1. A system for multi-source multi-modal activity recognition in conducting aerial video surveillance comprising: from a moving platform, detecting and tracking, with a video imager, multiple dynamic targets, wherein the detecting and tracking comprises differencing registered frames; using high pixel difference point features to establish correspondences between other points in a previous frame; and clustering point-velocity pairs into motion regions assumed to be individual targets; recording analyst call outs or chats, and appending said analyst call outs or chats to a file; representing full motion video (FMV) target tracks and chat-messages as graphs of attributes; associating said FMV tracks and said chat-messages using a probabilistic graph based mapping approach; detecting spatial-temporal activity boundaries; categorizing activity of said detected multiple dynamic targets; and on a display, presenting said activity.