Corrosive from the SignalsEverywhere YouTube channel has released a new episode of his podcast. In this episode Corrosive interviews an anonymous informant who has an interesting story about his involvement with the UHF Military SATCOM pirate radio scene in Brazil. Corrosive also explains a bit further about what SATCOM is and why it's so susceptible to piracy. He also notes that piracy on Inmarsat L-band frequencies is also becoming more common.
The UHF-SATCOM band is anywhere between 243 - 270 MHz and contains fairly strong signals from many several US satellites that can be received with a simple antenna and any UHF radio/SDR. Many of the satellites are simple repeaters without security, and pirates from Mexico and South America often hijack the satellite for their own personal use. In the past, and possibly even still today hijackers involved in drug trafficking and other illegal activities made use of these insecure military satellites for long range communications. Reception of these satellites is generally available in Canada, US, Mexico, South America, Europe and Africa.
Satcom Crackdown; Satellite Piracy on After The Show Podcast
CubeSats are small and light satellites that can these days be built and launched into orbit by almost anyone with a small budget of roughly $40,000. They are a great way for schools and other organizations to get into a space based technology project. A "simulated" CubeSat is one that is not designed to be really launched into space, and is made from low cost hardware. The idea is that simulated CubeSats can be used as tools to help demystify the inner workings of satellites to the public and help CubeSat builders get experience and competence before building the real thing.
If you're interested in the CubeSat simulator hardware itself, there was a presentation held back in 2018 that may be of interest to you. According to the presentation somewhere between 30% - 50% of CubeSats fail as soon as they're deployed, so building competence with simulated hardware is a good goal.
2018 AMSAT William A. Tynan W3XO Memorial Space Symposium - Saturday Sessions
NOAA weather satellites broadcast an Automatic Picture Transmission (APT) signal, which contains a live weather image of your area. With an RTL-SDR and antenna they can be received and downloaded every time one of the satellite's passes overhead which could be multiple times a day.
Our standard NOAA weather satellite tutorial makes use of SDR#, audio piping and the WXtoIMG to receive NOAA satellite images. Martin's guide and software might be slightly easier for newbies as it only involves recording an audio WAV file, then loading it up into his software. The disadvantage is that the image is not colorized, and not displayed in real time as it is in WXtoIMG.
As you may already know, the old standard software in NOAA image decoding, WXtoIMG, is now considered abandonware, and the only place to get it is from a third party mirror rehosting the now defunct WXtoIMG website. As WXtoIMG is closed source no further development can occur on it. Martin's NOAA-APT still misses a lot of the advanced features of WXtoIMG but it is fully open source and multiplatform, and so it is a very promising program.
Receiving NOAA satellite images with noaa-apt and SDR#
Last week we posted about M Khanfar's YouTube video that showed how to decode Es'Hail-2/QO-100 DVB-S2 on Ubuntu with the LeanDVB decoder. However, the method he showed was not in real time as it involved recording an IQ file in GQRX first, then decoding that IQ file. Similarly we also posted last week about a Windows based real time decoder.
M Khanfar recently wrote in again and wanted to show that real time decoding is possible with LeanDVB. The method is to simply pipe the output of the rtl_sdr command line decoder in LeanDVB, and then into VLC. He notes that his PC isn't actually fast enough to decode in real time without lag, but a modern i5 CPU would work well. The actual terminal command is shown in his YouTube video description.
This is Realtime live DVB-S2 Decoding done , without need to record .RAW file , its live and easy method by one click ! In this video i decoding 2MS symbol rate from wideband transponder of QO-100 beacon , you can decoding 1MS , 0.5MS , 333KS , 125KS symbol rate ! The lower Symbol, the faster speed for decoding! , the Amateurs operators on QO-100 Uplink DATV DVB-S2 at 0.5 , 333 , 125Ks , so its easy to Live Decoding Now ! With very low SNR ! , so the normal SDR can coverage wideband beacon of 2Ms symbol and all Ham uplink ! , if you have an SDR that can coverage 27.5 mb of bandwidth, so you can easy decoding Live a standard commercial satellite channels! But it need a high speed Pc .
