Vislink HDT-1000, Руководство пользователя и техническое руководство

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Page 55
HDT-1000 User and Technical Manual
Glossary
Term Definition
1080i 1080i is a standard HDTV video format.
1080 represents 1080 lines of vertical resolution and the letter i represents
“interlaced” or non-progressive scan. 1080i usually assumes a wide screen
aspect ratio of 16:9, implying a horizontal resolution of 1920 pixels and a
frame resolution of 1920 x 1080, or 2.07 million pixels.
16QAM 16-state Quadrature Amplitude Modulation
The signal [video + audio] is imposed onto the 70 MHz carrier by varying
both the phase and the amplitude of the signal while keeping the frequency
constant. There are 16 possible combinations of phase and amplitude that
can be used to carry information.
8 PSK 8-Phase Shift Keying
64QAM 64-state Quadrature Amplitude Modulation
The signal [video+audio] is imposed onto the 70 MHz carrier by varying
both the phase and the amplitude of the signal while keeping the frequency
constant. There are 64 possible combinations of phase and amplitude that
can be used to carry information.
720p 720 represents 720 lines of vertical resolution and the letter p represents
non-interlaced or progressive scan. When broadcast at 60 frames per
second, 720p features the highest temporal [motion] resolution possible
under the ATSC standard. Progressive scanning reduces the need to
prevent flicker by filtering out fine details, so spatial [sharpness] resolution
is much closer to 1080i than the number of scan lines would suggest.
ASI Asynchronous Serial Interface
A serial communications interface operating up to 270 Mbit/sec. Generally
used in field news-gathering operations.
ATSC Advanced Television Systems Committee
The group that developed the ATSC digital television standard for the US
and other countries.
BER Bit Error Ratio
The Bit Error Rate is the percentage of bits that have errors relative to the
total number of bits in the signal. The rate is an indication of how often a
packet or other data unit has to be retransmitted because of an error.