摘要 |
<p>A television station which receives remotely originated signals via relay satellite can time its local sync and burst signal generators with a standard reference frequency which it itself sends to the relay satellite and receives back from the relay satellite. This permits locally originated signals timed by the local sync and burst signal generators to be synchronized with the remotely originated signals to good approximation, despite time delay variations of the remotely originated signals caused by variations of the relay satellite orbit, permitting an adjustable delay line to then be used to compensate remnant delay variations. Consequently, cross fading or other special-effects mixing between locally and remotely originated programs is facilitated.</p> |