Saturday 23 March 2013

Digital SSTV Decoding

I've decoded analogue SSTV transmissions before (check out some earlier posts) using the MMSSTV program, but another form of picture transmission is referred to as Digital SSTV.. It isn't technically slow scan the the SSTV part has stuck because it sends images. In very basic terms it is file transfer using DRM "Digital Radio Mondiale" encoding.

The advantage over analogue SSTV is the use of error correction, with the error correction you can get a perfect image.

This afternoon while the snow was falling outside I had got SDR# with the FCDP+ running and noticed that there was some activitiy on 14.233 Mhz and fired up the EasyPal software and decoded a few images, and made a small video showing one image being received.


As you will observe in the video Easypal actually decoded the image before the end of the transmission because it didn't need the extra data to error correct because of the very strong clear signal.
 
These were the two nice pictures I decoded today from OE3AWA based in Austria



Interestingly the only other previous D-SSTV image I have received was at the end of December last year, from the same operator!

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