Tagged: meteor M

Decoding Meteor-M Images on a Raspberry Pi with an RTL-SDR

Thanks to Andrey for writing in and showing us his Java based Meteor-M decoder for the RTL-SDR which he uses on a Raspberry Pi. The decoder is based on the meteor-m2-lrpt GNU Radio script and the meteor_decoder which he ported over to Java. Essentially what he's done is port over to Java a bunch of GNU Radio blocks as well as the meteor decoder. The ported Java blocks could also be useful for other projects that want to be cross platform or run without the need for GNU Radio to be installed.

In his blog post (blog post is in Russian, use Google Translate for English) Andrey explains his motivation for writing the software which was that the Windows work flow with SDR# and LRPTofflineDecoder is quite convoluted and cannot be run headless on a Raspberry Pi. He then goes on to explain the decoding algorithm, and some code optimizations that he used in Java to speed up the decoding. Andrey notes that his Java version is almost 2x slower compared to the GNU Radio version, but still fast enough for real time demodulation.

Meteor-M2 is a Russian weather satellite that operates in the 137 MHz weather satellite band. With an RTL-SDR and satellite antenna these images can be received. Running on a Raspberry Pi allows you to set up a permanent weather satellite station that will consistently download images as the satellite passes over.

Decoded Images with Andry's Meteor-M software on Raspberry Pi.
Images received with Andry's Meteor-M software running on a Raspberry Pi.

A New Meteor M LRPT Image Decoder for Windows, Linux, MacOS and Raspberry Pi

Thanks to twitter user @LinuxSocist for submitting a link to this new Meteor M weather satellite LRPT decoder called ‘meteor_decoder’ which can be run on both Linux and Windows. Pre-built binary of the software for Windows, Linux Raspberry Pi and MacOS are available at orbides.org.

This software decoder appears to be an excellent choice for those people who want to perform their reception and decoding of Meteor M satellites all in Linux. Previously as explained in this previous post, you were able to receive the QPSK data in Linux with an RTL-SDR and a GNU Radio program, but then you’d still need to boot into Windows or run Wine to run LRPTofflinedecoder in order to generate the image. Now it appears that the image generation can be performed natively in Linux too with meteor_decoder. This help with creating portable automated Raspberry Pi based Meteor M decoder servers.

Meteor M is a class of Russian weather satellites that transmit live weather images of the earth as they pass over your location. They are somewhat similar to the NOAA satellites, although the Meteor satellites transmit higher quality images via a digital LRPT signal, rather than the analog APT signals used by NOAA. With an RTL-SDR, an appropriate antenna and decoding software they can easily be received.

An Example LRPT Image Received with an RTL-SDR from the Meteor-2 M2.
An Example LRPT Image Received with an RTL-SDR from the Meteor M-N2 Satellite.