Open telecommand for BY70-1
Recently, Wei BG2BHC has published instructions for the use of BY70-1's camera by Amateurs. Essentially, there are three commands that can be used: 0x00 to take a picture and send it, 0x55 to take a...
View ArticleUpdated format for Outernet LDP protocol
After my talk in 33C3, George Hopkins has been doing some further reverse engineering of the Outernet protocols. By looking at the ondd binary, he has discovered that the length of the LDP header is...
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free-outernet gets LDPC decoding
In my previous post I talked about some small updates made by George Hopkins to my free-outernet project. In fact, George has been reverse engineering the ondd binary quite in depth and he has been...
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An erasure code based on Vandermonde matrices
I've been looking at an erasure code by Luigi Rizzo which is based on Vandermonde matrices, since this code is used in Outernet. In fact, it is the code implemented by the zfec library. Luigi Rizzo...
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GNU Radio decoder for AO-73
During the last few days, I have been talking with Edson PY2SDR about using GNU Radio to decode digital telemetry from AO-73 (FUNcube-1) and other FUNcube satellites. I hear that in Virginia Tech...
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Sending data from GNU Radio into Linrad using the network
During the last few days I've been experimenting with feeding signals from GNU Radio into Linrad using Linrad's network protocol. Linrad has several network protocols designed to share data between...
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Monitoring IMD levels in the EAPSK63 contest
This weekend I have recorded the full EAPSK63 Spanish PSK63 contest in the 40m band with the goal of playing back the recording later and reporting the stations showing excessively high IMD levels. In...
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Waterfalls from the EAPSK63 contest
Last weekend, I recorded the full EAPSK63 contest in the 40m band with the goal of monitoring IMD levels. I made a 48kHz IQ recording spanning the full 24 contest hours (from 16:00 UTC on Saturday to...
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Calibrating the Hermes-Lite 2.0 beta2 in Linrad
Lately, I have been trying to make an amplitude and phase calibration of my Hermes-Lite 2 beta2 in order to use Linrad's smart noise blanker. This is quite a task because Linrad doesn't support the...
View ArticleQuick fixes for some bugs in LimeSDR drivers
These days I have been experimenting with my LimeSDR board. This is an SDR board based on the LMS7002M transceiver chip. The drivers for the LimeSDR are called LimeSuite. This bundle contains a...
View Articlegr-satellites refactored
In August last year I started my gr-satellites project as a way to make my experiments in decoding Amateur Satellite telemetry easier to use for other people. Since then, gr-satellites has become a...
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Low latency decoder for LilacSat-1
LilacSat-1 is one of the QB50 project cubesats. It will be released tomorrow from the ISS. The most interesting aspect of this satellite is that it has an Amateur Radio transponder with an FM uplink on...
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Decoding AO-40 uncoded telemetry
AO-40 is an Amateur satellite that was active between 2000 and 2004. It had several transponders and beacons covering many bands from HF to microwave and its position on a HEO orbit provided several...
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A tour of QB50
The QB50 project consists in a constellation of cubesats with the goal of studying the thermosphere. The cubesats are built by different universities around the world and each of them carries one of...
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Waterfalls from QB50
In the previous post, I analysed a QB50 recording. Now I have prepared some waterfalls from my recording using the procedure I already described a while ago. The image above is obtained from a...
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Testing LilacSat-1 Codec2 downlink and GPS telemetry
Today I've finally had some time to test the LilacSat-1 Codec2 downlink on the air. I've been transmitting and listening to myself on the downlink during the 17:16 UTC pass over Europe from locator...
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Viterbi decoding for NanoCom U482C
The NanoCom U482C is a a transceiver made by GOMspace intended for cubesats and other small satellites. Currently, it seems to be out of production, since it has been superseded by the newer NanoCom...
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LilacSat-1 image downlink
Yesterday, Wei BG2BHC posted on Twitter an IQ recording of LilacSat-1 sending an image. LilacSat-1 has an onboard camera and it can send images using the same format as BY70-1. However, one has to keep...
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LilacSat-1 downlink usage
In my previous post, I examined a recording of LilacSat-1 transmitting an image. I did some calculations regarding the time it would take to transmit that image and the time that it actually took to...
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A first look at DSLWP SSDV downlink
The Chang'e 4 is a Chinese lunar mission that will land a rover on the far side of the Moon by the end of 2018. To support this mission, the Chang'e 4 relay satellite will be launched six months before...
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