Installing goestools onto a Raspberry Pi 3 or 4

The first thing to remember is to have patience, this system works, but if you do not follow the instructions in order, or miss a character or add a blank space inadvertently, it will not work. I would suggest using copy and paste.

The second thing to remember is to have fun!

The third thing is……shoot, I can’t remember what the third thing was.

Goestools is a GOES receiver and processor Pieter Noordhuis developed for decoding HRIT into usable imagery. It is a LINUX product and was created for PI, but could (and can) be run on Ubuntu, and other Linux platforms and emulators. However, these instructions are for a PI, There are many tutorials out there, this is an edited amalgamation of mine and two others. This is the procedure that worked for me.

HINTS for Hardware connections:
This was my FIRST Raspberry PI project. This is a combination of the hardware and the software and dish alignment portion of the system. refer to my main GOES page for hardware options.
1. Mount the Sawbird+ LNA at the dish feed LNB.
2. If Possible attach the SDR to the LNA directly or with a very short cable as close as possible to the LNB on the dish. Then run a USB extension cable from the PI to the SDR/LNA combo. The longer the run of coax the worse your signal will be.
3. Waterproof, waterproof, waterproof, and this includes humidity and moisture from the air!

Assembly Diagram for Hardware connections:

[Grid Antenna]->[Adapter]->[(input side) SAWBird+ (output side)]-[6" pigtail]-[Nooelec SmarteeXTR]-[6" USB cable]-[Raspberry Pi]- WIFI Network or Ethernet

Waterproof those connections!

Waterproof those connections!

Temporary Test installation

Temporary Test installation

GOES Receiver

GOES Receiver

Close up of connections

Close up of connections

Dish in permanent position.

Dish in permanent position.

Added Cooling fan to PI4

Added Cooling fan to PI4

For a permanent hardware mount for the dish, I used a simple deck mount bracket – take the time to make it level side to side and up and down.

Setting up the Raspberry PI

country=US 
ctrl_interface=DIR=/var/run/wpa_supplicant GROUP=netdev 
update_config=1 
network={ ssid="your_real_wifi_ssid" scan_ssid=1 psk="your_real_password" key_mgmt=WPA-PSK 
}

sudo raspi-config

sudo apt update
sudo apt dist-upgrade

# reboot the device
sudo reboot

Note: you will have to SSH into your PI EVERYTIME you reboot!

2. Install dependencies

# get the packages necessary to build and run goestools
sudo apt install git build-essential cmake libusb-1.0 libopencv-dev libproj-dev

3. Install librtlsdr

Grab the latest librtlsdr source, compile it, and install the shared libraries/includes. This is what allows your Realtek RTL2832 based DVB dongle to work as an SDR receiver

# download, compile, and install librtlsdr
git clone https://github.com/steve-m/librtlsdr.git
cd librtlsdr
mkdir build
cd build
cmake -DCMAKE_INSTALL_PREFIX:PATH=/usr -DINSTALL_UDEV_RULES=ON ..
sudo make -j2 install

# load udev rules and blacklist the DVB driver shipped with the OS
sudo cp ../rtl-sdr.rules /etc/udev/rules.d/
sudo ldconfig
echo 'blacklist dvb_usb_rtl28xxu' | sudo tee --append /etc/modprobe.d/blacklist-dvb_usb_rtl28xxu.conf

# reboot the device
sudo reboot

4. Test your the RTL-SDR dongle

rtl_test 

You should see something like this:

Found 1 device(s):
  0:  Realtek, RTL2838UHIDIR, SN: 00000001
...

If it hangs, just press crtl-c to exit. It does not have to finish

If there are errors, or if the device is not recognized:

• Reinstall the driver from Step 3
• Ensure the dongle is secured in the USB port
• Remove all USB hubs and plug in into the Pi directly
• Make sure you power your Raspberry Pi with at least a 2.5A power supply
• Check the device using lsusb command. You should see ID 0bda:2838 Realtek Semiconductor Corp. RTL2838 or something of the like listed there. If not, try the previous steps.
• Run dmesg and check for errors such as error -71 related to the USB device. This may mean that your RTL-SDR receiver might be broken.

5. Install goestools

git clone https://github.com/pietern/goestools.git
cd goestools
git submodule init
git submodule update --recursive
mkdir build
cd build
cmake -DCMAKE_INSTALL_PREFIX:PATH=/usr ..

