I wonder how precise and definite that TDOA was? gh
re TDoA
Even though I do not agree one hundred percent with the TDoA direction
finding procedure result of the Kiwi SDRs worldwide, here is the
result of 4 x Kiwi SDR common work procedures together last 17.30 UT.
Close to the Maiac MDA site, there are also
some 'seldom strange radio relays'
via nearby Romanian Bacau Galbeni bcast center site...
In my amateur radio life or shortwave listener time span
over the past 60 years, a lot of operation modes were in use,
once like TDoA operation precisity has rarely been so unreliable.
It takes around 4 ... 5 strong Kiwi server signals with good antenna
equipment and little main power interference
and greater distance more than 1000 kilometers likely,
for accurate measurement ...
and still of doubts remain.
... and you need always time to set up TDoA measures
via different combined Kiwi server location examples.
wb
btw. Roger told some tips last summer:
Because I just saw a TDoA bearing in "AM":
1.) The central Kiwi (to control the others) does not have to be part of the
TDoA capable network.
2.) It doesn't matter how good or bad the station (that you want to locate)
can be heard.
3.) All you have to do is load the TDoA plugin on the central KIWI and
select the corresponding TDoA-capable Kiwis (exact time base).
These must (of course) be able to receive the relevant station well. This
can be checked (in each case) with the loudspeaker symbol.
4.) The best results are obtained on the basis of samples in the "IQ raw
format". So you should always select the "IQ" format on the central KIWI,
and not AM or S-AM. This also applies to the direction finding of signals in
SSB. A selection of signals only 3 kHz wide could then be made via the
passband.
The type of modulation or the digital mode does not matter.
Identical patterns are (only) searched for in the samples and the respective
time offset is determined. Possible starting points are then plottet on the
map from the differences in transit time.
----- Original Message -----
From: Glenn Hauser via Hard-Core-DX
Sent: Saturday, February 12, 2022 3:13 AM
Subject: [HCDX] Glenn Hauser logs February 11-12, 2022
UNIDENTIFIED. 5910, Friday Feb 11 at *1730-1800.7*, open carrier dead
air except for some hum, equally good into UTwente at S9/+15 and into
Kuwait SDR at S8-S9. Checking out the mystery in WRTH Updater which
says new unknown clandestine in Farsi for Iran, Fridays only, site
unknown too. At 1747 a trace of modulation, but maybe cross- or QRM.
1748 two brief noise bursts could be QRM or failed attempt to make a
connexion. Did not even try TDOA since no modulation for delay timing.
Evitable ACI from weak 5915 probably Zambia, and continuous CW on 5916
which EiBi lists as RCV, Russian Navy. I reminded the WOR iog of this
an hour earlier; Hansjoerg Biener and Zacharias Liangas report the
same results on 5910. Shortly Wolfgang Büschel replied:
``MOLDOVA 5910 / 5909.999 kHz ONLY CARRIER total empty channel from
late CRASH start 1730:51 UT, to TX-OFF switch at 1800:37, some 100 /
200 / 300 Hertz apart distance strings on both sidebands.
Kiwi-server TdOA function showed signal origin of
Radioteletsentr (PRTC) transmitter Grigoriopol Maiac
in Russian speaking community Pridnestrovie oblast.
S=9+5dB or -69dBm signal in Kuwait Kiwi remotedly,
S=9+10dB or -64dBm in western Europe and Athens Greece Kiwi_sets.
73 wb df5sx``
I wonder how precise and definite that TDOA was? Ivo Ivanov, Bulgaria
shortly responded elsewise: ``Tx hum is same as of RRTM Telecom
Tashkent [UZBEKISTAN] previous day at same time but on 5925 kHz for
Sae Nala`` (Glenn Hauser, OK, WOR)
This report despatched at 0213 UT February 12
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