Surveyed ground control and elevation checkpoints acquired at Barter Island, Alaska, 2014-2016

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Frequently anticipated questions:


What does this data set describe?

Title:
Surveyed ground control and elevation checkpoints acquired at Barter Island, Alaska, 2014-2016
Abstract:
Ground control points and checkpoints were collected during Global Positioning System (GPS) surveys conducted between September 6, 2014 and September 18, 2016 along the northern coast of Barter Island, Alaska. Data were acquired and post-processed using precise positioning and used to co-register and assess accuracy of photogrammetric data sets.
Supplemental_Information:
Additional information about the field activities from which these data were derived is available online at: https://cmgds.marine.usgs.gov/fan_info.php?fan=2014-652-FA https://cmgds.marine.usgs.gov/fan_info.php?fan=2016-645-FA.
Any use of trade, product, or firm names is for descriptive purposes only and does not imply endorsement by the U.S. Government.
  1. How might this data set be cited?
    Gibbs, Ann E., and Snyder, Alexander G., 2019, Surveyed ground control and elevation checkpoints acquired at Barter Island, Alaska, 2014-2016: data release DOI:10.5066/P9964TKX, U.S. Geological Survey Other_Citation_Details: The first Online Linkage link is to the publication landing page. The second link is to the page containing the data., Pacific Coastal and Marine Science Center, Santa Cruz, CA.

    Online Links:

    This is part of the following larger work.

    Gibbs, Ann E., Nolan, Matt, and Snyder, Alexander G., 2019, Orthophotomosaics, elevation point clouds, digital surface elevation models and supporting data from the north coast of Barter Island, Alaska: data release DOI:10.5066/P9964TKX, U.S. Geological Survey, Reston, VA.

    Online Links:

