| abstract |
One or more time delay and integration camera assemblies (A) are mounted in a housing (100) which is rotated by a motor (40, 106) relative to a vertical axis. A tachometer (44) monitors the rotation of the camera assembly about the axis and produces timing signals in accordance with the speed of rotation. Within each camera system, a zoom lens (10) focuses light from a field of view (12) on a light sensitive element array (14). A control circuit (24) is clocked by the timing signals to move vertical lines of data values (20) along the array (14) to a shift register (22). The shift register (22) an analog video processing circuit (32) converts the lines of data into an analog video signal. An analog-to-digital converter (62, 110) converts the analog video signal into digital pixel values which are stored in a panoramic memory (66). In the preferred embodiment in which the panoramic image represents 360° of rotation, the panoramic memory stores an image representation that includes a series of vertical lines of data which span a full 360°. With a light sensitive array which has 244 lines each with 600 elements and lens system that monitors a 0.1° field of view, i.e. a field of view that spans 1/10th° along the horizon, the video signal is a series of vertical data lines with no frame breaks. About 880,000 vertical lines of data are generated in 360° of rotation. Thus, the panoramic image memory stores an image which is about 880,000 x 600 pixels. A memory access circuit (70) and a scan converter (72) selectively withdraw portions of data from the panoramic memory to produce video signals that are converted into an array of different and selectable displays. |