ARISSat-1: Why is it cool and why do we care?

ARISSat-1 photo 2It looks like AMSAT is going to launch a new satellite! ARISSat-1 – the successor of SuitSat-1 – is ready to be launched on Progress-41P heading to the International Space Station on Friday, January 28, 2011. It will be deployed into its own orbit during EVA 27 currently scheduled for February 16. Once in orbit, it will slowly decay and eventually burn up in the Earth’ atmosphere. SuitSat-1 decayed after 7 months in orbit and that’s also a likely life time for ARISSat-1.

So, why is ARISSat-1 cool and why should we care?

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Packet radio from the ISS with GNU Radio and USRP

On July 10, 2010, I was listening to the linear transponder downlink of VO-52 when I suddenly noticed a very strong peak about 50 kHz below. I checked Gpredict and found out that it was the APRS downlink from the International Space Station RS0ISS on 145.825 MHz. Thanks to the flexible GNU Radio framework and the USRP, I could easily receive both satellites at the same time as shown on the video below.

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Binaural CW Receiver with GNU Radio and USRP

Today I felt like doing an experiment that is not quite on my TODO list – a binaural CW receiver. A binaural CW receiver is a receiver that gives a spatial feeling while you are tuning. As I understand it, you have to use stereo where the signals move from one side to the other as you tune and are in the middle when you are tuned to the frequency.

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Improved AGC for the simple SSB receiver

Few days ago I wrote about how I upgraded the simple double side band receiver implemented in the GNU Radio Companion to a simple single side band receiver. This initial implementation used some default values for the AGC attack and decay rates. These values were acceptable; however, I wanted to spend some time trying to find better values that would correspond to Fast, Medium and Slow AGC – just as we are used to in commercial radios.

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Fun with WebSDR and Fldigi

Tonight I had some fun with Fldigi connected to Web SDR. I could actually listen to and decode digital ham radio traffic on the 80 and 40 meter bands without using a radio or antenna. The way I achieved it was by configuring Fldigi to capture its data using the built-in microphone and turn the … Read more

GNU Radio Projects

This page provides an overview of the various projects and experiments I am or have been doing with GNU Radio and the Universal Software Radio Peripheral (USRP). GNU Radio is a free, open source software development toolkit that provides the signal processing runtime and processing blocks to implement software defined radio. The USRP provides a … Read more