In the application of the Discrete Address Beacon System (DABS) concept to Air Traffic Control (ATC) surveillance, estimates of aircraft position must be made using as few replies as possible, preferably one. This requires the use of monopulse techniques. Since the beacon system provides high signal-to-noise ratios (SNR), the fundamental limitation to direction finding (DF) performance is due to externally generated interference from multipath signals and from the present Air Traffic Control Radar Beacon System (ATCRBS). Since there are many bits in any one DABS reply it should be possible to generate an accurate azimuth estimate if those that bear interference could be detected and deleted from the sample. In the report, the generalized likelihood ratio test is used to derive an optimum interference statistic. The detector performance is then analyzed in detail with respect to its dependence on SNR, interference-to-signal ratio (ISR) on the relative phase between the target and interfering signals. It is shown that good detection performance can be obtained if the phase difference between the target and interference signals are either in- or out-of-phase. (Author)

  • Corporate Authors:

    Massachusetts Institute of Technology

    Linclon Laboratory, 244 Wood Street
    Lexington, MA  United States  02420-9180
  • Authors:
    • McAulay, R J
    • McGarty, T P
  • Publication Date: 1973-9-26

Media Info

  • Pagination: 38 p.

Subject/Index Terms

Filing Info

  • Accession Number: 00051591
  • Record Type: Publication
  • Source Agency: National Technical Information Service
  • Report/Paper Numbers: TN-1973-48 Tech Note
  • Contract Numbers: DOT-FA72WAI-261
  • Files: NTIS
  • Created Date: Mar 25 1974 12:00AM