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USGS:Biology arrow icon Biological Informatics Program arrow icon Vegetation Characterization Program arrow icon Appomattox Court House National Historical Park arrow icon Accuracy Assessment FAQ Metadata

Accuracy Assessment FAQ Metadata

Frequently-anticipated questions:

What does this data set describe?

Title:
Appomattox Court House National Historical Park Vegetation Mapping Project - Accuracy Assessment Points
Abstract:
This shapefile depicts the locations of thematic accuracy assessment sampling points used in the vegetation mapping of Appomottox Court House National Historical Park. It was developed by the Virginia Department of Conservation and Recreation, Division of Natural Heritage. The data were created following general guidelines set forth by the USGS-NPS Vegetation Mapping Program. Accuracy assessment field work was performed in the summer of 2005 by staff of the Virginia Division of Natural Heritage.
  1. How should this data set be cited?

    Virginia Department of Conservation and Recreation, Division of Natural Heritage, 20061026, Locations of thematic accuracy assessment sampling points in Appomattox Court House National Historical Park, 2005.

    Online Links:

    This is part of the following larger work.

    Patterson, Karen, 200806, Patterson, K.D. December 2008. Vegetation Classification and Mapping at Appomottox Court House National Historical Park. Technical Report NPS/NER/NRTR--2008/125. National Park Service. Philadelphia, PA..

  2. What geographic area does the data set cover?

    West_Bounding_Coordinate: -78.823789
    East_Bounding_Coordinate: -78.777522
    North_Bounding_Coordinate: 37.395842
    South_Bounding_Coordinate: 37.367242
    Description_of_Geographic_Extent: Appomattox Court House National Historical Park and environs

  3. What does it look like?

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

    Beginning_Date: unknown
    Ending_Date: unknown
    Currentness_Reference: ground condition

  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):

      • Entity point (74)

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

      Grid_Coordinate_System_Name: Universal Transverse Mercator
      Universal_Transverse_Mercator:
      UTM_Zone_Number: 17
      Transverse_Mercator:
      Scale_Factor_at_Central_Meridian: 0.999600
      Longitude_of_Central_Meridian: -81.000000
      Latitude_of_Projection_Origin: 0.000000
      False_Easting: 500000.000000
      False_Northing: 0.000000

      Planar coordinates are encoded using coordinate pair
      Abscissae (x-coordinates) are specified to the nearest 0.000008
      Ordinates (y-coordinates) are specified to the nearest 0.000008
      Planar coordinates are specified in meters

      The horizontal datum used is North American Datum of 1983.
      The ellipsoid used is Geodetic Reference System 80.
      The semi-major axis of the ellipsoid used is 6378137.
      The flattening of the ellipsoid used is 1/298.257222.

  7. How does the data set describe geographic features?

    apco_veg_aa_2005
    attribute table from shapefile (Source: Virginia Department of Conservation and Recreation, Division of Natural Heritage)

    FID
    Internal feature number. (Source: ESRI)

    Sequential unique whole numbers that are automatically generated.

    Shape
    Feature geometry. (Source: ESRI)

    Coordinates defining the features.

    AA_Obs_ID
    Accuracy assessment point number (Source: NPS four letter park code plus unique number)

    NPS four letter park code plus unique number

  8. What biological taxa does this data set concern?

    Taxonomy:
    Keywords/Taxon:
    Taxonomic_Keyword_Thesaurus: none
    Taxonomic_Keywords: Standardized National Vegetation Classification System
    Taxonomic_Keywords: vegetation classification
    Taxonomic_Keywords: alliance
    Taxonomic_Keywords: community association
    Taxonomic_Classification:
    Taxon_Rank_Name: Kingdom
    Taxon_Rank_Value: Plantae

Who produced the data set?

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

    • Virginia Department of Conservation and Recreation, Division of Natural Heritage

  2. Who also contributed to the data set?

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

    Virginia Department of Conservation and Recreation, Division of Natural Heritage
    Ecologist
    217 Governor Street
    Richmond, Virginia 23219
    USA

    804-786-5990 (voice)

Why was the data set created?

