Signal Propagation and 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.
|Backscatter radar target|
|Sonar target backscatter|
|Backscatter wideband signal from radar target|
|Free space environment|
|Narrowband LOS propagation channel|
|Scattering MIMO channel|
|Isospeed multipath sonar channel|
|Propagate signals in multipath channel|
|Wideband free-space propagation|
|Wideband LOS propagation channel|
|Radiate acoustic noise from underwater or surface sound source|
|Radar Target||Radar target|
|Backscatter Radar Target||Backscatter radar target|
|Wideband Backscatter Radar Target||Backscatter wideband signals from radar target|
|Free Space||Free space environment|
|LOS Channel||Narrowband line-of-sight propagation channel|
|Scattering MIMO Channel||Scattering MIMO propagation channel|
|Wideband Free Space||Wideband free space environment|
|Wideband LOS Channel||Wideband line-of-sight propagation channel|
|Range Angle Calculator||Range and angle calculations|
|Azimuth Broadside Converter||Convert azimuth angle to broadside angle or broadside angle to azimuth angle|
|RF signal attenuation due to fog and clouds|
|Free space path loss|
|RF signal attenuation due to atmospheric gases|
|RF signal attenuation due to rainfall|
|RF signal attenuation due to rainfall using Crane model|
|Path loss using Terrain Integrated Rough Earth Model (TIREM)|
|Range and angle calculation|
|Scattering channel matrix|
|Waterfill MIMO power distribution|
Propagation environments have significant effects on the amplitude, phase, and shape of propagating space-time wavefields.
Propagate a wideband signal with three tones in an underwater acoustic with constant speed of propagation.
A two-ray propagation channel is the next step up in complexity from a free-space channel and is the simplest case of a multipath propagation environment.
The example illustrates the use of Swerling target models to describe the fluctuations in radar cross-section.
Model targets with fluctuating and nonfluctuating radar cross-sections.