Mtd Definition

There have been other systems called, Moving Target Detectors, and the term could lead to confusion to some experienced technicians unfamiliar with air traffic control radar. Mti, discussed in previous chapters, is an abbreviation for moving target indicator, a broad class of radar systems which indicate moving targets. An FAA mtd system, the system type hereafter simply called, mtd, is within the broader class of mti radar systems, and may be called, an mti system, in some literature.

Improvement Over Canceler-Type Mti

Canceler-type mti systems have had many recognized shortcomings since the earliest days. Among them have been subclutter visibility limitations, blind phase effects, blind velocity effects, tangential effects, weather effects, anomalous propagation; excessive target data from birds, and insects; and antenna scan-motion residue. There are more. Solutions to these problems were envisioned long ago; but they were not practical, because of hardware technology limitations. As device speeds increased, and storage media became more compact and practical, mtd became possible. Several mtd systems have now been built, but the largest production effort was the FAA ASR-9, manufactured by the Westinghouse Corporation; it will be the basis for the discussion in this chapter.

Figure 14 1 depicts the contrast in displays for mti and mtd systems. The mtd system, illustrated to the right, offers a very clean display, free of grass, residue, and other distractions. The display is not in real time, but in a special, reconstituted, synthetic, real time; and the rotating sweep is considerably behind the radar antenna,...