[Italian] Spiegazione: Reception of the. Unlike previous decoder versions, the panel is now interactive, so you can click. Last batch is always available for review even after firing up the program for a new session. This software is closed source and has been since it was first released. Coverage (except the poles) within the Inmarsat-C communications system.

[Carl] just found a yet another use for the RTL-SDR. He’s been with it. Inmarsat is a British satellite telecommunications company. They provide communications all over the world to places that do not have a reliable terrestrial communications network.

STD-C is a text message communications channel used mostly by maritime operators. This channel contains Enhanced Group Call (EGC) messages which include information such as search and rescue, coast guard, weather, and more. Not much equipment is required for this, just the RTL-SDR dongle, an antenna, a computer, and the cables to hook them all up together. Once all of the gear was collected, [Carl] used an Android app called Satellite AR to locate his nearest Inmarsat satellite. Since these satellites are geostationary, he won’t have to move his antenna once it’s pointed in the right direction.

Hacked GPS antenna As far as antennas go, [Carl] recommends a dish or helix antenna. If you don’t want to fork over the money for something that fancy, he also explains how you can modify a $10 GPS antenna to work for this purpose. He admits that it’s not the best antenna for this, but it will get the job done. A typical GPS antenna will be tuned for 1575 MHz and will contain a band pass filter that prevents the antenna from picking up signals 1-2MHz away from that frequency. To remove the filter, the plastic case must first be removed.

Then a metal reflector needs to be removed from the bottom of the antenna using a soldering iron. The actual antenna circuit is hiding under the reflector. The filter is typically the largest component on the board. After desoldering, the IN and OUT pads are bridged together. The whole thing can then be put back together for use with this project.

Once everything was hooked up and the antenna was pointed in the right place, the audio output from the dongle was piped into the SDR# tuner software. After tuning to the correct frequency and setting all of the audio parameters, the audio was then decoded with another program called tdma-demo.exe.

If everything is tuned just right, the software will be able to decode the audio signal and it will start to display messages. [Carl] posted some interesting examples including a couple of pirate warnings. If you can’t get enough RTL-SDR hacks, be sure to check out of the we’ve in the. And don’t forget to! • • • • Posted in, Tagged,,,,,,,,,,,,,, Post navigation.

Inmarsat C provide broadcast messages known as Enhanced Group Calls (EGC). EGC is the system for broadcasting messages via Inmarsat C and it supports two services: SafetyNET and FleetNET. SafetyNET is a free service of maritime safety information and search and rescue related information via the Inmarsat EGC system.

SafetyNET receiving capability is part of the mandatory equipment required to be carried by certain ships.SafetyNET messages can be directed to all ships in an entire ocean satellite region, to fixed NAVAREAs/METAREAs, so is not private communications. FleetNET is a commercial service and allows information to be sent to a virtually unlimited number of predesignated mobile terminals simultaneously, irrespective of their position. To receive EGC FleetNET messages, ships should have an Enhanced Data ID (ENID) downloaded into the terminal by a FleetNET service provider using a poll command. The service may be used by shipping companies, organisations distributing news, commercial weather providers, etc.