Any access to these data, Web sites, computer systems, electronic services, and electronic networks is governed by University and campus policies, in particular, but not limited to, the Policy on Appropriate Use of Computers and Network Systems at the University of Illinois at Urbana-Champaign, the ISGS Terms of Use document available at the ISGS Web site, and the University of Illinois Web Privacy Notice.
Links to these are provided in the Cross References section.
Individuals or entities may make fair use of copyrighted ISGS material, such as reproducing a single figure or table, or using a brief text quotation, without obtaining formal permission, but in all cases the Illinois State Geological Survey must be credited as the source of the material. To reproduce ISGS information beyond the fair use standard, permission must be obtained from the ISGS Information Office, 615 East Peabody Drive, Champaign, Illinois 61820, 217-333-4747, isgs@isgs.illinois.edu. License fees and a license agreement may be required, depending on the proposed usage.
Any use of these data is governed by University and campus policies, in particular, but not limited to, the Policy on Appropriate Use of Computers and Network Systems at the University of Illinois at Urbana-Champaign, the ISGS Terms of Use document available at the ISGS Web site, and the University of Illinois Web Privacy Notice. Links to these are provided in the Cross References section.
Map information is to be used at a scientifically and cartographically appropriate scale, that is, at a scale no greater than indicated on the map or as described in the documentation of the map or map data. Map information is not appropriate for, and is not to be used as, a geodetic, legal, or engineering base. Map information has no legal basis in the definition of boundaries or property lines and is not intended as a substitute for surveyed locations such as can be determined by a registered Public Land Surveyor.
The data do not replace the need for detailed site-specific studies.
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
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).
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.
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
ISL - Illinois State Library
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
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Illinois Natural Resources Geospatial Data Clearinghouse
Generated by mp version 2.8.25 on Thu Apr 16 11:22:30 2009