Also see the original Pieter Noordhuis's guide
You need:
- Raspberry Pi Model B (or B+) with a MicroSD Card $35-40
- An RTL-SDR dongle:
- RTL-SDR.COM V3 ~$25 or
- NooElec NESDR SmarTee ~$25 or
- NooElec NESDR SmarTee XTR ~$40
- LNA and SAW filter for around 1.69GHz
- A 1.6 - 1.9 GHz parabolic grid antenna
- ZDAGP1900-20-15----1850-1990MHz 20dBi ~$100 or
- More dBi Options
- Or use a Modified 2.4 GHz WiFi grid antenna ~$60
- Adapter (depending on the antenna terminal):
- N-Male to SMA Male $5-10
- Cable(s)
- SMA Male to Male $5-10
Total: ~$185
Assembly:
[Antenna] --- [Adapter] --- [(input) SAWBird+ (output)] --- RTL-SDR (with Bias Tee)] --- [Raspberry Pi]
Prep your Raspberry Pi and install necessary drivers and software.
- Download Raspbian Lite Image and Etcher
- Use Etcher to write the image to the SD card.
- Mount the SD card as a volume on your machine.
- Follow this procedure to configure WiFi and SSH.
- Plug the card into your Raspberry Pi and turn it on.
- Find the IP address of the Raspberry Pi using your gateway/router administrative interface.
Now you can SSH into your Raspberry PI as pi with a default password raspberry.
From now on all commands should be run on the Raspberry Pi.
sudo apt update
sudo apt dist-upgrade
# reboot the device
sudo reboot# get the packages necessary to build and run goestools
sudo apt install git build-essential cmake libusb-1.0 libopencv-dev libproj-devGrab the latest librtlsdr source, compile it, and install the shared libraries/includes.
# 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 rebootrtl_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 doesn't 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
lsusbcommand. You should seeID 0bda:2838 Realtek Semiconductor Corp. RTL2838or something of the like listed there. If not, try the previous steps. - Run
dmesgand check for errors such aserror -71related to the USB device. This may mean that your RTL-SDR receiver might be broken. This happened to me, so I ordered another one, which ran fine.
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 cat <<EOF > ~/goesrecv.conf
[demodulator]
mode = "hrit"
source = "rtlsdr"
[rtlsdr]
frequency = 1694100000
sample_rate = 2400000
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"
EOFIf you're using a NooElec SmarTee dongle with an always-on bias tee, or if you're powering your SAWBird through the micro USB port, set bias_tee = false under [rtlsdr].
If you're using RTL-SDR.com dongle, set bias_tee = true to power the SAWBird board.
Find where the GOES-16 or GOES-17 satellites are in the sky at your location using agsattrack.com.
Note the azimuth and elevation.
Use an actual real compass to point your dish at the azimuth. I've been using the iPhone phone compass, which has a 20-30 degree error, rendering it practically useless.
You can also use https://www.dishpointer.com/ which will draw a line on the aerial map where to point your dish -- I found that to be more helpful than the compass.
Adjust your dish angle according to the elevation. Use your smartphone level app, or just eyeball it.
You should also adjust the skew of your dish roughly according to what https://www.dishpointer.com/ says under "LNB Skew". For GOES-17 I had to point the antenna's left long edge (if facing the same direction as the dish) up at 45 degree angle.
goesrecv -v -i 1 -c ~/goesrecv.confThis will show output every second that looks something like this:
...
2018-09-15T21:52:03Z [monitor] gain: 8.44, freq: -2121.4, omega: 2.589, vit(avg): 2400, rs(sum): 0, packets: 0, drops: 55
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.
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. Double check the antenna position again with a compass to make sure you're pointed at the intended satellite.
If you can't pinpoint the signal even after precicely adjusting the antenna, flip the dish 90 degrees and try again.
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. -
Cool the Raspberry Pi and the RTL-SDR dongle. I've noticed that temperature might significantly affect reception quality.
-
Play around with
goesrecv.confparameters. Try adjusting thegainandsample_rate. For the NooElec XTR or other E4000 tuners, you might need to set your gain to10or below.
Once you decreased the error rates, but your vit is still over 400, try making very slight adjustments to the antenna again.
While goesrecv is running, in a separate session, run:
goesproc -c /usr/share/goestools/goesproc-goesr.conf -m packet --subscribe tcp://127.0.0.1:5004Once goesproc receives enough packets, it will start writing images and text to the locations described in /usr/share/goestools/goesproc-goesr.conf.
Writing: ./goes16/m2/ch13/2018-09-15/GOES16_M2_CH13_20180915T231750Z.jpg
Writing: ./goes16/m2/ch13_enhanced/2018-09-15/GOES16_M2_CH13_enhanced_20180915T231750Z.jpg
Writing: ./goes16/m2/ch02/2018-09-15/GOES16_M2_CH02_20180915T231750Z.jpg
Writing: ./goes16/m2/fc/2018-09-15/GOES16_M2_FC_20180915T231750Z.jpg
Writing: ./goes16/m1/ch07/2018-09-15/GOES16_M1_CH07_20180915T231820Z.jpg
...
11. TODO: Automatically restart goesrecv, store images on S3, send metrics to statsd and Grafana, and make videos!
Stay tuned!
Does anyone have any tips on setting GAIN? I cant get vit under 700. Every time I set GAIN, it just sticks to 5, no matter what I put. I can modify the goesrecv.conf and adjust the sampling rate by adding a few 0s. I do this and it instantly throws and error when starting goesrecv and it stops itself from running. So I know modify config file is working since the bad sample rate clearly was read by goesrecv. Leaving everything in working order and changing the GAIN setting, it does nothing. Ive tweaked and tuned my antenna placement as best I can for now and then started to mess with GAIN and sampling rate. But for whatever reason I cant get it to adjust. Thanks for any help.