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Gamma value for different terrains

Since R2021a


G = surfacegamma(TerrainType) returns the γ value for the specified terrain. The γ value is for an operating frequency of 10 GHz.


G = surfacegamma(TerrainType,FREQ) specifies the operating frequency of the system.

surfacegamma displays several terrain types and their corresponding γ values. These γ values are for an operating frequency of 10 GHz.


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Determine the γ value for a wooded area, and then simulate the clutter return from that area. Assume the radar system uses a single cosine pattern antenna element and has an operating frequency of 300 MHz.

fc = 300e6;
g = surfacegamma('woods',fc);
clutter = constantGammaClutter('Gamma',g, ...
    'Sensor',phased.CosineAntennaElement, ...
x = clutter();
r = (0:numel(x)-1)/(2*clutter.SampleRate) * ...
xlabel('Range (m)')
ylabel('Clutter Magnitude (V)')
title('Clutter Return vs. Range')

Input Arguments

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Terrain type, specified as one of these:

  • "Sea State 3"

  • "Sea State 5"

  • "Woods"

  • "Metropolitan"

  • "Rugged Mountain"

  • "Farmland"

  • "Wooded Hill"

  • "Flatland"

Data Types: char | string

Operating frequency of radar system in hertz, specified as a scalar or a vector.

Data Types: double

Output Arguments

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Gamma value, γ, in decibels, for constant-γ clutter model, returned as a scalar.

More About

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A frequently used model for clutter simulation is the constant gamma model. This model uses a parameter, γ, to describe clutter characteristics of different types of terrain. Values of γ are derived from measurements.


The γ values for the terrain types "Sea State 3", "Sea State 5", "Woods", "Metropolitan", and "Rugged Mountain" are from [2]. The γ values for the terrain types "Farmland", "Wooded Hill", and "Flatland" are from [3].

Measurements provide values of γ for a system operating at 10 GHz. The γ value for a system operating at frequency f is:


where γ0 is the value at frequency f0 = 10 GHz.


[1] Barton, David. "Land Clutter Models for Radar Design and Analysis," Proceedings of the IEEE. Vol. 73, Number 2, February, 1985, pp. 198–204.

[2] Long, Maurice W. Radar Reflectivity of Land and Sea, 3rd Ed. Boston: Artech House, 2001.

[3] Nathanson, Fred E., J. Patrick Reilly, and Marvin N. Cohen. Radar Design Principles, 2nd Ed. Mendham, NJ: SciTech Publishing, 1999.

Extended Capabilities

Version History

Introduced in R2021a