If you've been following our blog, or have your own RTL-SDR based weather satellite station, then you'll know that the NOAA-15 APT satellite has been experiencing issues lately. There appear to be problems with it's camera scan motor resulting from it running low on lubrication. This is fully understandable as the satellite is 21 years old and well past it's expected life span. The satellite appears to be working some days, and producing garbage image other days.
When NOAA-15 fails for good, don't feel too bad as we still have NOAA-18 and NOAA-19, the Russian Meteor M2, and Meteor M2-2 satellites, and the GOES satellites, all of which can be received by an RTL-SDR. Several new weather satellites are also planned for 2020 and onwards.
Over on his YouTube channel Adam 9A4QV has uploaded a short video that demonstrates his 2.4 GHz homemade helical feed designed to be used with a reflector (prime feed satellite dish) for QO-100/Es'Hail-2 satellite reception. The antenna is made from an old can, 2-turns of copper wire, and a plastic insulator to hold the turns in place. The two turns are wound in left hand circular polarization (LHCP), because when used with a satellite dish reflector it will result in right hand circular polarization (RHCP), which is the polarization QO-100 uses.
One of the most important parts of the video is when Adam shows how he matches the antenna to 50 Ohms. He notes that without matching the antenna won't work properly, and the return loss will be about 8 dB or even less, resulting in poor performance. With matching he obtains 30 dB return loss.
Over on YouTube user [Radio Electronics] has uploaded a useful video showing how to install your own personal SDRplay or RTL-SDR based WebSDR for QO-100 (aka Es'Hail-2) reception. Es'Hail-2 is the first geostationary satellite with amateur radio transponders on board, and is positioned at 25.5°E which covers Africa, Europe, the Middle East, India, eastern Brazil and the west half of Russia/Asia.
The idea behind a WebSDR is to run your RTL-SDR QO-100 receiver on a remote Raspberry Pi (perhaps mounted close to the antenna on your roof etc). The Pi runs custom WebSDR software that has been created from scratch by [Radio Electronics] specifically for monitoring Es'Hail-2. Then you can access your QO-100 receiver from any device on your network that has a web browser (computer/phone/tablet etc). The interface of his WebSDR appears to be quite slick, which multiple QO-100 specific options and labels.
Quite a lot of work must have gone into this software which looks to be of high quality, so it is definitely worth checking out if you are interested in QO-100/Es'Hail-2 monitoring.
Es'Hail-2 QO-100 WebSDR
In the first video he first talks about various methods for downconverting the 10489.550 MHz QO-100 CW signal into a range receivable by the RTL-SDR or SDRplay. He then goes on to show the exact steps to install and run his WebSDR software on a Raspberry Pi 3.
In the second video he goes on to demonstrate the web browser interface highlighting the QO-100 specific features that he has implemented such as being able to compensate for any LNB frequency drift via a feature that can lock to the QO-100 PSK beacon.
With so many independent people receiving weather satellite images from the NOAA satellites daily, an interesting collaborative task is to stitch these images together to create a wide area composite image. Fortunately the WXtoIMG software already has stitching as a feature.
NOAA Weather Satellite Composite created with images from Jeff Kelly (New Jersey, US), Mike Kimzey (Philadelphia, US), David Kunz (San Francisco, US), Cornelius Danielsen (Norway), Alan Hinton (UK), Michael Sørensen (Denmark), and Hans-Juergen Luethje (Germany).
Weather Satellite Failure Updates
We also wanted to provide a brief update on some weather satellites that we RTL-SDR users often receive.
NOAA 15: About two weeks ago NOAA 15 failed and was producing glitched images. However after a few days it came right again, only to have failed again at the end of last month. It appears that the camera scanning motor is getting stuck due to being low on lubricant as the satellite is now well past it's intended life cycle at 11 years old. If you're interested, some info on how the camera on these satellites works can be found here. There is currently no plan for a fix, the only hope is to wait and see if the motor unsticks.
Meteor M2-1: Meteor M2-1 has also recently suffered problems yet again with it's orientation control, and we're regularly seeing off-axis or distorted images that show the curvature of the earth. Over the weekend it was turned off, and should be reset this week. This problem seems to occur and be fixed often, so hopefully it will be back online soon.
Meteor M2-2: The recently launched Meteor M2-2 is functional, but it is still in the testing phase, so is sometimes being turned off. Do not be alarmed if no signal is received sometimes.
GOES-17: GOES-17 is reported to be experiencing problems with it's infrared camera due to a blocked heatpipe, however it appears that they are able to work around this issue and obtain 97% uptime.
Es’hailsat, otherwise known as QO-100 is the first geostationary satellite with an amateur radio payload on-board. The satellite contains both a Wide Band transponder for experimental modes and DVB-S Digital Television and a Narrow Band transponder used mostly for SSB voice and some digital mode contacts with other amateur operators. If you’re unfamiliar with this satellite we’ve covered it in previous articles, like in [Es’hail Transponder Now Active]
While many choose to use a transverter connected to a traditional amateur transceiver, others have turned to use Software Defined Radios to complete their satellite ground stations.
[Radio Innovation] posted a video back in March showing his contact on QO-100 using a LimeSDR Mini as the 2.4 GHz transmitter and a 10 GHz LNB for the downlink.
The PlutoSDR has been frequently seen used for QO-100 satellite operation on the Wide Band transponder due to its ease of DVB-S transmission utilizing software such as [DATV Express] but more recently there have been more and more operators turning to SDR for their day to day satellite operation.
It will be interesting to see how these stations evolve, perhaps by the time North America has access to a similar satellite, we’ll be prepared to operate it.
Thank you to Happysat for submitting the following information about the updated LRPT decoder for Meteor M-N2-2. He has also provided a link to his very useful Meteor Satellite reception tutorial.
Today the official LRPT-Decoder V42 ready for release :)
Before we did use a older internal debug version from 2014, because this one was still in development.
This version 42 of LRPTDecoder will work with both Meteor M-N2 and Meteor M-N2-2.
Example ini configuration files for other modes are attached in the archive.
Lucky-7 is a Czech cubesat that carries some interesting sensors including a low power GPS receiver, a gamma ray spectrometer and dosimeter and a photo camera. The creators also claim that it is "probably the lowest-cost scientific space mission in human history". It was recently successfully launched and orbited together with the Meteor M2-2 weather satellite and several other small satellites.
"We did not build just another satellite. It is a flying laboratory. The satellite is going to test something that nobody has ever done before. Thanks to our background in electronics, materials and space effects, we implemented commonly used electrical parts from automotive and IoT industry in totally new ways. Gallium Nitride power transistors used in modern electric cars do not contain insulation layer to control its conductivity. That makes them much less vulnerable against the space radiation. We fly the world's first MOSFET-free power supply ever built for small satellites. The LED lighting industry has been used to make composite aluminum radiation shields for us. It is very cheap, lightweight and it naturally increases the mission lifetime," says Jaroslav Laifr, the CEO and founder.
If all goes well, the team will be able to measure the in-situ radiation background by miniature onboard Dosimeter and monitor the health of key subsystems, such as communication or data storage by complete satellite telemetry. The experimental Gamma Spectrometer payload informing about the energy of incident radiation will be able to detect Gamma Ray Bursts from distant galaxies. The platform also contains the VGA camera to demonstrate the data transfer capability. It may capture the first colour images ever taken by Czech satellite, possibly detecting the aurora glow. Such pictures would be greatly utilized for the outreach and inspire a new generation of scientists and engineers.
Daniel Estesvev has recently added a Lucky-7 decoder to gr-satellites, and has uploaded a post explaining some technical details on how he created the decoder. With this decoder, anyone with an SDR and appropriate antenna should be able to receive and decode the telemetry (no word on camera images yet). He writes that "Lucky-7 transmits 4k8 GFSK telemetry in the 70cm band. It uses a SiLabs Si4463 transceiver with a PN9 scrambler and a CRC-16. You must use FM mode to receive this satellite (437.525MHz)."
CubeSat companies like Sky Fox Labs are also tracking the satellite, and are tweeting results.
Lucky-7 #CubeSat Gamma Ray Spectrometer (0.3-3 MeV) data from first 1 hour of operations were compiled. It shows the contiuum in energy spectra as expected, no line spectra detected (obviously, there is no flying Cesium nearby). It corresponds to Dosimetry measurements!
On this episode of SignalsEverywhere on YouTube Corrosive shows off several antennas that can be used for Inmarsat and Iridium satcom reception. His video shows off a commercial Inmarsat branded satlink antenna which is designed to be used on moving ships, a grid dish antenna, a custom QFH iridium antenna made from a repurposed Vaisala radiosonde, a commercial Iridium patch, an older Outernet/Othernet Iridium patch and a custom Iridium patch that Corrosive built himself.
Satcom Antennas for L-Band Reception via RTL SDR
A few days prior Corrosive also released a new episode of his podcast. In this episode he interviewed Derek a student from The University of Michigan who is working on the MiTee CubeSat. The MiTee cubesat is a small experimental satellite that will explore the use of miniaturized electrodynamic tethers for satellite propulsion.
