SIR2012_5290_ACAD_Surveyedmarshpoints

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Frequently anticipated questions:

What does this data set describe?

Title: SIR2012_5290_ACAD_Surveyedmarshpoints
Abstract:
Marsh surface points surveyed in July 2010 at 20 marshes in the Acadia National Park area. Each point references a wooden stake installed at the marsh surface. Elevations of these points are accurate to +/- 2.5 centimeters (cm). These points were used to determine the root mean squared error (RMSE) of the LiDAR data in this study area, and the 95 percent confidence intervals.
Supplemental_Information:
Geodatabase product of a USGS study funded by National Park Service Climate Change Response funding, NPS PMIS # 161531, "Inventory and Protection of Salt Marshes from Risks of Sea Level Rise at Acadia National Park, Maine", 2012.
The database layers are collectively termed "appendix 1" of the USGS SIR report. Database layers included in appendix 1 include: Surveyed benchmarks used in surveying exercise (SIR2012_5290_ACAD_SurveyedBMs); Surveyed marsh points used for quality control for LiDAR data (SIR2012_5290_ACAD_Surveyedmarshpoints); Surveyed elevation reference marks for each surveyed marsh (SIR2012_5290_ACAD_SurveyedERMs); Salt marshes inventoried for this study (SIR2012_5290_ACAD_Saltmarshpolys); Inundation lines for each marsh under 60 cm of sea level rise (SIR2012_5290_ACAD_Inundationlines); Potential barriers to migration of salt marshes (SIR2012_5290_ACAD_Potentialbarriers).
The inundation lines presented are in no way a prediction of whether marsh migration will actually occur, only indications of where land will be inundated and would therefore be available for migration under 60 cm. of sea level rise.
  1. How should this data set be cited?

    U.S. Geological Survey, Maine Water Science Center, Augusta, Maine, 2012, SIR2012_5290_ACAD_Surveyedmarshpoints: U.S. Geological Survey, Augusta, Maine.

    Online Links:

    This is part of the following larger work.

    Nielsen, Martha G., and Dudley, Robert W., 2012, Estimates of Future Inundation of Salt Marshes in Response to Sea Level Rise in and Around Acadia National Park, Maine: U.S. Geological Survey Scientific Investigations Report SIR2012-5290, U.S. Geological Survey, Reston, Virginia.

    Online Links:

    Other_Citation_Details: XXX p.

  2. What geographic area does the data set cover?

    West_Bounding_Coordinate: -68.751374
    East_Bounding_Coordinate: -68.112956
    North_Bounding_Coordinate: 44.486092
    South_Bounding_Coordinate: 44.287125

  3. What does it look like?

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

    Beginning_Date: 12-Jul-2010
    Ending_Date: 28-Jul-2010
    Currentness_Reference: Currentness refers to when the marsh points were surveyed.

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

    Geospatial_Data_Presentation_Form: Vector digital data

  6. How does the data set represent geographic features?

    1. How are geographic features stored in the data set?

      This is a Vector data set. It contains the following vector data types (SDTS terminology):

      • Point (100)

    2. What coordinate system is used to represent geographic features?

      The map projection used is NAD_1983_UTM_Zone_19N.

      Projection parameters:
      Scale_Factor_at_Central_Meridian: 0.9996
      Longitude_of_Central_Meridian: -69.0
      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 0.0001
      Ordinates (y-coordinates) are specified to the nearest 0.0001
      Planar coordinates are specified in meters

      The horizontal datum used is D North American 1983.
      The ellipsoid used is GRS 1980.
      The semi-major axis of the ellipsoid used is 6378137.0.
      The flattening of the ellipsoid used is 1/298.257222101.

      Vertical_Coordinate_System_Definition:
      Altitude_System_Definition:
      Altitude_Datum_Name: North_American_Vertical_Datum_1988
      Altitude_Resolution: 1.0
      Altitude_Distance_Units: Meters
      Altitude_Encoding_Method: Attribute values

  7. How does the data set describe geographic features?

    Surveyed marsh points
    Point features (Source: Esri)

    OBJECTID
    Internal feature number (Source: Esri)

    Sequential unique whole numbers that are automatically generated.

    SHAPE
    Feature geometry (Source: Esri)

    Coordinates defining the features

    Northing_f
    Northing horizontal coordinate in feet (Maine State Plane East 1801 Survey Feet coordinate system) (Source: Esri)

    Range of values
    Minimum:176111.76235
    Maximum:276586.340928
    Units:Feet

    Easting_ft
    Easting horizontal coordinate in feet (Maine State Plane East 1801 Survey Feet coordinate system) (Source: Esri)

    Range of values
    Minimum:909255.669473
    Maximum:1113098.460934
    Units:Feet

    Elevation_ft
    Surveyed vertical coordinate in feet above NAVD88 (Source: USGS)

    Range of values
    Minimum:4.275
    Maximum:7.668
    Units:Feet above NAVD88
    Resolution:.025

    ERM
    Elevation Reference Mark (ERM) number used as datum for the given surveyed marsh point (Source: USGS)

    Range of values
    Minimum:1
    Maximum:20
    Units:Arbitrary idendification number of the appropriate ERM

    Elev_m
    Surveyed vertical coordinate in meters above NAVD88 (Source: USGS computed)

    Range of values
    Minimum:1.569
    Maximum:2.339
    Units:Meters above NAVD88
    Resolution:.025

    LiDAR_elev
    Land-surface elevation in meters above NAVD88 indicated by LiDAR data co-located at Marsh Point (Source: USGS)

    Range of values
    Minimum:1.241
    Maximum:2.381
    Units:Meters above NAVD88
    Resolution:.01

    LiDAR_error
    Difference between fields Elev_m and LiDAR_elev (in meters) (Source: USGS computed)

    Range of values
    Minimum:-0.831768
    Maximum:0.576925
    Units:Meters
    Resolution:.02

Who produced the data set?

