tirempl

Path loss using Terrain Integrated Rough Earth Model (TIREM)

Syntax

pl = tirempl(r,z,f)

pl = tirempl(r,z,f,Name=Value)

[pl,output] = tirempl(___)

Description

pl = tirempl(r,z,f) returns the path loss for a signal with the specified frequency when it is propagated over terrain. Represent the terrain by specifying the distance and elevation along the great circle path between the transmitter and the receiver. The Terrain Integrated Rough Earth Model™ (TIREM™) model combines physics with empirical data to provide path loss estimates. The TIREM model is valid from 1 MHz to 1000 GHz.

Note

tirempl requires access to the external TIREM library. Use tiremSetup to set up access.

pl = tirempl(r,z,f,Name=Value) specifies additional options using name-value arguments.

[pl,output] = tirempl(___) additionally returns an output structure that contains information about the TIREM analysis.

Examples

Path Loss Over Flat Terrain

Calculate the path loss over flat terrain. Define the terrain profile for distances up to 10 km with step size of 100 m.

freq = 28e9;
r = 0:100:10000;
z = zeros(1,numel(r));
    Lterrain1 = tirempl(r,z,freq,...
       'TransmitterAntennaHeight',5, ...
       'ReceiverAntennaHeight',5)

Lterrain1 =

  142.6089

Input Arguments

r — Distance in meters

numeric vector

Distance along the great circle path between the transmitter and the receiver, in meters, specified as a numeric vector. The number of distance values must be equal to the number of elevation values.

Data Types: double

z — Elevation in meters

numeric vector

Elevation corresponding to the distance along the great circle path between the transmitter and the receiver, in meters, specified as a numeric vector. The number of elevation values must be equal to the number of distance values.

Data Types: double

f — Frequency of propagated signal, in Hz

scalar | numeric vector

Frequency of the propagated signal, in Hz, specified as a scalar or numeric vector.

Data Types: double

Name-Value Arguments

Specify optional pairs of arguments as Name1=Value1,...,NameN=ValueN, where Name is the argument name and Value is the corresponding value. Name-value arguments must appear after other arguments, but the order of the pairs does not matter.

Before R2021a, use commas to separate each name and value, and enclose Name in quotes.

Example: 'TransmitterAntennaHeight',50

TransmitterAntennaHeight — Transmitter antenna height above ground, in meters

10 (default) | numeric scalar

Transmitter antenna height above the ground, in meters, specified as a numeric scalar in the range of 0 to 30000. The height is measured from ground elevation to the center of the antenna.

Data Types: double

ReceiverAntennaHeight — Receiver antenna height above ground, in meters

1 (default) | numeric scalar

Receiver antenna height above the ground, in meters, specified as a numeric scalar in the range of 0 to 30000. The height is measured from ground elevation to the center of the antenna.

Data Types: double

AntennaPolarization — Polarization of transmitter and receiver antennas

'horizontal' (default) | 'vertical'

Polarization of the transmitter and the receiver antennas, specified as 'horizontal' or 'vertical'.

Data Types: string | char

GroundConductivity — Conductivity of ground, in S/m

0.005 (default) | numeric scalar

Conductivity of the ground, in S/m, specified as a numeric scalar in the range of 0.00005 to 100. This value is used to calculate the path loss due to ground reflection. The default value corresponds to the average ground conductivity.

Data Types: double

GroundPermittivity — Relative permittivity of ground

15 (default) | numeric scalar

Relative permittivity of the ground, specified as a numeric scalar in the range of 1 to100. Relative permittivity is the ratio of absolute material permittivity to the permittivity of vacuum. This value is used to calculate the path loss due to ground reflection. The default value corresponds to the average ground permittivity.

Data Types: double

AtmosphericRefractivity — Atmospheric refractivity near ground, in N-units

301 (default) | numeric scalar

Atmospheric refractivity near the ground, in N-units, specified as a numeric scalar in the range of 250 to 400. This value is used to calculate the path loss due to atmospheric refraction and tropospheric scatter. The default value corresponds to average atmospheric conditions.

Data Types: double

Humidity — Absolute air humidity near ground, in g/m^³

9 (default) | numeric scalar

Absolute air humidity near the ground, in g/m^³, specified as a numeric scalar in the range of 50 to 110. This value is used to calculate path loss due to atmospheric absorption. The default value corresponds to the absolute humidity of air at 15 degrees Celsius and 70 percent relative humidity.

Data Types: double

Output Arguments

pl — Path loss in dB

scalar | 1-by-N vector

Path loss in dB, returned as a scalar or 1-by-N vector. N is the number of frequencies defined in the input f.

Path loss is calculated from free-space loss, terrain diffraction, ground reflection, refraction through the atmosphere, tropospheric scatter, and atmospheric absorption.

output — Information of TIREM analysis

structure

Information of TIREM analysis, returned as a structure. Each field of the structure represents an output from TIREM analysis.

Version History

Introduced in R2019b