# this will take a while on a raspberry pi
sudo make -j2 install 

6. Create goesrecv.conf config

sudo nano goesrecv.conf

Change the sample_rate to 2000000. Higher sample rates MAY cause goesrecv to require multiple restarts in order to get a lock on the frequency.  Check your dongle for the type of BiasTee (if any) it has. Bias tees are the components, that are used to supply DC voltages to bias RF circuits.

If you’re using an RTL-SDR V3 or another SDR with BiasTee function enable the bias tee with set bias_tee = true and increase the gain to 30:

Bias Tee is not needed for the Nooelec SmarTee XTR which supplies constant bias tee power to the LNA or if you’re powering your SAWBird through the micro USB port, set bias_tee = false under [rtlsdr].

cat <<EOF > ~/goesrecv.conf
[demodulator]
mode = "hrit"
source = "rtlsdr"

[rtlsdr]
frequency = 1694100000
sample_rate = 2000000
gain = 5
bias_tee = false

[costas]
max_deviation = 200e3

[decoder.packet_publisher]
bind = "tcp://0.0.0.0:5004"
send_buffer = 1048576

[monitor]
statsd_address = "udp4://localhost:8125"
EOF

Now the tricky Part! Getting your Dish pointed at the satellite.

7. Roughly point your antenna at the satellite

Remember that you are using a small dish to get signal from a satellite 23,000 miles away! Make sure your mount is STABLE, whether a tripod or verticle permanent mount keep it stable and level. I used a heavy base and a 2 inch piece of conduit for the pole. Did I say keep it stable? Here is a lesson learned, I had mine set up on my back deck. got it all adjusted, and working in the cold weather, two days later my vits went way up! How? The temps increased enough that the little bit of snow/ice under my base melted, and changed the levelness of my setup!

When searching for the signal I was reminded of the quote by Simon Pegg as Scotty

“The notion of transwarp beaming is like trying to hit a bullet with a smaller bullet whilst wearing a blindfold, riding a horse.”

– Montgomery Scott, 2258 (Star Trek)

Find where the GOES-16 or GOES-17 satellites are in the sky at your location using dishpointer.com, it will draw a line on the aerial map where to point your dish. Note the azimuth and elevation. Another great satellite location tracker is https://www.satellite-calculations.com/Satellite/lookangles.htm enter your address or coordinates and then select the satellite.

Use an actual real compass to point your dish at the azimuth. Even with my Note 9 I found many errors in digital compass. I have a guide on How to use a real compass here.

Elevation: Angle up/down
Azimuth: Angle left/right
Polarization/LNB Skew: Rotation angle of the dish

Adjust your dish angle according to the elevation. Use your smartphone level app, or just eyeball it.

IMPORTANT: Polarization Skew

You should also adjust the skew of your dish roughly according to what Satellite Calculations says under “Skew”. For GOES-16 I did not need to change the skew at all, my skew angle was 14.5° so it really wasn’t going to improve signal much.

8. Run goesrecv and perform fine antenna adjustments

To run the software open an SSH terminal on your main PC using PuTTy. Connect to the Raspberry Pi’s IP address, port: 2222 with SSH. Log into the Pi with the default username/password: pi/raspberry.

In the first terminal run the command:

goesrecv -v -i 1 -c ~/goesrecv.conf

This will show output every second that looks something like this:

The vit(avg) stat shows the average viterbi error rate over 1-second interval (if running with -i 1).

If there’s no signal, the vit value should be over 2000. When signal is stronger it should decrease. If you have no discernable signal double check the antenna position again with a compass to make sure you’re pointed at the intended satellite. Make sure there is nothing blocking line of sight to the satellite.

I used RaspController app by Ettore Gallina on my NOTE9 phone to monitor the goesrecv while I physically made adjustments to the dish. This should help you point the antenna correctly. Slightly rotate the dish right or left and note whether the vit errors are increasing or decreasing.

Once you’re at the local error minimum, perform the same process to find the minimum error rate while slightly adjusting the vertical angle.

When the vit errors are at their lowest, you’ve pointed the antenna. Monitoring the bits, you might want to try and adjust your reflector in or out, or try and bending it flatter to see if it lowers your vits. Remember moving your dish, just a little can cause you to increase your bits. Even putting your hand in front of dish will cause a loss of signal.

If you can’t pinpoint the signal even after precisely adjusting the antenna, flip the dish 90 degrees and try again. (Instead of wide horizontal it would now be tall in the verticle).

