l28f1.holds \ >l29f1.holds \ >l30f1.holds \ >l31f1.holds \ >l32f1.holds \ >l33f1.holds \ >l35f1.holds \ >l36f1.holds \ >l37f2.holds \ >l38f1.holds \ >l39f1.holds \ >l40f1.holds \ >l41f1.holds \ >l42f1.holds \ >l43f1.holds \ >l44f1.holds \ >l45f1.holds \ >l46f2.holds \ >l47f1.holds \ >l48f1.holds \ >l49f1.holds \ >l50f1.holds > jd105gps.csv Source_Used_Citation_Abbreviation: *.holds Process_Date: 201004 Source_Produced_Citation_Abbreviation: jd105gps.csv Process_Step: Process_Description: The text editor VI was used under Cygwin to add the following header line to the text file: >gpstime, gpsdate, longitude, latitude, depth_m, temp_c, line This text file was then imported to ArcMap 9.2 using Tools - AddXY Data. The X field is longitude; Y field is latitude, and the coordinate system was defined as Geographic, WGs84. This "Event Theme" was converted to a shapefile by right-mouse clicking on the layer - Data - Export Data. Source_Used_Citation_Abbreviation: jd104gps.csv Process_Date: 201004 Source_Produced_Citation_Abbreviation: jd104gps.shp Process_Step: Process_Description: Using ArcMap 9.2 - ArcToolbox - Projections and Transformations - Feature - Project, project the shapefile from Geographic, WGS84 to UTM, Zone 18, WGS84. Parameters: input - jd105gps.shp; input coordinate system - GCS_WGS_1984 (default, read from file); output - jd105gps_utm18.shp; output coordinate system - WGS_1984_UTM_Zone_18N. No transformation necessary. Source_Used_Citation_Abbreviation: jd105gps.shp Process_Date: 201004 Source_Produced_Citation_Abbreviation: jd105gps_utm18.shp Process_Step: Process_Description: With the jd105hypack.shp (available from http://pubs.usgs.gov/of/2011/1039/html/ofr2011-1039-catalog.html) loaded in ArcMap 9.2, set a definition query on the shapefile where depth_m <> -9999. Then with jd105gps_utm18.shp the active shapefile in the table of contents do a join on jd105gps_utm18.shp: Join data based on spatial location; join layer - jd105hypack. Select the option to give all the attributes of the joined shapefile, along with a distance field. Output to a new file: jd105gps_mod_spatjoin2.shp. The distances reported are in the units of the data layer initiating the join - hence the reason for projecting the CRP navigation shapefile to UTM, Zone 18. Units of meters are much easier to make sense of than decimal degrees distances. Of note, the reason for the filename *spatjoin2 is an error was detected in the first attempt at the spatial join and the process was run again - but not overwriting the original file. Source_Used_Citation_Abbreviation: jd105gps_utm18.shp Process_Date: 201004 Source_Produced_Citation_Abbreviation: jd105gps_spatjoin2.shp Process_Step: Process_Description: The join function changes the order of the records in the original starting shapefile (jd105gps_utm18.shp). So to put the records back in the order of time, the shapefile needs to be sorted by the FID_1 attribute. Resorting the shapefile was accomplished with an extension written by VeeAnn Cross in Woods Hole, MA - VAC Extras v. 2.1. Using VAC Extras - FeatConv - Table Sort, jd105gps_spatjoin2.shp was sorted with the primary sort field FID_1 in ascending order, no secondary field chosen, and the output sent to jd105gps_spatjoin2_sort.shp. Source_Used_Citation_Abbreviation: jd105gps_spatjoin2.shp Process_Date: 201004 Source_Produced_Citation_Abbreviation: jd105gps_spatjoin2_sort.shp Process_Step: Process_Description: Several additional attributes were added to the shapefile: timediff, fixdepth. Because these depths are not tide corrected, not only do I need to replace the missing CRP depths with values that are close in proximity, but have to be cognizant of the time offset. And although the gpstime and gpstime_1 are in the format HHMMSS, subtracting these values still has some benefit. First, set a definition query on jd105gps_spatjoin2_sort.shp to only display the records with depth_m = -9999. Then use the field calculator to calculate gpstime - gpstime_1. For the new fixdepth attribute, select all records where depth_m <> -9999, then use field calculator to set fixdepth = depth_m. Basically, this is just bringing over the good depths. To work on the rest of the depths used a query to select all records where ("timediff" < 60 AND "timediff" > -60) AND "Distance" < 20 AND "depth_m" =-9999. This query attempts to select those records that are spatially close (less than 20 meters), where there are no valid depths (depth_m = -9999) and have a relatively small time difference, which means tidal effect should be minimal. With these records selected, use the field calculator to have fixdepth = depth_m_1. The remaining "fixdepth" values were set manually. In most cases this means extrapolating the value of close (spatially and temporally) valid points from either the HYPACK or the CRP system. In some instances these values are probably acceptable, but in some places the gaps are too large to trust these values. Source_Used_Citation_Abbreviation: jd105gps_spatjoin2_sort.shp Process_Date: 201004 Source_Produced_Citation_Abbreviation: jd105gps_spatjoin2_sort.shp Process_Step: Process_Description: Using a bathymetry surface (of all positive values) generated from tide corrected bathymetry points (see irb_bathy to understand processing available at http://pubs.usgs.gov/of/2011/1039/html/ofr2011-1039-catalog.html), use VACExtras v 2.1 to extract the bathymetry values at each point location and place in the new attribute hyptidecor. However, the extracted depths are tide corrected, and what are needed in this case is the uncorrected bathymetric values - so the tide information needs to be added back into these values. Within ArcMap 9.2, also add the attribute jday to place the Julian day (105). Source_Used_Citation_Abbreviation: jd105gps_spatjoin2_sort.shp Process_Date: 201005 Source_Produced_Citation_Abbreviation: jd105gps_spatjoin2_sort.shp Process_Step: Process_Description: Then use XTools Pro 5.2 to export the shapefile to a text file. Export jd105gps_spatjoin2_sort to jd105gps_spatjoin2_sort_exp.txt with the exported fields of gpstime; longitude; latitude; hyptidecor; jday. Source_Used_Citation_Abbreviation: jd105gps_spatjoin2_sort.shp Process_Date: 201005 Source_Produced_Citation_Abbreviation: jd105gps_spatjoin2_sort_exp.txt Process_Step: Process_Description: Run the files through an AWK script to reformat for loading into MATLAB to extract tide information. The tidal correction procedure is described in detail in irb_bathy (available at http://pubs.usgs.gov/of/2011/1039/html/ofr2011-1039-catalog.html). In this case, because the tides are being added back in, the MATLAB code is modified slightly so instead of: >h_corrected_ir=htrack-tidetrack_ir; >h_corrected_rd=htrack-tidetrack_rd; >use: >h_corrected_ir=htrack+tidetrack_ir; >h_corrected_rd=htrack+tidetrack_rd; Source_Used_Citation_Abbreviation: jd105gps_spatjoin2_sort_exp.txt Process_Date: 201005 Source_Produced_Citation_Abbreviation: bathy.dat Process_Step: Process_Description: Proceed with converting the results to a shapefile and using the weighted distance calculations described in irb_bathy (available at http://pubs.usgs.gov/of/2011/1039/html/ofr2011-1039-catalog.html) to ADD the tide information back into the depth values. Now in the jd105gps_spatjoin2_sort.shp, add the attribute "addedtide" as double. Since the spatial locations are the same, a spatial join is not necessary, and the shapefiles can be joined record for record based on the FID attribute. Once joined, copy the value from the "tideadded" attribute to the newly created "addedtide" attribute. Then removed the join. Source_Used_Citation_Abbreviation: jd105gps_spatjoin2_sort.shp Process_Date: 201005 Source_Produced_Citation_Abbreviation: jd105gps_spatjoin2_sort.shp Process_Step: Process_Description: In order to select the best depth value for every CRP location, it's a combination of already valid values, valid values based on temporal and spatial offset, and values derived by adding tides back to a tidally corrected surface. For this reason, in ArcMap 9.2 a new attribute was added called "bestdepth" as type double to the shapefile jd105gps_spatjoin2_sort.shp. First priority is to use actual values, then