ISS SSTV image 4/12 received by Frank Heritage M0AEU at 19:21 UT on Dec 18, 2014
The Russian Federal Space Agency (Roscosmos) has announced another round of amateur radio Slow Scan Television (SSTV) activity from the International Space Station (ISS) will take place. Continuous operation, using the call sign RS0ISS, is expected to start at 1000 UT on Saturday, April 11 to commemorate the anniversary of the first human spaceflight by Yuri Gagarin which took place on April 12, 1961. Previous SSTV sessions have run for two days.
ISS SSTV image 9/12 received by Martin Ehrenfried G8JNJ using the SUWS WebSDR on Dec 18, 2014
Twelve different images will be sent on 145.800 MHz FM using the SSTV mode PD180, with a 3-minute off time between transmissions.
One of the photos shows the commemorative diploma created by PZK, the national Polish Amateur Radio society, on the occasion of the 80th anniversary of the birth of first cosmonautYuri Gagarin.
The equipment used will be the Kenwood D710 transceiver located in the Russian Service Module. It is thought the equipment may be producing about 25 watts output which should provide a very strong signal.
Plans are being discussed for transmitting new images from space enthusiasts around the world in the coming months. Additional details will be released.
In the UK newspaper the Daily Mail, Jonathan O’Callaghan wrote about how 22-year-old Radek Karwacki, an AMSAT-UK member, received pictures from the ISS using a £10 ($15) RTL-SDR dongle and a dipole antenna, see http://amsat-uk.org/2015/02/04/iss-sstv-in-uk-press/
International Space Station – Image Credit NASA
All you need to do to receive SSTV pictures direct from the space station is to connect the audio output of a scanner or amateur radio transceiver via a simple interface to the soundcard on a Windows PC or an Apple iOS device, and tune in to 145.800 MHz FM. You can even receive pictures by holding an iPhone next to the radio loudspeaker.
On Windows PC’s the free applicationMMSSTV can be used to decode the signal, on Apple iOS devices you can use the SSTV app for compatible modes. (Note: see comments below about MMSSTV clock adjustments which may be needed to reduce picture slant)
The ISS puts out a strong signal on 145.800 MHz FM and a 2m handheld with a 1/4 wave antenna will be enough to receive it. The FM transmission uses 5 kHz deviation which is standard in much of the world apart from the British Isles and Europe where 2.5 kHz deviation is more common.
Many FM rigs can be switched been wide and narrow deviation FM filters. For best results you should select the wider deviation filters. Handhelds all seem to have a single wide filter fitted as standard.
The ISS Fan Club website will show you when the space station is in range.
ISS SSTV image 12/12 received by Martin Ehrenfried G8JNJ using the SUWS WebSDR Dec 18, 2014
Paul Turner G4IJE, co-developer of the SSTV PD modes, says regarding the MMSSTVPD180 mode: “Don’t forget to either enable “Always show RX viewer” or use the “Picture viewer” (magnifying glass icon) to show the picture at its real resolution of 640 x 496. If you just view as normal you will only see 320 x 248 resolution, which kind of defeats the object of using a high resolution mode.”
On the AMSAT-BB Rick W2JAZ and Alan WA4SCA comment on the need to set the MMSSTV sound card setting to 48 kHz instead of the default 44.100 kHz • Options • Setup • Misc • Then the Clock section at the bottom of the page
The MMSSTV default setting may need to be set to 24000 (exactly half of the sound card setting). You then should get good clean images.
The sound card adjustments will vary slightly depending on the version of the OS you are running, but usually will be under the advanced properties for the device. You can probably use a higher sampling rate for the sound card so long as it is a power of 2 multiple (2,4,8, etc) of the value in MMSSTV. For instance 192k (8x) has no issues. The same applies to most similar software.