Category: Satellite

YouTube Tutorial: Software Set up for a Portable Raspberry Pi and RTL-SDR Based NOAA Weather Satellite Receiver

Last year in December we posted about Matt's element14 sponsored video which showed us how to create a portable briefcase contained NOAA satellite received based on a Raspberry Pi and RTL-SDR dongle. The build consisted of a heavy duty briefcase, modified ATX PSU and stripped down LCD monitor panel. This build resulted in a rugged and portable receiver. The full series of videos demonstrating the briefcase, ATX PSU conversion, LCD teardown, and NOAA satellite receiver demo can be found on his YouTube Playlist.

In his latest video Matt goes over the software installation procedure for creating an automated NOAA weather satellite receiver on the Raspberry Pi. He uses gpredict for predicting the satellite passes, and the Raspberry Pi version of WXtoImg for decoding the images. The rest of the video shows how to set up the software for your particular location, and how to set up decoding automation.

How To Set Up a Raspberry Pi as a NOAA Satellite Receiver with RTL-SDR

Es’hail-2 Transponder Tests + Narrow Band Web Stream

Es'hail 2 was launched last November and it is the first geostationary satellite to contain an amateur radio transponder. The satellite is positioned at 25.5°E which is over Africa. It's reception footprint covers Africa, Europe, the Middle East, India, eastern Brazil and the west half of Russia/Asia.

Although the satellite was launched last year, turning on the amateur transponders has been slow because the commercial systems of the satellite have higher priority for testing and commissioning. However, within the last day the Es'hail 2 team have now begin testing the amateur transponder, and the test signal has been successfully received by several enthusiasts (just check out the Twitter feed). There also appears to have already been a suspected pirate CW signal broadcasting "WELCOME DE ES2HAIL". Actual uplink use of the satellite is not currently wanted, and from the Amsat forums one of the engineers writes:

Before the IOT starts there will be a TRR (test readyness review) in front of the customer. All the testplans and test-specifications will be reviewed. When the test is done there will be a TRB (test readyness board). In the TRB they have to show/present all the measurement results (e.g. inband performance like Gainflatness, Groupdelay... aso.) and compare these results with the specification in the contract. Each unwanted signal makes the measurement difficult and needs to be explained or leads to a so named NCR (non conformance report).

The IOT will be done in shifts/nightshifts and with unwanted signals (if not explain able) some measurements needs to start again and again and leads in addition to a delay for the handover and operation of the satellite.

Maybe that helps to understand why it is really important to have only the IOT uplink signal.

To measure the pattern of each antenna the satellite will be moved east/west by the propulsion system of the DS2000 Bus and the signal level is measured by the IOT station on ground (some cuts) .

The commercial beacon can maybe be switched from LEOP Omni antenna to on station antenna when the satellite is placed in the final slot. This should be the reason for the change of the commercial Ku Band beacon signal level the last days.

If you are interested in receiving Es'hail 2, but live outside the footprint, or don't have a receiver then you can use Zoltan's OpenwebRX live stream of the narrow band portion of the Es'hail 2 downlink. At the moment the beacon doesn't appear to be transmitting, but we expect it to be on and off during the next few days. In his set up he uses an RTL-SDR V3, Inverto LNB, 90cm dish, a DIY bias tee and a Raspberry Pi 3.

He also took a recording of the pirates CW transmission shown in the video below.

Es'hail-2 live, CW signal 2019.01.17.

Es-hail 2 test transmission
Es-hail 2 test transmission

Video Showing How to Decode Meteor M2 with an SDRPlay in Windows

Thanks to "Lolo sdr" for submitting his videos that show his process for receiving and decoding Meteor M2 weather satellite images in Windows with an SDRplay and SDR-Console V3. Since the SDRplay is not supported by SDR#, it is not possible to use Vasilli's excellent Meteor Demodulator plugin (site in Russian, please use the Google Translate option) which is only available for SDR#.

