Illinois Historical Aerial Photographs: County Index Data v.2

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Frequently-anticipated questions:


What does this data set describe?

Title: Illinois Historical Aerial Photographs: County Index Data v.2
Abstract:
Aerial photograph center point Index Data are offered by county in ESRI Shapefile format. The center points direct the user to non-geometrically corrected Illinois historical black and white aerial photography acquired during the late 1930s and early 1940s. The center points were created on an county by county basis. These Index Data contain information for each aerial photograph, including digital file name, flight line, county name, historical county code, roll and exposure numbers, agency which contributed the original photographic paper print for scanning, acquisition date, time flown (if available), the CD-ROM on which the original file is stored at the ISGS, and any additional notes.
Supplemental_Information:
The center point locations are only approximate. More information about the center points can be found in the "Data_Quality_Information" section of this metadata.
  1. How should this data set be cited?

    Illinois State Geological Survey, Unpublished Material, Illinois Historical Aerial Photographs: County Index Data v.2.

  2. What geographic area does the data set cover?

    West_Bounding_Coordinate: -91.675280
    East_Bounding_Coordinate: -87.483350
    North_Bounding_Coordinate: 42.564692
    South_Bounding_Coordinate: 36.911398

  3. What does it look like?

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

    Beginning_Date: 1936
    Ending_Date: 1941
    Currentness_Reference: publication date

  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

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

      Horizontal positions are specified in geographic coordinates, that is, latitude and longitude. Latitudes are given to the nearest 0.000001. Longitudes are given to the nearest 0.000001. Latitude and longitude values are specified in Decimal degrees.

      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 6378137.000000.
      The flattening of the ellipsoid used is 1/298.257222.

  7. How does the data set describe geographic features?

    Entity_and_Attribute_Overview:
     Attribute items are in typical ARC/INFO feature class format.
    
     POINT ATTRIBUTES:
      Point attributes indicate approximate center points of historical
      aerial photographs. Point items other than the Arc/Info defaults are
      as follows:
    
      IMAGE_SCAN - Availability
                    YES - Aerial photograph is scanned and available on-line.
                    NO - Aerial photograph is shown or listed on a
                         county index but has not been scanned because of
                         the following reasons:
                         a)  not available,
                         b) damaged and/or unusable,
                         c) no funds were available.
    
      FILE_NAME - Electronic file name
                    Naming conventions for file names are based on annotation
                    included on the photographs and include codes for county,
                    roll number, and exposure number; zeros are used as
                    placeholders. Flight line information is not included in
                    the file name.
    
                    Annotation example from file "0bwq04036.sid":
                    11-15-38  12:30      AAA SCALE 1:20,000     BWQ  4-36
    
                    11-15-38 = acquisition date (November 15, 1938)
                    12:30 = acquisition time (12:30 PM Central Standard Time)
                    AAA = Agricultural Adjustment Administration
                    SCALE 1:20,000 = Representative Fraction (RF) scale,
                    1 unit on the photograph equals 20,000 units on
                         the ground.
                    BWQ = county code for Cook County, Illinois
                    4-36 = roll-exposure number; film roll=4, exposure=36
    
      CNTY_NAME - County name
    
      CNTY_CODE - Unique county code as annotated on the aerial photograph
    
      CNTY_FIPS - County 3-digit FIPS code
    
      DATE_FLOWN - Acquisition date of aerial photograph represented
                  as yyyymmdd (year, month, day)
    
      TIME_FLOWN - Time of exposure
                    Indicates acquisition time of aerial photograph
                      xx:xx    - Time of day (note: aerial photographs
                                 from these collections were not flown
                                 during night time hours)
                      unknown  - Aerial photograph was not available
                                 or county photograph mosaic index did
                                 not show any annotation regarding time.
                      no stamp - Aerial Photograph was available, but
                                 neither the photograph nor the
                                 photograph mosaic county index show a
                                 time stamp.
    
      FLIGHT_LIN - Flight line number
                    The location of the first flight line in each county is
                    dependent on whether the flight line orientation is north
                    to south or east to west. If the flight line orientation
                    is north to south, then flight line 1 is the first
                    vertical line of photographs on the left side of
                    the county index.
    
                    If the flight line orientation is east to west,
                    then flight line 1 is the first horizontal line
                    of photographs at the top of the county index.
    
      ROLL_EXP - Hyphenated number
                    The first number represents the film roll number which is
                    the source of the photograph. The second is the exposure
                    number of the photograph on that film roll.
    
      IMAGE_SRC - Abbreviation of collection from which the photograph
                  was acquired
                    OWR     - IDNR Office of Water Resources Collection
                    UIUC    - University of Illinois Urbana Champaign Map and
                               Geography Library
                    Peoria  - United States Department of Agriculture Farm
                               Services Agency in Peoria, Illinois
                    Lake    - Lake County, Illinois Planning Department
                    SIUC    - Southern Illinois University Carbondale
                               Morris Library
    
      CD_ROM - Number indicating CD # out of total # of CD's for a given county
    
      NOTES - Any notes or comments about the aerial photograph
    
      URL - Hyperlink to MrSID file for viewing or downloading image
    
    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?

     Funding source:   United States Army Corps of Engineers (USACE)
     Funding source:   Institute of Museum and Library Sciences (IMLS)
     Data automation:  Deette Lund, Sheena Beaverson
     GIS processing:   Robert White, Deette Lund, Tim Coulombe
     Documentation:    Deette Lund, Ray Peterlin, Andrew Baker, Tim Coulombe
     QA/QC:            Deette Lund, Sheena Beaverson
    

  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 assist the user in locating historical aerial photographs which have no spatial reference.


