Date   
docker rebuilding.

Roeland Jansen, PA3MET
 

in July I built docker on one of my systems and that worked in the sense that it started/showed the UI etc.

 

I recently wanted to fix the issue that I can see the pluto/rtl in the image but when I tried to rebuild the container:

 

in july it worked fine; now it doesn't. Maybe a bug somewhere in docker itself:

Docker version 19.03.1, build 74b1e89e8ac6

sdrangel build_vanilla:

=> ERROR [base 21/23] COPY pulse-client.conf /etc/pulse/client.conf 0.3s

[base 21/23] COPY pulse-client.conf /etc/pulse/client.conf:


no such file or directory

and the sdrangelcli:

=> [base 6/7] RUN sudo mkdir /opt/build && sudo chown node:node /opt/build 0.7s
=> ERROR [base 7/7] WORKDIR /opt/build 0.7s

[base 7/7] WORKDIR /opt/build:


no such file or directory

the latter happens on sdrangel too if I comment out the first COPY command where it fails.

any ideas?

(it's also an issue on github)

Networked receiver plugin development

Techfreakz
 

Hello,
I've developed a prototype wide band down-converter (3-15GHz) and a mating direct conversion receiver to digitise the IF (140MHz wide, centered on around 325MHz).

I'm currently able to stream IQ samples over gigabit Ethernet from the FPGA. The samples are 14 bits each padded to 16 bits, for a combined 32 bit sample. The system is more than capable of saturating gigabit (circa 989Mbit/s with 1500 byte packets).

I'd like to use SDRAngel as a sink for this data stream and thus need to write a device plugin.

Could any of the developers suggest a starting point? Perhaps another networked receiver plug-in exists that I can use as an example and then extend to add my required functionality? i don't yet need receiver control (this is currently managed in a separate LabVIEW application), I'd just like a real-time means of analysing the sample data.

Best regards,
Alex

Re: Networked receiver plugin development

Edouard Griffiths
 

Hello Alex,

this looks interesting particularly the 3-15 GHz coverage. The device to host sample rate is indeed very very fast. I hope you have provisioned some hardware decimation in the FPGA because only very few computers will be able to digest the samples and as you said at full speed you are also very close to the 1 Gbit limit of the network connection. There is hardly any example of network connected hardware the very few are either low speed or hide the networking process inside the support library which is indeed an option to consider. Anyway using UDP or the network all support libraries hide the gory details of the connection so an abstraction layer could be what you need to provide to the client applications. So... these examples are:
  • Kiwi SDR: low speed (12kS/s) based on web sockets to connect to a distant Kiwi SDR server. Looks far from what you are looking for
  • Pluto SDR: the support library (libiio) hides the fact that the hardware is connected via USB or via Ethernet. This may be worth looking at in more details.
I have briefly described the general architecture in this post: https://groups.io/g/sdrangel/topic/the_righ_way_to_design_sdr_in/32984542?p=,,,20,0,0,0::recentpostdate%2Fsticky,,,20,2,0,32984542

Any "samplesource" plugin could serve as an example. They are all based on the same principle but could work either with synchronous calls (the hardware interface returns the data directly) or asynchronous (you give to the interface the pointer to the callback function and this function is called whenever the interface decides to send samples). Most interfaces are synchronous but RTL-SDR for example is asynchronous. The call to the hardware interface is always located in the xxxThread class of the plugin.

Throughout the code there are also examples of communication with UDP using the Qt framework. However I am not sure the Qt framework supports extreme speeds.

Brgds,
Edouard.

An enhanced demodulator for the NOAA APT satellites?

yvandelaserge
 

Hi,
When we examine in real time an APT signal from a weather satellite, the impression is that we have about twenty peaks next to each other, the amplitude of which varies in the same way. So about twenty copies of the same information.
With digital signal processing, could we take advantage of this redundancy to improve the signal-to-noise ratio?

I draw a parallel with an image processing soft, used by amateur astronomers to photograph a celestial object such as a planet for example. By means of a camera, we take a series of a few dozen images. Each of these images contains a disturbance caused by atmospheric turbulence. Noise. But this disturbance related to noise is different in each image. On the other hand, the image of the planet is identical in each image.
By superimposing several images, the software makes it possible to attenuate the noise and thus to improve the signal-to-noise ratio and to obtain a more mette and more contrasted image.

