ABSTRACT
There are many factors to consider when ordering imagery. These factors include the purpose of the imagery, the size of the area requiring analysis, the amount of detail that is required, and the cost of the imagery. The answers to these questions will determine, for example, whether the imagery is color or black and white, if it is on film or digital, the available scales, whether it is from an aircraft or satellite, and whether it is in the visible range or thermal or microwave (radar) portion of the spectrum. There are several providers of imagery and image databases that are available once it is known what type of imagery is required. The principle sources and web sites are given.
