def selfs(self):
'''The self-starter'''
# Conditions for the delta function
si = self._zs / self._dz
_is = int(numpy.floor(si)) # Source depth index
dis = si - _is # Offset
self.u[_is] = (1 - dis) * numpy.sqrt(2 * numpy.pi / self.k0) / \
(self._dz * self.alpw[_is])
self.u[_is + 1] = dis * numpy.sqrt(2 * numpy.pi / self.k0) / \
(self._dz * self.alpw[_is])
# Divide the delta function by (1-X)**2 to get a smooth rhs
self.pd1[0] = 0
self.pd2[0] = -1
matrc(self.k0, self._dz, self.iz, self.iz, self.nz, 1,
self.f1, self.f2, self.f3, self.ksq, self.alpw, self.alpb,
self.ksqw, self.ksqb, self.rhob, self.r1, self.r2, self.r3,
self.s1, self.s2, self.s3, self.pd1, self.pd2)
for _ in range(2):
solve(self.u, self.v, self.s1, self.s2, self.s3,
self.r1, self.r2, self.r3, self.iz, self.nz, 1)
# Apply the operator (1-X)**2*(1+X)**(-1/4)*exp(ci*k0*r*sqrt(1+X))
self.epade(ip=2)
matrc(self.k0, self._dz, self.iz, self.iz, self.nz, self._np,
self.f1, self.f2, self.f3, self.ksq, self.alpw, self.alpb,
self.ksqw, self.ksqb, self.rhob, self.r1, self.r2, self.r3,
self.s1, self.s2, self.s3, self.pd1, self.pd2)
solve(self.u, self.v, self.s1, self.s2, self.s3,
self.r1, self.r2, self.r3, self.iz, self.nz, self._np)
def updat(self):
'''Matrix updates'''
# Varying bathymetry
if self.rd_bt:
npt = self._rbzb.shape[0]
while (self.bt_ind < npt - 1) and (self.r >=
self._rbzb[self.bt_ind + 1, 0]):
self.bt_ind += 1
jz = self.iz
z = self._rbzb[self.bt_ind, 1] + \
(self.r + 0.5 * self._dr - self._rbzb[self.bt_ind, 0]) * \
(self._rbzb[self.bt_ind + 1, 1] - self._rbzb[self.bt_ind, 1]) / \
(self._rbzb[self.bt_ind + 1, 0] - self._rbzb[self.bt_ind, 0])
self.iz = int(numpy.floor(z /
self._dz)) # First index below seabed
self.iz = max(1, self.iz)
self.iz = min(self.nz - 1, self.iz)
if (self.iz != jz):
matrc(self.k0, self._dz, self.iz, jz, self.nz, self._np,
self.f1, self.f2, self.f3, self.ksq, self.alpw,
self.alpb, self.ksqw, self.ksqb, self.rhob, self.r1,
self.r2, self.r3, self.s1, self.s2, self.s3, self.pd1,
self.pd2)
# Varying sound speed profile
if self.rd_ss:
npt = self._rp_ss.size
ss_ind_o = self.ss_ind
while (self.ss_ind < npt - 1) and (self.r >=
self._rp_ss[self.ss_ind + 1]):
self.ss_ind += 1
if self.ss_ind != ss_ind_o:
self.profl()
matrc(self.k0, self._dz, self.iz, self.iz, self.nz, self._np,
self.f1, self.f2, self.f3, self.ksq, self.alpw,
self.alpb, self.ksqw, self.ksqb, self.rhob, self.r1,
self.r2, self.r3, self.s1, self.s2, self.s3, self.pd1,
self.pd2)
# Varying seabed profile
if self.rd_sb:
npt = self._rp_sb.size
sb_ind_o = self.sb_ind
while (self.sb_ind < npt - 1) and (self.r >=
self._rp_sb[self.sb_ind + 1]):
self.sb_ind += 1
if self.sb_ind != sb_ind_o:
self.profl()
matrc(self.k0, self._dz, self.iz, self.iz, self.nz, self._np,
self.f1, self.f2, self.f3, self.ksq, self.alpw,
self.alpb, self.ksqw, self.ksqb, self.rhob, self.r1,
self.r2, self.r3, self.s1, self.s2, self.s3, self.pd1,
self.pd2)
# Turn off the stability constraints
if self.r >= self._rs:
self._ns = 0
self._rs = self._rmax + self._dr
self.epade()
matrc(self.k0, self._dz, self.iz, self.iz, self.nz, self._np,
