How does SSTV differ from ATV?
There are basically two methods used to send pictures over ham radio. Fast Scan TV is very similar to broadcast TV: full motion color images. This requires a few megahertz of bandwidth so it is used only on UHF. A single transmission is wider than the entire 2 meter ham band. The other method is Slow Scan TV: still images sent through voice transceivers over a period of a few seconds to a couple minutes. Early pictures were low resolution black and white. Now nearly all images are higher resolution color. You’d expect the term Amateur Television to apply to both Fast Scan and Slow Scan but it generally means only Fast Scan TV. The Russian Space Station MIR has been transmitting SSTV pictures recently.
