Category: Applications

BigWhoop now a finalist in the NASA Global People’s Choice Award

Previously we posted about BigWhoop which is a project entry into the NASA International Space Apps Challenge. The BigWhoop team aim to create a networked system where RTL-SDR’s are used around the world to continually monitor the global radio spectrum.

Now BigWhoop have won the Stuttgart chapter of Global NASA Space Apps Challenge and have been chosen as one of the 15 finalists in the competition. You can help the BigWhoop team by voting daily so that they can get into the top 5 finalists. Voting lasts until May 3.

Since our last post the BigWhoop team have also written an update on their project progress. They write:

Ultimately BigWhoop is intended to run on the Constellation computation grid with 60,000 computers. However, we started a pre-alpha test. So we asked for your help during the hackathon weekend to plug in your software defined radio devices and start a sensor node for us. Our BigWhoop software was already able to send this to our server at shackspace and we received data from nice people in Virginia, US and Bremen, Germany. With this help, we were able to show you a first live demo at the end of the hackathon. Since then, we received further data and are really overwhelmed by everyone’s support and want to say a big THANK YOU!

OpenWebRX: A Multi-User RTL-SDR Receiver with Web Interface

From Reddit we’ve learned of a new web based SDR receiver software for the RTL-SDR called OpenWebRX. This python based software allows you to run a web server that allows multiple users to connect to an RTL-SDR and listen to it through a web interface. The web interface also allows the RTL-SDR frequency and mode settings to be controlled. The software appears to still be in beta, so it may have some bugs.

The author has also written his BSc. thesis on this software and it is available for reading here. The thesis describes his software design and implementation as well as some SDR theory and may be useful to anyone wishing to implement similar SDR software.

OpenWebRX Web Interface.
OpenWebRX Web Interface.

New ADS-B Android App for North America

Previously we posted about Android programmer Tosis Nikolaos’s last app which was called “Track your flight Europe”. The app allows you to view aircraft tracked via ADS-B received by an RTL-SDR on an offline map. 

Now Nikos has written into us once again to let us know about his new app called “Track your flight North America“. It is the same as his previous app, but this one has high resolution offline maps for North America. He also writes that his Europe app has also been updated to support high resolution offline maps. The app costs 5.09 Euros + VAT. To run it you will need an Android device and an RTL-SDR with OTG cable.


Track My Flight HD Maps
Track My Flight HD Maps

Setting up the Linrad waterfall with high sensitivity for weak signals

Leif, the programmer of Linrad has uploaded a video on YouTube showing how to set up it’s waterfall for very high sensitivity reception of extremely weak signals. Linrad is an SDR GUI receiver software with a tough learning curve, but very advanced features. In the tutorial Leif uses an RTL-SDR dongle to receive a weak beacon at 144.412 MHz. He shows how to adjust the Linrad settings to produce a waterfall and FFT spectrum that it optimized for visualizing and tuning to very weak signals such as distant beacons.

Tutorial on using Modesdeco2 for ADS-B with the RTL-SDR

Over on the blog, the author has recently created a tutorial showing how to use Modesdeco which is a multi platform command line ADS-B decoding software application. ADS-B stands for Automatic Dependent Surveillance Broadcast and is a signal broadcast by aircraft that can be used to track them like a radar. 

Modesdeco is a command line ADS-B decoder quite similar in purpose to other software like dump1090, RTL1090 and ADSB#, however it has more available features built into it. The blog author writes about Modesdeco:

Want to feed BaseStation and PlanePotter at the same time? No problem. Want to add another data stream for Virtual Radar Server? No problem. Want statistics about the types of data being received? No problem. Want to run it on a variety of platforms, including Windows, Mac OS X, Linux, or the RaspberryPi? No problem.

The author’s tutorial goes over setting up the software on Windows and turning on some features like it’s web statistics interface, interactive map and how to feed data to another virtual radar application like Basestation. In the future the author plans to write a second tutorial showing how to use another feature which allows a user to combine the ADS-B feeds from various computers running Modesdeco.

Screenshot of the Modesdeco statistics web interface.
Screenshot of the Modesdeco statistics web interface.

SDRRecorder – A Linux Script for Recording an IQ Stream at a given Date and Time

Programmer MichelinoK has just released another one of his projects. This one is called SDRRecorder and is a Linux bash script that can be used to automatically record an IQ stream of any frequency and length at a given date and time. MichelinoK writes that he uses this script to automatically record International Space Station (ISS) passes at 145.8 MHz on his Raspberry Pi which is always powered on.

The script can easily be run by first editing the script to specify the frequency, dongle number, gain, PPM offset and destination folder. It can then be run by calling is with the start time, date, length and output file name. He also writes that you must be careful to not record for too long as long IQ files can use up a lot of disk space. To overcome this he uses a networked attached storage (NAS) device which is similar to an external hard drive.

Remote RTL_UDP: RTL-SDR Remote Control Android App

Over the past few weeks programmer MichelinoK has been working on an Android app that allows the RTL-SDR to be listened to and controlled remotely. The app is called “Remote RTL_UDP” and allows you to control the parameters such as frequency, modulation type and gain settings on a remote rtl_udp server. It also allows you to store frequencies in a database and import frequencies from a SDR# database. The server can be run on a Raspberry Pi, Linux PC or any Linux device that is capable of running rtl_fm.

The post contains a full tutorial on the set up which involves the installation of ezstream and icecast for streaming audio as well as instructions for the installation of the modified version of rtl_fm called rtl_udp which allows remote control of the parameters via udp.

Android RTL_UDP Interface
Android RTL_UDP Interface

AISRec for Android: New AIS Decoder

Back in December last year we posted about Jane feverlay’s work on his software called AISRec, which was a Windows AIS decoder for the RTL-SDR that he had developed.

AIS is an acronym for Automatic Identification System and is a system used by ships to broadcast position and vessel information. By monitoring AIS transmissions with the RTL-SDR we can build a boat radar system. We have a tutorial on this here.

Now from YouTube it looks as though Jane has developed a new Android version of AISRec which he describes as a high performance dual-channel AIS receiver for use with a single RTL-SDR dongle. The features of AISRec include:

1. Functions include AIS and GPS NMEA I/O, from/to USB devices and serial ports (special android devices with serial ports).
2. It supports TCP server and UDP forwarding jointly or independently for AIS and GPS.
3. It supports steaming in WIFI in AP or station modes and Ethernet.
4. It supports auto run on boot for especially rooted devices.

He also writes that AISRec also has companion implementations for Windows desktop and metro, Linux on Raspberry Pi 2 and the Radxa pro.

Unfortunately, at the moment there does not seem to be a link available to download the software and the video may only be a preview. The video does link to his Taobao shop at (in Chinese use Google Translate), which is where he might release the software when it is ready.