self.f1, self.f2, self.f3, self.ksq, self.alpw, self.alpb,
self.ksqw, self.ksqb, self.rhob, self.r1, self.r2, self.r3,
self.s1, self.s2, self.s3, self.pd1, self.pd2)
def setup(self):
'''Initialise the parameters, acoustic field, and matrices'''
if self._rbzb[-1, 0] < self._rmax:
self._rbzb = numpy.append(self._rbzb,
[[self._rmax, self._rbzb[-1, 1]]],
axis=0)
self.eta = 1 / (40 * numpy.pi * numpy.log10(numpy.exp(1)))
self.ib = 0 # Bathymetry pair index
self.mdr = 0 # Output range counter
self.r = self._dr
self.omega = 2 * numpy.pi * self._freq
ri = self._zr / self._dz
self.ir = int(numpy.floor(ri)) # Receiver depth index
self.dir = ri - self.ir # Offset
self.k0 = self.omega / self._c0
self._z_sb += self._z_ss[
-1] # Make seabed profiles relative to deepest water profile point
self._zmax = self._z_sb.max() + self._lyrw * self._lambda
self.nz = int(numpy.floor(
self._zmax / self._dz)) - 1 # Number of depth grid points - 2
self.nzplt = int(numpy.floor(self._zmplt /
self._dz)) # Deepest output grid point
self.iz = int(numpy.floor(self._rbzb[0, 1] /
self._dz)) # First index below seabed
self.iz = max(1, self.iz)
self.iz = min(self.nz - 1, self.iz)
self.u = numpy.zeros(self.nz + 2, dtype=numpy.complex)
self.v = numpy.zeros(self.nz + 2, dtype=numpy.complex)
self.ksq = numpy.zeros(self.nz + 2, dtype=numpy.complex)
self.ksqb = numpy.zeros(self.nz + 2, dtype=numpy.complex)
self.r1 = numpy.zeros([self.nz + 2, self._np], dtype=numpy.complex)
self.r2 = numpy.zeros([self.nz + 2, self._np], dtype=numpy.complex)
self.r3 = numpy.zeros([self.nz + 2, self._np], dtype=numpy.complex)
self.s1 = numpy.zeros([self.nz + 2, self._np], dtype=numpy.complex)
self.s2 = numpy.zeros([self.nz + 2, self._np], dtype=numpy.complex)
self.s3 = numpy.zeros([self.nz + 2, self._np], dtype=numpy.complex)
self.pd1 = numpy.zeros(self._np, dtype=numpy.complex)
self.pd2 = numpy.zeros(self._np, dtype=numpy.complex)
self.alpw = numpy.zeros(self.nz + 2)
self.alpb = numpy.zeros(self.nz + 2)
self.f1 = numpy.zeros(self.nz + 2)
self.f2 = numpy.zeros(self.nz + 2)
self.f3 = numpy.zeros(self.nz + 2)
self.ksqw = numpy.zeros(self.nz + 2)
nvr = int(numpy.floor(self._rmax / (self._dr * self._ndr)))
self._rmax = nvr * self._dr * self._ndr
nvz = int(numpy.floor(self.nzplt / self._ndz))
self.vr = numpy.arange(1, nvr + 1) * self._dr * self._ndr
self.vz = numpy.arange(1, nvz + 1) * self._dz * self._ndz
self.tll = numpy.zeros(nvr)
self.tlg = numpy.zeros([nvz, nvr])
self.tlc = -1 # TL output range counter
self.ss_ind = 0 # Sound speed profile range index
self.sb_ind = 0 # Seabed parameters range index
self.bt_ind = 0 # Bathymetry range index
# The initial profiles and starting field
self.profl()
self.selfs()
self.mdr, self.tlc = \
(outpt(self.r, self.mdr, self._ndr, self._ndz, self.tlc, self.f3,
self.u, self.dir, self.ir, self.tll, self.tlg)[:])
# The propagation matrices
self.epade()
matrc(self.k0, self._dz, self.iz, self.iz, self.nz, self._np, self.f1,
self.f2, self.f3, self.ksq, self.alpw, self.alpb, self.ksqw,
self.ksqb, self.rhob, self.r1, self.r2, self.r3, self.s1,
self.s2, self.s3, self.pd1, self.pd2)