ARTSystem

Autonomous Receiving and Tracking System for NOAA satellites using SDRPlay RSP1A

Disclamer

This project is currently in dev

The scripts are targeted for Raspberry application but it should be compatible on any device with python3

The gnuradio-compagnion software uses python2.7 for my setup (gnuradio v.3.7). If you have gnuradio on python3 you must change the line 84 in the Scheduler.py script and regenerate each gnuradio script :

gnuradio = subprocess.Popen('python -u $Path/GR_NOAA_script/ ...

Dependencies

• gnuradio-compagnion (https://www.gnuradio.org/) (tested with v.3.7 only)
• aptdec (https://github.com/Xerbo/aptdec)
• SDRPlay API and gnuradio bloc (https://www.sdrplay.com/) (If you are using another SDR you'll need the specific API and GR bloc)

First setup

Modifying APIUpdate_tomodify.sh

Go to ./n2yoAPI and open APIUpdate_tomodify.sh. From there you must replace 'YOUR-API-KEY' field with your API key from n2yo.com

Change the name of the file to APIUpdate.sh for the main script.

Modifying absolute paths to file

I used absolute path for pretty much everything to be "safe" I guess ??. The file concerned by that modification are :

n2yoAPI/APIUpdate.sh (or APIUpdate_tomodify.sh)
n2yoAPI/AAPIParser.py
NOAAScheduler/Predict.py
NOAAScheduler/Scheduler.py
NOAAScheduler/Tracker.py

On each concerned file a variable Path is declared to set your own Path. Scheduler.py also has a variable for Picture_path.

Modifying serial port for Rot2proG rotor

All the work here is done by jaidenfe. I just remove the stuff I don't need for this project. You can set the serial port for your rotor in the Tracker.py script :

Rotor = Rot2proG('/dev/ttyS0')

Create fifo for subprocesses

in the folder /NOAAScheduler do :

mkfifo az_alt.fifo
chmod 664 az_alt.fifo
mkfifo date.fifo
chmod 664 date.fifo

How to use ?

After setting everything up you just have to launch the Scheduler.py script with :

./Scheduler.py

If you don't have a Rot2proG or you have a fixed antenna for receiving you have to launch the script with:

./Scheduler.py noTracking

Modification for another SDR

If you have another SDR you can open the gr_NOAA.grc file with gnuradio to change the SDR source. You'll have to regenerate all the scripts. For NOAA satellite the frequencies are :

NOAA15 : 137.620 MHz
NOAA18 : 137.9125 MHz
NOAA19 : 137.100 MHz

What it does ?

When launching Scheduler.py the script will update all the files needed from n2yoAPI.

From there it will wait for the next satellite to cross the sky with a maximum elevation of at least 40°.

During fly-by the script launches 2 scripts :

• gnuradio script which save audio file of the WFM decoded signal
• tracking script (if tracking enable) which send to the rotor the azimuth/elevation coordinates of the satellite

When Fly-by ends the two previous scripts are closed and aptdec is called to decode the WAV file previously recorded.

By default aptdec saves 3 images to the ~/Pictures folder : the raw channelA, the false colored and the temperature image.

It then updates the files with n2yoAPI and loop to wait for the next passe.

TODO

• Test rotor in real condition with tracking activated
• Merge gnuradio scripts into one for every satellites
• Script for bladerf compatibility

Everything is a big mess for now but it should works as espected. I will probably clean thing up with the time.