Rejected originally on basis it was spam.
Date: Mon, 03 Sep 2007 00:58:34 +0000
To: [email protected]
From: VR2BrettGraham <[EMAIL PROTECTED]>
Subject: Re: [Elecraft] K3 NB
K6DGW replied to N6RY's apparently somewhat-not-serious
response:
> How about some simple countermeasures (for a future firmware release):
> Blank, then transmit an equal length pulse (on a clear frequency, of
> course), with optional automatic ID every N minutes.
If it's anything like the Russian woodpecker, it likely transmits a
string of bits using a psuedo-random code in each "pulse', and the radar
RX can separate it's own echoes from fake ones.
One suggestion we had from RAAF's 1RSU (VK air force's unit
that runs their OTHR systems) early on was that the Hainan
woodpecker might be a comms system.
A constant pulse train on HF would be hard to use to convey
any data with either amplitude or phase. And no one has yet to
see anything but the pulses that make the woodpecker sound.
The reason why we could force the Russian woodpecker to
move back in the late 70s/early 80s was because they
apparently could not differentiate between echoes from their
pulses & anything else that looked like them.
Since then, technology has come a long way & it is easy to
imagine the computing horsepower & DSP now available
would make most active countermeasures useless.
And in practice, that seems to be the case.
I get the impression here that OTHR isn't a problem in NA. You
lot are very lucky then. In ITU Regions 1 & 3, it is a _big_
problem.
73, VR10BrettGraham/p.
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