This data set was created to identify the locations of sampling points used to assess the thematic accuracy of the Appomottox Court House National Historical Park vegetation map.

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: May-2005 (process 1 of 1)
    The number and distribution of accuracy assessment sampling points was determined by map class abundance and frequency as recommended in the USGS/NPS Vegetation Mapping protocols (The Nature Conservancy and Environmental Systems Research Institute 1994c). Given the small size of the park, the relatively few vegetation polygons, and the fact that most map classes are rare (i.e. have few polygons and small acreages), a complete census was determined to be the best approach to validate the thematic accuracy of the vegetation map. Since 52 polygons were surveyed and verified as part of the initial vegetation mapping effort, random points within the remaining 74 polygons were selected to complete a census of all vegetation polygons. Polygons representing the Anderson Land-Use classes Other Urban or Built-up Land and Transportation, Communications, and Utilities were not included in the census. Seventy-four randomly selected accuracy assessment sampling points were generated using the Random Point Generator v. 1.3 (Jenness 2005) in ArcView 3.3. All points were reviewed over topographic maps and aerial photos. Points were reassigned if the randomly selected point fell on a road, outside the park boundary or if there were potential access limitations. From May through October 2005, all 74 accuracy assessment points were located in the field by VADNH staff using a Garmin Map76 WAAS enabled GPS. Field staff determined the map class at the accuracy assessment point using a dichotomous key to the vegetation map classes and detailed vegetation descriptions.

  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?

    Each accuracy assessment point is represented by one point in the shapefile. All points fall within vegetation map polygons.

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

    ESRI point geometry.

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: None

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

    USGS/CSS/Core Science Analytics and Synthesis
    c/o USGS-NPS Vegetation Mapping Program Coordinator
    Denver Federal Center, Building 810, Room 8000, MS 302
    Denver, Colorado 80225

    (303) 202-4220 (voice)
    303-202-4219 (FAX)
    gs-b-npsveg@usgs.gov

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

    Downloadable Data

  3. What legal disclaimers am I supposed to read?

    The U.S. Geological Survey and the National Park Service shall not be held liable for improper or incorrect use of the data described and/or contained herein. These data and related graphics (if available) are not legal documents and are not intended to be used as such.

    The information contained in these data is dynamic and may change over time. The data are not better than the original sources from which they were derived. It is the responsibility of the data user to use the data appropriately and consistent within the limitations of geospatial data in general and these data in particular. Any related graphics (if available) are intended to aid the data user in acquiring relevant data; it is not approriate to use the related graphics as data.

    The U.S. Geological Survey and the National Park Service gives no warranty, expressed or implied, as to the accuracy, reliability, or completeness of these data. It is strongly recommended that these data are directly acquired from an U.S. Geological Survey and National Park Service servers and not indirectly through other sources which may have changed the data in some way. Although these data have been processed successfully on a computer system at the U.S. Geological Survey, no warranty expressed or implied is made regarding the utility of the data on another system or for general or scientific purposes, nor shall the act of distribution constitute any such warranty. This disclaimer applies both to individual use of the data and aggregate use with other data. It is also strongly recommended that careful attention be paid to the contents of the metadata file associated with these data. Mention of trade names or commercial products in this metadata report does not constitute endorsement or recommendation for use by the U. S. Department of the Interior, U. S. Geological Survey and National Park Service.

  4. How can I download or order the data?

Who wrote the metadata?

Dates:
Last modified: 05-Dec-2007
Last Reviewed: 12-May-2010
Metadata author:
USGS/CSS/Core Science Analytics and Synthesis
c/o USGS-NPS Vegetation Mapping Program Coordinator
Denver Federal Center, Building 810, Room 8000, MS 302
Denver, Colorado 80225

(303) 202-4220 (voice)
303-202-4219 (FAX)
gs-b-npsveg@usgs.gov

Metadata standard:
FGDC Biological Data Profile of the Content Standard for Digital Geospatial Metadata (FGDC-STD-001.1-1999)
Metadata extensions used:

Generated by mp version 2.9.12 on Wed May 12 06:35:28 2010
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