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How to receive SSTV pictures from the ISS

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How to receive SSTV pictures from the ISS
License neededNone to receive in the US and most countries; transmitting needs an amateur license
TimeAn evening to set up; a pass lasts up to about ten minutes
Skill levelBeginner
You will needAn FM receiver, scanner or SDR, a decoding app or program, and a pass prediction
Recent events (2026)
Downlink437.550 MHz FM, shifted up to about 10 kHz by Doppler
ModeRobot 36
Cycle36 seconds per picture, then about 2 minutes off
Earlier events145.800 MHz FM, PD120 mode (through 2025)
After the event
AwardElectronic ARISS award, offered for past events, for images uploaded to the ARISS SSTV gallery

How to receive SSTV pictures from the ISS explains how to catch the pictures that the International Space Station (ISS) sends during its occasional slow-scan television (SSTV) events, and turn them into images on a computer or phone. SSTV sends a still picture as audio tones over an ordinary FM voice channel, and software turns the tones back into an image. The events are run by ARISS (Amateur Radio on the International Space Station), which says its radio on the station can be followed across most of a pass with a basic handheld or scanner.[1]

Before you start

  • No license is needed to receive in the US and in most other countries, because you are only listening to amateur transmissions. US federal law on intercepting radio messages does not apply to amateur transmissions,[2] and clubs elsewhere make the same point.[3] Rules differ by country; see How to start shortwave listening. Transmitting, to talk to the ISS or use its repeater, needs an amateur license from the FCC in the US or your own country's regulator; see How to get your first ham license and Amateur radio licensing around the world. Never transmit on the ISS downlink frequency.[1]
  • Events are occasional and announced. In 2026 ARISS ran four series from the ISS, numbered 31 to 34: in April, in May and two in October.[4][5] Each runs for several days. ARISS asks listeners to follow @ARISS_intl on X for official updates,[4] and its website links its other channels, including Facebook and Discord.[6] Its Upcoming SSTV events page is not always current (in November 2026 it listed nothing after May), and its older SSTV blog is no longer updated.[4]
  • Check the frequency and mode for each event. Recent events, such as Series 32 in May 2026, used 437.550 MHz FM on the 70-centimeter band, in Robot 36 mode, sending each picture for 36 seconds, then pausing about two minutes.[7] ISS events in 2025 used 145.800 MHz FM on the 2-meter band in PD120 mode, two minutes on and two minutes off.[8]

