Document Type : Research Paper

Author

• Alireza Owsati

Abstract

Photometric remote sensing systems are capable of detecting visible and electromagnetic near-infrared regions (0.4<l<0.9). Other regions of the electromagnetic spectrum with longer wavelengths can potentially be useful for remote sensing purposes. Unfortunately, conventional glass lenses and sensitive photo layers are not able to detect and record this region of electromagnetic spectrum.
Air scanners are significantly different from aerial cameras because air scanners can collect energy from the ground below as scanning lines, each of these lines making a right angle with flying path. Figure 1 indicates sweeping by means of a rotating mirror while the entering radiation conductor faces toward the detector.
 
The scanner detector is comparable to the sensitive layer of conventional cameras. Their goals are focused on the discovery, measurement and
recording of electromagnetic energy.
They are, compared to film’s sensitive layers, sensitive to wavelengths longer than 1m, such as the infrared and microwave parts of the electromagnetic spectrum. Air scanning systems can be categorized as active or inactive scanning systems.