Infrared aerial photos are used to show an image on infrared film. This then provides a record of point to point variations in the temperature of the photograph. Not only can it be used to to show the changes that have taken place in our environments, but it can also be used to monitor such items as damage to roofs, the tracking of dairy farm out flows, pinpointing the source of, and monitoring, insect or disease infested vineyards, or sites contaminated by toxic chemicals, and many more applications.
The above image is an Infrared areial photo of the Middle Mississippi River taken in 1994.
(Light Detection and Ranging, also known as Airborne Laser Swath Mapping or ALSM) - a technology that employs an airborne scanning laser. The above image is from NOAA is of the World Trade Center ground zero on September 27, 2001. LIDAR imaging can render topograhic areas dense in vegetation.
Black and White Aerial Photos were used in teh early part on the 20th century. This type of mapping is raster imaging. The image above from the New Zealand Electronic Text Centre shows part of the dock area at Dunkirk where the German invasion fleet was concentrated. Dock buildings round the upper of the two docks shown have been completely destroyed and unloading cranes smashed. Damaged barges can be seen near the entrance of the upper dock where a number of others have been sunk.
