Six ultimate quality forms of the digital television standard adopted for the United States featuring AC-3 digital surround sound, a wide aspect ratio screen (16:9), and a high-resolution picture capable of interlaced video with 1,080 horizontal lines (vertical resolution) by 1,920 vertical lines (horizontal resolution) at 24, 30 and 60 Hz refresh rate and progressive video at 720 horizontal lines by 1,280 vertical lines with refresh rates at 24, 30 and 60 Hz. The higher resolution, interlaced format presents 2,073,600 individual picture elements or pixels for each frame, and the lower resolution, progressive format presents 921,600 individual picture elements. The lower resolution format uses progressive scan, which is a superior display technology compared to interlaced scanning. The highest resolution HDTV format uses interlaced scanning to present the greatest resolution without needing as high a bandwidth as progressive scan, however, there are plans to update HDTV using progressive scan technology combined with the 1,080 by 1,920 resolution as the technology becomes more widely available and technically possible. DTV is an incredibly life-like broadcasting format that approaches the quality of film. For comparison, an analog television displaying DVD program material can achieve a maximum vertical resolution of just over 500 lines. A laserdisc can produce around 400 lines of resolution as can satellite reception. Analog broadcast television results in a resolution around 300 lines and the lowest resolution analog format, VHS tape as played through a typical VCR, generates closer to 200 lines of resolution. Obviously, HDTV has resolutions and resultant picture qualities far superior to those of the NTSC analog television standard. Compared to the analog NTSC television standard, HDTV images (the highest resolution of 1,080 by 1,920) contain about six times the amount of picture information resulting in an incredibly detailed image. Additionally, the digital nature of HDTV eliminates many of the problems encountered with analog televisions such as “snow,” poor color reproduction, color bleeding, etc. DTV uses AC-3 encoded sound resulting in the ability to transmit excellent quality surround sound audio in a 5.1 digital format (See 5.1). he wider aspect ratio of HDTV (16 units wide by 9 units tall versus the more square 4 units wide by 3 units tall used with NTSC analog television programming) allows movies to be presented in their full width, widescreen format. Movies for theater release are filmed in a wide aspect ratio different from that used in analog television sets. In order to fit a movie picture on a “square” television screen, portions of the image are cut off and discarded (pan-and-scan) or the movie is presented in its full width with black bars above and below the image (letterbox). The wider aspect ratio of HDTV will allow movies to be presented as intended without the use of black bars while still retaining their original information. This will also result in “wide” television programming making television shows more like movies. he primary disadvantages of HDTV (and digital television in general of which HDTV is the highest format) are cost and limited programming availability. For the near future, HDTV is a costly proposition with most HDTV sets (big screens in the 60 inch diagonal measurement area) starting at or above $7,000. Limited programming is related to how many cities receive HDTV broadcasts and when true HDTV playback media will become available. The ten largest television markets will have digital television in November 1998 with 30 additional markets (the next largest ones) receiving broadcasts in November 1999. Consumers will be able to watch DVDs, laserdiscs, VHS tapes and analog television signals on digital television sets, but there is currently no consumer playback medium capable of true HDTV playback. What this means is that there are no DVDs, laserdiscs, or videotapes available to the consumer that can output the extremely high-definition signals of HDTV. Manufacturers are working to design such playback devices, but they will not be available for two years or so.