Lolo's method gets around this limitation by initially recording an IQ file of the satellite pass in SDR-Console V3, then opening that IQ file in SDR# via the Fileplayer plugin, which is also by Vasilli and available here. The process is a bit of extra work, and the image isn't live, but the image comes out clearly in the end.

The videos are shown below, and subtitles are available in English, French and Italian via the YouTube player options.

Recibir y decodificar Satélite Meteor M2 con SDRplay, parte 1 de 2, grabar el pase, con subtitulos.

Recibir y decodificar Satélite Meteor M2 con SDRplay, parte 2 de 2, decodificar imagen y corrección.

Creating an Inmarsat STC-C EGC Live Stream with an RTL-SDR, Raspberry Pi and OpenWebRX

Thanks to Zoltan (aka Veryokay on YouTube) for submitting information about his Inmarsat STD-C EGC live stream setup. His setup allows him to access the Inmarsat STD-C signal from anywhere in the world over the internet, thanks to the use of an OpenWebRX server. Inmarsat STD-C is a geostationary satellite service that provides information for search and rescue, as well as news, weather and incident reports for mariners. We have a tutorial from a few years ago which shows some example messages. OpenWebRX is an efficient SDR streaming server platform that allows you to access RTL-SDR's and other SDRs from anywhere in the world via an internet connection.

In his setup Zoltan uses a Raspberry Pi 3, RTL-SDR Blog V3, L-band LNA and L-band antenna for receiving and processing the signal. Power is provided via a Power over Ethernet (PoE) adapter, and the whole thing is placed outside, in a weatherproof plastic lunchbox.

The video shows the hardware, and then goes on to describe the software setup, along with a demonstration of the OpenWebRX stream. More information as well as the link to his publicly accessible OpenWebRX Inamrsat STD-C stream can be found on his blog post.

INMARSAT STD-C EGC live streaming

Bitcoin Satellite Now Supports Lightning Payments: Receive with RTL-SDR

Bitcoin is a digital currency based on blockchain technology, and Blockstream are a large innovator in the Bitcoin world. They have recently been developing the 'lightning network' which is a layer that sits on top of the blockchain. The goal of the lightning network is to provide a second layer that helps to speed up bitcoin transactions and alleviate network congestion.

In a previous post we noted that Blockstream have data channels leased on several geostationary satellites. The goal of these satellites is to help users download the blockchain, which is the ledger of all bitcoin transactions ever made. Over time the ledger grows and becomes larger and larger, and at the time of writing is currently about 200 GB in size. Rural/field users of Bitcoin with slow, intermittent, or no internet connection can use this satellite to download or update their ledger and confirm that they have received payments.

To receive the satellite an RTL-SDR dongle together with a Linux PC, LNB and satellite dish antenna are used. More information about setting up a receiver can be found on their GitHub.

Recently Blockstream have released news that their satellites now support Lightning transactions. In addition the Asia-Pacific satellite is now online. This should help boost adoption of the lightning network among rural users.

Blockstream satellite currently covers almost the entire world
Blockstream satellite currently covers almost the entire world

Building a Carbon Fibre Dual Band Yagi Antenna for Amateur Radio Satellites with 3D Printed Parts for 20€

Back in early 2017 we posted about Manuel's (aka DO5TY / Tysonpower) design for a single band 140 MHz 3D printed carbon fibre Yagi antenna. Today he's submitted a new video about creating a dual band 3D printed carbon fibre cross Yagi antenna for only 20€. Note that the video is narrated in German, but there are English subtitles. He's also uploaded an English text tutorial to his blog, which includes links to the 3D printer STL files.

The antenna is designed to be a low cost replacement for the commonly used Arrow dual band 2m/70cm antenna which is designed for receiving and transmitting to amateur radio satellites. Many amateur radio satellites have an uplink frequency set at around 145 MHz, and a downlink frequency around 435 MHz (and some satellites have the frequencies reversed). So a dual band Yagi is ideal for these satellites. Manuel writes that with his 5W Baofeng handheld he's already made several successful contacts with his new antenna.

