Appendix A

Glossary

Background Temperature

The temperature of the surroundings, as seen by the target object. In practical terms, this is often considered to be the ambient or room temperature. When outdoors, this can be a very difficult value to estimate, due to the effects of very hot (the sun) and cold (clear sky) objects. By paying careful attention to the location of and direction from which an object is photographed, the effects of very hot and cold objects in the background can often be minimized.

Blackbody

A blackbody is a theoretically ideal radiator and absorber of energy at all electromagnetic wavelengths, i.e., a completely non-reflective object. The term comes from the fact that a cold blackbody appears visually black.

Color Palette

Color representation of the temperatures (temperature scale) in a displayed image.

Electro Static Discharge (ESD) event

A single-event, rapid transfer of electrostatic charge between two objects, usually resulting when two objects at different potentials come into direct contact with each other. ESD can also occur when a high electrostatic field develops between two objects in close proximity.

Emissivity

The ratio of the actual emitted radiance to that of an ideal blackbody at the same temperature. In practical terms, this means that objects with lower emissivity will be more affected by background radiation.

FAT or FAT16 file format

Stands for File Allocation Tables. Most computer operating systems store computer files by dividing the file into smaller pieces and storing those pieces in separate clusters of a hard disk, floppy disk, or Compact Flash memory card. The FAT file system allows an operating system to keep track of the location and sequence of each piece of a file, and also allows the operating system to identify which clusters are unassigned and available for new files. When a computer user wants to read a file, the FAT file system also reassembles each piece of the file into one unit for viewing.

A-1