JPL::AirAbsorptionCache Struct Reference

#include <JPLSpatial/AirAbsorption.h>

Public Attributes
const FrequencyBands	FrequencyBandCenters
const FrequencyBands	FrequencyBandLowerThirdCenters
const AbsorptionCoeffs	CenterFrequencyAbsorption_dB
const AbsorptionCoeffs	LowerThirdBandAbsorption_dB
const AbsorptionCoeffs	HighFreqWeightedAbsorption_dB
const AbsorptionCoeffs	FrequencyDecaySlope
struct {
const simd_mask   HasKnee
const simd   DistanceToKnee
const simd   LinearizedHFLossFactor
}	LinAprox
	Linearized approximation for non-linear frequency loss by distance.

Detailed Description

Cached data required to compute sound attenuation due to air absorption. The data depends on the environment parameters and frequency bands it was calculated for.

Member Data Documentation

CenterFrequencyAbsorption_dB

const AbsorptionCoeffs JPL::AirAbsorptionCache::CenterFrequencyAbsorption_dB

Air attenuation calculated for frequency band centers, in dB/m. This can be used for short path propagation filtering (e.g. direct sound, early reflections, diffraction)

DistanceToKnee

const simd JPL::AirAbsorptionCache::DistanceToKnee

FrequencyBandCenters

const FrequencyBands JPL::AirAbsorptionCache::FrequencyBandCenters

FrequencyBandLowerThirdCenters

const FrequencyBands JPL::AirAbsorptionCache::FrequencyBandLowerThirdCenters

FrequencyDecaySlope

const AbsorptionCoeffs JPL::AirAbsorptionCache::FrequencyDecaySlope

Air absorption in dB/s (effective contribution to RT60). Calculated as HighFreqWeightedAbsorption_dB * SpeedOfSound.

HasKnee

const simd_mask JPL::AirAbsorptionCache::HasKnee

HighFreqWeightedAbsorption_dB

const AbsorptionCoeffs JPL::AirAbsorptionCache::HighFreqWeightedAbsorption_dB

Air attenuation corrected for high frequency overestimate, in dB/m. The last band is energy-weighted for more accurate HF decay slope. This is more accurate for longer propagation paths and is a middleground compromize between performance and accuracy. This can be used directly as distance * absorption_dB

[struct]

struct { ... } JPL::AirAbsorptionCache::LinAprox

Linearized approximation for non-linear frequency loss by distance.

LinearizedHFLossFactor

const simd JPL::AirAbsorptionCache::LinearizedHFLossFactor

LowerThirdBandAbsorption_dB

const AbsorptionCoeffs JPL::AirAbsorptionCache::LowerThirdBandAbsorption_dB

Air attenuation calculated for center frequency of lower third of the frequency bands, in dB/m. This is only valid for linear approximation of the non linear air absorption behavior computed internaly in AirAbsorption class.

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The documentation for this struct was generated from the following file:

• JPLSpatial/AirAbsorption.h