DangerousPrototypes.com have brought to attention a GNU Radio RDS decoding project from the website at Anotherurl. Check out the original post here. Anotherurl uses a GNU Radio Companion flowgraph and a .NET program to decode FM RDS messages. RDS is an acronym for Radio Data System, which is used in FM radio transmissions to embed information such as radio station and programme/song information. Some conventional FM radios display this information on an LCD screen. The popular SDRSharp SDR receiver also has RDS decoding built into it’s FM receiver already, but a GNU Radio implementation is very useful for learning how RDS works.
It is now possible to decode the Meteor M2 weather satellite images in real time on Windows using an RTL-SDR and a plugin for SDR#.
Decode POCSAG pager messages with an RTL-SDR. Even in the modern day pagers are still popular with doctors, some fire and ambulance agencies and various service companies, as they tend to be more reliable and have greater coverage.
With an RTL-SDR dongle, a cheap $10 modified GPS antenna or 1-2 LNA’s and a patch, dish or helix antenna you can listen to Inmarsat satellite signals, and decode the STD-C NCS channel which contains information such as search and rescue (SAR) and coast guard messages as well as news, weather and incident reports.
New software defined radio (SDR) products are popping up every few months these days so we thought we’d compile a big list of available SDRs.
Modern planes use something called an ADS-B (Automatic Dependent Surveillance-Broadcast) Mode-S transponder, which periodically broadcasts location and altitude information to air traffic controllers. The RTL-SDR can be used to listen to these ADS-B signals, which can then be used to create your very own home aircraft radar system.
The RTL-SDR software defined radio can be told to run in a mode called “direct sampling mode”, which with a small hardware mod allows the dongle to tune to the HF frequencies where ham radio and many other interesting signals are found. This means that no upconverter circuit is required.
With the right additional hardware, the RTL-SDR software defined radio can be used as a super cheap radio telescope for radio astronomy experiments such as observing the Hydrogen Line and meteor detection.
Follow trunked radio conversations with your RTL-SDR and a program called Unitrunker. Also decode digital communications like P25 and DMR using the Digital Speech Decoder (DSD+) software.
Digital Radio Monodial (DRM) radio is a type of digital shortwave radio signal that is used by international shortwave radio broadcasters. It provides superior audio quality compared to AM signals by using digital audio encoding. With an upconverter, good antenna, and decoding software the RTL-SDR software defined radio can receive and decode DRM signals.
By using an RTL-SDR dongle together with a low cost noise source it is possible to measure the response of an RF filter. Also, with an additional piece of hardware called a directional coupler the standing wave ratio (SWR) of antennas can also be measured.