fill in voids with derived values. Did a query where depth_m <> -9999 and then copied those values to bestdepth. Then did a query: ("timediff" <= 10 AND "timediff" >= -10) AND "timediff" <>0. The "timediff" <> 0 was necessary because where timediff = 0 is where I have valid original CRP depths. The timediff attribute is the result of gpstime - gpstime_1 where gpstime_1 is the HYPACK navigation time. Copy these selected records over to bestdepth from depth_m_1. A value of 10 was chosen because the boat was travelling around 4 knots (2m/sec). That means a value of 10 represents points within 20 meters of the actual navigation reading. That seems reasonably conservative. What this leaves is some within 10 seconds, but that go around the minute mark. For example, if the gpstime is 130355 and the gpstime_1 is 130404, then the timediff is displayed as -49. But in reality, it's only 9 seconds - all an issue with how time is recorded as an attribute. Additional queries were run to accommodate this time oddity. > Query: "timediff" <= -41 AND "timediff" >= -50 > These are all within 10 seconds, so set bestdepth = depth_m_1. > Likewise, the opposite situation needed to be handled such as gpstime = 131601 and gpstime_1 = 131554. > Query: "timediff" >= 41 AND "timediff" <= 50 > And if there's an hour change: > "timediff" >=4041 AND "timediff" <=4050 (this didn't have any records) "timediff" >=-4050 AND "timediff" <=-4041 (this didn't have any records) > Now any records without a "bestdepth" ("bestdepth" = 0) the values from "addedtide" were copied over. Process_Date: 201005 Process_Step: Process_Description: Using ArcMap 9.2, jd105gps_spatjoin2_sort.shp was projected from UTM, Zone 18, WGS84 to Geographic, WGS84 using ArcToolbox - Data Management Tools - Projections and Transformations - Feature - Project. The output file was jd105gps_bestdepth.shp (no transformation necessary). Source_Used_Citation_Abbreviation: jd105gps_spatjoin2_sort.shp Process_Date: 201012 Source_Produced_Citation_Abbreviation: jd105gps_bestdepth.shp Spatial_Data_Organization_Information: Direct_Spatial_Reference_Method: Vector Point_and_Vector_Object_Information: SDTS_Terms_Description: SDTS_Point_and_Vector_Object_Type: Entity point Point_and_Vector_Object_Count: 6690 Spatial_Reference_Information: Horizontal_Coordinate_System_Definition: Geographic: Latitude_Resolution: 0.000001 Longitude_Resolution: 0.000001 Geographic_Coordinate_Units: Decimal degrees Geodetic_Model: Horizontal_Datum_Name: D_WGS_1984 Ellipsoid_Name: WGS_1984 Semi-major_Axis: 6378137.000000 Denominator_of_Flattening_Ratio: 298.257224 Vertical_Coordinate_System_Definition: Depth_System_Definition: Depth_Datum_Name: Local surface Depth_Resolution: 0.1 Depth_Distance_Units: meters Depth_Encoding_Method: Attribute values Entity_and_Attribute_Information: Detailed_Description: Entity_Type: Entity_Type_Label: jd105gps_bestdepth Entity_Type_Definition: ESRI point shapefile Entity_Type_Definition_Source: ESRI 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: FID_1 Attribute_Definition: Internal feature number from the original JOIN shapefile. Attribute_Definition_Source: ESRI Attribute_Domain_Values: Unrepresentable_Domain: Unique whole numbers that were automatically generated. Attribute: Attribute_Label: gpstime Attribute_Definition: GPS time in the format HHMMSS. GPS time is +4 hours from local time during the survey. Attribute_Definition_Source: U.S. Geological Survey Attribute_Domain_Values: Unrepresentable_Domain: Although the value is represented as a number, the number as a whole doesn't have a particular meaning. Only when the individual parts for hours, minutes, and seconds are broken out does the number have meaning. Attribute: Attribute_Label: gpsdate Attribute_Definition: The date recorded in the GPS navigation in the format DDMMYY. Because of the time offset from local time, this date could actually be different than the local acquisition date. Attribute_Definition_Source: U.S. Geological Survey Attribute_Domain_Values: Unrepresentable_Domain: Although the value is represented as a number, the number as a