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This web site is intended to provide programmers, and anyone else who might
be interested, with technical information about the different SSTV modes used by
The term SSTV is derived from the name "slow scan
television". In the early days small black and white images were
sent, and even short multi-frame moving image sequences were tried successfully.
With modern equipment, single images in full colour with medium or high definition are the
norm. The term "television" is therefore a misnomer, but the
name SSTV seems to have endured.
These pages are primarily concerned with
so-called analogue SSTV in which the picture information is sent by means of a
frequency modulated audio sub-carrier. The sub-carrier may be transmitted
by single side band (SSB) equipment, frequency modulated equipment (usually at
VHF or UHF), or even amplitude modulated (AM) transmitters.
picture transmission using multiple phase and amplitude modulated sub-carriers (DRM)
is not covered at present.
The main objective of this web site is
to provide a public source of reference information so that SSTV programmers can implement these modes to a common standard. Although SSTV developers might have
different ideas about the way in which an SSTV program should interface with its
users, it makes little sense for different programs to use different parameters
for the same modes. The image quality should be the same irrespective of which
SSTV workstation you opt to use. It should be noted, however, that these pages
do not aim to lay down rigid specifications. The parameters given here are not
necessarily correct, and anyone who has more accurate information is welcome to
submit details. It should also be noted that some SSTV developers
regard the specification of the modes which they have developed as their own
intellectual property. If anyone objects to the inclusion of any
information they are likewise invited to comment.
24 January 2008