Decoding Inmarsat STD-C EGC Messages

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.

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Receiving NOAA Weather Satellite Images

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.

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Listening to TETRA Radio

Use your RTL-SDR in Linux to listen to TETRA, a digital trunked radio communications system that stands for “Terrestrial Trunked Radio”.

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The BIG List of RTL-SDR Supported Software

There are now dozens of software defined radio packages that support the ultra cheap RTl-SDR. In this post we will attempt to list, categorize and provide a brief overview of each software program.

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Measuring filter characteristics and antenna VSWR with an RTL-SDR and noise source

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.

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Roundup of Software Defined Radios

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.

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Decoding Meteor-M2 Weather Satellite Images in Real-Time

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#.

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JAERO: A RTL-SDR compatible decoder for Inmarsat AERO signals

AERO is a system that provides a L-Band satellite based version of VHF ACARS (Aircraft Communications Addressing and Reporting System). ACARS is typically used by ground control and pilots to send short messages and is also sometimes used for telemetry. With JAERO and an RTL-SDR these signals can be decoded.

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List of SDRSharp Plugins

There are a number of SDRSharp plugins that extend its functionality. Here is a collection of all the plugins and download links that we know of.

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RTL-SDR for Budget Radio Astronomy

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.

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Tip to Reduce Radio Interference on the RTL-SDR

A few months back we posted about a tip to reduce RFI (Radio Frequency Interference) on the RTL-SDR. Now Akos from the SDR for mariners blog has tried this tip for himself and written about his experience with it, after getting inspired to by a post in the rtl-sdr.com/forum.

To reduce RFI, the tip recommends disconnecting the shield connection of the USB cable from the ground connection of the RTL-SDR dongle. This overcomes a design flaw in the RTL-SDR which allows the shield of the USB extension cable to act as an antenna, causing unwanted RFI.

What Akos did was to remove the metal part of the USB extension cables connector to prevent any ground connection. This already reduced an interfering signal by 10dB. He also found that wrapping the connection point in foil further reduced the noise. Connecting coax to the ground then coiling it up and putting the RTL-SDR in the center of the coil also appears to significantly reduce RFI.

Update: Akos has also tried using ferrite chokes on the USB cable, and also found they significantly reduce interference.

Check out the full post by Akos for more information here

RFI noise reduction in the RTL-SDR

4 comments

  1. Emily Taylor

    I use a big ferrite core on my USB cable helps really well. I also made a Faraday Cage with ground connection to set it in, I really only use it for HF most of the time VHF and higher is usually fine :3

  2. mars

    IMO, the very first thing one should do is mount the rtl in a good metal box (I like the cast Hammond) with proper UHF/USB connectors to the outside world. Then experiment with grounding/shielding.

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