State Line Boundary of Illinois

Metadata also available as - [Outline] - [SGML] - [XML]

Frequently-anticipated questions:


What does this data set describe?

Title: State Line Boundary of Illinois
Abstract:
This is an Arc/Info polygon and arc data set showing the state line boundary of Illinois. Nominal scale is 1:62,500.

Supplemental_Information:
Updates to the data: Edition 1.0 of these data were reviewed for internal logical consistency in March, 1998. As a result, several unneeded .AAT items were dropped, tics were replaced, and COVER-ID values were recalculated to be unique. See logical consistency report and process steps for March, 1998 for more details. The updated data set (this one) is edition 1.1.

  1. How should this data set be cited?

    Illinois State Geological Survey, 1984, 199803, State Line Boundary of Illinois: ISGS GIS Database state, Illinois State Geological Survey, Champaign, Illinois.

    Online Links:

  2. What geographic area does the data set cover?

    West_Bounding_Coordinate: -91.4244
    East_Bounding_Coordinate: -87.3840
    North_Bounding_Coordinate: 42.4951
    South_Bounding_Coordinate: 36.9540

  3. What does it look like?

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

    Calendar_Date: 1984
    Currentness_Reference:
    Data were digitized from USGS 7.5 minute and 15 minute topographic maps available circa 1984. Range of dates of those source maps is unknown.

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

    Geospatial_Data_Presentation_Form: map

  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 (1)
      • String (35)
      • GT-polygon composed of chains (2)

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

      The map projection used is Lambert Conformal Conic.

      Projection parameters:
      Standard_Parallel: 33 0 0.000
      Standard_Parallel: 45 0 0.000
      Longitude_of_Central_Meridian: -89 30 0.000
      Latitude_of_Projection_Origin: 33 0 0.000
      False_Easting: 914400.00000 meters
      False_Northing: 0.00000

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

      The horizontal datum used is NAD27.
      The ellipsoid used is CLARKE1866.
      The semi-major axis of the ellipsoid used is 6378206.4 meters.
      The flattening of the ellipsoid used is 1/294.98.

  7. How does the data set describe geographic features?

    Entity_and_Attribute_Overview:
     Attribute items are in typical ARC/INFO feature class format.
    
     ARC ATTRIBUTES:
     Arc attributes indicate line type.  Attribute items other than
     the Arc/Info defaults are:
     STATELINE - Indicates if arc is a part of the state boundary
                   1 - arc is part of the state boundary
                   0 - arc is not part of the state boundary
     COUNTLINE - Indicates if arc is a part of a county boundary
                   1 - arc is part of a county boundary
                   0 - arc is not part of a county boundary
     SECLINE   - Indicates if arc is a part of a section line
                   1 - arc is part of a section line
                   0 - arc is not part of a section line
     INDLINE   - Indicates if arc is a part of an Indian Treaty boundary
                   1 - arc is part of a an Indian Treaty boundary
                   0 - arc is not part of an Indian Treaty boundary
     TOWNLINE  - Indicates if arc is a part of a township or range line
                   1 - arc is part of a township or range line
                   0 - arc is not part of a township or range line
    
     POLYGON ATTRIBUTES:
     There are no user-defined polygon items.
    
    Entity_and_Attribute_Detail_Citation: none


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?

    GIS Processing:  ISGS Staff, C. Abert, D. Nelson
    Documentation:   D. Nelson and S. Beaverson
    Quality Control: ISGS Staff, D. Nelson
    

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

    Illinois State Geological Survey
    Information Office
    615 East Peabody Drive
    Champaign, Illinois 61820
    USA

    217-333-4747 (voice)
    217-244-0802 (FAX)
    isgs@isgs.uiuc.edu

    Hours_of_Service: 8:00 a.m. - 4:30 p.m., Monday-Friday, U.S. Central Time


Why was the data set created?

This data set was created to serve as base map information at scales of 1:62,500 or smaller. These data are appropriate for use in local and regional thematic analysis. Data are not appropriate as a geodetic or engineering base.


How was the data set created?

