Wouldn't the timescale based on leading edge TOF, be the rise time of the
pulse?
For triangulating on lightning bolts by TOF, rise time doesn't seem to be a
limiting factor because lightning bolts are fast enough to be broadband
across many MHz.
But for ham CW transmissions (which would include many tuner-uppers as well
as the kc cop QRM) rise time is milliseconds. A millisecond in time, is 200
miles, and I would expect a half dozen hams with beams or directional
arrays correlating their headings would be superior.
I have no doubt NSA and maybe FCC can avoid rise time limits through true
interferometry.
Tim N3QE
On Tuesday, February 10, 2015, Charlie Cunningham <
charlie-cunningham@nc.rr.com> wrote:
> Actually ,Jim, the velocity of propagation of radio waves (or light waves)
> in free space is about 1 foot/nanosecond, NOT 1 foot per microsecond. It
> would seem to me that one needs to have a measure of directivity as well a
> s
> time, an the time factor might boil down to phase difference measurements.
> Thinking of applying all of this to something complex like SSB modulation
> sounds pretty messy. And a lot of the interference originates outside our
> borders, so I don't see who would be the enforcement body?
>
>
> Just my $0.02
>
> 73,
> Charlie, K4OTV
>
>
> -----Original Message-----
> From: Topband [mailto:topband-bounces@contesting.com <javascript:;>] On
> Behalf Of Jim
> Garland
> Sent: Sunday, February 08, 2015 9:08 PM
> To: 'Lee K7TJR'; Topband@contesting.com <javascript:;>
> Subject: Re: Topband: K1N DQRM Tracking Project
>
> I agree, Lee. Locating a DQRM station involves accurately time stamping the
> arrival time of their transmissions, at (at least) three receivers at known
> locations. Once the arrival times are known, one can use trigonometry to
> calculate the location of the interfering station. Since radio waves travel
> about one foot in a microsecond, and since a microsecond is an eternity by
> modern frequency counter standards, it should be possible to get very
> precise locations. The city block mentioned earlier should be readily
> doable. Of course, this requires that the three receivers be able to copy
> the DQRM ground wave signal, since the arrival times would otherwise be
> dependent on ionispheric reflections. More than three receivers would
> result
> in more accurate position measurements.. There's no need to use direction
> finding equipment, which are very low resolution by comparison with time
> measurements..
>
> I'm no authority on FCC rules, but I'm under the impression that
> deliberately interfering with other licensed transmissions is against the
> law. Every month or so, the FCC nails some renegade ham or CBer for doing
> just that. Probably just publicizing the callsign of the culprits would be
> a
> large deterrant for all but the most sociopathic offenders.
> 73,
> 'Jim
>
> > -----Original Message-----
> > From: Topband [mailto:topband-bounces@contesting.com <javascript:;>] On
> Behalf Of Lee
> K7TJR
> > Sent: Sunday, February 08, 2015 4:47 PM
> > To: topband@contesting.com <javascript:;>
> > Subject: Re: Topband: K1N DQRM Tracking Project
> >
> >
> > Greetings top-band community,
> >
> > Interestingly enough the technology exists right here in our own Ham
> > community that could go a long way toward finding these DQRM culprits.
> > There are some beam forming arrays that operate with SDR
> > technology where a recording can be made of a target bandwidth and
> > later reviewed
> with
> > beam forming techniques to DF using a peak or notch completely after
> > the event has long gone. In fact directional and strength data can be
> > stored
> in
> > perpetuity.
> > So my comment is don't underestimate the ability to identify these
> idiots.
> > Being able to actually replay an entire contest and do a strength
> > and directional analysis in a narrow bandwidth after the fact to me is
> > the ultimate receiving system.
> >
> > Lee K7TJR OR
> >
> >
> > <I'd be interested in some project like that, but I'm afraid it would
> > only get to a general area. With maybe 3-10 idiots at any one time,
> > and the
> 3-10
> > active at any time probably varying every hour, it might be pretty
> > tough
> to
> > do anything meaningful.
> >
> > Since attention is what they want, I wonder if this effort would not
> > encourage participation in jamming at a faster rate than it solves
> anything?
> >
> > Has anyone ever looked to see if there is any correlation between
> > intentional QRM and the DX station spreading people over a wide swath
> > of
> the
> > band? More than once, I've heard people intentionally threaten to QRM
> > DX because they were POed that their QSO was interrupted by a pileup.>
> >
> > <73 Tom >
> >
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