Methods and systems are described herein for high-speed observation and recognition of objects or persons within a controlled area using 3D image data and tomography, stereo-photogrammetry, range finding and/or structured illumination. A wide area security system may comprise multiple pairs of 3D sensors surrounding a controlled area. Using at least two pairs of 3D sensors and a first 3D data collection technique such as tomography, a zone of interest within the controlled area is detected. Using at least one pair of 3D sensors and a second 3D data collection technique such as structured illumination, more 3D image data related to an object of interest is collected. The 3D image data may be compared to data representing known objects and used to identify an object of interest. Methods for fast processing of 3D data and recognition of objects of interest are also described.