archive: SETI NAS Technical Reports

SETI NAS Technical Reports

Dave Barstow - SSL ( davedoes@magicnet.net )
Wed, 09 Sep 1998 02:50:41 -0400

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This link may be of interest to those of you working on signal detection
software.

(http://science.nas.nasa.gov/Pubs/TechReports/RNRreports/dbailey/RNR-90-002/RNR-90-002.html)

NOTE: In case you are wondering why you have not heard much from me or
why there have been no updates to the SSL web-site the answer is that I
have been EXTREMELY busy lately. I will be getting married and
inheriting two boys ages 10 and 15 soon. We will be moving to the
Asheville, NC area in late December. Once we are settled in our new
home my SETI activities should increase dramatically. Stay tuned....

Dave

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<title>NAS Technical Reports</title>
<H1>NAS Technical Reports</H1>

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<h2>Efficient detection of a continuous wave signal with a linear frequency drift</h2><p>

<pre>Paul N. Swarztrauber and D.H.Bailey<br>
RNR Technical Report RNR-90-002<br>
January 24,1990
</pre>
<h2> Abstract</h2><p>
An efficient method is presented for the detection of a continuous
wave (CW) signal with a frequency drift that is linear in time.Signals of this
type occur if the transmitter and receiver are accelerating relative to one
another, e.g. transmissions from the Voyager space craft. We assume that both the
frequency and the drift are unknown. We also assume that the signal is weak compared
to the Gaussian noise. The signal is partitioned into subsequences whose discrete
Fourier transforms provide a sequence of instantaneous spectra at equal time intervals.
These spectra are then accumulated with a shift that is proportional to time.When the shift
is equal to frequency drift, the signal to noise ratio increases and detection occurs.
In this paper we show how to compute these accumulations for many shifts in an efficient
manner using a variant of the FFT.Computing time is proportional to <cite>L log L </cite>
where <cite>L</cite> is the length of the time series.Computational results are presented.
<p>
A hard copy version of this report can be ordered from the
<a href="/Services/Forms/Document.Request.Form.html">
ACSF/NAS Documentation Center</a>.

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<B>Updated:</B> February 24, 1998
<br> <I><B>WebWork:</B>
<a href="mailto:keslar@nas.nasa.gov">
Amie Keslar</A>
<br> <b>NASA Responsible Official:</b>
Lisa Reid</A></I>

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