Main Content

Signal Propagation and Targets

Narrowband and wideband free-space propagation, multipath underwater sound propagation, atmospheric losses, spatial MIMO channels, radar cross section, sonar target strength, Swerling targets

A radar or sonar system simulation requires models for wave propagation, clutter and interference, array and target motion, and target cross-section. The Phased Array System Toolbox™ lets you model free-space signal propagation in monostatic or bistatic scenarios. Alternatively, you can employ simple multipath propagation using a two-ray propagation model. You can model atmospheric attenuation using line-of-sight (LOS) propagation models. These models calculate signal propagation through atmospheric gases, rain, and fog and clouds. All models include range-dependent time delay, phase shift, Doppler shift, and free-space loss. You can specify scattering radar cross sections (RCS) for nonpolarized radiation or scattering matrices for polarized radiation. The toolbox implements the four standard Swerling target radar cross-section models. The toolbox supports constant velocity and constant acceleration motion models.

The toolbox supports sonar system simulation by providing multipath propagation models, hydrophone and projector models, underwater noise sources and target strength models. Target strength models let you create nonfluctuating and Swerling fluctuating targets.

The toolbox models target reflection and scattering by point-like reflectors. You can specify scattering radar cross sections (RCS) for non-polarized radiation or scattering matrices for polarized radiation. The four standard Swerling target scattering models are implemented. For the special case of backscattering radar scenarios, you can simulate an angle-dependent radar cross-section model. Radar cross-section models apply to both narrowband and wideband signals. You can also simulate the four standard Swerling backscattering models in sonar scenarios. For sonar system simulations, you can employ target strength models and create underwater noise sources.

Objects

phased.RadarTargetRadar target
phased.BackscatterRadarTargetBackscatter radar target
phased.BackscatterSonarTargetSonar target backscatter
phased.WidebandBackscatterRadarTargetBackscatter wideband signal from radar target
phased.FreeSpaceFree space environment
phased.LOSChannelNarrowband LOS propagation channel
phased.ScatteringMIMOChannelScattering MIMO channel
phased.IsoSpeedUnderwaterPathsIsospeed multipath sonar channel
phased.MultipathChannelPropagate signals in multipath channel
phased.WidebandFreeSpaceWideband freespace propagation
phased.WidebandLOSChannelWideband LOS propagation channel
phased.UnderwaterRadiatedNoiseRadiate acoustic noise from underwater or surface sound source

Blocks

Radar TargetRadar target
Backscatter Radar TargetBackscatter radar target
Wideband Backscatter Radar TargetBackscatter wideband signals from radar target
Free SpaceFree space environment
LOS ChannelNarrowband line-of-sight propagation channel
Two-Ray Multipath Propagation
Scattering MIMO ChannelScattering MIMO propagation channel
Wideband Free SpaceWideband free space environment
Wideband LOS ChannelWideband line-of-sight propagation channel
Range Angle CalculatorRange and angle calculations
Azimuth Broadside ConverterConvert azimuth angle to broadside angle or broadside angle to azimuth angle

Functions

fogplRF signal attenuation due to fog and clouds
fsplFree space path loss
gasplRF signal attenuation due to atmospheric gases
rainplRF signal attenuation due to rainfall
cranerainplRF signal attenuation due to rainfall using Crane model
tiremplPath loss using Terrain Integrated Rough Earth Model (TIREM)
rangeangleRange and angle calculation
scatteringchanmtxScattering channel matrix
waterfillWaterfill MIMO power distribution
physconstPhysical constants

Topics

Free Space Path Loss

Propagation environments have significant effects on the amplitude, phase, and shape of propagating space-time wavefields.

Free-Space Propagation of Wideband Signals

Propagate a wideband signal with three tones in an underwater acoustic with constant speed of propagation.

Swerling Target Models

The example illustrates the use of Swerling target models to describe the fluctuations in radar cross-section.

Radar Target

Model targets with fluctuating and nonfluctuating radar cross-sections.