Multi-Frequency Far-Field Wave Scattering Data

data/
└── dataset/
    ├── train_measurements_nu_*/    # We have directories for nu={1,2,4,8,16}, equivalently k={2pi,4pi,8pi,16pi,32pi}
    │   └── measurements_*.h5       # each measurements_i.h5 has 500 scattering potentials.
    ├── val_measurements_nu_*/
    │   └── measurements_*.h5
    └── test_measurements_nu_*/
        └── measurements_*.h5

The measurement files are saved in hdf5 format, with the following fields:

• q_cart: the scattering potentials sampled on a Cartesian grid.
• q_polar: the scattering potentials sampled on a polar grid.
• x_vals: 1d coordinates of the regular Cartesian grid for the scattering domain
• rho_vals: radius values of the regular polar grid for the scattering domain
• theta_vals: angular values of the regular polar grid for the scattering domain. Also used as the source/receiver directions when generating measurements.
• seed: the RNG seed used when generating this file.
• contrast: the maximum contrast setting.
• background_max_freq: the maximum frequency parameter used when defining the random background part of the scattering potentials.
• background_max_radius: the radius of the disk occupied by the background field.
• num_shapes: how many piecewise-constant shapes were generated.
• gaussian_lpf_param: parameter used to build Gaussian lowpass filter that slightly smooths the scattering potentials.
• nu_sf: non-angular wavenumber (in space).
• omega_sf: angular frequency (in time).
• q_cart_lpf: scattering objects transformed by a Gaussian LPF, sampled on the Cartesian grid.
• q_polar_lpf: scattering objects transformed by a Gaussian LPF, sampled on the polar grid.
• d_rs: Measurements of the scattered wave field, in the original (receiver, source) coordinates.
• d_mh: Measurements of the scattered wave field, in the (m, h) coordinates suggested by Fan and Ying, 2022.
• m_vals: Coordinates of the (m, h) transformed data.
• h_vals: Coordinates of the (m, h) transformed data.
• sample_completion: array of booleans indicating whether individual samples were generated.
• file_completion: single boolean set to True when the entire generation script is completed.