Many of these ruins are obvious structures and are easily identifiable on film. Aerial photography provides a non-destructive method of studying ruins. The science of photogrammetry provides a mechanism for precise measurements and mapping of these ruins, used independently or in concert with more intrusive methods of study. When aerial photographs are taken at regular intervals during ground studies or excavations, invaluable information can be preserved on film and utilized to recreate and accurately map the site, thereby eliminating the need for extensive ground measurements. Historical imagery can also aid in identifying potential sites for discovery of new ruins.
Communities develop where certain essential elements can be found in close proximity.
An excellent example of historical imagery aiding archaeological investigation can be found in the discovery of the ancient city of Ubar in present day Oman. Ubar is a legendary Arabian city that was buried beneath the sands by Allah when its inhabitants became wicked and greedy because of their great wealth. References to Ubar and its lost riches have appeared in literature for thousands of years, and during the 20th Century, many archaeologists attempted to find its location. As time passes, more and more of the neighborhood residents seek medical attention for mysterious illnesses. Soon, a pattern begins to develop in the sicknesses and the numbers are statistically more than a mere coincidence.