Back in August Maxim who runs his small company "ExpElectroLab" wrote in and shared with us news of his upcoming product called "SDR-Remote" which is a physical tuning knob and control panel for SDR#.
Recently the product was released for sale on his shop, and costs $57.50 USD + shipping. The vk.com store is for Russian customers only, but you contact him at [email protected] if you are non-Russian and are interested in his products. The features of the SDR-Remote are pasted below:
The heart is ARDUINO NANO V3.0, buttons, encoder and software.
Implemented by:
tuning the frequency of reception with frequency of 1 kHz, 100 kHz, 1 MHz (additionally 50 Hz)
Maxim hand builds these in his home country of Russia, and has noted that since the case is 3D printed he can only create a few per week at the moment. The knob interfaces with SDR# via an Arduino driver and SDR# plugin which can be downloaded.
SDR-Remote V2.1
Over on YouTube a Russian reviewer has uploaded a video showing SDR-Remote v2.1 in action. The video is narrated in Russian, but YouTube auto-captions combined with auto-translate does a decent job.
HRPT is a high resolution weather satellite image that is broadcast by the NOAA satellites. Receiving HRPT weather satellite signals is a little different to the more commonly received NOAA APT or Meteor M2 LRPT images which most readers may already be familiar with. HRPT is broadcast by the same NOAA satellites that provide the APT signal at 137 MHz, but is found in the L-band at around 1.7 GHz. The signal is much weaker, so a high gain dish antenna with motorized tracking mount, LNA and high bandwidth SDR like an Airspy is required. The payoff is that HRPT images are much higher in resolution compared to APT.
Manuel lives in Germany and on Twitter he found that he had a follower in Canada who was also receiving HRPT images. So he asked his follower to provide him with HRPT weather images that were received shortly after the pass in Germany. He then stitched the images together, and color corrected them which resulted in a nice large image covering Europe, the Atlantic, Canada and Florida.
[EN subs] HRPT over The Ocean - Ein Bild von Köln nach Kanada
JAERO was recently updated by programmer Jonti, and it now supports the decoding of AERO C-Channels which are voice audio channels that exist on both the L-Band and C-Band frequencies of AERO. AERO is a satellite based communications service used by modern aircraft. The information transferred are normally things like aircraft telemetry, short crew messages, weather reports and flight plans. It is similar information to what is found on VHF/HF ACARS.
Jonti notes that these C-Channel voice signals are very weak as they are spot beams, so a good antenna system is required to receive them. Over on Jonti's JAERO website there is now some information about these C-Channels (scroll all the way down to the C-Channel heading and read to the end of the page), as well as a frequency list. An excerpt of the information is pasted below:
Inmarsat C and in particular AERO C channels provide circuit switched telephony services to aircraft. The channels of interest are those that carry AMBE compressed audio at a channel rate 8400 bps and voice rate of 4800bps. There is also an older speech codec still in use, LPC at a voice rate of 9600 bps and an overall channel rate of 21000bps.
Telephone channels are two-way duplex. In the from-aircraft direction transmissions are roughly in the 1646 to 1652 Mhz range. The satellite up-converts these transmissions to C band, similar to T and R channel burst transmissions. So it is possible to receive the from-aircraft transmissions although it is significantly more difficult than those in the to-aircraft direction on the L band. So for those who want to get started receiving these transmissions the L band is by far the easiest place to start.
Another aspect of the C channels is that they most often use spot beams rather than global beams which makes it more difficult to receive transmissions for aircraft using a spot beam that is aimed at another region. However if you are inside the spot beam the transmissions are relatively easily received on L band. A 60 cm dish with an LHCP helical and L band LNA will provide excellent results but even with a patch antenna it can be done.
Decoding these channels to audio in JAERO takes a little effort to setup. Due to the uncertain legal status of the digital audio AMBE codec, the codec code needs to be compiled manually first, and then placed into the JAERO directory. Jontio has uploaded the AERO AMBE codec source code at https://github.com/jontio/libaeroambe. Since JAERO is a Windows program, compilation of libaeroambe involves using MSYS2.
Once fully set up with the audio codec, the audio will come out of default soundcard set in Windows audio properties, so ensure that any Virtual Audio Cables are not set as the default device.
On the L-band link you can get conversations from the ground to the plane. The C-band link would get you the plane to ground side of the conversation too, but that is a challenging signal that would require a large dish and Jonti doesn't know of anyone who has managed to receive that before. Typically the conversation topics are things like Medlink which is a multilingual medical support line that can provide backup to doctors or aircrew handling medical emergencies in the air. In Europe the USAF also apparently use C-Channel.
Recently reader Syed Ali wrote in and wanted to share some experiments in UFO detection that he's been performing with an image intensifier and an RTL-SDR. The RTL-SDR is used to detect a distant FM radio station reflecting from objects passing overhead, and the image intensifier is a sensitive camera that helps make events like satellite passes more visible. In his video some visually detected objects like a possible satellite pass or aircraft at 0:09 to 0:18 and 0:55 to 1:00 seem to correlate with a radio reflection.
