C INCLUDE 'initc.inc' C ------------------------------------------------------------------ INTEGER MYI PARAMETER (MYI=38) INTEGER MSRFCA PARAMETER (MSRFCA=128) INTEGER ISB1I,ICB1I,NPVI REAL YLI(6),YI(MYI),FSRFCA(MSRFCA) COMMON/INITC/ISB1I,ICB1I,NPVI,YLI,YI,FSRFCA SAVE /INITC/ C ------------------------------------------------------------------ C ISB1I,ICB1I... Indices of a simple and a complex blocks in which C the initial point of the ray is situated, see C C.R.T.6.1. C NPVI... Total number of the components of the polarization vectors C defined at the initial point of the ray. C NPVI=0: Isotropic medium. The polarization vectors C coincide with the basis vectors of ray-centred C coordinates. C YI(30:38) are undefined. C NPVI=3: P wave in an anisotropic medium. C YI(30:35) are undefined. C YI(36:38) is the P-wave eigenvector of the Christoffel C matrix. C NPVI=6: S wave in an anisotropic medium. C YI(30:35) are the S-wave reference polarization vectors. C YI(36:38) is the P-wave eigenvector of the reference C Christoffel matrix. C YLI... Array containing the values of the quantities YL(1)-YL(6), C see C C.R.T.5.5.4, C describing the local properties of the model C at the initial point of the ray, see C C.R.T.6.1. C They must not be changed outside the subroutine INIT2. C C Description of YL. C C YI... Array containing the following quantities describing the C properties of the rays and of the travel-time field, see C C.R.T.6.1. C C Following quantities, describing the properties defined for C a single ray, are defined in subroutine INIT2 of file 'init.for'. C INIT2 C YI(1)...Initial travel time. C YI(2)...Initial imaginary part of the complex travel time. C YI(3)-YI(5)... Coordinates of the initial point of the ray. C YI(6)-YI(8)... Covariant components of the initial slowness C vector. C YI(9)-YI(11)... Covariant components of the first basis vector of C the ray-centred coordinate system at the initial point of C the ray (perpendicular to the slowness vector C YI(6)-YI(8)). C YI(12),YI(16) QR11,QR12 C YI(13),YI(17) QR21,QR22 C YI(14),YI(18) PR11,PR12 C YI(15),YI(19)... PR21,PR22 C Elements of the ray geometrical spreading matrix QR, and C of the matrix PR (see C.R.T., C eq.(5.13)) C at the initial point of the ray. C YI(20),YI(21)... Take-off parameters of the ray. C C Following quantities YI(22)-YI(29), describing the properties C of the discrete system of computed rays in the vicinity of the C computed ray, are defined in subroutine RPAR4 of file 'rpar.for'. C RPAR4 C YI(22)..Area of the element of the ray-parameter surface, C corresponding to the ray, see C.R.T., C eq.(6.1). C YI(23),YI(24),YI(25)... Components 11, 12, 22 of the symmetric C matrix inverse to the specific moment of the element of C the ray-parameter surface corresponding to the ray, see C eq.(6.2). C C Additional quantities related to the shooting algorithm: C YI(26),YI(27)... Normalized take-off parameters of the ray, both C taking the values between 0 and 1. C YI(28),YI(29)... For a successful ray, values of the C X1 and X2 C functions parametrizing the reference surface. C Otherwise zeros. C C Reference polarization vectors in anisotropic media defined in C subroutine INIT2 of file 'init.for': C YI(30:32),YI(33:35)... S-wave reference polarization vectors C at the initial point of the ray. C YI(36:38)... P-wave eigenvector of the reference Christoffel C matrix at the initial point of the ray. C C The index of the last allocated numeric unit of array FSRFCA is C named MSRFCA. Dimension MSRFCA may be adjusted if necessary. C C Common block /INITC/ is included in external procedures INIT1 and C INIT2 of 'init.for', in OUTP of 'raycb.for', in 'rpar.for', C in 'writ.for', in 'scro.for', and may be included in any other C subroutine. C C Version: 7.00 C Date: 2013, April 19 C Coded by Ludek Klimes C C======================================================================= C