Tagged: international space station

Receiving Digital Amateur TV from the ISS with an RTL-SDR

The international space station (ISS) is currently testing transmission of a DVB-S digital video signal. At the moment only a blank test pattern is transmitted, but one day they hope to be able to transmit live video properly for the purposes of making live contact with astronauts, and possibly to stream video of scientific experiments, extravehicular activities, docking operations, or simply live views of the Earth from space.

Over at www.pabr.org the author Pabr has been experimenting with using an RTL-SDR dongle for the reception of these digital amateur TV (DATV) signals. Over on Reddit he also posted some extra information about his work:

I have been able to receive DVB-S broadcasts from the ISS (known as HamVideo or HamTV) with a high-gain 2.4 GHz WiFi antenna ($50), a custom downconverter ($65), a R820T2 dongle, and a software demodulator (Edmund Tse’s gr-dvb). I used to think this could only be done with much more expensive SDR hardware.

It is commonly known that rtl-sdr dongles do not have enough bandwidth to capture mainstream satellite TV broadcasts, but the ISS happens to transmit DVB-S at only 2Msymbols/s in QPSK with FEC=1/2, which translates to 2 MHz of RF bandwidth (2.7 MHz including roll-off).

Before anyone gets too excited I should mention that:

  • This was done during a favourable pass of the ISS (elevation 85°)
  • With a fixed antenna, only a few seconds worth of signal can be captured
  • Demodulation is not real-time (on my low-end PC)
  • Currently the ISS only transmits a blank test pattern.

I now believe the BoM will be less than $50 by the time the ISS begins broadcasting interesting stuff on that channel.

Pabr uses a 2.4 GHz parabolic WiFi antenna to receive the signal. He writes that ideally a motorized antenna tracker would be used with this antenna to track the ISS through the sky. Also since the DATV signal is transmitted at around 2.4 GHz, a downconverter is required to convert the received frequency into one that is receivable with the RTL-SDR. The DATV decoder is available on Linux and requires GNU Radio.

Receiving DATV from the ISS
Receiving DATV from the ISS with an RTL-SDR

International Space Station set to Transmit SSTV this Weekend (July 18 – 19)

To commemorate the 40th Anniversary of the Apollo-Soyuz mission the International Space Station (ISS) is set to transmit 12 Slow Scan TV (SSTV) images this weekend. The images are set to transmit Saturday morning, July 18 10:30 UTC and will run through until Sunday, July 19 21:20 UTC, but they note that the dates are tentative and could be subject to change. The images will be transmitted at 145.80 MHz and will probably be sent in the PD180 SSTV mode with 3 minute breaks between each transmission.

SSTV is a type of radio protocol that is used to transmit low resolution images over radio. An RTL-SDR with appropriate antenna can be used to receive these images from the ISS. The signal is usually quite strong, so even a simple whip or long wire antenna may receive these images if placed in a good unobstructed view of the sky. 

As with the last ISS SSTV event we suggest that to decode the images you use SDR# and pipe the audio into MMSSTV, a freeware SSTV decoding software program. We also suggest using the settings recommended by “happysat”, which are enabling “Auto slant” and “Auto resync” under Options->Setup MMSTV->RX.

To know when the ISS is overhead you can track it online using heavens-above.com or isstracker.com. If using heavens-above to predict pass times remember to set it to show all passes, not just the visible ones. Received SSTV images can be submitted to the ARISS Gallery.

This event is being discussed on Reddit here. Here is the official release from ariss.org:

40 years ago this week, the historic joint Apollo-Soyuz mission was conducted.   Apollo-Soyuz (or Soyuz-Apollo in Russia) represented the first joint USA-Soviet mission and set the stage for follow-on Russia-USA space collaboration on the Space Shuttle, Mir Space Station and the International Space Station.  The Soyuz and Apollo vehicles were docked from July 17-19, 1975, during which time joint experiments and activities were accomplished with the 3 USA astronauts and 2 Soviet cosmonauts on-board.  Apollo-Soyuz was the final mission of the Apollo program and the last USA human spaceflight mission until the first space shuttle mission in 1981.

To commemorate the 40th anniversary of this historic international event, the ARISS team has developed a series of 12 Slow Scan Television (SSTV) images that will be sent down for reception by schools, educational organizations and ham radio operators, worldwide.The SSTV images are planned to start sometime Saturday morning, July 18 and run through Sunday, July 19.  These dates are tentative and are subject to change. The SSTV images can be received on 145.80 MHz and displayed using several different SSTV computer programs that are available on the Internet. 

