Category: Satellite

Layering Geo-Spatial Fire Data onto GOES Satellite Imagery

Thank you to Carl Reinemann (aka usradioguy) for writing in and sharing with us how he has developed a script to layer FIRMS data (Fire Information for Resource Management System US / Canada) onto GOES satellite images (usradioguy blog post) that can be received with an RTL-SDR. We have a tutorial on GOES reception here.

The script is a Windows batch file that downloads FIRMS data from the internet every 12 hours, then converts that data into a format that can be processed by goestools. Once converted the resulting JSON file is uploaded to the Raspberry Pi running goestools. A custom goestool process is then used to layer the data onto the received images.

The result is accurate red polygons on the satellite image in areas where fires have been recorded. With this data visualized it is easy to see where smoke seen on the satellite images is coming from. For example, the image below shows the location of wildfires in the Western USA and the resulting smoke trailing across the continent.

Carl has also tested the fire data layer with GK-2A and Himawari-8 and notes that it works well with images from those satellites as well. 

Fires data in Western USA layered on top of received GOES satellite images.

Elektro-L3 Geostationary Weather Satellite: Easy to Receive LRIT Signal Being Tested

Back in September 2020 we posted about the release of an X-Band decoder for the Elektro-L2 and Elektro-L3 Russian geostationary satellites. These satellites are receivable from Europe, the Middle East, Asia, Africa, South America and Australia. Unlike the HRIT and LRIT L-band transmissions from other geosynchronous satellites like GOES and GK-2A, the X-band Elektro signal is quite difficult to receive, requiring a large dish and more expensive hardware.

However we've recently seen exciting news on Twitter that a new L-band LRIT transmission has been activated on Elektro-L3. Like the Korean GK-2A satellite, this L-band LRIT transmission at 1691 MHz should be much easier to receive requiring only a WiFi dish, SAWBird GOES LNA and an RTL-SDR. We haven't yet confirmed if like GK-2A, the smaller 600 x 400 mm WiFi dish is sufficient, or if Elektro requires the larger 600 x 1000 mm dish size. (See our GOES satellite and GK-2A tutorial for information about the hardware being discussed in this paragraph.)

We note that the Elektro-L3 signal appears to be in testing, and the transmission could be turned on and off, or even turned off permanently. The transmission schedule is also not yet clear although in this recent tweet @HRPTEgor has mapped out some current transmission times for Eletro-L3.

It is hoped that LRIT will also eventually be activated on Elektro-L2, and perhaps even HRIT will be activated too. It is also exciting that more Elektro-L satellites are planned to be launched from 2022 onwards and we expect those to have hopefully LRIT and HRIT transmissions as well. To add further excitement, it is hoped that the L3 LRIT activation means that a LRIT or HRIT signal will be activated on the high elliptical orbit (HEO) northern hemisphere Arctic monitoring ARKTIKA-M1 satellite launched in Feb 2021, as this satellite is derived from the Elektro-L design.

The LRIT activation of Elektro-L3 hopefully means that Europeans should finally have access to a geostationary weather satellite that can be easily received with modest low cost hardware. The current coverage map from Orbitron of the two Elektro satellites is shown below (note that Elektro-L2 LRIT does not appear to have been activated yet).

Elektro-L2 and Elektro-L3 Coverage (Currently only Elektro-L3 LRIT transmissions have been discovered)

Over on Twitter @aang254 has noted that he has already updated his satdump software, adding support for Elektro LRIT decoding, and adding support for all of the available channels and for color. Satdump is available as a binary for Windows, and on Linux can be built from source. Experimentally, Satdump can also be built and run on Android.

The Tweet from @aang254 provides a nice sample image of what can be received.

Using an RTL-SDR Dongle to Receive Pictures from the ISS

Over on YouTube we've seen a good video from channel Ham Radio DX where presenter Hayden shows how to use an RTL-SDR to receive slow scan television (SSTV) images from the International Space Station (ISS). Often the ISS will transmit SSTV images down to earth on the VHF 2 meter bands as part of an event. With an RTL-SDR and simple antenna it's possible to receive those images.

In the video Hayden discusses the SSTV transmission, and demonstrates some SSTV decoding happening in real time as the ISS passes over his location. If you're looking to get started in ISS SSTV reception, this is a good video to get an idea of what's involved. He finishes the video with some useful tips for reception.

Using a RTL SDR Dongle to receive pictures from the ISS! | Software Defined Radio

SDR4Space: Software Tools for SDR Based Satellite Ground Stations

Over on Reddit we've seen that SDR4Space, a provider of a satellite ground station receiver hardware and software has released a free feature limited lite version of their embedded software over on their GitHub page. In the Reddit comments the software is explained as follows:

It's a command-line tool using scripts, for SDR users. You can write your own scripts to: record IQ samples, predict satellite passes, start a record for a specific satellite and correct doppler at the same time.