    Other_Citation_Details:
    Suggested citation: Gibbs, A.E., Nolan, M., and Snyder, A.G., 2019, Orthophotomosaics, elevation point clouds, digital surface elevation models, and supporting data from the north coast of Barter Island, Alaska: U.S. Geological Survey data release, https://doi.org/10.5066/P9964TKX
  2. What geographic area does the data set cover?
    West_Bounding_Coordinate: -143.70893380600
    East_Bounding_Coordinate: -143.58867480000
    North_Bounding_Coordinate: 70.13473389030
    South_Bounding_Coordinate: 70.13014187070
  3. What does it look like?
  4. Does the data set describe conditions during a particular time period?
    Beginning_Date: 06-Sep-2014
    Ending_Date: 18-Sep-2016
    Currentness_Reference:
    ground condition
  5. What is the general form of this data set?
    Geospatial_Data_Presentation_Form: Shapefile
  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. It contains the following vector data types (SDTS terminology):
      • Entity point (11007)
    2. What coordinate system is used to represent geographic features?
      Grid_Coordinate_System_Name: Universal Transverse Mercator
      Universal_Transverse_Mercator:
      UTM_Zone_Number: 7
      Transverse_Mercator:
      Scale_Factor_at_Central_Meridian: 0.9996
      Longitude_of_Central_Meridian: -141.0
      Latitude_of_Projection_Origin: 0.0
      False_Easting: 500000.0
      False_Northing: 0.0
      Planar coordinates are encoded using coordinate pair
      Abscissae (x-coordinates) are specified to the nearest 0.6096
      Ordinates (y-coordinates) are specified to the nearest 0.6096
      Planar coordinates are specified in Meter
      The horizontal datum used is D_WGS_1984.
      The ellipsoid used is WGS_1984.
      The semi-major axis of the ellipsoid used is 6378137.0.
      The flattening of the ellipsoid used is 1/298.257223563.
  7. How does the data set describe geographic features?
    Attribute Table
    Table containing attribute information associated with the data set. (Source: Producer defined)
    Latitude
    Latitude in decimal degrees (Source: Producer defined)
    Range of values
    Minimum:70.1301419
    Maximum:70.1347339
    Longitude
    Longitude in decimal degrees (Source: Producer defined)
    Range of values
    Minimum:-143.7089338
    Maximum:-143.5886748
    Northing
    Y-coordinate in meters relative to UTM zone (Source: Producer defined)
    Range of values
    Minimum:7782670.776
    Maximum:7783007.574
    Easting
    X-coordinate in meters relative to UTM zone (Source: Producer defined)
    Range of values
    Minimum:397271.07
    Maximum:401850.835
    E_height
    WGS84 ellipsoid height in meters (Source: Producer defined)
    Range of values
    Minimum:-1.333
    Maximum:11.015
    SurveyDate
    Date of GPS survey (Source: Producer defined)
    Range of values
    Minimum:9/6/2014
    Maximum:9/18/2016
    SiteID
    Site name (Source: Producer defined)
    ValueDefinition
    Center of nail in unnamed survey crossNail in center of white plastic survey panel
    Center of survey disc marked BTI CP-3 2010 (adjusted to ground level; -25 cm)Center of circular aluminum disk marked BTI-CP-3 in center of white plastic survey panel located atop a vertical rebar pipe at a height of 25 cm above ground level. This point was corrected to ground level by subtracting 25 cm from the measured value.
    Center of survey disc marked BTI CP-3 2010 (at ground level)Center of circular aluminum disk marked BTI-CP-3 in center of white plastic survey panel located atop a non-vertical rebar pipe at a height of approximately 25 cm above ground level. This point was measured at the location of the ground surface and rebar pipe.
    Center of survey disc marked BTI TSM-1 2010Center of circular aluminum disk marked BTI-TSM-1 in center of white plastic survey panel
    Center of survey disc marked BTI TSM-2 2010Center of circular aluminum disk marked BTI-TSM-2 in center of white plastic survey panel
    ERT BTI-2-1Electrical resistivity transect line BTI-2-1
    ERT BTI-2-2Electrical resistivity transect line BTI-2-2
    ERT BTI-2-3Electrical resistivity transect line BTI-2-3
    ERT BTI-2-4Electrical resistivity transect line BTI-2-4
    ERT BTI-2-5Electrical resistivity transect line BTI-2-5
    ERT BTI-2-6Electrical resistivity transect line BTI-2-6
    ERT BTI-2-7Electrical resistivity transect line BTI-2-7
    ERT BTI-2-8Electrical resistivity transect line BTI-2-8
    ERT BTI-2-9Electrical resistivity transect line BTI-2-9
    Northeast POL tank padBoundary of northeast Petroleum-Oil-Lubricant concrete pad
    Northwest POL tank padBoundary of northwest Petroleum-Oil-Lubricant concrete pad
    Southeast POL tank padBoundary of southeast Petroleum-Oil-Lubricant concrete pad
    Southwest POL tank padBoundary of southwest Petroleum-Oil-Lubricant concrete pad

Who produced the data set?

  1. Who are the originators of the data set? (may include formal authors, digital compilers, and editors)
    • Ann E. Gibbs
    • Alexander G. Snyder
  2. Who also contributed to the data set?
  3. To whom should users address questions about the data?
    PCMSC Science Data Coordinator
    U.S. Geological Survey, Pacific Coastal and Marine Science Center
    2885 Mission Street
    Santa Cruz, CA
    USA

    831-427-4747 (voice)
    pcmsc_data@usgs.gov

Why was the data set created?

The data were acquired in support of a larger study to demonstrate the utility of using structure-from-motion photogrammetric methods for deriving digital elevation data using imagery acquired from a fixed-wing aircraft in remote environments. Companion data sets, including orthophotomosaics, elevation point clouds, and digital surface models are used to evaluate fine-scale morphological and volumetric change to beaches and permafrost bluffs.

