Response spectral parameter is pseudo-velocity for 5% damping.
Use records from stiff soil/rock sites.
Focal depths between 15 and 122km.
Use square-root-of-sum-of-squares (SRSS) to combine horizontal components to reduce strong azimuthal
dependence of ground motions. Note that dividing predicted spectra by 1.41 gives spectrum for each
Do not derive equations for T > 1s because of baseline problems and noise in accelerograms at longer
Try more complex functional forms but not enough data to constrain all parameters to physically-realistic
Smooth coefficients using unspecified technique.
Report residual spectra for different probability levels not σ.