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Sunset Image Transmission | |
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Slow-scan television ( SSTV ) is a way of transmitting a black-and-white or color image through narrow-band channels. For data transmission, amateur short-wave or ultra -short - wave radio communications are most often used. Unlike classic broadband television , requiring a bandwidth of 5 MHz or more, and, depending on the system transmitting 25 or 30 frames per second, a slow-scan television allows you to transmit one frame in a time from about 8 seconds to several minutes using the band about 3 kHz .
Content
History
The concept of television with a slow scan was proposed in the USSR by S. I. Kataev in 1934 [1] . In the United States, a similar idea was put forward by American radio amateur Koptorn MacDonald in 1957 . Initially, displays with ultra-long afterglow were used to display the picture. This allowed the image to remain on the screen for the duration of the frame transmission. With the development of integrated microelectronics, pictures began to be stored in RAM chips.
Space exploration
Slow-scan television was used to transmit images over long distances, for example, images of the far side of the moon during the expedition of the Soviet interplanetary station Luna-3 . In most cases, photo-television systems were used to transmit high-definition photographs over a narrow-band radio channel [2] .
Modern systems
Modern slow-scan television systems use a personal computer and appropriate software to generate a signal that is usually output through the analog output of a sound card . Image input can be done using a digital camera or webcam .
See also
- Slow tv
- Photo-TV device
- Photo telegraph
Notes
- ↑ Kataev Semen Isidorovich
- ↑ Processed Images of the Back of the Moon Archived on September 29, 2007.