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Accuracy Assessment FAQ Metadata

Frequently-anticipated questions:


What does this data set describe?

Title: Tuzigoot National Monument Vegetation Mapping Project - Accuracy Assessment Points
Abstract:
The accuracy assessment field work was performed in May, 1997 to verify the accuracy of the vegetation communities spatial data developed by the USGS-NPS Vegetation Mapping Program for Tuzigoot National Monument. The data points were randomly distributed stratified according to vegetation association over the project area according to protocols developed by the Program. Points were located by GPS navigation and the community information was collected at the point, without knowledge of the attributes of the vegetation spatial data.
  1. How should this data set be cited?

    U.S. Geological Survey, and Department of the Interior, 199705, Tuzigoot National Monument Accuracy Assessment: USGS-NPS Vegetation Mapping Program Tuzigoot National Monument, USGS Core Science Systems, Core Science Analytics and Synthesis, Denver, CO.

    Online Links:

  2. What geographic area does the data set cover?

    West_Bounding_Coordinate: -112.028
    East_Bounding_Coordinate: -112.017
    North_Bounding_Coordinate: 34.78583
    South_Bounding_Coordinate: 34.6584
    Description_of_Geographic_Extent: Tuzigoot National Monument, Nebraska and environs.

  3. What does it look like?

    <http://biology.usgs.gov/npsveg/tuzi/images/tuziaa.pdf> (PDF)
    507 kbyte file showing vegetation associations and location of accuracy assessment points

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

    Calendar_Date: May-1997
    Currentness_Reference: Source of data collection

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

    Geospatial_Data_Presentation_Form: database and report

  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: 12
      Transverse_Mercator:
      Longitude_of_Central_Meridian: -111
      Latitude_of_Projection_Origin: 0
      False_Easting: 500000
      False_Northing: 0
      Scale_Factor_at_Central_Meridian: .9996

      Planar coordinates are encoded using Coordinate Pair
      Abscissae (x-coordinates) are specified to the nearest 1
      Ordinates (y-coordinates) are specified to the nearest 1
      Planar coordinates are specified in Meters

      The horizontal datum used is North American Datum of 1983.
      The ellipsoid used is Geodedic Reference System 80.
      The semi-major axis of the ellipsoid used is 6378137.
      The flattening of the ellipsoid used is 1/298.257.

  7. How does the data set describe geographic features?

    Entity_and_Attribute_Overview:
    The National Vegetation Classification Standard is organized hierarchically to support conservation and resource stewardship applications across multiple scales. The upper levels of the hierarchy are based on the physical form or structure of the vegetation (physiognomy) and have been refined from the international standards developed by the United nations Educational, Scientific, and Cultural Organization (UNESCO). The two most detailed levels of the hierarchy are based on the species composition of existing vegetation (floristics) and reflect the phyto-sociological standards that were originally developed by European ecologists. The vegetation classification is continually advanced through the collection and analysis of new field data and will be greatly strengthened during the course of the USGS-NPS mapping efforts. Data file attributes include species, alliance, community element, and land cover.
    Entity_and_Attribute_Detail_Citation:
    Grossman, D. Et al. 1994. National Park Service/ National Biological Service Vegetation Mapping Project, Standardized National Vegetation Classification System 209 pp.

  8. What biological taxa does this data set concern?

    Taxonomy:
    Keywords/Taxon:
    Taxonomic_Keyword_Thesaurus: None
    Taxonomic_Keywords: vegetation classification
    Taxonomic_Keywords: Standardized National Vegetation Classification System
    Taxonomic_Keywords: alliance
    Taxonomic_Keywords: community association
    Taxonomic_System:
    Classification_System/Authority:
    Classification_System_Citation:
    Citation_Information:
    Originator: U.S. Government; Federal Geographic Data Committee
    Publication_Date: 19971022
    Title: National Vegetation Classification Standard (NVCS)
    Geospatial_Data_Presentation_Form: document
    Publication_Information:
    Publication_Place: Washington D.C.
    Publisher: Federal Geographic Data Committee
    Online_Linkage:
    <http://www.fgdc.gov/standards/projects/FGDC-standards-projects/vegetation/index_html>
    Taxonomic_Procedures:
    Vegetation alliances were identified; no specimens nor vouchers were collected as a part of this process
    Taxonomic_Completeness:
    Conforms with FGDC standardized vegetation classifiction system.
    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)

    • U.S. Geological Survey
    • Department of the Interior

  2. Who also contributed to the data set?

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

    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


Why was the data set created?

