Bruise, scratch, decay and insect pest are the most common defects in thin skin fruits. To detect these defects with the
use of infrared thermography, the mathematic model of spherical shaped fruits based on heat transfer theory is developed
and a further classification research is carried out. By using a commercial infrared thermal imaging camera, the radiation
temperature on the fruit surface of various defect tissues can be observed after thermal excitation. Both model and
experimental studies reveal that the cooling rate of specimen is related to the fruit thermal properties and fruit size, and
the logarithmic temperature is directly proportional to detection time. Bruise has a steeper cooling slope than other
defects and sound tissue, while insect pest performs poor during the fruit cooling range from 29 oC to 24 oC, this may be
related to their more cracked wax layer and higher amount of lenticels.
It is important to study the interaction effect between laser and photoelectric detector. In most of the laser detecting systems, laser must irradiate the photoelectric detector. The detector will be saturated or damaged easily if the fluence of the laser is higher than the saturation threshold of the detector. Now, many photoelectric detectors are used in space. To achieve their interaction, "Cat’s eye" effect is applied to find and locate the remote aerial detector by laser. The possibility and mechanism of disturbance to remote aerial detector induced by laser are analyzed, and the factors of influence are also analyzed. The fluence of laser on the photoactive area of remote aerial detector is estimated. With two samples of CCD and TV tracking system, the mechanism of soft damage to CCD and TV tracking system induced by laser are introduced. The saturation of CCD and crosstalk of CCD are the main reasons of disturbance. When the tracking system is used in wave-door tracking mode, it will lose its tracking target if the saturation or crosstalk of CCD can enter into wave-door. At last, the influence to disturbance induced by atmosphere effect is also analyzed.