An FPGA-based dual-wavelength correlated imaging system with flexible frame rates for temperature distributions

A correlated imaging system with a flexible frame rate was proposed and fabricated on a field programmable gate array for the acquisition of temperature images. Real-time images of temperatures are reconstructed on chip at a frame rate of 10 Hz, and higher rates up to 1280 frames per second are also achieved in the case of resolution sacrifice. The compressive sensing method enables the flexible frame rate for dynamic temperature images. An incandescent filament was imaged and compared using the proposed imaging system and a commercial charge-coupled device (CCD) camera. Reconstructed images of temperature distributions agree well with those from the camera in the range from 1500 K to 2500 K. Moreover, the proposed system captures the excitation frequency of an acoustically excited flame by varying the frame rate. The simple structure and flexible frame rate provide an alternative to dynamical temperature imaging, especially in cases where the common CCD camera fails to work due to its slow response.