  1. From what previous works were the data drawn?

    none (source 1 of 1)
    United States Geological Survey, unknown, various - 7.5 minute and 15 minute topographic quadrangles depicting Illinois state boundary.: Topographic quadrangles Those which depicted a portion of the Illinois state boundary at time of automation (1984)..

    Type_of_Source_Media: paper
    Source_Scale_Denominator: 24000 and 62500
    Source_Contribution: Lines depicting Illinois state boundary.

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

    Date: 1984 (process 1 of 2)
    This is a legacy dataset compiled circa 1984. It is assumed that the automation process was typical of that for Arc/Info geo-data sets, implying digitization from source maps, editing and error checking, building topology, and subsequent revision and update. This coverage was extracted from parent coverage re-state1. See metadata for re-state1. Specific process descriptions prior to 1997 are unavailable, other than those listed in the associated Arc/Info log file.

    Date: Mar-1998 (process 2 of 2)
    An internal logical consistency check was performed in March, 1998. See entry for logical consistency. As a result, the following changes/updates were made to the data:

    TICS - The data set had eight tics along the northern border of the state. For better tic distribution, these were replaced with ten tics from *path_name_suppressed*/quad100, evenly distributed around the state. However, users needing registration tics for use with these data (or a subset of these data) should expect to create a task-specific tic set, usually based on section corners.

    REMOVAL OF ITEMS - The following empty .AAT items were dropped: STATE2C.OLD#, STATE2C.OLD-ID, ORIG-ID, SYMBOL, SYMB.

    UNIQUE COVER-ID VALUES - COVER-ID values in the .AAT and .PAT were calculated to equal (COVER# - 1) in order to make them unique.

    For detailed review see *path_name_suppressed*/illimap_v1_0_rev.txt.

  3. What similar or related data should the user be aware of?

    Illinois State Geological Survey, 1984, 199803, Illinois Public Land Survey System: ISGS GIS Database re-state1, Illinois State Geological Survey, Champaign, Illinois.

    Online Links:

    Illinois State Geological Survey, 1984, 199803, Illinois County Boundaries: ISGS GIS Database counties, Illinois State Geological Survey, Champaign, Illinois.

    Online Links:

    Illinois State Geological Survey, 1984, 199803, Township Lines of Illinois: ISGS GIS Database townships, Illinois State Geological Survey, Champaign, Illinois.

    Online Links:

    Illinois State Geological Survey, 1984, 199803, Township Center Points of Illinois: ISGS GIS Database townpts, Illinois State Geological Survey, Champaign, Illinois.

    Online Links:

    Illinois State Geological Survey, 1984, 199803, Indian Treaty Boundary Lines of Illinois: ISGS GIS Database indianlns, Illinois State Geological Survey, Champaign, Illinois.

    Online Links:


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

  1. How well have the observations been checked?

    This coverage was extracted from coverage re-state1, the primary public land survey data set in the ISGS GIS database. The attributes of that coverage were reviewed in 1990 using a variety of visual techniques (polygon shading, line shading and line thicknesses tied to attribute values) and GIS processing techniques (checking for logical consistency). See the metadata for re-state1 for a more complete description of this review. There is no quantitative assessment of attribute accuracy available, however, this coverage has been used extensively by ISGS personnel since 1984, and it can be assumed most attribute errors have been detected and corrected. There are no arc attribute values outside the appropriate value domains.

  2. How accurate are the geographic locations?

    Horizontal positional accuracy has been spot verified by manual overlay of source and hard-copy plots. Arcs within line-width of source maps are deemed acceptable. For positional accuracy of source maps, contact the USGS.

  3. How accurate are the heights or depths?

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

    In 1995, the state boundary along the Ohio River was officially changed, but these changes have not been incorporated. Also, this coverage does not include the portion of the state boundary that extends into Lake Michigan. Rather, the lake shore is depicted as the state boundary.

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

    A logical consistency review was performed in March, 1998. The following checks were made:

    Data set was DESCRIBED and coverage files listed to determine the feature types present. In this data set, the following feature types were found and checked: polygons, arcs, labels, and nodes. The presence of spatial indices was also checked.

