Page 284 - Satellite Communications, Fourth Edition
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264 Chapter Nine
Figure 9.8 (a) Conventional analog TV broadcasting of the video and aural signals; (b)
generation of a satellite uplink signal for analog TV.
As mentioned previously, three color TV systems—NTSC, PAL, and
SECAM—are in widespread use. In addition, different countries use
different line frequencies (determined by the frequency of the domes-
tic power supply) and different numbers of lines per scan. Broadcasting
between countries utilizing different standards requires the use of a
converter. Transmission takes place using the standards of the coun-
try originating the broadcast, and conversion to the standards of the
receiving country takes place at the receiving station. The conversion
may take place through optical image processing or by conversion of
the electronic signal format. The latter can be further subdivided into
analog and digital techniques. The digital converter, referred to as