If each peak of the APT signal transmitted by the weather satellite contains the same information, could we imagine in order to improve the signal-to-noise ratio, a signal processing program which would cut the received spectrum into slices each corresponding to a peak and then add them all together to average the noise and thus improve the signal/noise ratio?

Re: An enhanced demodulator for the NOAA APT satellites?

Edouard Griffiths
 

Hello,

are you sure it is the same transmission repeated along in frequency? This seems to be a waste in a fairly constrained band. I am a total newbie in APT so I just went to Wikipedia (https://en.wikipedia.org/wiki/Automatic_picture_transmission) and read "The signal itself is a 256-level amplitude modulated 2400Hz subcarrier, which is then frequency modulated onto the 137 MHz-band RF carrier. Maximum subcarrier modulation is 87% (±5%), and overall RF bandwidth is 34 kHz."  so it does not seem to be exactly as you describe. But maybe some specialists could give a better answer.

Brgds,
Edouard.   

Re :Re: [sdrangel] An enhanced demodulator for the NOAA APT satellites?

yvandelaserge
 

Dear Édouard,
I tried to ask this question on a math forum, but so far, I got no precise answer. It is on this forum, and I included a photo of the signal as it looks.
 https://forums.futura-sciences.com/mathematiques-superieur/
If you look at an FM transmission modulated with a fixed 2400 sub carrier, you have several fixed peaks spreaded 2400 Hz apart. 
With an APT signal, since the subcarrier is amplitude modulated, you see the amplitude of all the peaks vary, all in the same way.

The NOAA used this kind of modulation in the 1960s, probably because the Doppler effect is less of a nuisance than for an SSB signal. The APT signal could thus be received with the simple analog receivers available at the time, at the cost of more bandwidth and a s/n ratio not as good as for SSB.
But nowadays, maybe a digital decoder specially designed for the APT could be more effective than a classical FM demodulator?

Thanks for you interest anyway and kudos for SDR angel!

Regards,

Yvan

Le mer., oct. 9, 2019 à 17:45, Edouard Griffiths
<f4exb06@...> a écrit :
Hello,

are you sure it is the same transmission repeated along in frequency? This seems to be a waste in a fairly constrained band. I am a total newbie in APT so I just went to Wikipedia (https://en.wikipedia.org/wiki/Automatic_picture_transmission) and read "The signal itself is a 256-level amplitude modulated 2400Hz subcarrier, which is then frequency modulated onto the 137 MHz-band RF carrier. Maximum subcarrier modulation is 87% (±5%), and overall RF bandwidth is 34 kHz."  so it does not seem to be exactly as you describe. But maybe some specialists could give a better answer.

Brgds,
Edouard.   

Re: An enhanced demodulator for the NOAA APT satellites?

Siegfried Jackstien
 

he sees the "sidebands" as 20 or 24 carriers in parallel ...

the apt signal is

one tone only (the 2k4 subcarrier)

but if you frequency modulate a signal with a single tone .... you see a main carrier ... and lots of signals left and right from it (the fm sidebands)

those are normal ... and there is not the signal send out several times in parallel

dg9bfc sigi

Am 09.10.2019 um 15:45 schrieb Edouard Griffiths:

Hello,

are you sure it is the same transmission repeated along in frequency? This seems to be a waste in a fairly constrained band. I am a total newbie in APT so I just went to Wikipedia (https://en.wikipedia.org/wiki/Automatic_picture_transmission) and read "The signal itself is a 256-level amplitude modulated 2400Hz subcarrier, which is then frequency modulated onto the 137 MHz-band RF carrier. Maximum subcarrier modulation is 87% (±5%), and overall RF bandwidth is 34 kHz."  so it does not seem to be exactly as you describe. But maybe some specialists could give a better answer.

Brgds,
Edouard.   

Re: docker rebuilding.

Roeland Jansen, PA3MET
 

so far it seems to be a race condition while building. If the storage is taken locally on an ssd; it works fine.

If the disk is remote (filer, 1Gbit/ spinning rust) -- it fails. 

