Radar Time Series Measurements Collected at Duck, North Carolina – Middle of Pier (x = 300 meters)

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?
   Brown, Jenna A., McClenney, Bryce J., and Suttles, Steve E., 20260317, Radar Time Series Measurements Collected at Duck, North Carolina – Middle of Pier (x = 300 meters):.

   This is part of the following larger work.
   Brown, Jenna A., McClenney, Bryce J., and Suttles, Steve E., 20260311, Oceanographic Radar Time Series Measurements Collected at Duck, North Carolina: U.S. Geological Survey data release doi:10.5066/P1NLPWRP, U.S. Geological Survey - St. Petersburg Coastal and Marine Science Center, St. Petersburg, Florida.

   Online Links:

   • https://doi.org/10.5066/P1NLPWRP

2. What geographic area does the data set cover?

   West_Bounding_Coordinate: -75.748296
   East_Bounding_Coordinate: -75.748296
   North_Bounding_Coordinate: 36.182868
   South_Bounding_Coordinate: 36.182868
   

3. What does it look like?
4. Does the data set describe conditions during a particular time period?

   Beginning_Date: 18-Jan-2024

   Ending_Date: 23-Apr-2024

   Currentness_Reference:

   ground condition

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

   Geospatial_Data_Presentation_Form: raster digital data
   

6. How does the data set represent geographic features?
   1. How are geographic features stored in the data set?
      This is a Raster data set.
   2. What coordinate system is used to represent geographic features?
      Horizontal positions are specified in geographic coordinates, that is, latitude and longitude. Latitudes are given to the nearest 0.00001. Longitudes are given to the nearest 0.00001. Latitude and longitude values are specified in Decimal degrees. The horizontal datum used is WGS 84.
      The ellipsoid used is WGS 84.
      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 1988
      Altitude_Resolution: 0.1
      Altitude_Distance_Units: meters
      Altitude_Encoding_Method:

      Explicit elevation coordinate included with horizontal coordinates

7. How does the data set describe geographic features?

   Entity_and_Attribute_Overview:

   The Climate and Forecast (CF)-compliant metadata (version CF-1.8) in the header of the netCDF files provide information about the conventions used for attributes in the dataset. Times are in Coordinated Universal Time (UTC). NetCDF filenames include location (FRFx300 to represent the local FRF cross-shore coordinate of x=300m), deployment date (YYYYMM), an abbreviation of the instrument type ("glx" for Geolux® radar), and a designation for the file type, which is either "cont" for continuous time series data, or "spec" for wave spectra and statistics.

   Entity_and_Attribute_Detail_Citation:

   The entity and attribute information were generated by the individual and/or agency identified as the originator of the dataset. Please review the rest of the metadata record for additional details and information.

Who produced the data set?

1. Who are the originators of the data set? (may include formal authors, digital compilers, and editors)
   • Jenna A. Brown
   • Bryce J. McClenney
   • Steve E. Suttles
2. Who also contributed to the data set?
3. To whom should users address questions about the data?
   U.S. Geological Survey, St. Petersburg Coastal and Marine Science Center

   Attn: USGS SPCMSC Data Management

   600 4th St S

   St Petersburg, FL
   

   727-502-8000 (voice)

   gs-g-spcmsc_data_inquiries@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: 18-Jan-2024 (process 1 of 3)

   DEPLOYMENT - An instrument package was developed by the USGS consisting of a commercially available, non-contact oceanographic radar sensor, a data logger, a cellular modem, and an external battery housed inside a water-tight box, with a cellular antenna and solar panel affixed on the outside of the lid. Multiple radar instrument packages were built, with one each being deployed at three locations along the USACE FRF research pier including at the seaward ocean-facing end (x=600m) from August 18, 2022, to present, and at the middle (x=300m) and near the beginning (x=200m) from January 18, 2024, to April 23, 2024. Each box was attached to the FRF pier railing using specially fabricated stainless-steel L-shaped mounting arms that can be installed quickly and do not require drilling into the structure. Each radar was deployed such that the sensor extends over the water surface with no obstructions below (e.g., pier deck, piling, rocks) and with the box secured and as level as possible. The elevation of each sensor was surveyed to a known datum (NAVD88) using differential leveling. Person who carried out this activity:
   

   Bryce J. McClenney

   Hydrologic Technician

   3916 Sunset Ridge Rd

   Raleigh, NC
   

   USA

   919-571-4082 (voice)

   bjmcclen@usgs.gov

   Date: 23-Apr-2024 (process 2 of 3)

   DATA COLLECTION - The non-contact oceanographic radar sensor (Geolux® LX-80-15 10 Hz) directly measured the elevation of the sea surface using a frequency-modulated electromagnetic (radio) wave to detect the distance from the sensor to the water surface and relating that to the surveyed elevation of the radar sensor. The radar sampled continuously at 10 Hz, and a data logger was used to save down-sampled 5 Hz time series data, which was transmitted in near real-time over a cellular network connection. Person who carried out this activity:
   

   Bryce J. McClenney

   Hydrologic Technician

   3916 Sunset Ridge Rd

   Raleigh, NC
   

   USA

   919-571-4082 (voice)

   bjmcclen@usgs.gov

   Date: 31-Jan-2025 (process 3 of 3)

