L-Band DME Multipath Environment in the Microwave Landing System (MLS) Approach and Landing Region.

Abstract

The multipath environment in the approach and landing region represents an important factor in the optimization and ultimate performance of the Microwave Landing System (MLS) Precision Distance Measuring Equipment (DME/P). Various types of multipath are assessed in the context of the proposed DME/P implementation error characteristics to ascertain the principal challenges. It is shown (analytically and experimentally) that specular reflections from buildings represent a significant challenge, particularly at low altitudes (e.g., category II decision height and below) where terrain lobing can cause the effective multipath levels to exceed the effective direct signal level. However, the time delay discrimination capabilities of the proposed DME/P should effectively eliminate the bulk of such multipath. Limited S-band (3 GHz) measurements of diffuse reflections from nominally flat terrain indicated very low levels. However, specular reflections from bare, hilly terrain may present problems in some cases. (Author)

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Document Details

Document Type
Technical Report
Publication Date
Apr 13, 1982
Accession Number
ADA119367

Entities

People

  • James E Evans

Organizations

  • Massachusetts Institute of Technology

Tags

Communities of Interest

  • Air Platforms
  • C4I
  • Energy and Power Technologies
  • Engineered Resilient Systems

DTIC Thesaurus Topics

  • Aircrafts
  • Airports
  • Altitude
  • Computer Programs
  • Computers
  • Databases
  • Diffuse Reflection
  • Distance Measuring Equipment
  • Elevation
  • Fresnel Zones
  • Geometry
  • Low Altitude
  • Low Elevation
  • Measurement
  • Scattering
  • Specular Reflection
  • Transport Aircraft

Readers

  • Aviation Safety and Air Traffic Management
  • Radar Systems Engineering.