It's also useful to record narrow subband IQ streams ( example: 48kHz wide instead of 2.048 MHz on rtlsdr, a single signal on HF is only few kHz wide).

You can work on IQ files: cut, resample, merge, convert formats and so on.

Having said that you can recognize features from predict, rx_sdr/rtl_sdr ,rtl_power/rx_power.

Regarding installation, a Debian package is provided, installing application and some examples in /opt/vmbase directory. Most of dependencies are installed by the package. But you should install SoapySDR and Soapy drivers for your SDR device first by yourself if not yet done !

To understand how it works, the best is perhaps starting download TLE and print a passes list, using scripts in ./sat/ directory.

For the next SSTV event I'd try to run unattended reception of ISS (from ./sat/sat_receiver directory).

From the examples, it appears that you can script a fully automated doppler corrected satellite signal receiver with the SDR interface connecting through Soapy, and all the DSP handled by the SDR4lite library.

SDR4Space Logo

Frugal Radio: How To Decode L band Satellite ACARS and CPDLC messages with JAERO and your SDR

In the latest episode of his YouTube series on Aviation monitoring Rob explores how to decode L-band satellite ACARS (Aircraft Communication Addressing and Reporting System) and CPDLC (Controller Pilot Data Link Communications) messages using JAERO, an SDR like an RTL-SDR, and a appropriate L-band antenna such as our RTL-SDR Blog Active L-Band Patch (currently out of stock).

In the video Rob shows examples of what you might receive such as CPDLC ATC instructions, digital ATIS information, arrival information and suggested landing data configuration instructions. He goes on to show satellite coverage maps, what hardware is required to receive these signals, and finally how to setup the receiving and decoding software.

How To Decode L band Satellite ACARS and CPDLC messages with JAERO and your SDR

Decoding NOAA on an Debian Chrooted Android Smartphone

Over on Reddit Ian Grody (u/DutchOfBurdock) has posted about his success in using a modded Android smartphone to run an RTL-SDR Blog V3 and NOAA decoder software all within the phone itself.

In the past we posted about Ian's work in getting rtl_power scans to work in conjunction with the Tasker app, in order to generate automated frequency scans on his phone on the go. His more recent work from the past year includes showing us how it's possible to install Debian chroot on an Android phone, and run Linux software like GQRX, GNU Radio, DSD, rtl_433, multimon-ng and dump1090 directly on the phone with an RTL-SDR.

His latest Reddit post shows that the NOAA-APT decoder also runs well on the Debian chroot, leading to a truly portable NOAA decoding setup. He notes that he is now working on the possibility of Meteor M2 decoding on the phone.

Below is his video from last year demonstrating SDR GQRX and GNU Radio running on the Debain chrooted phone.

GQRX, GNU Radio, Rooted Android

Tech Minds: Remote SDR V2 with Orange Pi and Transmit Capable

In his latest YouTube video Tech Minds explains and demonstrates Remote SDR V2, which is software that allows you to easily remotely access either a PlutoSDR, HackRF or RTL-SDR software defined radio. It is designed to be used with the amateur radio QO-100 satellite, but version 2.0 now include multiple demodulation modes, NBFM/SSB transmission capability, CTCSS and DTMF encoders, modulation compression and a programmable frequency shift for relays.

In his video Tech Minds shows how to install Remote SDR V2 onto an Orange Pi via the SD card image, how to access the web interface, and how to access and use the connected SDR.

Remote SDR V2 with Orange Pi and Transmit Capable

We note that the code is designed to be run on Orange Pi boards, which are low cost single board computers similar to Raspberry Pi's. However over on Twitter @devnulling has indicated that his own fork of the code should run on x86 systems. Aaron @cemaxecuter is also working on including it into a DragonOS release.

The image below demonstrates a typical Remote SDR V2 transceiver setup with two HackRFs.

A full QO-100 Transceiver Setup with Remote SDR V2 and two HackRF's.

Frugal Radio: A Review of the NooElec Inmarsat Patch Antenna Bundle

In his latest video Rob from Frugal Radio has reviewed the NooElec Inmarsat Patch Antenna Bundle. The US$79.95 bundle includes a PCB patch antenna, Inmarsat SAWBird LNA, SMA DC Block, SMA Barrel adapter and SMA pigtail. In the video Rob tests the bundle out on various AERO signals using the JAERO software, before moving on to compare the bundle with our own RTL-SDR Blog Active L-Band Patch antenna. The comparison results show that our $49.95 L-band antenna is better by about 5-6dB in SNR.

Our RTL-SDR Blog Active L-Band Patch antenna set is available on our store. However, please note that this antenna is currently in short supply due to the global electronics supply chain shortage. We expect to be sold out within a few days but we are aiming to be able to restock within 1-2 months from now.

Review : NooElec L Band Inmarsat Patch Antenna Bundle