Lambert's Law defines the scattering strength from an ideal diffuse reflector.
In optics, the radiant intensity (power per unit solid angle) is constant at all observed angle for ideal diffuse reflectors. Mathematically, this leads to the relationship below.
where = incident grazing angle,
= scattered grazing angle,
= scattering strength coefficient, and
= ensonified area.
In underwater acoustics, this is often referred to as the Mackenzie model, based on at-sea measurements which indicated that indicated that Lambert's Law was also a good fit for ocean bottom backscattering strength. This model is only used for bottom reverberation.
scattering_lambert | ( | double | bss = -27.0 |
) | [inline] |
Initializes scattering strength model with a Mackenzie coefficient.
Defaults to a value of the scattering strength coefficient such that .
bss | Bottom scattering strength coefficient (dB) |
virtual void scattering | ( | const wposition & | location, | |
const seq_vector & | frequencies, | |||
double | de_incident, | |||
matrix< double > | de_scattered, | |||
double | az_incident, | |||
matrix< double > | az_scattered, | |||
matrix< vector< double > > * | amplitude | |||
) | [inline, virtual] |
Computes the broadband scattering strength for a collection of scattering angles from a common incoming ray.
Each scattering has its own location, de_scattered, and az_scattered. The result is a broadband reverberation scattering strength for each scattering.
location | Location at which to compute attenuation. | |
frequencies | Frequencies over which to compute loss. (Hz) | |
de_incident | Depression incident angle (radians). | |
de_scattered | Depression scattered angle (radians). | |
az_incident | Azimuthal incident angle (radians). | |
az_scattered | Azimuthal scattered angle (radians). | |
amplitude | Reverberation scattering strength ratio (output). |
Implements scattering_model.
virtual void scattering | ( | const wposition1 & | location, | |
const seq_vector & | frequencies, | |||
double | de_incident, | |||
double | de_scattered, | |||
double | az_incident, | |||
double | az_scattered, | |||
vector< double > * | amplitude | |||
) | [inline, virtual] |
Computes the broadband scattering strength for a single location.
location | Location at which to compute attenuation. | |
frequencies | Frequencies over which to compute loss. (Hz) | |
de_incident | Depression incident angle (radians). | |
de_scattered | Depression scattered angle (radians). | |
az_incident | Azimuthal incident angle (radians). | |
az_scattered | Azimuthal scattered angle (radians). | |
amplitude | Reverberation scattering strength ratio (output). |
Implements scattering_model.
double _coeff [private] |
Bottom scattering strength coefficient in linear units.