mercoledì 20 dicembre 2017

HF Fax / JAPAN METEOROLOGICAL AGENCY-TOKYO, JMH

Japan Meteorological fax received via remote sdr ( KiwiSdr ).

Facsimile test chart

Facsimile test chart

500HPA HEIGHT, VORTICITY PROGNOSIS (24HOUR ) and SURFACE PRESSURE, PRECIPITATION PROGNOSIS 0440 AWJP 00 COASTAL WAVE ANALYSIS (24HOUR )

Meteorological satellite picture


850HPA HEIGHT, TEMPERATURE, DEW POINT 0320 ASAS 00 THE FIRST RETRANSMISSION OF 0240 DEPRESSION


More info about Japan Metereological Agency

mercoledì 6 dicembre 2017

M42


Russian diplomatic station heard some weeks ago on HF.


Fsk modulation with a symbol rate of 100 Bd and 500 Hz shift.


The bitstream after demod shows a typical 7-bit structure (5 bit + 1 bit START and 1 STOP bit).


By removing the start and end bits, we obtain sequences of 10 groups of 5 letters each as shown in the figure.


Fsk transmission followed by op chat in morse code.

venerdì 24 novembre 2017

Inmarsat D+ / Inmarsat's satellite paging system

Inmarsat D+ paging system received yesterday night on L-Band. This is a signal downlink from satellite.


The symbol rate is 4 symbols/sec and 5 bits / symbol ( 20 bps ).


Modulation is a 32-MFSK


"The main use of this technology nowadays is in tracking trucks and buoys and SCADA applications".





mercoledì 8 novembre 2017

802.15.4 IoT - Internet of Things...


"IEEE 802.15.4 is a technical standard which defines the operation of low-rate wireless personal area networks (LR-WPANs)". This signal and many other signal like this are easily recevible in our house with a simple antenna. Probably this is a ZigBee device working on 868 MHz ( european standard frequency ).


Modulation and symbol rate.


Burst sequence.


Packet frame: 199 bits: "32 bits synchronization + 8 bits packet delimiter + 7 bits PSDU lenght + 1 bit reserved service" followed by PSDU ( variable lenght from 0 to 127 bytes )


in the next post a more in-depth analysis.

martedì 7 novembre 2017

Nokia Adaptive Message Terminal

Another interesting signal heard some days ago.


Looks like an FSK modulation....


Symbol rate: 301 Bd


Shift ~ 755 Hz Yes ! it's a Fsk modulation...



Bitstream after demod.


Bandwidth: ~950 Hz

...yes, it's a Nokia Adaptive Message Terminal...

More technical info:

- Antonio Anselmi's blog
- radioscanner
- SigidWiki.com

S4538, FLSU Asynch Request


Short burst, a BW5 waveform ( STANAG 4538 ).



FLSU Asynch Request.

Short encrypted data


A short FSK transmission transporting encrypted data.


Looking the bitstream is visible a KG84 encryption.

sabato 28 ottobre 2017

GMSK 6500 Bd

Heard today on 16248 KHz.....







Tks to "linkz" for the informations.

TADIRAN AutoCall

Looking in my archive i found this interesting system. AutoCall is a proprietary function of the Tadiran HF-6000 radio systems.


The signal is composed of two parts: a single tone followed by an MFSK-4.


Symbol rate: 125 Bd


MFSK modulation : 4 tones, shift 300 hz



Bitstream after demod ( 2 bits / symbol ).

giovedì 26 ottobre 2017

D-STAR / streaming audio DV mode


This is a fragment of a D-STAR transmission.


Symbol rate : 4800 Bd


Modulation: GMSK



Bitstream after demod:



I found a structure frame of 72 bits + 24 bits. The first 72 bits constitutes the voice frame and the last 24 bits constitutes the "data frame" ( 96 bits for each slot ).


This is the D­STAR radio frame structure in DV mode.



mercoledì 25 ottobre 2017

S4285 / KG84

Voice/PSK traffic spotted this morning.




ACF: 106 ms ( in this case STANAG-4285 ).


Bitstream after demodulator, packet frame lenght: 64 bits.


Header structure: 64 bits ( kg84 ) followed by 128 bits key ( 64 bits x 4 + 64 bits x 4 ).

lunedì 23 ottobre 2017

MIL188-141A / UKE304 / XSS


Aircraft UKE304 requesting to XSS, RAF base in UK, Meteorological Air Report...




.....

[2017-10-23 11:58:05] [NORMAL MODE][TO][?][TO][?][CMD AMD][EGVN 230850Z 21005KT 9999 OVC008 13/12 Q1016 ][TIS][XSS][EOM]
[2017-10-23 11:58:16]
[2017-10-23 11:58:16] [NORMAL MODE][TO][?][TO][?][CMD AMD][TEMPO 6000 -RADZ SCT006 ][TIS][XSS][EOM]
[2017-10-23 11:58:42]
[2017-10-23 11:58:42] [NORMAL MODE][TO][?][TO][?][CMD AMD][TAF EGVN 230734Z 2309/2409 24008KT 9999 BKN010 ][TIS][XSS][EOM]

.......

[2017-10-23 11:59:34] [NORMAL MODE][TO][?][EOM]
[2017-10-23 11:59:37]
[2017-10-23 11:59:37] [NORMAL MODE][TIS][XSS][EOM]
[2017-10-23 11:59:44]
[2017-10-23 11:59:44] [NORMAL MODE][TO][?][TO][?][CMD AMD][ 3000 RADZ SCT003 ][TIS][XSS][EOM]
[2017-10-23 11:59:57]
[2017-10-23 11:59:57] [NORMAL MODE][TO][?][TO][?][CMD AMD][BECMG 23132315 FEW015 PROB30 ][TIS][XSS][EOM]
[2017-10-23 12:00:08]
[2017-10-23 12:00:08] [NORMAL MODE][TO][?][TO][?][CMD AMD][TEMPO 2315/2317 SCCT010 ][TIS][XSS][EOM]
[2017-10-23 12:00:23]
[2017-10-23 12:00:23] [NORMAL MODE][TO][?]

......

[2017-10-23 12:00:42] [NORMAL MODE][TO][?][TO][?][CMD AMD][TEMO 2400/2408 3000 -RADZ BKN004 ][TIS][XSS][EOM]
[2017-10-23 12:00:48]
[2017-10-23 12:00:48] [NORMAL MODE][TO][?][TO][?][EOM]
[2017-10-23 12:00:51]
[2017-10-23 12:00:51] [NORMAL MODE][TIS][XSS][EOM]




Whole session....