Install the satnogs_gr-satellites "addon" and use your station more!

I get to the “cmake …” command and get this:

CMake Error at CMakeLists.txt:97 (find_package):
  By not providing "FindGnuradio.cmake" in CMAKE_MODULE_PATH this project has
  asked CMake to find a package configuration file provided by "Gnuradio",
  but CMake did not find one.

  Could not find a package configuration file provided by "Gnuradio"
  (requested version 3.8) with any of the following names:


  Add the installation prefix of "Gnuradio" to CMAKE_PREFIX_PATH or set
  "Gnuradio_DIR" to a directory containing one of the above files.  If
  "Gnuradio" provides a separate development package or SDK, be sure it has
  been installed.

-- Configuring incomplete, errors occurred!

I just realized this is the same error as mfalkvidd, however simply clearing out the build folder and retrying the cmake gave me the same results…

I’ll review my command history tmoorrow to see what I did and report back.


This is my history file:

2021-06-13 19:00:15 - PKGLIST="libqwt6 libfontconfig1-dev libxrender-dev libpulse-dev swig g++ libtool python-dev libfftw3-dev it-dev libboost-all-dev libusb-dev libusb-1.0-0-dev fort77
2021-06-18 13:18:06 - -wxgtk2.8 git-core
2021-06-18 13:18:06 - -numpy ccache python-opengl libgsl0-dev
2021-06-18 13:18:06 - -cheetah python-mako python-lxml doxygen qt4-default qt4-dev-tools libusb-1.0-0-dev
2021-06-18 13:18:06 - wtplot3d-qt4-dev pyqt4-dev-tools python-qwt5-qt4
2021-06-18 13:18:06 - -docutils gtk2-engines-pixbuf r-base-dev python-tk
2021-06-18 13:18:06 - d2-dev python-gtk2 libzmq libzmq-dev libzmq1 libzmq1-dev python-requests
2021-06-18 13:18:06 - -sphinx comedi-dev python-zmq libncurses5 libncurses5-dev python-wxgtk3.0"
2021-06-13 19:00:26 - echo $PKGLIST
2021-06-14 07:03:25 - cd gr-satellites/build/
2021-06-14 07:03:28 - cmake ..
2021-06-14 07:03:34 - cmake clean
2021-06-14 07:03:39 - ls
2021-06-14 07:03:44 - rm -rf *
2021-06-14 07:03:47 - cmake ..
2021-06-14 07:06:47 - rm -rf *
2021-06-13 19:01:45 - for pkg in $PKGLIST; do sudo apt-get -y install $pkg; done
2021-06-14 12:10:10 - cd gr-satellites/build/
2021-06-14 12:10:12 - cmake ..
2021-06-14 12:16:16 - sudo apt-get install gnuradio-dev
2021-06-14 12:16:29 - apt-cache show gnuradio-dev
2021-06-14 12:17:27 - sudo add-apt-repository ppa:gnuradio/gnuradio-releases
2021-06-14 12:17:46 - apt-cache search add-apt
2021-06-14 12:19:46 - sudo apt-get install software-properties-common
2021-06-14 12:34:47 - sudo apt-get update
2021-06-14 12:36:06 - sudo apt-get upgrade
2021-06-14 12:40:33 - sudo add-apt-repository ppa:gnuradio/gnuradio-releases
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Ok, now I am stuck at this step:

Copy the,,, satnogs-pre and satnogs-post to /usr/local/bin

Where are these files located? The instructions are little bit difficult to follow… for example, why does it ask you to git gr-satellites twice?

They all should be in should be in ~/satnogs_gr-satellites/
or search via

 find ~/ -name

to home in on the directory.

sudo make install will copy the files for you.
If you prefer to do it manually, the paths are visible at satnogs_gr-satellites/Makefile at main · kng/satnogs_gr-satellites · GitHub

I developed the IQ to UDP for external demodulators as a way of using other software that already exist but not necessarily in a flowgraph. The built in demods still run and there’s currently not a way of switching between internal or external. The claim is not to take over all the demodulation, rather to get the possibility of external programs to add quality or protocols etc. The BPSK is a good example which was not working in the flowgraphs, but gr-satellites had good support for it. How the future of the flowgraphs will look I don’t know, it can perhaps be split into hier blocks etc.

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That line was only made as an example and not a exhaustive list of satellites that gr-satellites handles and satnogs does not. Perhaps a poor example with two of them deorbiting slightly before this sw was sritten (:

I thought of making a better list, but realized I would have to maintain that and did not want to.
If someone has a better example that is more up to date I can certainly add that.

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The instructions are quite minimalistic and I make no claim they’re pedagogic nor exhaustive (:
It does not suggest to git clone anything twice, there’s gr-satellites and satnogs_gr-satellites for example.

I am all ears if you have any suggestions on the instructions.

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My appologies - I did not notice that. I’ve gone back and installed satnogs_gr-satellites now, and hoping that it’s fixed the issues (my station 187 was completely broken after the install attempt - hopefully this fixes it). I don’t understand where the “makefile” tab/space changes need to be made, though…

Looks like it is working now! Question, does it upload a data file automatically for every observation, even if there are no decodes? I’ve only got one result so far, and the uploaded data is empty.

That was my mistake, somewhere in the creation of that file it got messed up, some make seems to accept this mistake and others don’t. I updated the makefile, so a git pull in the directory should fetch that.

Short answer; no. The results goes to a kiss-file that is split into satnogs json format and placed in the upload queue. If there’s no frames demodulated then nothing gets uploaded.

However, sometimes gr-satellites produces very short frames, and possibly other sporadic ‘bad’ frames.
This discussion if somewhat outside my expertise and belongs to gr-satellites, @EA4GPZ excellent work.
The 0-length could be filtered out in the, but it’s very hard to make more assumptions on what the shortest length should be.

Sounds a bit strange, satnogs-client is pretty resilient and always tries to push through is there’s small problems with the setup. Checking the log and seeing what is going on:
journalctl -f -u satnogs-client.service -n 50
or on other systems than the official raspberry-pi client:
tail -f /var/log/daemon.log -n 50

Hi, the reason for these short bad frames is that the AX.25 protocol uses only a CRC-16, which is rather short and vulnerable to false decodes. For satellites using other better protocols this doesn’t happen (or doesn’t happen so often).

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what is the strongest UHF satellite that I can test my station on?


If you are using the latest SatNOGS Pi image GNURadio 3.8 can be installed from the satnogs repository. Make sure you are using the latest version.


You can also have a look at my stations SatNOGS Network - Ground Station PE0SAT-U they all use a minimal setup.

I don’t know where the root cause for this is located, but the file names created when using this add on are not following the conventions! There’s sometimes a ‘_g0’ appended where an index should be!

Maybe @SA2KNG has an idea…

It’s located here: satnogs_gr-satellites/ at main · kng/satnogs_gr-satellites · GitHub
I used that to avoid collisions with the flowgraph generated data files and did not find a better solution. No one complained and all seemed to work just fine so I thought it was ok.

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It should be an index when more than one frame is received within a second, as the granularity of the sink is 1 sec.