Super DARN- is the interesting signal from UDXF discussion.

After some discussions, it became known, that the mysterious signal, about which we were spoken about in previous post is Super DARN (Finland).

Here is some details about this signal:

Super DARN

Super Dual Auroral Radar Network

An awesome example of Super DARN signal, send by RadioKoteg.

Author: SergUA6

Band Width ~5900-6000 Hz

Low Range hopping

RX mode source IF record

Sonograms:

pic.1 Generall view

pic.2 Detalization
pic.3 Detalization

Super DARN - there is developed enough international network for studying of an upper atmosphere and an ionosphere (Super Dual Auroral Radar Network) regions. The signal of one of radar of this network is represented in this case. The signal is curious enough, as possesses rather narrow spectrum of radiation, that is not characteristic for various probing systems. As a rule, spectrum's width of such systems, is located 20-80 kHz and higher limits. In generall, the measured parametres have relative/conditional character as can vary depending on tasks.

Many thanks to Leif Dehio for help with identification of the signal.

An interesting signal from UDXF conference discussion.

The very interesting signal, which record has been represented by Mike, appeared in UDXF conference.

The record itself, is ~2 minute I/Q file, with capacity 16 bits, the size of the file is nearby 80-90 mbyte.

Actually, there are many various signals in this record, we have marked some on the general spectrogram.

General view.

Presence of two chirps seemed very interesting to us. That has allowed to measure key parametres and to find out some curious nuances.

There is an interesting gaps(breaks), in the same positions, on two independent chirps.

In generall, the basic interest, certainly represents, not absolutely clear/understandable system, which is well visible on this spectrogram and designated on the general sonogram by green colour.

Unfortunately, on this record, it is impossible to tell precisely what width of a spectrum has this signal. Presumably it can be about 20 kHz. Nevertheless, it is well visible, that the signal has FHSS signs. It is also rather not difficult to receive key/basic parameters. It is well visible that the nature of impulses, practically in all bursts, is absolutely identical. That is strange enough, if the system is intended for real information transfer.

We are still have difficulty to classify this signal. Firstly, there is not enough data - the only one record. In the second, we didn't have similar records before. Besides, the subject of interest has too blurred limits(boundaries) and relatively weak level, plus it is liable to considerable selective fadings.

At the conference, also the other signal is discussed. The parameters of this signal, differ from the first signal, but both these signals have similar impulse nature, and close structure (an alternation of the small identical bursts). Probably, there are a lot of such signals in the air, all these signals can be different, but they are very interesting signals observe to.

PSK: INMARSAT Satellite

INMARSAT Satellite

INMARSAT AERO. OQPSK, Br-10500

The perfect example of INMARSAT AERO, send by RadioKoteg.

Author: SergUA6

Band Width ~10500 Hz

Low Range ~750 Hz, in this example only!

Baud Rate 10500 Hz

n-Ary (PSK/MPSK) OQPSK, constellation looks as square PSK-8

Count of Carriers single mode

Carrier frequency 6079 Hz, in this example only!

ACF 500 ms

RX mode SSB

Sonograms:

pic.1 Generall view

pic.2 Baud rate

Diagrams:

pic.3 Typical characteristics of OQPSK and other half-modes.

pic.4 ACF

pic.5 View of the signal in VMW

Pictures:

pic.6 Phase constellations

INMARSAT AERO - INMARSAT is using wide enought line of different protocols. In this record, it is presumably AERO-H. The signal is very bright. All the parameteres of this signal can be easily determined.

Updating SA to the version v 6.2.0.7

Updating SA to the version v 6.2.0.7

Updating SA to the version v 6.2.0.7

It is regular updating, which includes fixing of the small errors and problems, which are not having basic value, but nevertheless demanding the decision.

new demo clip "the Review of the top ruler of tools" is added in section of demo of files. The top ruler answers basically for management of a display mode sonograms, and it is desirable to have full idea about possibilities which is in SA.

Good luck.

PSK:TETRA - DMO, terminal to terminal connection

TETRA - DMO, terminal to terminal connection

Direct Mode Operation, Br-18000, pi/4 DQPSK

Perfect example of TETRA-DMO signal, send by geka.

Author: SergUA6

Band Width ~25000-26000 Hz

Baud Rate 18000 Hz

n-Ary (PSK/MPSK) pi/4 DQPSK

Carrier frequency 15639 Hz, in this example only!

RX mode source I/Q record

Sonograms:

pic.1 Generall view

pic. Manipulation speed

pic.3 Getting of carrier frequency

Diagrams:

pic.4 Generall frame structure

Pictures:

pic.5 Constellation

TETRA - DMO, terminal to terminal connection - the mode of direct terminal (mobile stations, phones etc) connection of TETRA standard, without participation of base stations equipment.

SA update to version v 6.2.0.6

SA update to version v 6.2.0.6

We certainly cannot guarantee SA work under various emulators, including virtual machines, but nevertheless, for rather popular in LINUX environment WINE, something is already done.

In the current version, we have corrected everything that depends on us, to make SA work more or less correct in WINE.

Althought, we can't solve part of problems, because these are not SA problems, but WINE problems.

***

The format of demo files is reconsidered. Thereupon, the old format is not supported by the current version.

Support of colour scale in comments is added.

Grey colour - the comment is not actual in the present moment of time.

Yellow colour - the new comment.

Light blue (Aqua) - the comment is carried out.

There is the pause in 5 seconds after each comment. This time should be enought to read the comments.

Interruption of the demo, is reazlied throught "Space" key as before. The program supervises possibility of interruption of the demo, and in case of impossibility to stop the demo right now, it warns about it.

The previous demo clip in the new format is here. Also added small demo for check version SA. We do not plan to change format further, as in the current format, possibility of the future expansions is put in advance.

***

Possibility of virtual/analytical shift of a signal by frequency is added in OFDM module.

The sense is that absolutely exact shift on a step, which is multiple to a grid of channeles, sometimes is required atanalysis of OFDM signals. In cases of fractional values of the step, to realize it physically is hard enought, besides it demands presence of free space on/by frequency.

Virtual shift guarantees absolutely exact displacement and, because it is done purely analytically, it does not require neither signal redigitization, nor presence of free space, that is especially important if it is nessecary to shift the signal on 10-30-100 channels upwards or downwards.

Virtual shift, is actual for signals of model A, on signals of B model, this ability is blocked, as it is not necessary in

this case. There will be separate article about it.

***

In generall, providing functioning SA under WINE (in reasonable limits ofcourse), we have solved weight of small implicit problems as a whole. But nevertheless, SA is intended to work under high-grade OS, where we can guarantee something.

Good luck~

Scrambler: Yachta T-219

Yachta T-219

the analogue domestic synchronizable scrambler

The signal is here.

Author: SergUA6

Band Width ~2700 Hz

Low Range ~300 Hz

Pilot tone(s): FSK-2 Synchronising sequence with frequency of manipulation 100 Hz, and spacing 150 Hz precisely on the

middle of the speech spectrum

RX mode SSB

Sonograms:

pic.1 Generall view

pic.2 Detalization of sinhro-sequence

Diagrams:

pic.3 Manipulation speed

Scrambler: Yachta T-219 - is the analogue Russian domestic synchronizable scrambler. It's principle is used by many developers of the different countries, at a speech exchange. In FSK mode Sinhro-sequence, which is located precisely on the spectrum middle is transferred. The speech spectrum breaks on two parts, above and below this sequence. All that breaks into unequal time pieces, in which limits these two speech channeles are rearranged by places and inverted. It is considered that Yachta has temporary resistence. This scrambler is widely used by military men for transfer of the operative information with limited limited term of use.