Ground control points collected for Helikite operations at the Pea Island National Wildlife Refuge DUNEX Site, North Carolina in September and October 2021

Frequently anticipated questions:

• What does this data set describe?
  1. How might this data set be cited?
  2. What geographic area does the data set cover?
  3. What does it look like?
  4. Does the data set describe conditions during a particular time period?
  5. What is the general form of this data set?
  6. How does the data set represent geographic features?
  7. How does the data set describe geographic features?
• Who produced the data set?
  1. Who are the originators of the data set?
  2. Who also contributed to the data set?
  3. To whom should users address questions about the data?
• Why was the data set created?
• How was the data set created?
  1. From what previous works were the data drawn?
  2. How were the data generated, processed, and modified?
  3. What similar or related data should the user be aware of?
• How reliable are the data; what problems remain in the data set?
  1. How well have the observations been checked?
  2. How accurate are the geographic locations?
  3. How accurate are the heights or depths?
  4. Where are the gaps in the data? What is missing?
  5. How consistent are the relationships among the data, including topology?
• How can someone get a copy of the data set?
  1. Are there legal restrictions on access or use of the data?
  2. Who distributes the data?
  3. What's the catalog number I need to order this data set?
  4. What legal disclaimers am I supposed to read?
  5. How can I download or order the data?
• Who wrote the metadata?

What does this data set describe?

1. How might this data set be cited?
   Over, Jin-Si R., Olson, Alex J., and Randall, Noa R., 20220607, Ground control points collected for Helikite operations at the Pea Island National Wildlife Refuge DUNEX Site, North Carolina in September and October 2021: data release DOI:10.5066/P9DPZZG2, U.S. Geological Survey, Coastal and Marine Hazards and Resources Program, Woods Hole Coastal and Marine Science Center, Woods Hole, MA.

   Online Links:

   • https://doi.org/10.5066/P9DPZZG2
   • https://www.sciencebase.gov/catalog/item/623e13aad34e915b67d6d7ee

   This is part of the following larger work.
   Over, Jin-Si R., Sherwood, Christopher R., Traykovski, Peter, Brosnahan, Sandra, Olson, Alex J., and Randall, Noa R., 2022, DUNEX topographic, bathymetric, and supporting GPS data collected in Pea Island National Wildlife Refuge, North Carolina 2020-2021: data release DOI:10.5066/P9D94NZ3, U.S. Geological Survey, Reston, VA.

   Online Links:

   • https://doi.org/10.5066/P9DPZZG2
   • https://www.sciencebase.gov/catalog/item/623dca6cd34e915b67d65110

   Other_Citation_Details:

   Over, J.R., Sherwood, C.R., Traykovski, P.A., Olson, A.J., Randall, N.R., and Brosnahan, S.M., 2022, DUNEX topographic, bathymetric, and supporting GPS data collected in Pea Island National Wildlife Refuge, North Carolina 2020-2021: U.S Geological Survey data release, https://doi.org/10.5066/P9DPZZG2

2. What geographic area does the data set cover?

   West_Bounding_Coordinate: -75.48101037
   East_Bounding_Coordinate: -75.47935361
   North_Bounding_Coordinate: 35.68001754
   South_Bounding_Coordinate: 35.67542504
   

3. What does it look like?

   https://www.sciencebase.gov/catalog/file/get/ 623e13aad34e915b67d6d7ee?name=PINWR_GCP_browse.jpg&allowOpen=true (JPEG)

   Black and white tarp target ground control point on the beach at Pea Island.

4. Does the data set describe conditions during a particular time period?

   Calendar_Date: 07-Sep-2021

   Currentness_Reference:

   Ground condition; ground control data collected on eight days.

5. What is the general form of this data set?

   Geospatial_Data_Presentation_Form: tabular digital data
   

6. How does the data set represent geographic features?
   1. How are geographic features stored in the data set?
      This is a Point data set.
   2. What coordinate system is used to represent geographic features?
      

