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scripts for sceduled lrpt reception and decoding

A project log for skywave weather satellite rxr

a low cost ground station for weather sat receiving using an oPiZero, sdr dongle, and a home brew antenna

timaddisontim.addison 11/25/2017 at 20:363 Comments

I've been working on a ground station to receive LRPT images from the Russian meteor-m2 satellite for a while now.  The scripts for automated recording, decode, and uploading are working reliably now so I thought I'd share.

All of this work is based on haslettj instructables guide, I modified his scripts to work with the tools below  to receive and decode LRPT signals. 

Tools:

In addition to the tools haslettj uses you'll need to get the following setup and working. Most are pretty self explanatory.

Reception and QPSK decode

I hacked up Otti's gnuRadio flow graphs to work from the command line for easier scheduling. There is a single input variable for the output file name. The output is a .s file which works with artlav's meteor_decoder tools.

You'll want to change the rtl=xxx string on line 52 to work with your rtl device ID.

This py needs gnuRadio 3.7 or newer installed, use your package manager.

Image decode

artlav's meteor_decode handles taking the captured qpsk data and turning it into a bitmap.

Uploader

i'm using prasmussen's gdrive tool to upload the decoded image to my google drive folder.

Scheduler

The github of my modified scripts is here.  Create a soft link to schedule_all so that it runs as a  cron task daily.  You'll need to modify each of the scripts to work with your own home directory location.  The qpsk decoder is dumping the received data into a file on a ramdisk. This is to lower latency and prevent gnuRadio from complaining about buffer overruns "OOOO".

Discussions

Dominik wrote 01/16/2018 at 14:34 point

Hello, i am from Germany  and do´nt understand how to install the modified scripts. How to get the right Gnuradio Version? Do you have instructions to run this? It may make it  easyer for me.

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Ruben EA5BZ wrote 12/12/2017 at 21:02 point

Really GREAT.

I was looking for something like this.

I will test it tomorrow.

Now i was saving Meteor IQ Files with rx_sdr and decoding after with SDR# and Plugins.

Now i will have a FULL Raspberry NOAA + Meteor receiver.

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tim.addison wrote 12/14/2017 at 04:44 point

Ya man, sit back and let the machine do the work.  It's nice to wake up in the morning and see your images from 4 am waiting for you!

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