воскресенье, 7 июня 2009 г.

Signal MSK, Submarine broadcast or the practical application of previous article (FSK, GFSK, MSK, GMSk and other modes).

VLF, MSK, Submarine broadcast, Anthorn station(?) GBK(?)
Br - 200, Shift - 100

The example of the signal is here

Author: SergUA6
Band Width: 300 Hz
Low Range: floating
Baud Rate: 200 Hz
n-Ary (PSK/MPSK): conditionally 4
Count of Carriers: 2 indistinguishable frequency of manipulaion
Step between carriers: 100 Hz
The modulation, in which the signal was recieved )RX mode): Source I/Q record


pic.1 The group of signals. General view.

pic.2 the graphical spectrum

pic.3 speed of manipulation signal 4


pic.4 MSK in 2 and 4 degree

pic.5 the frequency manipulation spacing

pic.6 MSK on the Phase Plane

pic.7 MSK after frequency detector

VLF, MSK, Submarine broadcast, Anthorn station(?) GBK(?) The VLF range is very rich with curious enough signals. It seems like the group of signals is managed to be identified. There are lot of information in we-bsearchers by the word "Anthorn", and also the infromation about frequency 19.6khz is mentioned. In this record this is the signal number one. All five signals have the classical set of parametres for MSK: the spectrum is equal to 1.5*Br,characteristic bell-looking-like shape, and others. Pay attention that the carrier in the fourth degree it is expressed very poorly, sometimes it is almost not visible at all.

There shouldn't be problems with an identification of modulation, but there are some problems with determination of belongings, because the signals are faceless enough (encryption) and without features, that does not eliminate a possible error.

MSM team