whole doesn't have a particular meaning. Only when the individual parts for month, day, and year are broken out does the number have meaning. Attribute: Attribute_Label: longitude Attribute_Definition: Longitude coordinate of the point in decimal degrees, WGS84. Attribute_Definition_Source: U.S. Geological Survey Attribute_Domain_Values: Range_Domain: Range_Domain_Minimum: -75.194617 Range_Domain_Maximum: -75.0748 Attribute_Units_of_Measure: decimal degrees Attribute: Attribute_Label: latitude Attribute_Definition: Latitude coordinate of the point in decimal degrees, WGS84. Attribute_Definition_Source: U.S. Geological Survey Attribute_Domain_Values: Range_Domain: Range_Domain_Minimum: 38.5708 Range_Domain_Maximum: 38.615317 Attribute_Units_of_Measure: decimal degrees Attribute: Attribute_Label: depth_m Attribute_Definition: Depth of the water below the fathometer in meters recorded by the ship's fathometer/navigation system. Datum is local surface (no tides taken into account). A value of -9999 indicates no data. Attribute_Definition_Source: U.S. Geological Survey Attribute_Domain_Values: Range_Domain: Range_Domain_Minimum: 0.3 Range_Domain_Maximum: 9.5 Attribute_Units_of_Measure: meters Attribute: Attribute_Label: temp_c Attribute_Definition: Water temperature in degrees Celsius as recorded at the Lowrance fathometer transducer. A value of -9999 indicates no data. Attribute_Definition_Source: U.S. Geological Survey Attribute_Domain_Values: Range_Domain: Range_Domain_Minimum: 10 Range_Domain_Maximum: 17.9 Attribute_Units_of_Measure: degrees Celsius Attribute: Attribute_Label: line Attribute_Definition: The alphanumeric name corresponding to the prefix of the GPS filename. This name reflects the name assigned to the line of data acquisition and incorporates modifiers to reflect modification of the GPS file if the GPS file was split into more than one part. Attribute_Definition_Source: U.S. Geological Survey Attribute_Domain_Values: Unrepresentable_Domain: Character set. Attribute: Attribute_Label: FID_2 Attribute_Definition: Internal feature number from the JOINED shapefile (representing HYPACK navigation). Attribute_Definition_Source: U.S. Geological Survey Attribute_Domain_Values: Unrepresentable_Domain: Unique whole numbers that were automatically generated. Attribute: Attribute_Label: gpstime_1 Attribute_Definition: GPS time in the format HHMMSS from the JOINED HYPACK navigation. GPS time is +4 from local time during the survey. Attribute_Definition_Source: U.S. Geological Survey Attribute_Domain_Values: Unrepresentable_Domain: Although the value is represented as a number, the number as a whole doesn't have a particular meaning. Only when the individual parts for hours, minutes, and seconds are broken out does the number have meaning. Attribute: Attribute_Label: longitud_1 Attribute_Definition: Longitude coordinate of the JOINED HYPACK navigation point in decimal degrees, WGS84. Attribute_Definition_Source: U.S. Geological Survey Attribute_Domain_Values: Range_Domain: Range_Domain_Minimum: -75.192233 Range_Domain_Maximum: -75.074783 Attribute_Units_of_Measure: decimal degrees Attribute: Attribute_Label: latitude_1 Attribute_Definition: Latitude coordinate of the JOINED HYPACK navigation point in decimal degrees, WGS84. Attribute_Definition_Source: U.S. Geological Survey Attribute_Domain_Values: Range_Domain: Range_Domain_Minimum: 38.5708 Range_Domain_Maximum: 38.615317 Attribute_Units_of_Measure: decimal degrees Attribute: Attribute_Label: depth_m_1 Attribute_Definition: Depth of the water below the fathometer in meters recorded by the ship's fathometer/navigation system in the JOINED HYPACK file. Datum is local surface (no tides taken into account). Suspected spurious points were not edited or deleted. Attribute_Definition_Source: U.S. Geological Survey Attribute_Domain_Values: Range_Domain: Range_Domain_Minimum: 0.3 Range_Domain_Maximum: 198.5 Attribute_Units_of_Measure: meters Attribute: Attribute_Label: Distance Attribute_Definition: Distance in meters (UTM, Zone 18, WGS84) between the CRP GPS point and the closest HYPACK navigation