Amateur radio hobbyist LA3ZA shows an image on his blog showing how busy the 70cm ISM band can be in his area in Norway. He uses a roof mounted 1.7 m long vertical antenna with 7.2dBi gain in the 70 cm band. Each signal burst may come from a remote car key, weather monitor, electricity monitor, or other telemetry device. Some of these signals may be decodeable with rtl_433.
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.
The Meteor-M N2 is a polar orbiting Russian weather satellite. With an RTL-SDR an appropriate antenna, you can receive and decode its image downlink and download LRPT weather satellite images.
ACARS is an acronym for Aircraft Communications Addressing and Reporting System and is a digital communications system that aircraft use to send and receive short messages to and from ground stations. With an RTL-SDR these messages can be decoded.
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.
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.
Everyday multiple NOAA weather satellites pass above you. Each NOAA weather satellite broadcasts an Automatic Picture Transmission (APT) signal, which contains a live weather image of your area. The RTL-SDR dongle combined with a good antenna, SDRSharp and a decoding program can be used to download and display these live images several times a day.
Use your RTL-SDR to decode data from weather balloons (aka Radiosondes) that are launched twice daily by meteorological agencies all around the world.
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.
The RTL-SDR software defined radio can be used to analyze cellular phone GSM signals, using Linux based tools GR-GSM (or Airprobe) and Wireshark.
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#.