difference between sbr and image method in ray tracing

I am trying to use ray tracing model to calculate path loss of a complex environment and I was confused to use sbr or image method. But a sentence in matlab help center made me more confused " The SBR method includes effects from surface reflections but does not include effects from diffraction, refraction, or scattering. The image method considers surface reflection only." so it means that both method do not consider diffraction refraction or scattering which make the model inaccurate.

Is there any way to calculate path loss accuratly using ray tracing method in matlab?

Answer 1

[Shlok]

Hi Sharifi,

I understand that you're exploring the two primary methods used in ray tracing. The SBR (Shooting and Bouncing Rays) method simulates multiple ray interactions, including reflections and diffractions, providing a comprehensive analysis of signal propagation in complex environments. In contrast, the image method simplifies calculations by using virtual images of the transmitter for single reflections, making it less computationally intensive but potentially less accurate. Overall, SBR is more versatile for intricate scenarios, while the image method is straightforward for simpler cases.

Starting with R2023a, the documentation has been updated to mention, "The model calculates path loss from free-space loss, reflection and diffraction losses due to interactions with materials, and antenna polarizations.” Hence, to calculate the path loss with reflection and diffraction, here is a sample code:

tx = txsite("cartesian", AntennaPosition=[0; 0; 1.5], TransmitterFrequency=2.4e9); % sample transmitter site  
rx = rxsite("cartesian", AntennaPosition=[10; 10; 1.5]); % sample receiver site  
pm = propagationModel("raytracing", MaxNumReflections=3, MaxNumDiffractions=2, SurfaceMaterial="concrete");  
r = raytrace(tx, rx, pm);  
pathLoss = r{i}.PathLoss; % Access path loss for each ray i 

To know more about raytracing and path loss, refer to the following MathWorks documentation link:

https://www.mathworks.com/help/releases/R2023a/antenna/ref/rfprop.raytracing.html