No Mars Express experiment this time

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It was a difficult decision to accept, but the Mars Express experiment with the USRP and GNU Radio is not going to happen this time! It’s a shame because the link budget looked quite promising. An optimistic estimate gives almost 20 dB signal to noise ratio, which is more than we need, so the problem … Read more

Aiming for planetary science with GNU Radio and the USRP

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Thanks to the European Space Agency (ESA) and the Mars Express mission, we might have an opportunity just around the corner for doing big science with GNU Radio and the USRP!

On March 3, 2010, Mars Express will visit the Martian moon Phobos by performing a close flyby. According to ESA, the ESOC ops team is working with a number of possible scenarios, including one that would take the spacecraft to just 50 km above Phobos. At that distance the orbit of the spacecraft is expected to be influenced by the gravitational pull of Phobos. I knew this already for about a week when I first read it on the Mars Express Blog but it was first today that I realized the opportunities this event offers.

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WBX Transceiver Tests using GNU Radio and USRP

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This video shows my first on-the-air tests with the WBX transceiver using the USRP (Universal Software Radio Peripheral) and GNU Radio.

The receiver was tested using wide band FM broadcast, APT signal from NOAA 17 satellite and Copenhagen VOLMET. I have also performed some tests using DVB-T signal and wireless sensor signals but I wanted to keep the video short so these were not included. I can post them in separate videos if there is interest.

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WBX receiver test on the air: Copenhagen VOLMET

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I have been quite busy during the last weeks doing overtime at work, nonetheless, I have managed to carry out some small on the air tests of my newly acquired WBX transceiver boards for the USRP and GNU Radio. Tonight, I tuned in to Copenhagen VOLMET that transmits AM on 127.000 MHz.

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The WBX 50-2200 MHz transceiver

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It was a good day today. At long last, I have received my WBX transceiver boards for the USRP! I have been waiting for this transceiver board for quite some time now because I didn’t really have and transmit capabilities in the VHF and UHF bands. This board was expected to cover 50 MHz to … Read more

High Definition Broadcasting Experiments

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As you may know I have been flirting with live broadcasting on Ustream for a while now. While it is a great free service I was not particularly happy about the default webcam stream, which appears to be very low resolution, not much higher than 320×240. Ustream offers high quality streaming using their browser plugin and even high definition-like using the Flash Media Live Encoder from Adobe. Unfortunately, neither of these is available for anything else than Windows.

I wanted to try so much that I even tried the Flash Media Live Encoder under Vista. Well, it was a total fail… My computer froze after broadcasting a few seconds even at VGA-like resolutions. I think I spent a whole Sunday trying various configurations and setting but no luck. Slow computer? Buggy software? Probably both.

Few days ago I learned that Adobe is now in the process of making a Mac version of Flash Media Live Encoder. Hurray! In fact, it is already available for selected beta testers but no timeline for public release. Fortunately, I was able to find a kind soul who has shared the beta package for Mac with the rest of the world (thanks Google search for finding me this) and so I got the opportunity to become an unofficial beta tester.

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