      Grid_Coordinate_System_Name: Universal Transverse Mercator
      Universal_Transverse_Mercator:

      UTM_Zone_Number: 18
      Transverse_Mercator:

      Scale_Factor_at_Central_Meridian: 0.999600
      Longitude_of_Central_Meridian: -69.000000
      Latitude_of_Projection_Origin: 0.000000
      False_Easting: 500000.000000
      False_Northing: 0.000000
      

      Planar coordinates are encoded using row and column
      Abscissae (x-coordinates) are specified to the nearest 0.001
      Ordinates (y-coordinates) are specified to the nearest 0.001
      Planar coordinates are specified in meters
      The horizontal datum used is North American Datum of 1983 (National Spatial Reference System 2011).
      The ellipsoid used is GRS_1980.
      The semi-major axis of the ellipsoid used is 6378137.000000.
      The flattening of the ellipsoid used is 1/298.257224.
      

      Vertical_Coordinate_System_Definition:

      Altitude_System_Definition:

      Altitude_Datum_Name: North American Vertical Datum of 1988
      Altitude_Resolution: 0.001
      Altitude_Distance_Units: meters
      Altitude_Encoding_Method:

      Explicit elevation coordinate included with horizontal coordinates

7. How does the data set describe geographic features?

   2021029FA_PINWR_Helikite_GCPs.csv

   Positions, elevations, and attributes of ground control points used during the field activity. (Source: U.S. Geological Survey)

   INFO

   USGS Field Activity Number (Source: USGS)

   Value	Definition
   2021-029-FA	Year, USGS generated ID, and Field Activity

   GPS

   Equipment distinction, information was either collected with the SP80 (RTK), see larger citation for other methods of collection. (Source: USGS) Character string.

   Date

   Date measurements were taken, in YYYYMMDD (Source: USGS) Character string.

   Attributes

   Identification of surveyed equipment or GCP. (Source: USGS) Character string.

   Latitude

   Estimated position in decimal degrees (NAD83[2011]). (Source: USGS)

   Range of values
   Minimum:	35.67542504
   Maximum:	35.68001754
   Units:	decimal degrees

   Longitude

   Estimated position in decimal degrees (NAD83(2011)). Negative values represent W. (Source: None)

   Range of values
   Minimum:	-75.48101037
   Maximum:	-75.47935361
   Units:	decimal degrees

   Ellipsoid_height_NAD83

   Estimated vertical position based on the NAD83(2011) reference ellipsoid. (Source: None)

   Range of values
   Minimum:	-37.841
   Maximum:	-31.505
   Units:	meters

   Northing

   Estimated Y position in NAD83(2011)/UTM Zone 18N. (Source: USGS)

   Range of values
   Minimum:	3948055.360
   Maximum:	3948565.183
   Units:	meters

   Easting

   Estimated X position in NAD83(2011)/UTM Zone 18N. (Source: USGS)

   Range of values
   Minimum:	456472.687
   Maximum:	456620.717
   Units:	meters

   Orthometric_height_NAVD88

   Estimated vertical position using NAVD88 (Geoid 18). (Source: USGS)

   Range of values
   Minimum:	1.003
   Maximum:	7.340
   Units:	meters

   Visibility

   Yes (Y) or No (N) to whether or not the ground control point is visible in any of the imagery collected using the Helikite from the larger work citation. (Source: USGS) Character string.

   Entity_and_Attribute_Overview:

   These attribute definitions describe each column of information in the CSV files. The ‘no data’ value is NA.

   Entity_and_Attribute_Detail_Citation: USGS Field Activity 2021-014-FA
   

Who produced the data set?

1. Who are the originators of the data set? (may include formal authors, digital compilers, and editors)
   • Jin-Si R. Over
   • Alex J. Olson
   • Noa R. Randall
2. Who also contributed to the data set?
3. To whom should users address questions about the data?
   Jin-Si R. Over

   U.S. Geological Survey, Northeast Region: Woods Hole Coastal and Marine Science Center

   U.S. Geological Survey 384 Woods Hole Rd.

   Woods Hole, MA
   

   508-548-8700 x2269 (voice)

   jover@usgs.gov

Why was the data set created?