point. Attribute_Definition_Source: Software defined and calculated in the Spatial Join function. Attribute_Domain_Values: Range_Domain: Range_Domain_Minimum: 0.000102 Range_Domain_Maximum: 414.482178 Attribute_Units_of_Measure: meters Attribute: Attribute_Label: timediff Attribute_Definition: Represents the time difference between the original CRP navigation and the JOINED HYPACK navigation. Calculated by gpstime - gpstime_1. Attribute_Definition_Source: U.S. Geological Survey Attribute_Domain_Values: Unrepresentable_Domain: The value represents a number which in most cases is the time offset between the original shapefile and the joined shapefile in the units of seconds. However, because of the format of the GPSTIME fields, this value does not always represent a seconds time difference. Most notably the problem arises around the minutes and hours boundaries. Attribute: Attribute_Label: fixdepth Attribute_Definition: An attempt to establish valid depth values based on existing CRP depths, HYPACK depths, and best guess based on surrounding points. Specific criteria are discussed in the process steps. Attribute_Definition_Source: U.S. Geological Survey. Attribute_Domain_Values: Range_Domain: Range_Domain_Minimum: 0 Range_Domain_Maximum: 20 Attribute_Units_of_Measure: meters Attribute: Attribute_Label: hyptidecor Attribute_Definition: Depth in meters at the point extracted from an interpolated bathymetric grid based on the HYPACK fathometer data. These values have been tide corrected. Attribute_Definition_Source: U.S. Geological Survey Attribute_Domain_Values: Range_Domain: Range_Domain_Minimum: 0.39508 Range_Domain_Maximum: 8.288633 Attribute_Units_of_Measure: meters Attribute: Attribute_Label: jday Attribute_Definition: This number represents the Julian day of data collection based on the GPS day. Julian day is the integer number representing the interval of time in days since January 1 of the year. Attribute_Definition_Source: U.S. Geological Survey Attribute_Domain_Values: Range_Domain: Range_Domain_Minimum: 104 Range_Domain_Maximum: 104 Attribute_Units_of_Measure: days Attribute: Attribute_Label: addedtide Attribute_Definition: This value represents the hyptidecor attribute value with the tidal component removed using calculations in MATLAB. Attribute_Definition_Source: U.S. Geological Survey Attribute_Domain_Values: Range_Domain: Range_Domain_Minimum: 0.341818 Range_Domain_Maximum: 8.889661 Attribute_Units_of_Measure: meters Attribute: Attribute_Label: bestdepth Attribute_Definition: The best available depth in meters based on various calculations and criteria discussed in the process steps. (datum is local surface - no tide corrections) Attribute_Definition_Source: U.S. Geological Survey Attribute_Domain_Values: Range_Domain: Range_Domain_Minimum: 0.3 Range_Domain_Maximum: 9.5 Attribute_Units_of_Measure: meters Distribution_Information: Distributor: 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 Resource_Description: Downloadable Data Distribution_Liability: 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. Standard_Order_Process: Digital_Form: Digital_Transfer_Information: Format_Name: Shapefile Format_Version_Number: ArcGIS 9.2 Format_Information_Content: This WinZip (v. 14) file contains the point shapefile as well as the associated metadata files. Transfer_Size: 0.47 MB Digital_Transfer_Option: Online_Option: Computer_Contact_Information: Network_Address: Network_Resource_Name: http://pubs.usgs.gov/of/2011/1039/data/navigation/resistivity/jd105gps_bestdepth.zip Network_Resource_Name: http://pubs.usgs.gov/of/2011/1039/html/ofr2011-1039-catalog.html Network_Resource_Name: http://dx.doi.org/10.3133/ofr20111039 Fees: None. Technical_Prerequisites: This zip file contains data available in Esri point shapefile format. The user must have software capable of uncompressing the zip file and reading/displaying the shapefile. Metadata_Reference_Information: Metadata_Date: 20140630 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: 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 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