Topband: [Bulk] Re: K1N DQRM Tracking Project

[Grant Saviers]

Adding on, 200Ksps to 1 Msps 8bit (and more) A/D convertors are good 
enough and cheap if one can store the data stream for a few seconds or 
so and the stations are time sync'd to record.  Then correlate the 
wavefront to accurately resolve the time.  A bonus is the transmitter 
signature is captured for the "gotcha".   Saving the data at those rates 
to flash with an Arduino/PIC like processor is the hard part.

Grant KZ1W

On 2/10/2015 4:30 AM, Tim Shoppa wrote:
> 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 at 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 at contesting.com <javascript:;>] On
>> Behalf Of Jim
>> Garland
>> Sent: Sunday, February 08, 2015 9:08 PM
>> To: 'Lee K7TJR'; Topband at 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 at contesting.com <javascript:;>] On
>> Behalf Of Lee
>> K7TJR
>>> Sent: Sunday, February 08, 2015 4:47 PM
>>> To: topband at 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 >
>>>
>>> _________________
>>> _________________
>>> Topband Reflector Archives - http://www.contesting.com/_topband
>> _________________
>> Topband Reflector Archives - http://www.contesting.com/_topband
>>
>> _________________
>> Topband Reflector Archives - http://www.contesting.com/_topband
>>
> _________________
> Topband Reflector Archives - http://www.contesting.com/_topband
>