DESIGN STEPS TO TEMPERATURE AND PRESSURE INSENSITIVE OPTICAL SYSTEMS FOR DIGITAL AERIAL IMAGING


Yilmaz O., Selimoglu O., Ucar B., Sengul O.

ISPRS Istanbul Workshop on Modeling of Optical Airborne and Spaceborne Sensors, İstanbul, Turkey, 11 - 13 October 2010 identifier

  • Publication Type: Conference Paper / Full Text
  • City: İstanbul
  • Country: Turkey

Abstract

Imaging from air has evolved from film cameras to digital cameras over the last years. Here we give the design steps of an aerial objective lens for a given CCD sensor. Matching to the pixel pitch of the sensor and providing desired field of view according to CCD size are traditional steps. Besides these, to minimize the environmental effects, design should be insensitive to the temperature and pressure as much as possible. Performance of a lens, designed at room temperature and pressure will be degraded if temperature and pressure changes. This is firstly caused by the change of relative refraction indices of materials, and secondly thermal expansion or contraction of both glass and housing materials. Here it is shown that according to the environmental working conditions, custom designs are necessary to provide images with sufficient resolution up in the air. These design principles are also valid for the fore optics of spectroscopic imaging tools. Since designs are insensitive to temperature and pressure, working environmental range is wide.