Syed Ali writes:
These are three small video clips taken from an hour observation. I had an idea how to use RTL-SDR for meteor detection. So I tuned my rtl-sdr to a distant FM Radio station behind a mountain range from my own location. Any object flying over mountain range can be detected by receiving the transmission of that FM radio station via its signal being reflected from that flying object.
So I set up my image intensifier pointing towards the sky in the same direction above those ranges. I recorded a few unknown objects in the video viz a viz their RF reflections and Dopplers in sdrsharp software.
You will also notice a strange laser beam which seems to be coming from the sky to the ground because it encircles and changes its position around the field of view of my image intensifier. Moreover, in the last few seconds of the clip, you will see a strange object hovering and then taking a U turn near left edge of the video frame. Those were indeed strange findings. Please see for yourself and do leave your comments. Thanks. Observation Time : 1:20 am to 2:30 am, 21 October 2018
We're a little skeptical about the UFO claims though, as the lasers may just be car headlights, and the fast moving object may just be a bug reflecting light, and the lack of radio reflections around those points seem to confirm that nothing large is there.
The programmers of SDR# have just released a new version which now includes a SpyServer directory browser. SpyServer is an Airspy and RTL-SDR compatible SDR streaming server for SDR#. It allows you to access your SDR remotely over the internet or a network connection by using efficient data compression techniques.
The new browser allows you to browse for active and publicly shared SDRs that are running SpyServer. To launch the browser in the latest SDR#, choose "SpyServer Network" in the Source drop down menu, and click on the "..." button. At the moment there are only a few servers listed, and not all work. But we expect more to show up and work as people update their SpyServer software.
For SpyServer users, the latest server version will automatically list your server in the directory, but it can be turned off in the config file.
Thank you to ON7NDR as well as CM2ESP for submitting and figuring out a way to get GOES 16 decoding working with RTL-SDR using the free XRITDecoder,Xrit2Pic software and GNU Radio for Windows.
ON7NDR's story is that he wanted to be able to receive GOES 16, but not being familiar with Linux he wanted a Windows based solution. He writes that the credit to finding the solution goes to CM2ESP who has written up a tutorial (pdf) explaining how to set everything up in Windows. ON7NDR has also written a separate complimentary tutorial (docx) that explains some steps in CM2ESPs tutorial a little further and provides a few tips on choosing correct the correct version of GNU Radio. He's also provided a screenshot showing what the correct config file looks like for an RTL-SDR dongle.
We note that for Windows there is also USA-Satcom's XRITDecoder, however this is closed source software which costs $100 USD.
Thank you to Neoklis (5B4AZ) for writing in and letting us know about his recently completed project which is a RTL-SDR compatible receiver and decoder application for the Meteor M2 weather satellite. It is a combination of other open source programs and he writes:
I combined the recently released Meteor-M2 LRPT demodulator by Davide Belloli (dbdexter-dev), and the older image decoder (translated to C) released by Artem Litvinovich (artlav), with relevant code from my own "sdrx" SDR Receiver application to create a complete monolithic Meteor-M2 Receiver and Image Decoder application, "glrpt".
Neoklis' glrpt application is available on his website www.5b4az.org under the "Weather Imaging -> Meteor M LRPT Receiver" menu. The application is open source and appears to be Linux only. In order to install it you'll need to download and compile the source code, and compilation instructions are available in the documentation stored in the doc folder. Neoklis also writes that you can find his older APT image decoder called "xwxapt" under the same Weather Imaging heading of his website.
GLRPT User Interface Showing Processed Meteor M2 Images
As promised we announced the release to KerberosSDR mailing list subscribers first, so that they'd be the first to get the initial discounted early bird units. However due to much higher than expected interest, we have released a few "second early bird" units at a still discounted price of $115 + shipping. We're only going to release 300 of these so get in quick before the price jumps up to $125. Our pre-order campaign will last 30 days, and afterwards the retail price will become $150.
If you weren't already aware, over the past few months we've been working with the engineering team at Othernet.is to create a 4x Coherent RTL-SDR that we're calling KerberosSDR. A coherent RTL-SDR allows you to perform interesting experiments such as RF direction finding, passive radar and beam forming. In conjunction with developer Tamas Peto, we have also had developed open source demo software for the board, which allows you to test direction finding and passive radar. The open source software also provides a good DSP base for extension.
KerberosSDR with Calibration Board Attached (Metal Enclosure with SMA connectors Not Shown)KerberosSDR Main Board (Metal Enclosure with SMA connectors Not Shown)
![[EN subs] HRPT over The Ocean - Ein Bild von Köln nach Kanada](https://www.rtl-sdr.com/wp-content/plugins/wp-youtube-lyte/lyteCache.php?origThumbUrl=https%3A%2F%2Fi.ytimg.com%2Fvi%2FhbvsSyplsDk%2F0.jpg)