To verify the accuracy of the mapped vegetation communities at Tuzigoot National Monument


How was the data set created?

  1. What methods were used to collect the data?

    Method 0 of 2
    Type: Field

    Data points were located by use of a PLGR GPS receiver. Vegetation communities were identified on the basis of a dichotomous field key and plant species present.

    Method 0 of 2
    Type: Lab

    Accuracy assessment points were compiled into an ARCINFO point coverage and intersected with the vegetation community coverage. The resulting INFO file was exported into a text file, imported into a spreadsheet, and the attributes from the accuracy assessment and the spatial data were compared. If the attributes did not compare, an analysis of the mismatch was made and either the AA attribute or the map attribute was changed based on identification of the community on the aerial photo.

  2. From what previous works were the data drawn?

    Accuracy Assessment Procedures Document (source 1 of 2)
    U.S. National Biological Survey, U.S. National Park Service, and Department of the Interior, 199411, Accuracy Assessment Procedures, NBS/NPS Vegetation Mapping Program: USGS, Core Science Systems, Core Science Analytics and Synthesis, Denver, CO.

    Other_Citation_Details:
    Prepared by: Environmental Systems Research Institute; Redlands, CA and National Center for Geographic Information and Analysis, University of California, Santa Barbara, CA anbd The Nature Conservancy, Arlington, VA under contract from U.S. Department of the Interior National Biological Survey and National Park Service.
    Type_of_Source_Media: electronic document
    Source_Contribution:
    This document established the procedures and protocols for the accuracy assessment at Tuzigoot National Monument.

    Spatial data of vegetation communities for Tuzigoot National Monument. (source 2 of 2)
    U.S. Geological Survey, and Department of the Interior, 199705, Tuzigoot National Monument Spatial Vegetation Data: Cover type / Association level of the National Vegetation Classification System: USGS-NPS Vegetation Mapping Program Tuzigoot National Monument, USGS, Core Science Systems, Core Science Analytics and Synthesis, Denver, CO.

    Other_Citation_Details:
    Created in large part by Environmental Systems Research Institute, Inc. Redlands, CA under contract rom USGS/CSS/CSAS.
    Type_of_Source_Media: Disc
    Source_Contribution:
    The vegetation spatial data were tested for accuracy with the AA data.

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

    Date: Oct-1998 (process 1 of 1)
    The accuracy assessment field work was performed in May, 1997 to verify the accuracy of the vegetation communities spatial data developed by the USGS-NPS Vegetation Mapping Program for Tuzigoot National Monument. The data points were randomly distributed stratified according to vegetation association over the project area according to protocols developed by the Program. Points were located by GPS navigation and the community information was collected at the point, without knowledge of the attributes of the vegetation spatial data.

    Data sources used in this process:

    • Spatial data of vegetation communities for Tuzigoot National Monument.
    • Accuracy Assessment Procedure Document

  4. 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?

    The attributes for the accuracy assessment were recorded in the field in May, 1997. Vegetation associations were identified based on the field key and plant identification. If additional communities were found within a 50 meter radius of the plot center, they were recorded as well. During the analysis, it was concluded that some attributes were in error and changed to match the mapped attributes. This was done by examination of the aerial photographs under stereoscopic view. The attributes were in error due to 1) spatial error in the GPS derived coordinates (4-8 meters), 2) change of vegetation community due to temporal changes, or differences between observation team identifications.

  2. How accurate are the geographic locations?

    X,Y UTM coordinates representing each of the 35 plots were collected by P-code PLGR (Precise Lightweight GPS Receiver) receivers, with an accuracy ranging from +/- 10 m. to +/- 30 m. based on 60 second averaging at each point.

  3. How accurate are the heights or depths?

    Not applicable

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

    All points were collected and analyzed. Several points fell outside the mapping area, so were discarded.

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

    All attributes are codes that correspond to vegetation communities and have been checked for typographical and logical errors.


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:
Any person using the information presented here should fully understand the data collection and compilation procedures, as described in these metadata, before beginning analysis. The burden for determining fitness for use lies entirely with the user. For purposes of publication or dissemination, citation or credit should be given to the U.S. Geological Survey and the National Park Service.

  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?

  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: 22-Oct-2001
Last Reviewed: 16-Jun-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 Jun 16 12:44:27 2010

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