With an aspect ratio of 4:3, this quality standard offers resolutions of720 x 576 pixels for the PAL television standard and 640 x 480 pixels for NTSC. In addition to the 4:3 aspect ratio, SDTV also offers a 16:9 aspect ratio.
The frame rates are 25 or 30 frames per second. The transmission bandwidth for the video signal is about 5 MHz, and the sampling frequency is 13.5 MHz. The standard was developed by the Advanced Television Systems Committee( ATSC) and standardized by the International Telecommunication Union( ITU) in Recommendation BT.601.
SDTV can use interlaced or progressive scan. Both methods are compatible with each other, because Progressive Segmented Frame( psF) can be used to compensate for the difference. This means that the motion resolution with progressive scan is only half that with interlaced scan.