SSTV, an acronym for Slow Scan Television, is a method of transmitting still images or photographs over radio frequencies. It is an analog form of image transmission, widely used by radio amateurs and hobbyists to convey visual information over radio channels.
In SSTV, images are transmitted in a sequential manner, slice by slice, or line by line, as opposed to being sent as a whole image in a single transmission. Each frame is divided into lines, which are further divided into pixels, representing different shades of gray. These lines are then transmitted one at a time, often with a short pause between each line, to form the complete image on the receiving side.
During transmission, the grayscale image is converted into a series of audio tones, which are then transmitted using a radio frequency. The receiving station decodes these audio tones back into the original image, reconstructing it line by line.
SSTV allows for relatively high-quality image transmission over radio frequencies, with a tradeoff between transmission time and image resolution. It is commonly used in applications such as weather fax, where weather maps are transmitted via SSTV transmissions over radio frequencies.
Overall, SSTV offers a practical and efficient way to transmit visual information over radio channels, enabling communication and sharing of images over long distances, often by enthusiasts and amateur radio operators.
