Green Function Database in ak135 for synthetic cross-correlation computation in WMSAN.

## Description
This file is an HDF5 file containing synthetic seismic waveforms computed with AxiSEM in an axisymmetric Earth in model ak135f.
It contains waveforms at various distances for a vertical point force source of 1E20 N.

## Parameters

Distance range from 0° to 180° with a 0.1° step.
Source location latitude  = 90°, longitude = 0°.
Sampling frequency 1Hz. 
Duration 3600s.
Dominant period 1s.

## Architecture
Network  "L" 

Station "SYNTH0000" : station at distance = 0° from the source location.

|-- NOISE_vertforce_dirac_0-ak135f_1.s_3600s.h5/
│   └── L/
│       └── SYNTH0000/
│       └── ...
│       └── SYNTH1800/
│   └── _metadata/