Yesterday we posted about a real time Windows demodulator for receiving amateur TV DVB-S/S2 on Es'Hail-2/QO-100. Recently another YouTube user "M Khanfar" also submitted a video tutorial showing how to decode Es'Hail-2 DVB-S2 on Ubuntu with an RTL-SDR and the LeanDVB decoder.
Khanfar notes that although the LeanDVB decoding method is not real time, his tests show that the LeanDVB method is able to work with a much lower SNR signal compared to the Windows demodulator. The process is to simply capture an IQ file with GQRX, then run LeanDVB on the command line with the recorded IQ file. It will create a TS file that can be played in any media player.
His receiving setup consists of an RTL-SDR, 100cm dish, modified LNB and a home made bias tee that can switch his LNB between horizontal and vertical polarization.
Thank you to Happysat for writing in and noting that over on the Amsat-DL forums user Markro92 has uploaded a realtime Windows DVB-S demodulator with GUI. The demodulator works with the RTL-SDR, HackRF, SDRplay and PlutoSDR support is due to be added soon. Happysat notes the following:
It can demodulate DVB-S and S2 signals with very low symbolrate on Es Hail-2 geosat on 25,9 East from the Wideband Transponder. So you do not need a modified lnb or modified satelitte stb :) Of course you can also see the amateur tv streams which people uplink theirself.
To see if there is any stream active one can visit the wideband WebSDR and above the stream the info is displayed which parameters in use (symbol rate and mode dvbs(2)) so you can adjust in the Demodulator program. Stream + Chat: https://eshail.batc.org.uk/wb/ .
COMS-1 is a geostationary weather satellited operated by the Korean Meteorological Agency (KMA) which was launched back in 2010. It is similar to NOAA GOES satellites as it is also geostationary orbit (@128.2°E - footprint covers all of Asia + AUS/NZ), and so is far away enough to image the entire disk of the Earth at once. Unfortunately, unlike the GOES satellites which have in the past few years become relatively easy for hobbyists to decode, the COMS-1 LRIT and HRIT downlink data is encrypted by KMA. KMA only appear to provide decryption keys to governments, research institutes and large organizations upon request.
However, recently Australian @sam210723 was able to successfully create code to decrypt the key message file and obtain the images. From a previous Twitter post of his, it appears that the encryption keys from the KMA example code are actually valid and can be used without needing to apply for a key.
Sam notes that he'll soon release a full blog post on his results, but for now he has an older post from last year that explains a bit about the satellite and decryption of the LRIT Key. His code is available on GitHub, and in a recent Twitter post he shows some example images that he's been able to receive using an Airspy SDR.
HackSpace is a monthly magazine dedicated to modern maker projects. This month issue 18 was released and it focuses on space based projects. The HackSpace Magazine is available for free online in PDF form, and physical copies can also be purchased. There are several interesting articles but one in particular shows us how to set up a SatNOGS ground station with a Raspberry Pi 3, RTL-SDR and a satellite antenna such as a turnstile.
A problem with low cost satellites like cubesats is that it is difficult to monitor them as data can only be collected when they are passing over a ground station. So in areas with no ground stations data is simply lost. SatNOGS is an open source project that aims to make it easy for volunteers to build and run RF ground stations that automatically monitor satellite data, and upload that data to the internet for public access. SatNOGS ground stations typically use RTL-SDR dongles as the radio.
A related article in the magazine also discusses cubesats, giving an overview of some previous cubesat launches and what sort of payloads are available. A third article under the space topic discusses the Libre Space Foundation which is the team behind the SatNOGS and various other space based projects that aim to democratize space. Readers may also be interested in the articles showing how to build an ISS countdown timer and how to build a Slim Jim antenna.