clouds exhibit consistent identifiable signatures in their growth and movement using the present invention 39 s discovery that the tracking clusters for various types of physical phenomena of interest e g a smoke cloud exhibit consistent identifiable signatures in their growth and movement one is able to develop an analysis algorithm for analyzing such captured images so as to identify the occurrence of such phenomena of interest step i of fig2 depicts acquiring a next frame or image the analysis scheme of the present invention then involves the identification of a blob of interest as depicted in step ii at its simplest form this step could be achieved by for example searching a captured digital image for a group of pixels with consistent brightness changes once such a blob has been identified the analysis scheme checks as to whether this new image 39 s blob should be chronologically associated on the basis of the likelihood of the existence of smoke in the monitored area with any of the blobs that are being tracked from earlier images this is achieved by checking for spatial overlap between this new blob and the database of tracking clusters identified from the prior images as depicted in steps iii and v in case of such overlap the blob is appended to the appropriate tracking cluster as depicted in steps iv and vi if no such overlap exists this blob becomes the first of what may be a sequence of blobs that will make up yet another cluster clusters that have no new blobs added to them are assumed to no longer be active and are.