After introducing the hardware and the devices we have used, we would like to talk a little about the software which is the main part of the SDR concept.
There are 3 types of software that we have to use to process and visualize the data in our computers.
The first one is the drivers to make the computer to recognize the hardware of the RTL-SDR USB dongle.
The second kind of software is the decoding software which will receive the data of the ADS-B from the USB dongle and decode it to get all the information of the message. We must remember that the ADS-B data is encoded by formulas defined in the ICAO doc.9871 and that the messages are broadcasted in hexadecimal format, which means, that must be translated to binary format or decimal format to get the data in an understandable form.
The third kind of software is the visualizer or plotter that catches the processed data and plot in a visual way to make the information to be easily seen in a screen.
Another kind of software is for example the FlightRadar24 feeding software that the only task that performs is to get the decoded data and send it to his web server to show the data in real-time like we could do in plotters but in this case anyone can view it.
There are these three types of software for windows and for linux, which means there is no a problem to get the raspberry pi running any kind of linux software to get it working.
3 categories of software:
- Drivers: to recognize the device and get the information received.
- Decoding software: to process and decode all the information we receive.
- Plotting software: to plot in a real-time map all the information and update it every certain period.
- Driver: Zadig.
- Decoding software: SDRsharp, ADSBsharp, rtl1090…
- Plotting software: Planeplotter (trial-period of 30 days), ADSBScope (free software), VirtualRadar3D…
- Driver: git://git.osmocom.org/rtl-sdr.git
- Decoding software: dump1090, gnuradio with gqrx…
- Plotting software: dump1090 (it has plotting options like a web server).
Options of software for linux: http://zr6aic.blogspot.co.uk/2013/02/setting-up-my-raspberry-pi-as-sdr-server.html
- All the software runs on the Rpi.
- All the software runs on a laptop.
- Sending the data by Internet(IP) from the Rpi to a laptop to process the data.
Advantatge: We can locate the Rpi closer to the antenna.
Knowing all of the prerequisites to understand how we can get this working, we have different possibilities depending on the kind of scenario that we think could be the most interesting.
We have one scenario that runs all the software on the raspberry pi but, in this case, we do not visualize the data but that we share the data to the FlightRadar24 website in real-time.
By taking into account this possibility the dump1090 software can be considered of the second and third kind of software. We mean that it decodes the information and then it plots the information like a web server in a google maps web page to show the result of what we are receiving.
Another possibility is to run all the software on a laptop or personal computer by connecting the USB dongle into it. This option allows us to visualize the information in our laptop.
And the third possibility is to get the information with the raspberry pi, for antenna position problems for example, and then send via Internet(IP) this information to the laptop, which will process and plot this information. Although for the kind of data we must treat, there is no a problem to run all the software on the raspberry pi instead of having a laptop on all the day consuming electricity.
- FlightRadar24.com (we have used this one).
- PlaneFinder.net (planeplotter sharing option).
- RadarVirtuel.com (not able to share with SDR concept).
There are a lot of web pages that plot in real-time the data of lots of receivers around the world and shows the airborne traffic of the majority part of the world but we have chosen the FlightRadar24 to feed the data because it gives us the possibility of running a linux pre-compiled version of his feeding software to run on the raspberry pi.
Another reason to have chosen this web is because they give us free premium applets to get the aircraft traffic in your smart phone, in our tablet and includes other tracking options like radar view in the maps, etc.
This is the scenario we have created and we are running nowadays to get all of this working: