Tagged: satellite

Meteor-M N2-2 Weather Satellite Updates: No More 137 MHz LRPT, L/X-Band Working in Daylight

In late December 2019 we posted about Russian weather satellite Meteor M N2-2 which had unfortunately been struck by a micro-meteorite on Dec 18, causing it to lose control and go offline. Meteor M N2 and N2-2 satellites are often monitored with RTL-SDR dongles as it is relatively simple to receive their LRPT signal at 137 MHz which contains a high resolution weather satellite image.

Recently Happysat updated his Meteor M status page, noting that Meteor M N2-2 has been partially recovered, but due to low power it can no longer transmit a 137 MHz LRPT signal ever again. However, the L and X-bands are transmitting while the satellite is in daylight. Happysat writes:

January 2020 There will be only short-term power-ups in the radio visibility zone, and the battery life will be reduced tenfold.

Of particular concern are the batteries they are very quickly overheated and switching from regular to backup.

Unfortunately the power supply features do not allow the 137 MHz transmitter to be used in abnormal power, mode (from solar panels) which is used now although technically it is working fine.

There will be no LRPT Transmission's anymore.

The older Meteor M N2 satellite remains operational transmitting at 137.100 MHz.

The Meteor-M2 Satellite
The Meteor-M N2 Satellite

Meteor M N2-2 Has Failed but Recovery May be Possible

UPDATE: It has now been confirmed by Roscosmos that the satellite was struck by what is presumed to be a micrometeorite which caused a leak of thermal transfer gas, and hence a sudden orbit change. It seems unlikely that the satellite will begin operations again as the satellite cannot operate it's camera sensors without thermal cooling. Data is being transmit currently on the X-Band, however, it appears to be a stored image only, rather than live images.

On December 18, 2019, an abnormal situation was recorded on the Meteor-M spacecraft No. 2-2 associated with an external impact (presumably a micrometeorite) on its structure. As a result, he changed the parameters of the orbit and switched to a non-oriented flight mode with high angular velocities.

In accordance with the inherent logic of operation, the device stopped fulfilling the target task and automatically switched to energy-saving mode when the on-board systems that were not involved in ensuring its functioning (including all on-board target equipment) are turned off.

After entering into the zone of Russian ground-based controls with the Meteor-M spacecraft No. 2-2, communication was established and work began to restore its operability: damping angular velocities, transferring to the standard orientation, receiving telemetric and target information.

Currently, work is underway with the satellite under the program of the chief designer. Meteor-M No. 2-2 is in an oriented flight; regular control sessions are conducted with it to receive telemetric information and information from target equipment.

Happysat's Notes:

Depressurization caused gas that was inside and used for heat transfer to leak out.

Resulting in some devices onboard overheating, while others did stop working.

Batteries are working under harsh thermal conditions.

Experts analyzing MSU-MR images during the incident to confirm collision.

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On December 18 Meteor M N2-2 suffered a failure that appears to have changed it's orbit. Roscosmos is quiet on the issue, but speculation by R4UAB is that there was a depressurization or on board explosion. However, Happysat who appears to be in contact with Roscosmos insiders has noted that on December 20 the orbit has been stabilized, and that they are working on recovering the operation of the satellite. Currently the LRPT signal and all sensors remain OFF.

Meteor M N2-2 is a Russian weather satellite that was successfully launched into orbit on July 5 2019. Like with the NOAA and Meteor M N2 satellites, it is possible to receive weather satellite images from this satellite with an RTL-SDR (when it is operational).

The older but still operational Meteor M2 satellite has failed several times in it's history too, each time with the satellite entering an unstable tumble. However, each time the satellite was recovered back into full operation after a few days.

The Meteor-M2 Satellite
The Meteor-M N2-2 Satellite

Building a FossaSat-1 LoRa IoT Ground Station

FossaSat-1 is a recently launched open source "picosatellite" with an onboard LoRa repeater designed for Internet of Things (IoT) communications. It was launched via the Electron Rocket in New Zealand on December 6. At only 5 x 5 x 5cm in size and 250g in weight, a picosatellite is a tiny satellite that fits in your hand and can be affordably built and launched for around US$40k. 

Since the launch, it has been confirmed that FossaSat-1 was successfully launched, and is working correctly. However, the antennas have not properly deployed yet resulting in a weak signal that cannot be received by small ground stations. The team are currently working on getting the antenna manually deployed from earth and the latest updates can be found on their Twitter @FossaSys. They note that if the antennas cannot be deployed, then there is still the future launches of FossaSat-1B and FossaSat-2 to look forward to.

While waiting for the antennas to deploy you can watch Andreas Speiss' YouTube video where he explains the satellite in more detail, and shows how to build a FossaSat-1 ground station that can receive the FossaSat-1 LoRa transmission and upload it to the internet. While not SDR-related as it uses a hardware based LoRa chip, this is still an interesting project that some readers may be interested in.

We build a 20 Dollars LoRa Satellite Ground Station and we follow the FossaSat-1 launch

The Toosheh Project: An Outernet-like Service for Iran and the Middle East

If you've been following our blog over the years, you'll know that we've mentioned the "Outernet" (now known as "Othernet") service a few times. Othernet is a satellite service that wants to provide one way data such as news, weather, audio, books and Wikipedia articles to those in areas with poor, censored or no internet connection. Previous iterations made use of home satellite TV equipment, then L-band (with RTL-SDR receivers) and now the Ku-band with LoRa receivers. Currently it's only available in North America and Europe.

However, thanks to a reader we were recently informed about an interesting and long running Othernet-like service for the Middle East called "Toosheh" (aka Knapsack) which makes use of satellite TV dishes and receivers that are very common in the Middle East. While not specifically related to SDRs, this is an interesting RF related project and situation that we wanted to post about.

Our reader is from Iran where the government recently shutdown the entire country's internet for 7-days due to anti-government protests. The reader wanted to share information about the Toosheh project which has been operating for several years now, and is one of the ways Iranians can get around heavy internet censorship and blockages.

After two rough weeks of no internet access at all, finally, we're gaining access again and getting back online slowly. As you may know (if you are following the news) a complete internet shutdown conducted by the I.R. of Iran due to some intense protests across the whole country against the government because of a 200% sudden and unannounced gas price increment. The internet is censored in my country anyhow but this time it was a big one. We only had access to a few domestic websites and NOT even Google services! That was tough!

I know it may be irrelevant to the subject of your blog but it's good for your audience to understand and know the people who have worked hard way before the OUTERNET project to develop a satellite offline broadcast with almost no special devices to receive and use and bring free and uncensored information to the people in Iran.

The major role of the Toosheh project occurred in the Iran 2012 presidential election protests which there were no major broadband internet services all over the country and it a lot to bring daily updates of news and TV programs.
The Toosheh is a one-way receive only from the satellite but the tricky part is that Toosheh is not just like a simple satellite data link but it appears as a TV channel in all satellite TV receivers which are very common in Iran, so the blockage of it is hard for the government. However, some trials were arranged by the government back in that time to collect the satellite dishes or jam the signals or mass destruction (!) of the satellite receivers which they currently no longer common in most parts of the country. (at least without unnecessary violence. check out this link: بجستان نیوز » معدوم سازی تجهیزات ماهواره‌ای در بجستان+عکس (Admin note: Article is in Perisian, use Google Translate to translate Persian to English)

The procedure to use this service is freaking simple. Set your dish to Yahsat and search for the channels on 11766 Mhz. Select the Toosheh channel, plug a flash drive to your receiver and record the blank screen in.TS format using the PVR capability. After several hours of recording unplug your flash drive and connect it to your phone, tablet or laptop. Then open the Toosheh app and you are good to go. Now you have access to dozens of free podcasts, music, books, movies, news, webpages, TV shows and much more that will be updated every single day and if you need something specifically just send them an email. Exactly as same as the OUTERNET but without any special equipment and only with ordinary receivers that are available in almost every home nowadays.

Also if you see their website at toosheh.org and search some other press blogs about Toosheh you can gain more info about the topic.
Toosheh Website Image
Toosheh Website Image

We also note that this appears to be the English language version of Toosheh project which provides some more information about coverage and the technology used: https://knapsackforhope.org. Coverage is only available in the middle east.

Toosheh Coverage
Toosheh Coverage

Creating An Automated Raspberry Pi and RTL-SDR Based NOAA Weather Satellite Station

The nootropicdesign blog has recently uploaded a comprehensive tutorial showing how to create an automated NOAA Weather Satellite ground station using an RTL-SDR V3 and an Raspberry Pi 3. The project also makes use of an Amazon S3 bucket, which is a cheap web storage platform that allows you to store and access the downloaded images.

The tutorial starts by showing you how to set up your Amazon AWS credentials and bucket on the Raspberry Pi, and how to host a simple webpage that can be accessed publicly. The second stage shows how to set up the RTL-SDR drivers and wxtoimg which is used to decode the images. Finally, the third stage shows how to create the automation scripts that automatically schedule a decode, and upload images to the AWS bucket.

