Radio noise and RFI at and near frequencies employed by Loran-C radio navigation systems were investigated in portions of Los Angeles, California. Emphasis was placed on the definition of the detailed time and frequency domain structure of noise and RFI which might degrade the reception of Loran-C signals in urban, suburban, and industrial areas of Los Angeles. The measurements were directed toward obtaining an understanding of the noise and RFI environment which would be encountered by vehicularly installed Loran-C navigation systems. Measurements were made at and around the 100 kHz band of frequencies employed by Loran-C, and they were made from a mobile van. The noise and RFI instrumentation is described in this report. This report describes the tests that were conducted to determine the nature of Loran-C RFI in the Los Angeles area. Six important noise types were identified: 1) Impulsive Noise, 2) Power Line Carrier Communications, 3) Localized Continuous Wave Signals, 4) Low Level Signals, 5) Ignition Noise, and 6) Conventional Power Line Noise. They were traced to probable sources in each case. Their spatial distribution precludes gradient mapping; rather, there are strong-signal regions juxtaposed with sharp boundaries to a large number of regions of various sizes in which noise predominates so as to make the available signal unusable. This report contains a list of references, a bibliography, and 3-axis views for fixed sites. (UMTA)

  • Availability:
  • Corporate Authors:

    Systems Control, Incorporated

    1801 Page Mill Road
    Palo Alto, CA  United States  94304

    Urban Mass Transportation Administration

    400 7th Street, SW
    Washington, DC  United States  20590
  • Authors:
    • Vincent, W R
    • Sage, G
  • Publication Date: 1980-10

Media Info

  • Pagination: 233 p.

Subject/Index Terms

Filing Info

  • Accession Number: 00330145
  • Record Type: Publication
  • ISBN: DOT-TSC-UMTA-80-38
  • Report/Paper Numbers: UMTA-MA-06-0041-80-1Final Rpt.
  • Contract Numbers: DOT-TSC-1237
  • Files: TRIS, USDOT
  • Created Date: Aug 15 1981 12:00AM