Stratospheric SSTV transmitter

Last Saturday, 19-08-2023, the new stratospheric SSTV (Slow Scan Television) transmitter has been tested, during the “SP6ZWR Emergency Communication Amateur Digital Communication” club meeting in the Lower Silesian Forest (pol. Bory Dolnośląskie) in the south-west part of Poland.

The transmitter was designed and developed jointly by Łukasz Pieczonka LPI Consulting (computer, software, peripherals), and SP6ZWR (chassis, radio transmitter, power). The stratospheric mission was operated by WroSpace society.

The transmitter takes a picture of a surrounding environment, similarly as in case of the stratospheric probes which were lifted-off earlier. The onboard computer processes the image and converts it into the sound file, containing encoded video information. Then, the sound is played and send to the radio transmitter which sends it via the RF signal through the air.

During the mission, the transmitter was lifted more than 39 616 meters of altitude. The SSTV signal was received across the Poland and presumably Germany and Czechia. We received confirmation of successful image reception at Podlasie, the north-east region of Poland.

This kind of video transmission can be received by SDR (Software Defined Radio) and dedicated PC software or simply by ham radio and decoding program on smartphone, as depicted below.

The transmitter supports image encoding using Martin M1, Scottie S1, Scottie DX, PD90, PD120, PD160, PD180 and PD240 and will be used by the WroSpace society during future missions, especially in case of educational ones. This will help children to associate with technology, which in this case can be heard and thus be better understood. It is important in times, when everyone has a magic black box called the smartphone which is capable of doing almost everything but few understand how it works.

One of the goals of the mission was to send to the stratosphere a tiny astronaut sculpture, created by the artist Mariusz Potyszka. The photo below shows the astronaut just before and after the apogee of the flight (39 616m).

Note the balloon’s envelope debris at the right of the last photo.

The stratospheric SSTV transmitter project will be continued in future, i.e. a new functionalities will be developed.