Building Earth Observation Cameras

55Imaging Optics

very tight and cannot be realized in practice then the design is not practicable.

Putting tight tolerances in the optical design, even if it is achievable, increases

the cost of fabrication. The designer should also look for ease of fabrication of

the element, availability of the material, and its cost. Therefore, a judicial com-

promise has to be made between optical performance and other aspects such

as material choice, limits on tolerances, and so on so as to realize the optical sys-

tem meeting the laid down specications within the schedule and budgetary

constraints. Once the design is frozen, the next task is to realize t ...