open letter to the seti institute

SETI
Is the present form of the search for extraterrestrial signals likely to
succeed?
I attach, below a letter sent to the SETI Institute.

Dear Sir,
I see that you are attempting to find carriers in your search for
extraterrestrial signals. I have a little knowledge of radio and TV
transmission theory. Our most modern radio and television signals do not
emit a carrier. The SSB signals (Single Side Band) have no detectable
carrier and will not be detected by your search. The Mpeg signals sent by
digital television also have no carrier. FM when used properly also does
not have a carrier and is equivalent to SSB.
These signals do have something in common, they contain repeated sequences
of data. If you want to detect this sort of signal below noise level (as it
will be) then a broad band (20KHz for sound and 4MHz for pictures) detector
is needed. The noise is then recorded and compared with itself in sections
of various periods with previously collected noise within the same band.
The waveform of the noise over periods of 1 sec, 1 minute, 1 hour, is
compared with similar periods over the total length of time of the recoded
data.
If you compare each section (effectively by sliding the signal recording
along a copy of itself and looking for autocorrelation
(=Integral(S(t)XS(t-p)Xdt)) (over t now to t start) where p is the time
shift. Alter p and plot the autocorrelation against p. For a significant
signal there will be peaks in the graph, these may be at regular intervals.
This interval could mean something and will be the first clue of an
organised signal. Over a long integrating time, signals below noise level
would be detectable.
I hope this reaches the right people and is acted on. I see no hope for
the project if you only look for carriers. You do have plenty of past data
to analyse, so I suggest that this is the place to start.
Chris,