Re- sending.

Take time to watch! Good Job Henk !

73 Fabiano

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Hello all,

In case you didn't see the announcement about a video produced by Henk,

below is the link. It is a really nice video showing amateur radio contribution to space science. I plan on using this video when I give presentations to high school students. I also plan on showing it to my bosses so I

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can get more science missions made available to the amateur radio

community.

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These two satellites have been a learning experience. There are some

things I will want to do differently. I enjoyed getting reports from you and working with you. I want to do it again and it looks like it may happen. We have another science experiment in proposal and are starting to get some

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funding. The mission will be to map the radiation environment in real

time. The trick will be to get the potentially large amount of data down. 9600 baud may not be fast enough. I will try to work something out to stay within the common amateur radio gear. I may have to switch to KISS mode for

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more compact data.

Also, if anyone has captured any audio, hold on to it. I know one of the

experiments was to try out FX.25. This is an experimental protocol that wraps forward error correction data around the standard AX.25 packet. This method allows standard TNCs and software to decode error free packets

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while allowing FX.25 decoders to recover AX.25 packets with a few bit

errors. We tried getting the FX.25 software completed but time constraints have been the issue. Last Friday, we were able to test the FX.25 decoder on some audio files and were able to recover corrupted packets. Our small

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sample showed up to 50% recovery rate. We will be processing more audio

files. Our next step is to make the code available. It runs on linux only. Our first problem was trying to get access to the raw data stream before any AX.25 decoder. We were able to find where to tap the raw bit stream in

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the soundmodem software and pipe it to our FX.25 decoder program. We will

write up some

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documentation and release the software in the next couple weeks. You can

try running your audio files through the software and see if you see any improvements.

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So, next question. How many people are running linux for their ground

station? How many would be interested? We are thinking for the next satellite to develop a telemetry protocol with forward error correction that will greatly improve packet decoding. We will target FM modulation since that

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is easier to track and capture. Since we only know how to program in

linux, we would target that platform. Anyone wanting to port to Windows or Mac is welcomed to our code.

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Ivan

http://www.youtube.com/watch?v=WGvRnqII0j8&feature=channel_page (enable HD for best quality)

73, Henk

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73 Fabiano Moser CR7/PY5RX ARISS-PORTUGAL (Amateur Radio on the International Space Station) Representative at Teleconference and Portugal Telebridge Coordinator. AMRAD/AMSAT-CT http://www.amrad.pt/ariss.php

"There is no great talent without great will. (Honoré de Balzac)"