APT_COLOR: Add False Color to Black and White NOAA APT Images

Thank you to Sasha for submitting news about the release of their latest application called "apt_color". The most popular application for decoding APT weather satellite images from NOAA polar orbiting satellites is WXtoIMG. However, WXtoIMG is closed source and is abandonware. There are APT decoder alternatives, however unlike WXtoIMG most other open source APT decoders only provide black and white images, and do not have a false color feature.

The apt_color application can be used to turn black and white APT images received from NOAA satellites into false color images. Sasha writes:

I am working on an APT false color application here. The application is still in the very, very, early stages but still seems to produce good results. It does not need to rely on any overlays, it simply works off the data you give it - the original decoded image data. I will attach some results. NOAA-18 seems to be the best suited spacecraft for this program.

apt_color: Turn black and white NOAA images into false color
apt_color: Examples

Rolling-Pwn: Wireless rolling code security completely defeated on all Honda vehicles since 2012

Back in May we posted about CVE-2022-27254 where university student researchers discovered that the wireless locking system on several Honda vehicles was vulnerable to simple RF replay attacks. A replay attack is when a wireless signal such as a door unlock signal is recorded, and then played back at a later time with a device like a HackRF SDR. This vulnerability only affected 2016-2020 Honda Civic vehicles which came without rolling code security.

Recently a new vulnerability discovered by @kevin2600 that affects ALL Honda vehicles currently on the market (2012-2022) has been disclosed. The vulnerability is dubbed 'Rolling-PWN' (CVE-2022-27254) and as the name suggests, details a method for defeating the rolling code security that exists on most Honda vehicles. Rolling code security is designed to prevent simple replay attacks, and is implemented on most modern vehicles with wireless keyfobs. However @kevin2600 notes the following vulnerability that has been discovered:

A rolling code system in keyless entry systems is to prevent replay attack. After each keyfob button pressed the rolling codes synchronizing counter is increased. However, the vehicle receiver will accept a sliding window of codes, to avoid accidental key pressed by design. By sending the commands in a consecutive sequence to the Honda vehicles, it will be resynchronizing the counter. Once counter resynced, commands from the previous cycle of the counter worked again. Therefore, those commands can be used later to unlock the car at will.

The vulnerability has been tested on various Honda vehicles with HackRF SDRs, and this seems to indicate that all Honda vehicles since 2012 are vulnerable.

Although no tools have been released, the vulnerability is simple enough and we've already seen people replicate results.

The story of Rolling-Pwn has already been covered by magazines and news organizations such as TheDrive, Vice, NYPost, and FoxLA.

It should be noted that when the previous replay attack vulnerability was highlighted, Honda released a statement noting that it has no plans to update its older vehicles. It is likely that Honda will not issue updates for this vulnerability either. It is possible that this vulnerability extends beyond just Honda vehicles too.

SelfieStick: Combining noisy signals from multiple NOAA APT satellites for clean imagery

Researchers from Carnegie Mellon University have recently presented a paper detailing how they combined noisy signals from multiple passes of low earth orbit (LEO) satellites NOAA 15, NOAA 18 and NOAA 19 in order to create a higher quality image. For a receiver they used a low cost RTL-SDR Blog V3 mounted indoors with a whip antenna.

In a normal setup, weather satellite images from NOAA LEO weather satellites can be received with an RTL-SDR, computing device and an appropriate outdoor mounted antenna that has a good view of the sky. If the antenna is not suited for satellite reception, and/or is mounted indoors, at best only poor quality very noisy images can be received.  

The researchers demonstrate that it is possible to combine noisy images received over time, and from different satellites in order to generate a higher quality image. The challenge is that the different satellites and different receiving times will all produce different images, because the satellites will be at a different location in the sky each pass. They note that simply transforming the images in the image domain would not work very well for highly noisy images, so instead they have devised a method to transform the images in the RF domain. The RF signals are then coherently combined before being demodulated into an image.

The results show that 10 noisy satellite images from the indoor system are comparable to one from a comparison outdoor system. However, they note some limitations in that the system assumes unchanging cloud cover during passes. In the future they hope to extend the system to cover other modulation schemes used by other low earth orbit satellites in order to increase the number of usable satellites.

Selfiestick: Combining noisy images from multiple NOAA satellites received by an indoor RTL-SDR system.

TechMinds: Using a LEO Bodnar GPSDO with a PlutoSDR

Over on the TechMinds YouTube channel Matt has been experimenting with using a PlutoSDR for QO-100 amateur radio satellite communications. The PlutoSDR is a low cost RX/TX capable SDR with up to 56 MHz of bandwidth and 70 MHz to 6 GHz frequency range (with mods). The PlutoSDR can suffer from frequency instability, especially when warming up, however on the latest model C/D PlutoSDRs it's possible to inject an external clock signal.

In his video experiment, Matt uses a Leo Bodnar GPSDO as an external clock source. A GPSDO is a "GPS Disciplined Oscillator", as it uses the accurate timing information found in GPS signals to create a high quality clock signal. Matt shows how to set up the GPSDO, and how to tell the PlutoSDR to use the external clock.

