We have developed a technique that enables us to acquire images
of high speed (>60 Hz), repetitive thermal phenomena. A prototype
system has been built and used successfully to image events occurring
at frequencies as high as 1 kHz. The theoretical upper frequency limit for
the system is 4 kHz. The time required to acquire images with this technique
is proportional to the frequency of the event of interest. The prototype
system consists of an off-the-shelf imaging radiometer (Inframetrics
lR 600), a microcomputer, and specially developed hardware and software.
In this paper, we describe the theory and operation of the system.