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Tracking an RS41-SGP radiosonde and reporting to APRS
In the past, I've talked about the RS92-SGP radiosonde launched from Madrid-Barajas. Recently, Barajas has replaced the RS92-SGP with the newer Vaisala RS41-SGP (except for ozone sounding, which is is...
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A brief study of TLE variation
During my research and experiments about using WSJT-X modes through linear transponder satellites, one of the questions I had is by how much do TLEs of different epochs for the same satellite vary....
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Using CODAR for ionospheric sounding
CODAR is an HF radar used to measure surface ocean currents in coastal areas. Usually, it consists of a chirp which repeats every second. The chirp rate is usually on the order of 10kHz/s, and the...
View ArticleRespuesta al artículo "¿Por qué asociarse?" por EA1URA
English summary: This is an opinion post discussing the reasons given by EA1URA to join URE, the National Amateur Radio Spanish society. My main point is that the services offered by the society do not...
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A CODAR advent
Over the last few days, I have been recording CODAR on 4463kHz to produce images of the ionosphere. I started on Friday 15th and the plan was to leave the recording running until Christmas Day, thus...
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Interfacing the Hardrock-50 HF amplifier to the Hermes-Lite 2
Since several months ago, I'm operating my HF station "remotely" from another room in the house. The station consists of a Hermes-Lite 2.0 beta2, a Hardrock-50 HF amplifier, and an outdoor MFJ-993BRT...
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Saving and plotting bandscope data with the Hermes-Lite 2
The Hermes-Lite 2 and other SDR transceivers based on the openHPSDR protocol support sending bandscope data from the SDR to the PC. The bandscope data consists in fixed-length chunks of samples taken...
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Decoding satellites from the PSLV 2018-004 launch
On Friday 12 at 03:59 UTC, a PSLV-CA launched from Satish Dawan Space Centre, India, to deliver Cartosat-2F, as well as some smaller satellites, into a Sun-synchronous polar orbit. Cartosat-2F is an...
View ArticlePicSat telemetry parser added to gr-satellites
PicSat is a recently launched cubesat from the Observatoire de Paris. It is designed to observe the Beta Pictoris star system, using a telescope based on an optical fibre. It transmits telemetry in the...
View ArticleA first look at TY-2
TY-2 is a 6U Chinese cubesat that was launched on January 19th in a CZ-11 rocket from Jiuquan, together with several other small satellites, including TY-6. According to the IARU Satcoord, TY-2 and...
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Analysis of my Hermes-Lite 2 bandscope recording
A few weeks ago I posted how I make wideband recordings of bandscope data with my Hermes-Lite 2. In that post, I sort of promised to do a small analysis of the waterfall I showed. After being busy with...
View ArticleMystery 9k6 BPSK satellite
On January 28th, Tetsu JA0CAW reported on Twitter his reception of an unknown satellite. The time of reception was 2018-01-28 12:15 UTC and the frequency was around 435.525MHz. The time and frequency...
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Studying IONEX files
Many Amateur radio operators are familiar with the effects of the ionosphere at HF frequencies. However, the effects of the ionosphere are also noticeable at much higher frequencies. In particular, at...
View ArticleSTARcon 2018 announcement
English translation below. Me tomo la libertad de usar este blog para anunciar un congreso que estoy organizando, junto con otros Radioaficionados Españoles. Como se puede ver en la descripción del...
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Outernet LDPC code revisited
I have been preparing the slides for my future talk about reverse-engineering Outernet at FAQin 2018. While doing this, I have been re-reading some of the material about the work done on LDPC code and...
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Testing LDPC code erasure decoding performance
In my previous post I talked about the RFC5170 LDPC codes used in Outernet. There I explained in some detail the pseudorandom construction of the LDPC codes and the simple erasure decoding algorithm...
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Amateur VLBI experiment with LilacSat-2
On 23 February, Wei Mingchuan BG2BHC published on Twitter the first Amateur VLBI experiment. This consisted of a GPS-synchronized recording of signals from LilacSat-2 using USRPs in groundstations at...
View ArticleTY-2 decoded
In January, I took a look at TY-2 telemetry. This is a Chinese cubesat that transmits 9k6 FSK telemetry in the 70cm Amateur band. In my previous post I tried to reverse engineer the packets from TY-2...
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Improved signal processing for LilacSat-2 VLBI
Last week I published my results about the LilacSat-2 VLBI experiment. There, I mentioned that there were some things I still wanted to do, such as studying the biases in the calculations or trying to...
View ArticleDecoding S-NET
S-NET is a swarm of 4 cubesats from TU-Berlin. Their mission is to test SLink, an S-band transceiver for inter-satellite communications. They were launched on February 1 this year and they use use...
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