| Popis: |
Land-based infrared (IR) video cameras are used to detect heat plumes expelled at the initial stages of a forest fire around the clock. Two promising methods which are based on characterization and identification of IR temporal heat plume signature are discussed. The first method uses the difference of video frames from two co-located cooled long-wave infrared (CLWIR) and cooled mid-wave infrared (CMWIR) cameras. Processing the sequence of CLWIR and CMWIR frame differences allow for effective extraction of the heat plume’s “flickering” features, which are characteristic to the early stages of a forest fire. The second method involves spectral analysis of CLWIR and CLWIR videos followed by design and implementation of a pertinent temporal filter to detect fire heat plume signal. Spikes in the Fourier transform spectra of CLWIR and CLWIR videos are identified and attributed to various dynamic features in the scene being monitored. A subsequent digital bandpass filter is implemented to detect the presence of fire heat plume by isolating and identifying its main spectral components. Further experimentation is needed to optimize performance and assess sensitivity to observation height, viewing angle, range, climate, and day/night time operation. |
