How to Retrieve Reflection Coefficients and Determine Amplitude Attenuation in Sionna Ray Tracer

[Virusx51]

I'm currently using the Sionna ray tracer and I'm curious about the process of retrieving reflection coefficients for each reflection of rays within the software. Additionally, I'd like to understand how the amplitude attenuates with each subsequent reflection. Could someone provide guidance or point to relevant resources/documentation on GitHub regarding these aspects

[Virusx51]

Dear colleagues,

Upon reviewing the files in our repository, I came across the utils.py file, which contains a function enabling the computation of reflection coefficients. The next step involves understanding from which file to obtain eta and cos_theta. The objective of my investigation is to evaluate the attenuation of rays due to reflections.

def reflection_coefficient(eta, cos_theta):
    """
    Compute simplified reflection coefficients

    Input
    ------
    eta : Any shape, tf.complex
        Complex relative permittivity

    cos_theta : Same as ``eta``, tf.float
        Cosine of the incident angle

    Output
    -------
    r_te : Same as input, tf.complex
        Fresnel reflection coefficient for S direction

    r_tm : Same as input, tf.complex
        Fresnel reflection coefficient for P direction
    """
    cos_theta = tf.complex(cos_theta, tf.zeros_like(cos_theta))

    # Fresnel equations
    a = cos_theta
    b = tf.sqrt(eta-1.+cos_theta**2)
    r_te = tf.math.divide_no_nan(a-b, a+b)

    c = eta*a
    d = b
    r_tm = tf.math.divide_no_nan(c-d, c+d)
    return r_te, r_tm