Evaluates the far-field scattering amplitude from a previously computed
TMM object using the stored transition-matrix blocks. This allows the same
retained
modal operator to be reused for arbitrary single-target incident and
receive-angle combinations without rebuilding the boundary solve.
Usage
tmm_scattering(
object,
theta_body = NULL,
phi_body = NULL,
theta_scatter = NULL,
phi_scatter = NULL
)Arguments
- object
Scatterer-object previously evaluated with
target_strength(..., model = "TMM", store_t_matrix = TRUE).- theta_body
Incident polar angle (radians). Defaults to the stored TMM incident angle.
- phi_body
Incident azimuth angle (radians). Defaults to the stored TMM incident angle.
- theta_scatter
Receive polar angle (radians). Defaults to the exact monostatic direction,
pi - theta_body.- phi_scatter
Receive azimuth angle (radians). Defaults to the exact monostatic direction,
phi_body + pi.
Value
A data frame with the frequency, complex scattering amplitude, the corresponding differential cross section, and its level in dB.
Examples
target <- fls_generate(
shape = sphere(radius_body = 0.005, n_segments = 20),
g_body = 1,
h_body = 1
)
stored <- target_strength(
target,
frequency = 12e3,
model = "tmm",
boundary = "pressure_release",
store_t_matrix = TRUE
)
tmm_scattering(stored)
#> frequency f_scat sigma_scat sigma_scat_dB
#> 1 12000 -0.004474609+0.001246817i 2.157667e-05 -46.66015