SCANNED AERIAL PHOTOS FOR CONSERVATION SPATIAL DATABASES 
Brian Huberty 
USDA-Natural Resources Conservation Service 
Midwest Regional Office 
2820 Walton Commons West; Suite 123 
Madison, Wisconsin 53704 
USA 
ABSTRACT 
Scanning aerial photographs for use in digital computer systems is not new. Thirty years 
ago, many potential users tried scanning their aerial photographs but became frustrated at the 
immense data volumes needed to view just a small portion of the original photograph at a relatively 
coarse resolution. Lately, the tools for scanning and storing aerial photographs have improved. 
Recent developments, such as the Kodak Photo CD, system has allowed users to get their 35mm or 
70mm photographs scanned at a high resolution and compressed without loss onto compact discs 
(CD ROM). This paper will highlight a working program using Photo CD technology to scan and 
store hundreds of thousands of 35mm aerial slides onto CD ROMs. The paper will also highlight 
how users are able to provide improved conservation services by using scanned 35mm aerial 
photography. 
1. INTRODUCTION 
For approximately the past 20 years, 
the Farm Services Agency (FSA, formerly 
Agricultural Stabilization and Conservation 
Service - ASCS) has funded and directed the 
Supplementary Aerial Compliance (SAC) 
program nationwide (USDA, 1985). SAC is 
designed to acquire yearly, inexpensive 35mm 
aerial photographic slides over American 
farmlands for the purpose of comparing crop 
acres and types for FSA crop compliance 
programs. This relatively large, unknown 
aerial photo program has proven to be a very 
cost effective system. SAC has substantially 
reduced the time required for expensive field 
checking. SAC also demonstrated the utility 
of 35mm aerial photography as contrasted to 
traditional, expensive large format (9x9) 
aerial photography or even more expensive 
coarse resolution satellite imagery. 
As a result of the FSA program, 
Natural Resources Conservation Service 
31 
(NRCS, formerly Soil Conservation Service - 
SCS) field personnel and county Land 
Conservation Departments have discovered the 
utility of SAC photography for farmland 
conservation programs. NRCS uses SAC 
slides for soil mapping, National Resources 
Inventory, windbreak surveys, wetland 
mapping, and other farmland conservation 
projects. 
1.1. Image Access 
Quick and easy access to information is 
becoming mandatory in a world where 
information generation increases exponentially 
everyday. The manual method of pulling and 
using SAC slides over a particular farm from 
year to year requires massive amounts of time 
and energy. For example, if one wants to 
compare crop types and acreage patterns over a 
ten year period for a farm requires numerous 
steps: 
1) find the slides,