surface_gather(model, q, data; offsets=nothing, options=Options())

Compute the surface offset gathers volume (nx (X ny) X nz X no) for via the double rtm method whith no offsets.

Parameters

• model: JUDI Model structure.
• q: Source, judiVector.
• data: Obeserved data, judiVector.
• offsets: List of offsets to compute the gather at. Optional (defaults to 0:10*model.d:model.extent)
• options: JUDI Options structure.

double_rtm_cig(model, q, data, offsets, options)

Compute the single shot contribution to the surface offset gather via double rtm. This single source contribution consists of the following steps:

1. Mute direct arrival in the data.
2. Compute standard RTM $R$.
3. Compute the offset RTM $R_o$ for the the weighted data where each trace is weighted by its offset (rec_x - src_x).
4. Compute the envelope $R_e = \mathcal{E}(R)$ and $R_{oe} = \mathcal{E}(R_o)$.
5. Compute the offset map $\frac{R_e \odot R_{oe}}{R_e \odot R_e + \epsilon}$.
6. Apply illumination correction and laplace filter $R_l = \mathcal{D} \Delta R$.
7. Compute each offset contribution $\mathcal{I}[:, h] = R_l \odot \delta[ha - h]_{tol}$ delta_h.
8. Return $\mathcal{I}$.

J = judiExtendedJacobian(F, q, offsets; options::JUDIOptions, omni=false, dims=nothing)

Extended jacobian (extended Born modeling operator) for subsurface horsizontal offsets offsets. Its adjoint comput the subsurface common offset volume. In succint way, the extened born modeling Operator can summarized in a linear algebra frmaework as:

Options structure for seismic modeling.

omni: If true, the extended jacobian will be computed for all dimensions. dims: If omni is false, the extended jacobian will be computed for the dimension(s) specified in dims.

delta_h(ha, h, tol)

Compute the binary mask where ha is within tol of h.

envelope(x)

Envelope of a vector or a 1D vector (see DSP hilbert)

envelope(x)

Envelope of a vector or a 2D matrix. The envelope over the first dimension is taken for a 2D matrix (see DSP hilbert)

laplacian(image; hx=1, hy=1)

2D laplacian of an image with grid spacings (hx, hy)

mute!(shot, offsets;vp=1500, t0=1/10, dt=0.004)

In place direct wave muting of a shot record with water sound speed vp, time sampling dt and firing time t0.

mute(shot, offsets;vp=1500, t0=1/10, dt=0.004)

Direct wave muting of a shot record with water sound speed vp, time sampling dt and firing time t0.

mv_avg_2d(x; k=5)

2D moving average with a square window of width k

offset_map(rtm, rtmo; scale=0)

Return the regularized least-square division of rtm and rtmo. The regularization consists of the envelope and moving average followed by the least-square division surface_gather