Manuel's antenna consists of several 3D printed joints, with a carbon fibre rod used as the main boom. Aluminum rods make up the receiving and transmitting elements. The video also discusses impedance matching and how he uses a diplexor so that there is only one connection required to the radio. The advantage of his antenna over the Arrow is that it is significantly cheaper, and also much lighter in weight.

[EN subs]Carbon Arrow Yagi Antenne - leichte Dual Band Yagi für 20€ bauen

Help Track Data from CubeSail with an RTL-SDR

On December 16 Rocket Lab launched 13 new cubesats into orbit via it's Electron rocket which was launched from New Zealand. One of those Cubesats is "CubeSail" which is a set of two satellites that aims to deploy a 260 m long solar sail between the two.

CubeSail is a technology demonstration by CU Aerospace which shows the viability of solar sail propulsion for deep space missions. It was built and is operated by students at the University of Illinois at Urbana-Champaign through the Satellite Development, or SatDev student organization.

Over on Reddit, one of the engineers working on the Cubesail project has put out a request to help receive and upload any telemetry that you receive from the Cubesail satellite. Currently they only have one ground station which makes monitoring the satellite difficult as they can only collect data when it is passing overhead.  By employing the help of radio enthusiasts from around the world they hope to gather more data. He writes:

Hello amateur radio enthusiasts! I'm part of the CubeSail mission, one of the 13 satellites deployed early this morning (2018/12/16) from RocketLab's Electron rocket.

The reason why I'm posting is that we need your help! We're trying to gather as much data as possible from the beacons, but only have one groundstation at the moment. I've put together a little Python script which can be used to decode the data, so if you're interested and willing to help out a bunch of eager fellow space enthusiasts to get some data, please try and get a packet or two!


Here's the information you need to know (let me know if I'm missing anything):

Frequency: 437305 kHz

Modulation: GFSK (GR3UH scrambling)

Bandwidth: 15kHz

Callsign: WI2XVF

Link Layer: AX.25/HDLC

Baud Rate: 9600

TLE:

cubesail_temp
1 99999U          18350.31100694  .00048519  00000-0  21968-2 0 00004
2 99999 085.0351 178.2861 0013006 291.7248 120.7146 15.20874873000012

Here's a link to the decoder, it runs in Python 3: https://github.com/ijustlovemath/cubesail-decoder

According to the information a 437 MHz antenna is required, and most likely it will need to be a directional antenna that is hand or motor tracked. Some SatNOGS ground stations are already receiving and recording Cubesail data too.

An artists rendition of the CubeSail solar sail deployment
An artists rendition of the CubeSail solar sail deployment

Using a 25 Meter Radio Dish and an RTL-SDR as a SatNOGS Ground Station

SatNOGS is an open source project that aims to make it easy for volunteers to build and run RTL-SDR or other SDR based RF ground stations that automatically monitor satellites, and upload that data to the internet for public access. The antennas used in a typical home based SatNOGS station are small enough for a single person to handle, however recently the SatNOGS team have been working on setting up a monitoring station at the Dwingeloo Radio Observatory in the Netherlands.

Dwingeloo has a large 25 meter satellite dish antenna, and they connect it to an RTL-SDR on a laptop running the SatNOGS software. In the video they show it tracking the PRISM amateur radio satellite, and note that the use of this large dish will only be used in special circumstances. They write:

This week the Dwingelooradio Observatory tested their 25 meter dish as a SatNOGS station! Although not set up as a permanent SatNOGS station it is great to see this historic observatory linked to the network. Dwingeloo radio observatory was built between 1954 and 1956 near the village of Dwingeloo in the Netherlands. Since 2009 this single 25 meter dish has been a national heritage site.

Dwingeloo Radio Observatory as a SatNOGS 📡 station

Dwingleloo Satellite Antenna in the Netherlands
Dwingleloo Satellite Antenna in the Netherlands [Source: Wikipedia]