He goes on to show the effectiveness of the GPSDO with some transmit experiments.

LEO BODNAR GPSDO With the Adalm Pluto SDR

Watch out for new RTL-SDR Blog V3 Counterfeits

Over the past few years our company has been targeted by counterfeiters who copy our RTL-SDR Blog V3 logos and put it on inferior or old RTL-SDR designs. Up until now determining a fake from an original unit has been possible due to obvious differences in the enclosure.

However, we've now recently seen new counterfeit products appearing on marketplaces with enclosures that look almost exactly like our originals. The counterfeit units copy our logos on the front and back, and text exactly. They also now use rounded enclosures, green PCBs and two screws on the side panels. The only real defining features of the more sophisticated clones are that the side panel screws are not diagonally offset, and that there is no NSY QC sticker on the back noting the batch date.

Again, we want to reiterate that anyone can manufacture and sell RTL-SDRs in general as there is no owner of the RTL-SDR idea itself. However we do have our own specific circuit design and trademarked branding that has become popular over the years due to the features and improvements that we designed and implemented whilst still maintaining a reasonable cost. Other manufacturers/sellers should not trick people into thinking they are ordering an RTL-SDR Blog V3 and they should obviously create their own PCB design and branding.

If you want to ensure that you purchase an original RTL-SDR Blog V3 unit, please use the links on our store page to our official global marketplace listings, or the links to our official local resellers (also on the store page), or order direct from our store if your region is supported. Please note that we cannot provide email support or the two year warranty for counterfeit units.

We are doing our best to enforce our trademark and logos on marketplace sites, but it is a never ending task as once one listing is removed, 10 more appear. If you find that you were tricked by a marketplace listing and received a counterfeit, please be sure to report that store and try to get a refund.

Thanks to all our customers and blog readers for your support over the years! We still have a lot of ideas for new products, tutorials and posts and your support helps us keep this all going!

MagicSDR: Streaming Audio over UDP to Decoders like Multimon-NG

Back in May 2021 we first posted about the release of MagicSDR, which is an Android and iOS SDR app that receives data from an rtl_tcp server elsewhere on your network. Apart from the RTL-SDR, MagicSDR also supports the SDRplay, LimeSDR, HiQSDR, Flex 6-seris and sound card based radios.

Recently MagicSDR programmer Vlad wanted to share a new feature in MagicSDR that allows users to stream audio over UDP. He notes that this allows external data decoders such as direwolf or multimon-ng to be used. The example in the video below shows MagicSDR sending demodulated audio over UDP to multimon-ng running on the same Android device.

Decoding Morse CW on android phone

MagicSDR sending demodulated audio over UDP to multimod-ng decoder

SDR Academy 2022 Recorded Livestream now Available

The Software Defined Academy is a group that organizes an SDR focused conference during the yearly HAMRADIO fair that is usually held in Friedrichshafen, Germany. The past two years have seen the conference go exclusively virtual, however this year the conference was a hybrid of real life and virtual presentations. The conference was held a few days ago, and the recorded livestream is now available on YouTube for viewing.

The full program of presentations can be found on the SDRA 2022 website.

Day 1:

Day 2:

An Improved ExtIO for RTL_TCP

Back in 2020 we posted about a modified ExtIO interface which exposed advanced RTL-SDR driver settings such as decimation, manual gain and tuner bandwidth and filtering controls. These features allow users to tune filters to avoid ADC overload and to overall fine tune reception better, especially for narrowband signals. ExtIO is the driver interface used by some popular SDR programs like HDSDR.

Thanks to contributor Ladislav (OK1UNL) for notifying us about an improved version of that ExtIO interface by DG2YCB.

DG2YCB improved version adds the following features:

  • Auto-Q: The RTLSDR stick automatically switches to direct sampling (Q channel) for frequencies below 24.5 MHz and direct sampling is automatically disabled when tuned to any frequencies above 24.5 MHz.
  • My ExtIO_RTLTCP_improved.dll drivers set the chip AGC to ON, which brings you a better RX sensitivity than the original version.
  • My ExtIO_RTLTCP_improved.dll drivers are available in the following versions:
    • ExtIO_RTTCP_improved1.dll uses autoGain for the tuner gain.
    • ExtIO_RTTCP_improved2.dll uses optimized manual gain settings for the tuner gain, which shall prevent that the RTLSDR stick is overdriven on VHF / UHF frequencies.
    • ExtIO_RTTCP_improved3.dll has Auto-Q as well as the optimized gain settings profile but has a more sophisticated GUI, so that you can adjust more parameters manually. (Currently available as beta version.)
       

This ExtIO also allows users to connect to an RTL-SDR when software like HDSDR is run on Linux via an emulator such as WINE.

Ladislav also pointed out that DG2YCB has improved versions of WSJT-X and JTDX that might be of interest to some.

ExtIO Improved dll 3