Flowgraph for an automated NOAA satellite weather image station.
Flowgraph for an automated NOAA satellite weather image station.

Video About Receiving The Othernet Satellite Data Service: Free APRS, News, Weather

The Othernet project aims to bring live data such as news, weather, video, books, Wikipedia articles and audio broadcasts to the world via cheap receivers and a free satellite service. Although an internet connection provides the same data, Othernet's satellite broadcast is receivable in remote areas, will continue working in disasters, and costs nothing to continually receive roughly 100-200 MB of data a day. The trade off is that the service is downlink only, so the data that you get is only what is curated by the Othernet team. Currently the service is only available in North America and Europe, but service to other areas in the world may eventuate in the future.

We've posted about this project a few times in the past, as previously they used an L-band satellite service that was received by RTL-SDR dongles. However, these days they operate using LoRa hardware chips on the Ku-band.

Over on YouTube the TechMinds YouTube channel has just uploaded a video that demonstrates the Othernet service being received from the UK via their Dreamcatcher hardware. In particular he shows off the APRS feature which sends any APRS message containing the string "OUTNET" to the Othernet satellite stream. Later in the video he also shows the news articles, weather data, Wikipedia and audio data that was received.

OTHERNET - Free Data Anywhere - For everyone!

Mike Tests our RTL-SDR Blog L-Band Active Patch Antenna on an SDRplay RSP1a

Over on YouTube Mike Ladd (KD2KOG) from the SDRplay technical support team has uploaded a YouTube video showing him running our recently released RTL-SDR Blog L-Band Active Patch antenna on an SDRplay RSP1a. In the video he receives and decodes AERO signals from his car with his RSP1a powering the active patch antenna via the built in bias tee.

If you didn't already hear, we recently released an active (amplified + filtered) high performance patch antenna designed for receiving L-Band satellites such as Inmarsat, Iridium and GPS. The patch is designed to be easily mountable outside on a window, surface, stick, tree branch etc as it comes with easy to use mounting solutions and extension coax, and is enclosed in a fully weather proof plastic cover. If you're interested the product is available over on our store for US$39.95 with free shipping.

You also might want to keep an eye on Mike's YouTube channel, as he notes that in the yet to be released part 2 video he will be giving away the antenna in a competition.

RTL-SDR Blog L-band patch antenna part 1

ORBCOMM Receiver: New Open Source Software for Monitoring Orbcomm Satellites

Thank you to Frank for submitting his new RTL-SDR compatible Orbcomm Satellite monitor software called "Orbcomm Receiver". Orbcomm is a low earth orbit satellite communications system that operates in the 137 - 138 MHz frequency range. The satellites specialize in remote IoT and machine to machine (M2M) connectivity, an example use case being a GPS tracker on a shipping container regularly uploading GPS coordinates from anywhere in the world via the Orbcomm satellites. Orbcomm satellite signals are fairly strong and can easily be received with an RTL-SDR and V-Dipole antenna.

We haven't posted about Orbcomm on this blog since 2015 since there is not many interesting things to say about it. The data is all encrypted, and the only information you can really see is Orbcomm satellite ID, frequency and positioning data. Franks software doesn't change this fact, but his software is all open source, so it may be a useful tool for learning about satellite signal DSP processing. Frank writes:

There are a couple different projects out there to decode ORBCOMM signals (Orbcomm-Plotter and MultiPSK). What makes my project different from these is that I wrote it as a learning project. So all of the signal processing, written in Python, is available to the user and is decently documented. I hope this can be a good learning resource for people who want to see a practical example of satellite communications signal processing. Also, my software is open source and free to use.

Currently, the software can do offline or real-time decoding of a single ORBCOMM downlink channel. The transmitted bits of the ORBCOMM signal are demodulated and when the packet type is known, the packet information is decoded. There are a lot of ORBCOMM packets that can't be decoded and of course the message data is encrypted so that information is not available. But, there is still a ton of interesting information available.

The project is still in development so it has some limitations. For real-time recordings, I only support RTLSDRs currently. Also, I'm having trouble getting the real-time processing to work on mac OS, so currently that mode is only supported on linux. However, I have included a couple data files in the repo, so even without an SDR, users can experiment with the signal processing. I welcome any bug reports or suggestions.

Orbcomm Packet Decoding. Showing Realtime Satellite Position.
Orbcomm Packet Decoding. Showing Realtime Satellite Position.