A setup to build a satellite ground stations that can tune, record and generate images for FM and APT weather satellites. This is the software recipe, in the hardware part I used an Orange Pi Prime Board but you can use any Single Board Computer, including Raspberry Pis, O-droids, etc. The only advice is to use a medium power one (multi core and at least 1GB of RAM)
I used Armbian as OS, but you can manage it to make it work with RaspiOS with a little work.
A sample of the main view:
A sample view of a pass (PO-101 DIWATA-2B FM sat):
This proyect is inspired and heavily based on the work of Luick Klippel and his work on his NOAA Satellite Station repository.
- Web interface to see the next passes, the recorded ones, and details for it.
- Receive any satellite in FM mode (SSB is possible but no there is doppler control yet, so no SSB by now)
- Record the satellite pass and keep the audio for later.
- APT WX audio is preserved in wav format and 22050 hz of sampling (the format wximage needs to work with)
- FM audio satellites is preserved in .mp3 mode but with high quality settings, and other tricks.
- The spectrogram of the audio is embedded as album art (see below).
- The pass data and receiving station are stored in the mp3 tags.
- Automatic decode APT images from WX sats (NOAA 15, 18 and 19)
- For the voice FM sats we craft a spectrogram and embedd the metadata of the pass on the image
- Migrate to python3 for the main processing.
- Control a rotor via Hamlib.
- Craft a solution to allow for doppler corrections while receiving (will allow to receive SSB signals, at least for CW beacons)
- Any other.
As this tool relies on many tools I will not explain how to setup each one, but I will give you clues of where to get info about it.
- Web server + PHP support
You need a web server with php 7.x support installed (no MySQL or MariaDB support needed), google has a lot of guides indexed, just google for "install nginx and php in [your-operating-system]"
- Predict
You need to install predict the software to make predictions of satellite passes.
For RaspiOS / Raspbian:
sudo apt install predictFor Armbian you need to compile it from source, you can get it from the Predict home page.
- WXtoImage
This wonderful piece of software was deprecated by the original authors but a group of enthusiast keep it alive in the Restored WXtoImage site.
Just download it here: WXtoImage deb package for ARM
To install it copy it to your SBC computer and run:
sudo dpkg -i wxtoimg-armhf-2.11.2-beta.deb
# [ignore errors if any]
sudo aptitude install -f
# [this will fix any dependency error]To register the software in the SBC you need to install it on a linux box (can be another SBC or another real linux box); then fill your coordinates and settings, register with the credentials and just then locate a hidden file under your home directory called .wxtoimgrc and copy it to /root/.wxtoimgrc in the SBC. You are done.
- Utilities
You need at least git and make, in most linux (including SBCs) you are set by running this:
sudo apt install git make- Login in your into SBC and clone this repository
git clone https://github.com/stdevPavelmc/FAASGS. - Run install script
make install. - Configure your local data (see Configuring below)
- Execute it by hand to check if all works
sats.sh.- Go to your IP address and check if there is any 'next pass' scheduled.
- If all gone ok, run the schedule script to make it run for good
make permanent
After the install step you need to configure your local data, you callsign (use N0NAME if you are not a ham radio operator), name, locator (use this tool if you are in doubt), coordinates (use locator tool to check the coordinates too), QTH and the satellites you want to capture.
Just go to /etc/sat_data and edit a file named user.conf with the command nano user.conf. You will find a proxy tsetting there to, if you don't use a proxy just remove or comment it.
Next step is to select the satellites you want to monitor, the file is named sats.json and it has a very common web format, you can add or remove sats as your need.
Please note that the satellites has a name and a nickname, the name reffers to the one that appears in the TLE file and the nickname is a friendly name for us (and must not contain spaces, parenthesis, slashes, etc)
I have not spoken about antennas and RF in this document because that relies on your expertice, I will mentioned my experience with some and I trust your internet skills to find them
- A 2m J-pole: normal for voice FM sats, bad for APT images (the image of PO-101 above was taken with just a J-pole + 12m of RG-8X)
- A horizontal 120 degrees V for APT satellites (137 Mhz): better for APT, regular-to-bad for voice FM satellites
- The mentioned V but plus a wide LNA (+8 dB on 137 and 145 Mhz): very good for APT, normal-to-good for voice FM sats (actual antenna)
- A 1/4 wave 2m ground plane (120 degrees elements) regular for 2m voice, regular for APT and regular-good for 70cm sats (yes, it works on 70cm too) (down for maintenance)
As usual, the higher and un-obstructed view for the antenna the better, also for coax: top quality ones and as short as possible.
You can improve the software, donate equipment, top up my cell phone, or kust share your impressions on social media; all of that in the Contributing file.
Free as in freedom, see the LICENCE file for details.