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".





lunedì 20 novembre 2017

MIL188-110A transporting FED-1052 protocol


MIL188-110A waveform ( acf 200ms ) sending encrypted email data.


Output bitstream.


FED-1052 protocol.


CFB encryption.



Source about CFB

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.

lunedì 30 ottobre 2017

STANAG-4538 circuit mode traffic


STANAG-4538 traffic spotted some days ago. 3G ( BW5 waveform ) used as link and 2G ( M188-110A waveform ) transporting data.


3G-2G switching


ACF: 67ms ( M188-110A ) / PSK-8 waveform



Output bitstream show evidence of citadel Harris encrypted data.

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.