Räckviddsanalys för mobila taktiska kommunikationssystem på L-bandet

Authors:

  • Gunnar Eriksson
  • Peter Holm
  • Anders Hansson

Publish date: 2019-03-06

Report number: FOI-R--4733--SE

Pages: 37

Written in: Swedish

Research areas:

  • Ledningsteknologi

Keywords:

  • Communication range
  • transmission loss
  • terrain
  • forest
  • L-band

Abstract

On the L-band, significantly higher data rates are possible compared to VHF and UHF, which are traditionally used for tactical mobile applications. However, the range decreases significantly if vegetation and terrain dampens the signal between transmitter and receiver, which we investigate for two radio system examples with ground vehicles and anchored UAVs. The report describes a communication range analysis for tactical systems on the L-band, in a plain area and in a more hilly terrain area. A statistical analysis of the radio range has been performed by randomly placing transmitters and receivers at different distances in the areas and calculate the transmission loss based on geographical height and terrain type. Two types of forest characteristics with different attenuation properties have been investigated, one with attenuation properties based on measurements made by FOI and one forest type according to ITU recommendations. We evaluate three different transmitter and receiver antenna height combinations: (1) 3-3 m, (2) 3-25 m and (3) 25-25 m. At 50% availability, the ranges are up to 2, 5, and 13 km respectively for alternative (1), (2) and (3) in the flat the terrain and decreases to about 20-30% of these values in the hilly terrain. For higher availability levels, the ranges drop drastically due to the large variation between different positions in the terrain. We also calculate the transmission loss in and above an idealized homogeneous forest section on flat ground, to describe the attenuation in the forest and the discovery range for an airborne signal intercept sensor. Detection distances are calculated for transmitters with antenna height 3 m and 25 m, in the case where the transmitter is completely open and the case where the transmitter is obscured by forest. Since the signal intercept sensor is airborn, the effects from height and vegetation are smaller and thus the intercept distance much longer than the communication distances.

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