  1. Who are the originators of the data set? (may include formal authors, digital compilers, and editors)

  2. Who also contributed to the data set?

    Produced in cooperation with the National Park Service. LiDAR data for the Northeast funded largely by USGS American Reinvestment and Recovery Act funds, and provided by the Maine Office of GIS (MEGIS). These data are in the public domain unless otherwise stated; please credit the USGS and the National Park Service in products derived from these data.

  3. To whom should users address questions about the data?

    Robert W. Dudley
    U.S. Geological Survey Maine Water Science Office
    Hydrologist
    196 Whitten Rd.
    Augusta, ME 04330

    207-622-8201 x115 (voice)
    207-622-8204 (FAX)
    rwdudley@usgs.gov

Why was the data set created?

Marsh Points were used as part of independent accuracy assessment of LiDAR data at salt marsh surfaces. Five surveyed points at each of the 20 marshes were used for LiDAR elevation accuracy assessment. Each of these points is located at a wooden stake pounded into the marsh surface and flush with the marsh surface.

How was the data set created?

  1. From what previous works were the data drawn?

    Bing maps imagery (source 1 of 2)
    USGS, 2010, Microsoft Bing Bird's eye imagery: Microsoft Corporation, Redmond, Washington.

    Online Links:

    Other_Citation_Details:
    Copyright 2010 DigitalGlobe, Image courtesy of USGS Copyright 2012 Microsoft Corporation
    Type_of_Source_Media: Online digital image
    Source_Scale_Denominator: 1200
    Source_Contribution:
    The Bing map server was used to verify positions of the marsh points after they were processed into a GIS datalayer.

    NGS database (source 2 of 2)
    National Oceanic and Atmospheric Administration (NOAA), National Geodetic Survey, 2010, Horizontal and Vertical Geodetic Control Data for the United States: Unknown Unknown, NOAA's Ocean Service, National Geodetic Survey (NGS), NOAA Campus, Silver Spring, MD.

    Online Links:

    Other_Citation_Details:
    Questions concerning this data may be addressed to the NGS Information Center (ngs.infocenter@noaa.gov)
    Type_of_Source_Media: online database
    Source_Contribution:
    Spatial and attribute (elevation) information for permanent benchmarks.

  2. How were the data generated, processed, and modified?

    Date: 2010 (process 1 of 2)
    Marsh points were located on flat terrain within each marsh with a minimum spacing of 10 meters (m) between points. Control point elevations were surveyed relative to nearby ERMs using a Sokkia Set 4B Total Station (TS) infrared laser transit and survey rods with retro-reflectors (prisms). Survey data provided the horizontal and vertical positions of these points.

    Date: 2010 (process 2 of 2)
    X, Y, and Z coordinates from the survey data were put in a text file and imported into ArcGIS and saved as a shapefile.

  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?

    All attributes in the accompanying data layers were checked.

  2. How accurate are the geographic locations?

    Surveyed point data solved using total station (TS) data relating ERMs to MPs. The Sokkia TS provided 5-second angular precision and millimeter-scale precision in both distance and elevation with shots up to 1 km distance depending on atmospheric conditions. Potential errors were controlled by resurveying if survey loops did not close to less than 2 cm. Horizontal positions considered accurate to +/- 2.5 cm.

  3. How accurate are the heights or depths?

    Surveyed point data solved using total station (TS) data relating ERMs to MPs. The Sokkia TS provided 5-second angular precision and millimeter-scale precision in both distance and elevation with shots up to 1 km distance depending on atmospheric conditions. Potential errors were controlled by resurveying if survey loops did not close to less than 2 cm. Vertical positions considered accurate to +/- 2.5 cm.

  4. Where are the gaps in the data? What is missing?

    The data are complete.

  5. How consistent are the relationships among the observations, including topology?

    Data are internally consistent.

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:
No legal use constraints. Users must assume responsibility in determining the usability of these data for their purposes.

  1. Who distributes the data set? (Distributor 1 of 1)

    U.S. Geological Survey
    Ask USGS -- Water Webserver Team
    445 National Center
    Reston, VA 20192
    USA

    1-888-275-8747 (1-888-ASK-USGS) (voice)
    <http://water.usgs.gov/user_feedback_form.html>

  2. What's the catalog number I need to order this data set?

    Downloadable Data

  3. What legal disclaimers am I supposed to read?

    This database, identified as “SIR2012_5290_ACAD_Surveyedmarshpoints”, has been approved for release and publication by the U.S. Geological Survey (USGS). Although this database has been subjected to rigorous review and is substantially complete, the USGS reserves the right to revise the data pursuant to further analysis and review. Furthermore, it is released on condition that neither the USGS nor the U.S. Government may be held liable for any damages resulting from its authorized or unauthorized use. The use of firm, trade, or brand names in this report is for identification purposes only and does not constitute endorsement by the U.S. Geological Survey. The names mentioned in this document may be trademarks or registered trademarks of their respective trademark owners.

  4. How can I download or order the data?

Who wrote the metadata?

Dates:
Last modified: 20-Dec-2012
Metadata author:
U.S. Geological Survey, New England Water Science Center, Maine Office
Hydrologist
196 Whitten Rd.
Augusta, ME 04330
USA

207-622-8201 (voice)
mnielsen@usgs.gov

Metadata standard:
FGDC Content Standards for Digital Geospatial Metadata (FGDC-STD-001-1998)

Generated by mp version 2.9.20 on Wed Mar 13 14:45:52 2013