Step by step

  1. Choose a receiver. Any radio that receives the event frequency in FM will do: a dual-band ham handheld, a mobile or base radio, a scanner, or a software-defined radio (SDR) such as a low-cost RTL-SDR dongle plugged into a computer.[3][9] If the radio offers wide and narrow FM filters, choose the wide one; handhelds usually have only a wide filter.[4]
  2. Pick an antenna. A handheld's stock rubber antenna works, but a longer whip or a small Yagi pointed at the station gives a stronger signal.[3] Because the ISS is well above the horizon for most of a pass, AMSAT-UK reports good results from plain outdoor antennas such as a quarter-wave ground plane or a dipole, and poorer ones from long colinear verticals, which favor the horizon.[9] Cut any antenna for the event's band (70 cm in 2026). The handheld Yagi used in How to make your first satellite contact also works if aimed by hand.
  3. Install a decoder. These are examples from different authors, not recommendations:
    • MMSSTV by Makoto Mori, JE3HHT, for Windows, free for amateur use.[10]
    • QSSTV, packaged for Linux distributions such as Ubuntu[11] and tested by its author on the Raspberry Pi.[12]
    • Robot36 by Ahmet Inan for Android, which decodes the Robot 36 and PD120 modes, among others.[13]
    • SSTV Slow Scan TV by Black Cat Systems for iPhone and iPad ($3.99 as of November 2026), and the same maker's Black Cat SSTV for Windows and macOS ($24.99 as of November 2026, including a year of updates).[14][15]
  4. Find the passes. A pass is short: the European Space Agency notes that only about ten minutes of direct radio contact are available at a time,[16] and low passes give less. ARISS points to AMSAT's online pass predictor, which runs in a web browser.[1] Other options include Heavens-Above, a website with an Android app;[17] Gpredict, free software for Linux, macOS and Windows;[18] and Look4Sat, an ad-free, open-source tracker for Android.[19] Pick high passes, and convert times from UTC.
  5. Allow for Doppler. Because the ISS moves so fast, its signal arrives slightly above the published frequency as it approaches and slightly below as it leaves: the Doppler shift. On 145.800 MHz, used before 2026, the shift is about 3.5 kHz either way.[4] On 437.550 MHz it reaches about 10 kHz either way, and ARISS strongly suggests correcting for it.[20] Store memories at 437.560, 437.555, 437.550, 437.545 and 437.540 MHz, start at the top as the station rises, and step down through them during the pass.[20]
  6. Set up the audio. Open the squelch fully so it can't cut off a picture. Hold the phone near the speaker in a quiet room, or run a cable from the radio's audio output to the computer, ideally through a sound card interface.[9] With an SDR, a virtual audio cable can pass the sound straight to the decoder.[9]
  7. Record the audio as well. A recording lets you decode the pass again later with different settings, which often gives a cleaner picture.[3] On a computer, Audacity, a free, open-source recorder and editor, runs on Windows, macOS and Linux.[21]
  8. Receive the pictures. Pictures come in a cycle, so if you hear nothing, wait two minutes before changing anything.[4] Most decoders detect the mode from a code at the start of each picture; if yours doesn't, set Robot 36 or PD120 by hand to match the event.
  9. Upload and claim the award. ARISS runs an online gallery for decoded images from each series. For past events, it asked listeners to upload images and request the electronic ARISS SSTV award within 72 hours after transmissions ended, using a button in the gallery; certificates arrived by email, so check your spam folder.[4] Check each announcement for its deadline. During the May 2026 event the gallery was offline and ARISS asked listeners to hold their images,[7] but by late October 2026 it showed Series 34 pictures.[5]
When decoding with a phone held to the speaker, any talking, barking or traffic noise in the room shows up as streaks. Use a cable or a quiet room, and record at the same time in case the live decode fails.

Common problems

  • Nothing heard → Check that an event is running today, since transmissions pause for school contacts[8] and schedules can change.[4] Check the time, mode, frequency and squelch.
  • Sound but no picture → The decoder may be on the wrong mode, or the phone app may lack microphone permission.
  • Picture slanted → The sound card's sample rate doesn't match the decoder's clock. For MMSSTV, AMSAT-UK suggests setting the sound card to 48 kHz rather than 44.1 kHz.[9]
  • Streaks and noise → The signal is weak, usually because the station is low or Doppler has moved it off frequency. Step through the Doppler memories or find a clearer view of the sky.

See also

References

  1. ↑ 1.0 1.1 1.2 Contact the ISS, ARISS.
  2. ↑ 47 U.S. Code § 605, Legal Information Institute.
  3. ↑ 3.0 3.1 3.2 3.3 How to receive SSTV from the International Space Station, BARC.
  4. ↑ 4.0 4.1 4.2 4.3 4.4 4.5 4.6 4.7 Upcoming SSTV events, ARISS.
  5. ↑ ARISS, ARISS.
  6. ↑ 7.0 7.1 ARISS News Release No. 26-28, ARISS, May 2026.
  7. ↑ 8.0 8.1 ARISS press releases, ARISS.
  8. ↑ 9.0 9.1 9.2 9.3 9.4 ISS SSTV, AMSAT-UK.
  9. ↑ MMSSTV, HamSoft.
  10. ↑ Package qsstv, Ubuntu.
  11. ↑ QSSTV, ON4QZ.
  12. ↑ Robot36 - SSTV Image Decoder, Google Play.
  13. ↑ SSTV Slow Scan TV, App Store.
  14. ↑ Black Cat SSTV, Black Cat Systems.
  15. ↑ Amateur radio on the Space Station, European Space Agency.
  16. ↑ Heavens-Above, Heavens-Above.
  17. ↑ Gpredict, OZ9AEC.
  18. ↑ Look4Sat, GitHub.
  19. ↑ 20.0 20.1 SSTV Event 437.550 MHz Doppler summary, ARISS.
  20. ↑ Audacity, Audacity Team.
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