If you want to hear or see the signal via SDR# software or other SDR software you will need to install a Spyserver or RTL_TCP on your PI. This is not required for goestools to run!! Otherwise JUMP to Step 9 (you can always add this later!!)

1. Create a new folder for the spyserver and navigate into it. 
   mkdir spyserver  
cd spyserver
2. Download the latest SpyServer and extract it using the commands below.
   The link used in this example is for the 32-bit ARM version which is what Raspberry Pi’s and most other single board PCsww like Odroids and Orange Pi’s use.
   wget -O spyserver.tgz http://airspy.com/?ddownload=4247 tar xvzf spyserver.tgz
   
3. Use a text editor like nano to edit the spyserver.config file. Change the “device_type” to “device_type = RTL-SDR” (without quotes).
    nano spyserver.config
    If you are unfamiliar with Nano, then note that you cannot use the mouse. You will need to use the arrow keys to move the cursor. Editing is done with the bakspace/del keys and keyboard keys as usual. To save and exit, Press “Ctrl + X”, and then the “y” key.
4. Find your device’s IP address using the “ifconfig” command. Note NOT “ipconfig” from windows, notice the “f”. Write this IP address down as it is the address you’ll use to connect to the SpyServer.
5. Now you can run SpyServer
    ./spyserver
6. Use SDR# by going to “Source” in SDR# and then selecting “Spyserver Network and enter your PI’s IP address like:
   sdr://192.168.1.32:5555/

9. Restart goesrecv and play around with the config parameters.

If your vit errors are under 400, and you’re observing no packet drops, you’re all set!

If the average errors are at around 1500-1800, try the following:

• Terminate and restart goesrecv. This should allow it to readjust the gain and frequency offset to get a better read on the signal. This is done by editing the goesr.conf file.
• Cool the Raspberry Pi and the RTL-SDR dongle. Too hot and your PI will throttle down.
• Play around with goesrecv.conf parameters. Try adjusting the gain and sample_rate. For the NooElec XTR or other E4000 tuners, you might need to set your gain to 10 or below.

Once you decreased the error rates, but your vit is still over 400, try making very slight adjustments to the antenna again. Try adjusting the reflector in or out, and try flipping it. In each case monitor your  vit .

10. Turning packets into images

While goesrecv is running in one SSH session, start another separate SSH session, and run:

goesproc -c /usr/share/goestools/goesproc-goesr.conf -m packet  --subscribe tcp://127.0.0.1:5004

This can take a few minutes until it has received enough packets. Once goesproc receives enough packets, it will start writing images and text to the locations described in /usr/share/goestools/goesproc-goesr.conf.

Writing: /home/pi/goes/./goes16/fd/staticimage/GOES16_FD_FC_NOMAP20200527T140016Z.jpg (took 1.838s)
Writing: /home/pi/goes/./goes16/fd/NOMAP/2020-05-27/GOES16_FD_FC_NOMAP20200527T140016Z.jpg (took 1.804s)
Writing: /home/pi/goes/./goes16/fd/ch02/2020-05-27/GOES16_FD_CH02_20200527T140016Z.jpg (took 1.474s)
Writing: /home/pi/goes/./goes16/fd/fc/2020-05-27/GOES16_FD_FC_20200527T140016Z.jpg (took 1.981s)

...

Congratulations your receiving and decoding GOES!

Periodically, the code for goestools is updated. You should periodically do the distribution upgrades, and the apt package upgrades, but also go to the goestools directories and do a “sudo git pull” and then the recompile the tools periodically as well. BACKUP YOUR CONF FILES!!!!!

cd goestools
git pull
cd build
cmake -DCMAKE_INSTALL_PREFIX:PATH=/usr ..
sudo make -j2 install

Transferring files to your PC

I use the software called Syncthing. This software allows you to synch the files on your RPI with your PC. I find it nice and simple to use.

You can choose between the “stable” (latest release) or “candidate” (earlier release candidate) tracks. The stable channel is updated usually every first Tuesday of the month.

# Add the release PGP keys:
curl -s https://syncthing.net/release-key.txt | sudo apt-key add -

# Add the "stable" channel to your APT sources:
echo "deb https://apt.syncthing.net/ syncthing stable" | sudo tee /etc/apt/sources.list.d/syncthing.list

# Update and install syncthing:
sudo apt-get update
sudo apt-get install syncthing

The candidate channel (may have bugs!) is updated with release candidate builds, usually every second Tuesday of the month. These predate the corresponding stable builds by about three weeks.

