Comparison of optomechanical and focal plane array methods for enhanced temporal resolution

摘要

Abstract: Temporal aliasing is a problem common to all video imaging systems. Infrared video systems are particularly susceptible because of the relatively low (30 Hz) RS-170 frame rate. We have developed two systems which compensate for the effects of aliasing, and allow above-frame-rate events to be imaged. An optomechanically based system utilizes an unmodified commercial imager (Inframetrics IR 600) and allows images of repetitive thermal events at frequencies up to 4 kHz to be acquired. It acquires data selectively using a line-by-line scheme which compares the motion of the camera's horizontal scanning mirror to a reference signal correlated to the event of interest. The resulting images have an effective integration time of 125 microseconds. The focal plane array system is based on a 160 $MUL 244 PtSi detector operating at the standard 30 Hz frame rate. Frame integration time is variable to a minimum of 100 microseconds. Data can be acquired synchronously with respect to an external reference signal derived from the target. The systems will be compared, and relative merits of each will be discussed.!4