   DATA PROCESSING - The 5 Hz time series data were minimally quality-controlled, with erroneous spikes (when distance = 15 and/or water level = 7999, which are the instrument default values for bad data) replaced with the fill value (not-a-number) and gaps in the water level time series of less than 60 seconds filled with linear interpolation; longer time gaps are due to insufficient power when the solar panel was dirty or sensor maintenance. Then the data were processed to compute mean water levels and wave conditions and converted into network common data form (netCDF, .nc) files with stglib python libraries (Nowacki and others, 2024), a package of code to process data consistent with procedures of the USGS Coastal/Marine Hazards and Resources Program. More information about stglib can be found here: https://stglib.readthedocs.io/en/latest/. Attributes describing the variables and conforming to CF (Climate and Forecast) Metadata Convention (version 1.8) were added to each file by stglib. Times are in Coordinated Universal Time (UTC) and water levels are in meters, referenced to NAVD88. NetCDF filenames include location (FRFx300 to represent the local FRF cross-shore coordinate of x=300m), deployment date (YYYYMM), an abbreviation of the instrument type ("glx" for Geolux® radar), and a designation for the file type, which is either "cont" for continuous time series data, or "spec" for wave spectra and statistics. Person who carried out this activity:
   

   Jenna A. Brown

   Physical Scientist

   700 W Research Blvd

   Fayetteville, AR
   

   USA

   479-442-4888 (voice)

   jenniferbrown@usgs.gov

   Data sources produced in this process:

   • *.nc

3. What similar or related data should the user be aware of?
   Brown, J.A., McClenney, B., and Dickhudt, P., 20260305, Measuring storm waves and water levels from a fixed structure with a rapidly deployable oceanographic radar: Coastal Research Library Volume 41, Springer, Cham, Switzerland.

   Online Links:

   • https://doi.org/10.1007/978-3-032-15473-6_106

   Other_Citation_Details: Pages 696–702
   

   Nowacki, D.J., Suttles, S.E., Bales, R.D., and De Meo, O.A., 20241202, Oceanographic Time Series Data Processing Library: U.S. Geological Survey software release doi:10.5066/P13IQYFW, U.S. Geological Survey - Pacific Coastal and Marine Science Center, Santa Cruz, CA.

   Online Links:

   • https://doi.org/10.5066/P13IQYFW

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

1. How well have the observations been checked?
   The Geolux® oceanographic radar sensor (Geolux® LX-80-15 10 Hz) has a stated measurement accuracy of 2 millimeters (mm).
2. How accurate are the geographic locations?
   Site location was determined based on the local USACE FRF coordinate system and using USACE survey maps to determine the world coordinates in the World Geodetic System of 1984 (WGS84) coordinate system.
3. How accurate are the heights or depths?
   The elevation of the radar sensor, referenced to the North American Vertical Datum of 1988 (NAVD88), was surveyed with differential leveling based from a known benchmark (NGS Designation: 865 1370 K Tidal) and had a closure of 0.002 feet (less than 1 millimeter).
4. Where are the gaps in the data? What is missing?
   Dataset is considered complete for the information presented, as described in the abstract. Users are advised to read the rest of the metadata record carefully for additional details. Data quality assurance and control was performed by removing erroneous values (when distance = 15 and/or water level = 7999) and linearly interpolating over small (less than one minute) time gaps; longer time gaps are due to insufficient power when the solar panel was dirty.
5. How consistent are the relationships among the observations, including topology?
   Data was compared with nearby long-term monitoring observations to validate the measurements. For further information, refer to the associated journal article (Brown and others, 2025).

How can someone get a copy of the data set?

1. Who distributes the data set? (Distributor 1 of 1)
   
   U.S. Geological Survey, St. Petersburg Coastal and Marine Science Center

   Attn: USGS SPCMSC Data Management

   600 4th St S

   St. Petersburg, FL
   

   727-502-8000 (voice)

   gs-g-spcmsc_data_inquiries@usgs.gov
2. What's the catalog number I need to order this data set? FRFx300_202401glx_cont.nc, FRFx300_202401glxs_spec.nc, FRFx300_202402glx_cont.nc, FRFx300_202402glxs_spec.nc, FRFx300_202403glx_cont.nc, FRFx300_202403glxs_spec.nc, FRFx300_202404glx_cont.nc, FRFx300_202404glxs_spec.nc, FRFx300_2024.zip
3. What legal disclaimers am I supposed to read?
   Unless otherwise stated, all data, metadata and related materials are considered to satisfy the quality standards relative to the purpose for which the data were collected. Although these data and associated metadata have been reviewed for accuracy and completeness and approved for release by the U.S. Geological Survey (USGS), no warranty expressed or implied is made regarding the display or utility of the data on any other system or for general or scientific purposes, nor shall the act of distribution constitute any such warranty. Any use of trade, firm, or product 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:	Time-series data in netCDF format following Climate and Forecast (CF) Metadata Conventions (version 1.8). in format NetCDF (version netCDF-4, CF-1.8) Size: 462
     Network links:	https://doi.org/10.5066/P1NLPWRP

   • Cost to order the data: None

5. What hardware or software do I need in order to use the data set?
   These data can be viewed with any software capable of reading netCDF files.

Who wrote the metadata?

Dates:

Last modified: 17-Mar-2026

Metadata author:

U.S. Geological Survey, St. Petersburg Coastal and Marine Science Center

Attn: USGS SPCMSC Data Management

600 4th St S

St. Petersburg, FL

727-502-8000 (voice)

gs-g-spcmsc_data_inquiries@usgs.gov

Metadata standard:

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