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: 2001 (process 1 of 5)
    SCANNING METHODOLOGY: Original copies of the county indexes are located at the University of Illinois Map and Geography Library. Special permission was granted by the Library for the county index sheets to be scanned at an offsite location. The indexes were scanned on a large format Eagle 4080 scanner located at the Illinois State Geological Survey. The photo indexes were scanned at 600 dpi and the line indexes were scanned at 300 dpi (2001-2004).

    In December 2004 Historic Information Gatherers, Inc.(HIG), Hopkins, Minnesota, scanned all of the remaining county index sheets (photo mosaic and line indexes that hadn't already been scanned by the ISGS) available at the UIUC Map and Geography Library (~1700 sheets). In Spring 2005 HIG provided the ISGS with digital images of the photo and line indexes. The indexes were scanned on a large format Vidar Titan Atlas P93 scanner temporarily located at the UIUC Map and Geography Library. The photo indexes were scanned at 300 dpi and the line indexes were scanned at 400 dpi (2004).

    Date: 2003 (process 2 of 5)
    GEOREFERENCING: The scanned images were georeferenced using Erdas Imagine (version 8.5 (2003-2004); version 8.7 (2005-2006)). The reference base used were United States Geological Survey Digital Raster Graphic (DRG) files , which are available on the Illinois Natural Resources Geospatial Clearinghouse. A minimum of 5 ground control points (GCP's) were selected for each image. The maximum RMSE allowed was 1.0 (5 meters).

    Date: 2003 (process 3 of 5)
    CENTER POINT CREATION: Using a combination of software (ArcView 3.2 and ArcGIS 8.3 (2003-2004); ArcGIS 9.0 (2005-2006)) center point data layer shapefiles were created in ArcView using the georeferenced county indexes for each county. Center points were created for all known aerial photographs listed or shown on the county index sheets, whether or not the photographs were available for scanning.

    Photo center point locations are best approximation.

    Points were established by the following method. Two different methods were employed, one for the photo mosaic indexes and a second for the line indexes.

    Photo mosaic index:

    Example: 20 center points are needed in the flight line.
    1) Place the first point in what would be the approximate center of the first photo in the flight line.
    2) Start adding additional points after the first one, spaced closely together.
    3) When you get to point 19, make certain it is not already beyond the last photo in the flight line on the index sheet.
    4) Place the 20th point on the approximate center of the last photo in the flight line.
    5) Use the alignment tool and evenly distribute the points between the two end points.
    6) Use the rotation tool and adjust the entire flight line as needed, so that the center points for each of the photos are still situated at the approximate center of their respective photo locations.
    7) Repeat steps 1-6 for each flight line.
    
    Line index:
    Example: 20 center points are needed in the flight line.
    1) Place the first point on the center of the annotation for the first photo in the flight line.
    2) Start adding additional points after the first one, spaced closely together.
    3) When you get to point 19, make certain it is not already beyond the last annotated photo in the flight line on the index sheet.
    4) Place the 20th point at the approximate center of the annotation for the last photo in the flight line.
    5) Use the alignment tool and evenly distribute the points between the two end points.
    6) Use the rotation tool and adjust the entire flight line as needed, so that the center points for each of the photos are still located at the approximate center of their respective annotations.
    7) Repeat steps 1-6 for each flight line.
    

    Date: 2003 (process 4 of 5)
    ADD ATTRIBUTES: Import supplemental information about each photograph into the appropriate record entry in the associated .dbf file.

    Date: 2003 (process 5 of 5)
    ADD PROJECTION INFORMATION: Define the projection of the shapefile.

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

    Illinois State Geological Survey, Unpublished Material, Illinois Historical Aerial Photographs: 1936 to 1941: Illinois State Geological Survey, Champaign, Illinois.

    Online Links:

    Illinois State Geological Survey, Unpublished Material, Illinois Historical Aerial Photographs: Schematic County Indexes: Illinois State Geological Survey, Champaign, Illinois.

    Online Links:

    Illinois State Geological Survey, Unpublished Material, Illinois Historical Aerial Photographs: Photo Mosaic County Indexes: 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?

    Center point locations are approximate.

  2. How accurate are the geographic locations?

    Center point locations are approximate.

  3. How accurate are the heights or depths?

    Not applicable.

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

    Not Applicable

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

    Not Applicable


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 there from outside of licensee 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 the Illinois Department of Natural Resources (IDNR).

Any hardcopies utilizing IDNR 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 IDNR data sets, nor to imply that changes they made were approved by IDNR.

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?

    A county shapefile is currently available free of charge at the Illinois Natural Resources Geospatial Data Clearinghouse. Refer to the Identification_Information portion of this file for access to downloadable data and metadata.

  3. What legal disclaimers am I supposed to read?

    The Illinois Department of Natural Resources provides these geographic data "as is." IDNR makes no guarantee or warranty concerning the accuracy of information contained in the geographic data. IDNR 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 IDNR, no warranty, expressed or implied, is made by IDNR 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 IDNR 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 IDNR.

  4. How can I download or order the data?


Who wrote the metadata?

Dates:
Last modified: 11-Aug-2006
Last Reviewed: 11-Aug-2006
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 15:19:37 2007