horizonrange

Horizon range

Syntax

Rh = horizonrange(H)
Rh = horizonrange(H,Re)
Rh = horizonrange(___,'SurfaceHeight',surfht)


Description

Rh = horizonrange(H) returns the horizon range, Rh, of a radar system H meters above the surface. The computation uses an effective earth radius of approximately 4/3 times the actual earth radius.

Rh = horizonrange(H,Re) specifies the effective earth radius, Re.

Rh = horizonrange(___,'SurfaceHeight',surfht) also specifies the surface height, surfht.

Input Arguments

H	Height of radar system above surface, specified as a scalar or a length-M vector. Units are in meters.
Re	Effective earth radius, specified as a positive scalar. Units are in meters Default: effearthradius, which is approximately 4/3 times the actual earth radius

surfht

Height of earth surface at the horizon, specified as a scalar or length-M vector. This input can also be interpreted as the height of significant ground clutter at the horizon. If H and surfht are vectors, their lengths must be equal. Defaults to 0 m.

Output Arguments

Rh	Horizon range in meters of radar system at altitude H.

Examples

Compute Range to Horizon

Find the range to the horizon from an antenna that is 30 m high.

R = horizonrange(30)

More About

Horizon Range

The horizon range of a radar system is the distance from the radar system to the earth along a tangent. Beyond the horizon range, the radar system detects no return from the surface through a direct path.

The value of the horizon range is:

$$\sqrt{2R_{e}H+H^2}$$

where R_e is the effective earth radius and H is the altitude of the radar system.

References

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

[2] Skolnik, M. Introduction to Radar Systems, 3rd Ed. New York: McGraw-Hill, 2001.

Extended Capabilities

C/C++ Code Generation

Generate C and C++ code using MATLAB® Coder™.

Usage notes and limitations:

Does not support variable-size inputs.