# Add the release PGP keys:
curl -s https://syncthing.net/release-key.txt | sudo apt-key add -

# Add the "candidate" channel to your APT sources:
echo "deb https://apt.syncthing.net/ syncthing candidate" | sudo tee /etc/apt/sources.list.d/syncthing.list

# Update and install syncthing:
sudo apt-get update
sudo apt-get install syncthing

Depending on your distribution, you may see an error similar to the following when running apt-get:

E: The method driver /usr/lib/apt/methods/https could not be found.
N: Is the package apt-transport-https installed?
E: Failed to fetch https://apt.syncthing.net/dists/syncthing/InRelease

If so, please install the apt-transport-https package and try again:

sudo apt-get install apt-transport-https

Syncthing is configured via a web interface, with default IP address of 127.0.0.1 (localhost). As we’re running Raspbian Lite, we don’t have a GUI and therefore can’t run a web browser on the Pi. So we’ll need to open the browser-based configuration GUI on a networked PC. To do this we need to set the IP address of the GUI to the Pi’s local network address. Edit the syncthing config, and under the <gui> entry, change the <address> value to 0.0.0.0 which will allow you to connect to the Pi’s IP Address.

sudo nano /home/pi/.config/syncthing/config.xml

Save and Exit the nano editor with CTRL+X then Y then ENTER

Run “syncthing” on the PI

On your PC web browser, navigate to http://yourPIipaddress:8384

On the PC you will be syncing files with, download the appropriate version of syncthing. There are versions for Windows, macOS, Linux, etc. after you install and run it, your browser will open with the GUI for syncthing. Click “Add Remote Device” Just let it sit for about 5 minutes or so (not sure why this takes so many minutes, but it did on mine), Within a few minutes the Raspberry PI GUI should pop up with a new device as well. Add The Device.

Within the raspberry PI GUI set the folder path to /home/pi/goes and create a label, like Goes Images, or Satellite Imagery. Go to the sharing tab and share it with your Windows PC.

Again, after a few minutes or two, the Windows GUI web interface should pop up with a “New Folder” alert. Click on “Add”, then under “Folder Path” set where you want the all the image files to be copied to. Then click on save.

After a few minutes, things should start syncing.

Autostart Goestools and Syncthing

First a word about automatically starting your RPI and goestools, etc. Work with the processes listed above, get comfortable with how they run, where the imagery is saved, and make sure everything is running BEFORE you add auto-start. Any trouble shooting should be done ahead of time!

I added the ability to have my PI automatically start all of the goestools processes and the syncthing software on boot or after a power glitch.   You can add other goesproc processes if you wish as well. be sure and match the file structure to your own set up!

By editing the rc.local file in the /etc/ directory on the PI as such:
#!/bin/sh -e
#
# rc.local
#
# This script is executed at the end of each multiuser runlevel.
# Make sure that the script will "exit 0" on success or any other
# value on error.
#
# In order to enable or disable this script just change the execution
# bits.
#
# By default this script does nothing.
# Print the IP address
_IP=$(hostname -I) || true
if [ "$_IP" ]; then
printf "My IP address is %s\n" "$_IP"
fi
#
#Start Goestools
#
/usr/bin/sudo -u pi /usr/bin/screen -dmS goesrecv /usr/local/bin/goesrecv -v -i 1 -c /home/pi/goesrecv.conf
#
/usr/bin/sudo -u pi /usr/bin/screen -dmS goesproc /usr/bin/goesproc -c /usr/share/goestools/goesproc-goesr.conf -m packet --subscribe tcp://127.0.0.1:5004 --out /home/pi/goes
#
#
#Start Syncthing
#
/usr/bin/sudo -u pi /usr/bin/screen -dmS syncthing /usr/bin/syncthing
exit 0

If the ‘screen’ app is not on your PI, run

sudo apt update
sudo apt-get install screen 

You can view the Processes running by /using the commands

screen -r goesrev 
or screen -r goesproc 
or, lastly 
screen -r syncthing   

To stop viewing press ‘ctrl A then D’. The processes will keep running in the background.

I just remembered the third thing! Pay it forward! I had some help from a wide variety of folks. Quite literally from all corners of the planet. So if you’ve got all this working, consider helping someone else out! Maybe go to a school or girl scouts, and show them the fundamentals!