1. Indiana Geological Survey (IGS)
Created by
Denver Harper (IGS)
Chris Dintaman (IGS)
Alex Zlotin (ESRI)
Funded by
Indiana Dept. of
Transportation
(INDOT)

2. Collected by the Soil Conservation Service (NRCS) of the U.S.D.A.
Started in late 1930s
Collected as county-based surveys
Used for agricultural and topographic mapping
Compiled in various archival collections

3. Individual Photos Size = 9 x 9 inches Date of collection
Unique ID number

4. Individual Photos Significant overlap for stereo viewing Usually N-S
flight lines
Several hundred
photos per county
per year

5. Created to facilitate retrieval
Individual photos were physically mosaicked and then re-photographed
Photomosaics are low-resolution

6. 951 photo-mosaic index maps, showing locations of 113,035 individual photos

7. Digitization of the IGS Archive
Scanned by Historical Information Gatherers, Inc.
Photomosaics scanned at 300 dpi
Individual photos scanned at 600 dpi
Scans of individual photos are not available for public distribution
Upon request, IGS personnel will re-scan individual photos at 800 dpi

8. Digitization of the IGS Archive
2006 – Photomosaics georeferenced by IGS
ArcGIS georeferencing tool
Leica Image Analyst extension for ArcGIS used to mosaic index maps that were split into parts
Loaded into SDE as raster catalog

9. Digitization of the IGS Archive
Point index layer completed by IGS
A point was placed over each ID number on each photomosaic (113,035 points)
Each point was attributed with county name, year, photo ID, flight orientation, and availability from various archives
Loaded into SDE

10. Digitization of the IGS Archive
IHAPI interactive map was developed and made public on January 23

11. Purpose: Create an interactive map, so that the public can obtain historical aerial photos of interest without leaving their home or office.
IHAPI Features
ESRI ArcIMS AXL-based map service
Customized definition queries are accessed through the user interface to display the photomosaics and ID points
Customized interface to assist users in finding their site of interest

12. Read the instructions or watch the narrated video tutorial
Open the interactive map (
Specify your county of interest
Select your year of interest
Find your site of interest
Zoom tools
Locate by address or coordinates
Reference layers
Determine identification number
Contact archival collections (such as IGS) for copies of high-resolution photos

13.
Find historical aerial photos showing the site of the football stadium of Indiana University