How was the data set created?

1. From what previous works were the data drawn?
2. How were the data generated, processed, and modified?

   Date: Sep-2021 (process 1 of 1)

   Over the field activity, the SP80 equipment was used to take the location information of ground control points and equipment installed at the field site. At the end of the field activity all GPS points were corrected to the OPUS solution averages of the reference marks (see larger citation GPS data) by shifting the XYZ in Carlson SurvCE v. 6.08 (http://survce.com/home, accessed August, 2021).
   Ground control points for the Helikite surveys were either black and white square plastic tarps with a number on them or AeroPoint yellow and black targets that were replaced every survey – a random letter was used for each survey to distinguish between surveys that used the same GCPs. All GCPs were measured at the center of the tarp or target with the SP80 pole and equipment. Process date reflects the beginning of the events. Data processing ended in 2021-11. Person who carried out this activity:
   

   Jin-Si R. Over

   U.S. Geological Survey, Northeast Region: Woods Hole Coastal and Marine Science Center

   Geographer

   U.S. Geological Survey

   Woods Hole, MA
   

   508-548-8700 x2269 (voice)

   jover@usgs.gov

3. What similar or related data should the user be aware of?

How reliable are the data; what problems remain in the data set?

1. How well have the observations been checked?
   Positions and elevations are produced by either a Spectra Precision (SP)80 Base Station and Rover or Rover and North Carolina CORS Network. AeroPoint post processed network positions and Rover positions were all within 2 cm in the XYZ directions as a QC check, but for consistency all positions provided are from the SP80.
2. How accurate are the geographic locations?
   The SP80 RTK systems used to collect location data have a theoretical horizontal accuracy of 2 cm on any single point, but QC and repeat occupations of the same spot suggest slightly higher uncertainties up to 5-10 cm including user error.
3. How accurate are the heights or depths?
   The SP80 RTK systems used to collect location data have a theoretical vertical accuracy of 1 cm on any single point, but QC and repeat occupations of the same spot suggest slightly higher uncertainties up to 5-10 cm including user error.
4. Where are the gaps in the data? What is missing?
   GCPs are not always visible in associated imagery or are visible but do not have location information – as much information as is available is provided.
5. How consistent are the relationships among the observations, including topology?
   The file contains USGS field activity 2021-029-FA ground control points.

How can someone get a copy of the data set?

1. Who distributes the data set? (Distributor 1 of 1)
   
   U.S. Geological Survey - ScienceBase

   Denver Federal Center, Building 810, Mail Stop 302

   Denver, CO
   

   1-888- 275-8747 (voice)

   sciencebase@usgs.gov
2. What's the catalog number I need to order this data set? Ground control points from multiple days are provided in one CSV file
3. What legal disclaimers am I supposed to read?
   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 U.S. Geological Survey 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.
4. How can I download or order the data?
   • Availability in digital form:

     Data format:	The CSV file 2021029FA_PINWR_Helikite_GCPs.csv contains ground control point data collected during the field activity. in format CSV (comma-delimited text) (version Exported from Excel Office 365 16.01) Size: 0.02
     Network links:	https://www.sciencebase.gov/catalog/file/get/623e13aad34e915b67d6d7ee https://www.sciencebase.gov/catalog/item/623e13aad34e915b67d6d7ee https://doi.org/10.5066/P9DPZZG2

   • Cost to order the data: None.

5. What hardware or software do I need in order to use the data set?
   The user must have software capable of reading CSV format.

Who wrote the metadata?

Dates:

Last modified: 07-Jun-2022

Metadata author:

Jin-Si R. Over

U.S. Geological Survey, Northeast Region: Woods Hole Coastal and Marine Science Center

Geographer

U.S. Geological Survey

Woods Hole, MA

508-548-8700 x2269 (voice)

whsc_data_contact@usgs.gov

Contact_Instructions:

The metadata contact email address is a generic address in the event the person is no longer with the USGS.

Metadata standard:

Content Standard for Digital Geospatial Metadata (FGDC-STD-001-1998)