    For PAT and AAT files, each ITEM was checked for the following:

    - DOMAIN of allowable values
    - adherence of values to the DOMAIN
    - definition of ITEMS
    - requirement of all UNIQUE values for an item
    - logic of ITEMS REDEFINED over other ITEMS
    - length of ITEM name as regards conversion to shape file
    
    BUILD statuses of data sets were checked, as were LABELERRORS and NODEERRORS (where appropriate), and PROJECTION definition.

    The presence of a BND file was verified.

    The presence and location of TICS were checked.

    Polygon and chain-node topology present. There are no dangling arcs. There is one polygon label per polygon, except for universe polygon. Boundary values appropriate for map projection and map units. "Fuzzy" tolerance is suitable for nominal scale. Several unneeded .AAT items were dropped, tics were replaced, and COVER-ID values were recalculated to be unique. See process steps for March, 1998. There are no attribute values outside the appropriate domains.


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:
Reproduction or redistribution of copyrighted digital data sets or products derived therefrom outside of licensee's organization or entity is expressly forbidden. The only exception is redistribution to consultants working for the licensee, and then only for purposes, related to work for the licensee. Such consultants may not further reproduce or redistribute these data sets. None of these data shall be electronically duplicated on magnetic or optical media for use by others, in whole or in part, without permission of the appropriate custodial division within DNR.

Any hardcopies utilizing DNR data sets shall clearly indicate their source. If the licensee has modified the data in any way they are obligated to describe the types of modifications they have performed on the hardcopy map. Licensee specifically agrees not to misrepresent DNR data sets, nor to imply that changes they made were approved by DNR.

These data are not to be used for commercial profit.

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

    Illinois State Geological Survey
    Information Office
    615 East Peabody Drive
    Champaign, Illinois 61820
    USA

    217-333-4747 (voice)
    217-244-0802 (FAX)
    isgs@isgs.uiuc.edu

    Hours_of_Service: 8:00 a.m. - 4:30 p.m., Monday-Friday, U.S. Central Time
  2. What's the catalog number I need to order this data set?

    An Arc/Info .e00 (export) file is currently available free of charge at the Illinois Natural Resources Geospatial Data Clearinghouse. Refer to the Citation Information portion of this file for access to downloadable data and metadata, and a visual (GIF image) representation of the data. Shift-click to download the data set and related documentation. (Data and metadata offered separately, please download both files.)

  3. What legal disclaimers am I supposed to read?

    The Illinois Department of Natural Resources (DNR) provides these geographic data "as is." DNR makes no guarantee or warranty concerning the accuracy of information contained in the geographic data. DNR further makes no warranties, either expressed or implied as to any other matter whatsoever, including, without limitation, the condition of the product, or its fitness for any particular purpose. The burden for determining fitness for use lies entirely with the user. Although these data have been processed successfully on computers of DNR, no warranty, expressed or implied, is made by DNR regarding the use of these data on any other system, nor does the fact of distribution constitute or imply any such warranty.

    In no event shall the DNR have any liability whatsoever for payment of any consequential, incidental, indirect, special, or tort damages of any kind, including, but not limited to, any loss of profits arising out of use of or reliance on the geographic data or arising out of the delivery, installation, operation, or support by DNR.

  4. How can I download or order the data?


Who wrote the metadata?

Dates:
Last modified: 24-Mar-1998
Last Reviewed: 31-Mar-1998
To be reviewed: Mar-2000
Metadata author:
Illinois State Geological Survey
Information Office
615 East Peabody Drive
Champaign, Illinois 61820
USA

217-333-4747 (voice)
217-244-0802 (FAX)
isgs@isgs.uiuc.edu

Hours_of_Service: 8:00 a.m. - 4:30 p.m., Monday-Friday, U.S. Central Time
Metadata standard:
FGDC Content Standards for Digital Geospatial Metadata (FGDC-STD-001-1998)


Illinois Natural Resources Geospatial Data Clearinghouse

Generated by mp version 2.8.11 on Mon Jan 29 15:19:43 2007