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: 2014 (process 1 of 2)
    USGS field crews collected GPS coordinates on September 6 and 7, 2014 at a stationary base station, 3 fixed, monumented locations (CP-3, TSM-1, and TSM-2) and along 9 (walking) transects across low tundra bluffs that coincided with electrical resistivity survey transect (ERT) locations. The base station was an Ashtech Z-Extreme GPS receiver and external 2.25 m high antenna mounted on a tripod secured on the eastern railing to the ramp of the U.S. Fish and Wildlife bunkhouse in Kaktovik, Alaska. The coordinates of the base station were determined from On-line Positioning User Service (OPUS) solution based on GPS data from an average over multiple days. The rover was an Ashtech Z-Extreme GPS. The rover antenna was mounted on 2-m survey rod with a bubble level and 5-cm diameter, flat base. Rover data were post-processed using the OPUS derived position of the base station position and the PPP method in Grafnav software. A single position for each of the 3 monument points was determined from the mean value of a cluster of points collected over 1 minute. Positions along the walking transects along the ERT lines were edited to remove obvious spurious and duplicate points, but may be biased upward 5-10 cm because of the data collection techniques.
    Date: 2016 (process 2 of 2)
    USGS field crews collected GPS coordinates on September 17 and 18, 2016 at a stationary base station, 4 fixed, monumented locations (unnamed, CP-3, TSM-1, and TSM-2) and at 4 circular concrete pads at the former Petroleum-Oil-Lubricant (POL) tank farm of the Radar Station at Barter Island, Alaska. The base station was an Ashtech Z-Extreme GPS receiver and external 2.25 m high antenna mounted on a tripod secured on the eastern railing of the ramp to the U.S. Fish and Wildlife bunkhouse in Kaktovik, Alaska. The coordinates of the base station were determined from On-line Positioning User Service (OPUS) solution based on GPS data from an average over multiple days. The rover was an Ashtech Z-Extreme GPS. The rover antenna was mounted on 2-m survey rod with a bubble level and 5-cm diameter, flat base. Rover data were post-processed using the OPUS derived position of the base station position and the PPP method in Grafnav software. A single position for each of the 3 monument points was determined from the mean value of a cluster of points collected over 1 minute. Positions along the walking transects at the POL pads represent the ground surface.
  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?
    GPS data were acquired using precision Ashtech Z-Extreme receivers and external antenna mounted on a separate tripod or survey rod. Data were acquired kinematically at both fixed locations and along walking transects. Data were differentially post-processed using an On-line Positioning User Service (OPUS) derived base station solution based on GPS data from an average over multiple days.
  2. How accurate are the geographic locations?
    Horizontal accuracy at static locations is approximately ±0.03 m. Horizonatal positions of points along the walking survey transects could be biased upward by 5 to 10 cm because of the data collection techniques.
  3. How accurate are the heights or depths?
    Vertical accuracy at static locations is approximately ±0.03 m. Vertical positions of points along the walking survey transects could be biased upward by 5 to 10 cm because of the data collection techniques.
  4. Where are the gaps in the data? What is missing?
    Data set 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.
  5. How consistent are the relationships among the observations, including topology?
    The differential processed GPS was checked for outliers and anomalies.

How can someone get a copy of the data set?

Are there legal restrictions on access or use of the data?
Access_Constraints: none
Use_Constraints:
USGS-authored or produced data and information are in the public domain from the U.S. Government and are freely redistributable with proper metadata and source attribution. Please recognize and acknowledge the U.S. Geological Survey as the originator(s) of the dataset and in products derived from these data.
  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? An Esri point shapefile with ground location coordinates and site identification.
  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.
  4. How can I download or order the data?
  5. What hardware or software do I need in order to use the data set?
    These zip files contain data available in Environmental Systems Research Institute (Esri) shapefile format. The user must have ArcGIS or ArcView 3.0 or greater software to read and process the data file. In lieu of ArcView or ArcGIS, the user may utilize another GIS application package capable of importing the data. A free data viewer, ArcExplorer, capable of displaying the data is available from Esri at www.esri.com.

Who wrote the metadata?

Dates:
Last modified: 30-Jan-2019
Metadata author:
U.S. Geological Survey, Pacific Coastal and Marine Science Center
Attn: PCMSC Science Data Coordinator
2885 Mission Street
Santa Cruz, CA
United States

831-427-4747 (voice)
pcmsc_data@usgs.gov
Metadata standard:
Content Standard for Digital Geospatial Metadata (FGDC-STD-001-1998)

This page is <https://cmgds.marine.usgs.gov/catalog/pcmsc/alaska/BTI_GPS_metadata.faq.html>
Generated by mp version 2.9.49 on Thu Mar 28 18:03:50 2019