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IN A TELEVISION SYSTEM, it is through the agency of the scanning process that the two-dimensional space function, comprising the image at the camera, is transformed into a one-dimensional time function for transmission; at the receiver, the reverse procedure is used to recreate the image. Ideally, the velocities of the scanning apertures should be uniform in both the horizontal and vertical directions; furthermore, these two directions of motion should be orthogonal at all points in the raster. Finally, the ratio of the maximum excursions of the apertures in the horizontal and vertical directions of the transmitted picture, i.e., the aspect ratio, should be the same at both the transmitter and receiver. If there is departure from any of these conditions, geometric distortion results (except in the trivial case where the transmitter and receiver happen to contain compensating errors). It should also be noted that even in the case where the scanning aperture itself meets the desired conditions, the optical systems may contribute to the total geometric distortion; this applies to either the transmitter or receiver.
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This report presents an economic and engineering analysis of direct broadcast satellites' (DBS) prospects for competing with cable television systems in the United States and, hence, alleviating the need for extensive reregulation of cable. The authors examine relevant technologies, some implications of the technological advances that can reasonably be foreseen, and the comparative costs of DBS and cable systems. They also consider the prospects for second cable, wireless cable, satellite master antenna cable systems, and home satellite dish systems as alternatives to DBS systems to assess whether they hold more promise than DBS as competitors to cable. They then address a number of policy issues, including the effects on local broadcasting, whether cable operators should be permitted to buy into DBS systems, and the problems posed by access to programming. The findings suggest that high-power DBS systems are more likely than are the alternatives to provide widespread competition to cable. However, the outcome is dependent on several interrelated economic and technical factors, including the cost of earth terminals, the degree to which video compression reduces the per-channel cost of satellites, and the level of operating expenses including program acquisition.
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Direct broadcast satellite television --- Law and legislation
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Broadcasting --- Cable television --- Direct broadcast satellite television --- Broadcasting. --- Cable television. --- Direct broadcast satellite television. --- United States.
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Broadcasting --- Cable television --- Direct broadcast satellite television --- Broadcasting. --- Cable television. --- Direct broadcast satellite television. --- United States.
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