Re: Test sdrangel port for Mac OSX Mojave #osx

Иван Кравченко <wizz@...>
 

I got error 

2019-10-18 14:51:40.882 (D) DeviceSoapySDRScan::scan: driver: uhd

dyld: lazy symbol binding failed: Symbol not found: __ZN5boost16re_detail_10700027cpp_regex_traits_char_layerIcE4initEv

  Referenced from: /usr/local/opt/uhd/lib/libuhd.3.14.1.dylib

  Expected in: /usr/local/opt/boost/lib/libboost_regex-mt.dylib

 

dyld: Symbol not found: __ZN5boost16re_detail_10700027cpp_regex_traits_char_layerIcE4initEv

  Referenced from: /usr/local/opt/uhd/lib/libuhd.3.14.1.dylib

  Expected in: /usr/local/opt/boost/lib/libboost_regex-mt.dylib

gprect interaction

sebastien durand
 

Hello.
I am currently using Gprectic to listen to satellites.
I would like to know if I can drive the frequency of sdrangel via gpredic to compensate the Doppler effect?

I would also like to demodulate and decode the signal via gnuradio / gr-satellite. Put recover the UDP stream as on GQRX?

thanks
Sébastien Durand

Sdrangel use for Upconverter QO100

haye Jean Louis
 

Hi,

My name is Jean-Louis Haye living in RSA, callsign ZS6AAG, i am busy equiping my station for the AO100 satellite. The reception side is ok using SDR console. 
For the uplink on 2.4G, i have the upconverter as follow> https://www.passion-radio.com/sat-accessory/converter-qo100-803.html 
This upconverter requires injecting the local oscillator frequency that is not included. I heard that it is possible to use a hackrf as a local oscillator, so i thought to use SDRangel but how to inject and which type of modulation, i am not sure, maybe it is not possible.
I am new on hyper frequencies, any help is really welcome,
73 to everybody

ZS6AAG

Re: Sdrangel use for Upconverter QO100

Edouard Griffiths
 

Hello,

if the point is to drive a pure carrier AM or FM without modulation will do.

Brgds,
Edouard.

Re: docker rebuilding.

Edouard Griffiths
 

Hello,

I think trying to build an image on network storage is asking for trouble. Docker uses its own file system (default: overlayfs) over another and I am not sure this another is expected to be accessed via network. A safer option is to build on local storage and then share the resulting image via network storage if necessary. 

Brgds,
Edouard.

Doppler shift correction

Freddy ON7VQ
 

Hi all,
I wonder if there is a possibility in SDRangel to correct for doppler shift for example from Gpredict?
Thanks !
Freddy, ON7VQ

Re: Doppler shift correction

Edouard Griffiths
 

Hello,

controlling the various components of the application automatically can be done using the REST API interface. You could design something similar to this but taking its reference from Gpredict instead of the Frequency Tracker plugin:
https://github.com/f4exb/sdrangel/blob/master/scriptsapi/freqtracking.py

Brgds,
Edouard.

Re: Doppler shift correction

Freddy ON7VQ
 

Grand merci Edouard, I will explore this.
73
Freddy, ON7VQ

Op ma 4 nov. 2019 om 10:58 schreef Edouard Griffiths <f4exb06@...>:

Hello,

controlling the various components of the application automatically can be done using the REST API interface. You could design something similar to this but taking its reference from Gpredict instead of the Frequency Tracker plugin:
https://github.com/f4exb/sdrangel/blob/master/scriptsapi/freqtracking.py

Brgds,
Edouard.

kiwisdr

Gene Imes
 

Trying to connect to my kiwisdr on my local network. Documentation says that this is to connect publicly available kiwisdr. Does this mean I can not connect to my kiwisdr which is not publicly available. When I try to connect the indicator goes yellow then magenta.

Perseus support on Windows #windows #perseus

Andrea IW0HDV
 

Hi everybody (my first message on this group).

Just a quick one: is the Perseus receiver supported on the Windows release?

   *am* IW0HDV

Re: Perseus support on Windows #windows #perseus

Edouard Griffiths
 

Hello Andrea,

welcome to the group! The short answer is: no. The longer answer is that it seems the libperseus-sdr library is working in the MinGW context but the SDRangel Windows build is based on MSVC.

Brgds, Edouard. 

sdr angel with perseus

iz8eyp@...
 

Hello guys could anyone help me to use the perseus receiver with sdr angel program ?

73s