We encourage you to submit your best received SSTV images to:
http://spaceflightsoftware.com/ARISS_SSTV/submit.php

The ARISS SSTV image gallery will post the best SSTV images received from this event at:
http://spaceflightsoftware.com/ARISS_SSTV/index.php

Also, as a special treat, on Saturday July 18 the ISS cosmonauts will take time out to conduct an ARISS contact with students attending the Moon Day/Frontiers of Flight Museum event in Dallas Texas.  This Russian cosmonaut-USA student contact is planned to start around 16:55 UTC through the W6SRJ ground station located in Santa Rosa, California.  ARISS will use the 145.80 MHz voice frequency downlink (same as the SSTV downlink) for the Moon Day contact. More details about these contacts are provided at Upcoming Contacts.

The ARISS international team would like to thank our ARISS-Russia colleague, Sergey Samburov, RV3DR, for his leadership on this historic commemoration.

An example SSTV image from the last ISS SSTV event
An example SSTV image from the last ISS SSTV event which was to commemorate first man to space Yuri Gagarin’s would be 80th birthday.

The International Space Station is Transmitting SSTV Images

Happysat, a reader of RTL-SDR.com has written in to remind us that the International Space Station (ISS) is currently transmitting slow scan television (SSTV) images out of respect of the 80th birthday of Russian cosmonaut and first man to go to space Yuri Gagarin. The images will be transmitted continuously until 24 February 21.30 UTC.

SSTV is a type of radio protocol that is used to transmit low resolution images over radio. A RTL-SDR dongle and satellite antenna (QFH, turnstile, even terrestrial antennas like random wire antennas and monopoles have been reported to work) can be used to receive and decode these images. Happysat writes that it is expected that the ISS will continuously transmit 12 images at a frequency of 145.800 MHz FM using the SSTV mode PD180, with 3 minute off periods between each image.

To decode the images it is recommended to use SDR# and pipe the audio into MMSSTV, a freeware SSTV decoding software program. To get the best results out of MMSSTV happysat recommends enabling “Auto slant” and “Auto resync” under Options->Setup MMSTV->RX.

To know when the ISS is overhead you can track it online using http://spotthestation.nasa.gov/sightings/, http://www.isstracker.com/ or http://www.mcc.rsa.ru/English/trassa.htm.

Received SSTV images can be submitted to the ARISS Gallery, and Happysat has also uploaded a collection of his own personal received images here.

Happysat also shows us some images from the ISS showing the Kenwood D710 transceiver located in the Russian service module, the computers used to generate the SSTV signal and the antennas used for amateur radio transmission.

One of the broadcast SSTV images from the ISS
One of the SSTV images broadcast from the ISS
Computers on the ISS used to transmit SSTV images
Computers on the ISS used to transmit SSTV images
Antennas on the ISS used to transmit SSTV images
Antennas on the ISS used to transmit SSTV images

Listening to Spacewalk Communications from the International Space Station

Over on YouTube user LEGION ELMELENAS has uploaded a video showing his reception of voice communications from a Russian spacewalk on the International Space Station (ISS).

Legion used a Funcube Dongle Pro+ which is a software defined radio USB dongle similar to the RTL-SDR, but with better performance and higher cost. He also used a home made turnstile antenna, the SDRSharp software and the Orbitron satellite tracking software to automatically correct for the signals doppler shift as the ISS flies over.

International Space Station spacewalks(Russian astronauts EVA) received with Funcube Dongle Pro+

Receiving ISS Data Comms with the RTL-SDR

YouTube user mutezone has uploaded a video showing some data communication packets from the International Space Station (ISS) being received with the RTL-SDR. To receive the packets he used SDRSharp, and piped the audio using a virtual audio cable to the Qtmm AFSK1200 Decoder.

I tried to get the ISS (International Space Station) data comms on 145.825 MHz while the satellite was in orbit close to my location & it worked, even though it can go off frequency due to atmospherics & such. On this day, I caught it when it orbited twice around my location in the space of almost three hours. The data comms was decoded on the 2nd attempt. The antenna I used was an omni placed outdoors, & also using a TV + radio signal booster.
For anyone interested in getting the ISS, you have to wait until it orbits close to your location, & I fully recommend a decent aerial that should be placed externally. You can check the ISS tracker websites to see live updates of when & where it will orbit. Here is a link to one website…

http://www.isstracker.com

List of frequencies link…

http://www.issfanclub.com/frequencies

Receiving ISS Data comms on RTL-SDR in UK, 6th June 2013

RTL-SDR Receiving ISS EVA Comms

Over on the Radio Antics blog, Andrew has posted about how he was able to receive Russian International Space Station communications during an EVA (Extravehicular Activity aka Spacewalk). He used a simple random wire antenna mounted in his loft and an RTL-SDR with SDRSharp tuned at 143.625 MHz.

See his recorded video below.

ISS - Russian EVA-33 Comms (RTL-SDR)

ISS Packet Repeater Received with RTL-SDR

YouTube user ronpaulatemybaby has posted a video showing his reception of the International Space Station (ISS) amateur packet repeater on 145.825 MHz, using the rtl-sdr. He used a R820T dongle, two meter dipole, SDRSharp and decoding software MixW.

RTL SDR International Space Station Packet Repeater 145.825 Mhz