C INCLUDE 'pointc.inc' C ------------------------------------------------------------------ INTEGER IWAVE,IRAY,IPT,NYF,ICB1F,ISRFF,NY,ICB1,ISRF INTEGER ICB1I,IEND,ISHEET,IREC REAL XF,YLF(6),YF(39),X,YL(6),Y(39),YLI(6),YI(25) COMMON/pointc/IWAVE,IRAY,IPT, NYF,ICB1F,ISRFF,XF,YLF,YF, * NY,ICB1,ISRF,X,YL,Y, ICB1I,IEND,ISHEET,IREC,YLI,YI SAVE /POINTC/ C ------------------------------------------------------------------ C IWAVE...Index of the elementary wave (output of the subroutine C CODE1). Elementary waves are indexed by 1,2,3,... . C IWAVE=0 if the end of the input file is encountered. C IRAY... Index of the ray (output of the subroutine RPAR2). Rays C within each elementary wave are indexed by 1,2,3,... . C Note that some of the indexed rays need not exist. C IRAY=0 if the end of the input file is encountered. C IPT... Index of the point on a ray. The points O/S are indexed C sequentially along each ray, taking the values 1,2,3,... C If the point is the first considered point of a new C elementary wave, IPT=0 instead of 1. C NYF,ICB1F,ISRFF,YLF,YF... Quantities at the point O/F. They need C not be defined (option in the subroutine AP00). Their C meaning is the same as of NY,ICB1,ISRF,YL,Y below. C NYF=0... Indication that these quantities are not defined, C i.e. that the point O/F has not been defined. C NY,ICB1,ISRF,YL,Y... Quantities at the point O/S. C The detailed description of the quantities YL and Y may be C found in the file 'ray.for'. A brief description follows: C NY=IY(1)=27+NAMPL... Number of the basic quantities describing the C point of the ray, see the file 'ray.for'. C ICB1=IY(5)... Index of the complex block in which the stored point C of the ray is situated, supplemented by a sign '+' for P C wave and sign '-' for S wave. C ISRF=IY(6)... Index of the surface at which the endpoint of the C computed element of the ray is situated, supplemented by C a sign '+' or '-' for the endpoint situated at the C positive or negative side of the surface, respectively. C Zero inside the complex block. Note: The sign of this C quantity is the exeption to the definition in the original C paper on C.R.T. C YL... Array containing local quantities at the point of the ray C (C.R.T.5.5.4). C Y... Array containing basic quantities computed along the ray C (C.R.T.5.2.1). C ICB1I,YLI,YI... Quantities at the initial point O/O of the ray: C ICB1I...Index of the complex block in which the initial point of C the ray is situated, supplemented by a sign '+' for P wave C and sign '-' for S wave (see C.R.T.6.1). C YLI... Array containing the values of the quantities YL(1)-YL(6) C (see C.R.T.5.5.4) describing the local properties of the C model at the initial point of the ray, see C.R.T.6.1. 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. The detailed description of the quantities YI C may be found in file 'initc.inc'. C IEND... Reason of the termination of the computation of a ray (see C C.R.T.5.4). For a detailed description see subroutines C RAY2 (file 'ray.for') and INIT2 (file 'init.for'). C ISHEET..Ray-history index. The different ray histories are C consecutively indexed by positive integers 1,2,3,... C according to their appearance during ray tracing. C The ray histories are indexed independently within each C elementary wave. The indices are the output of subroutine C RPAR4 of the file 'rpar.for'. C The ray-history indices are complemented with sign: C positive - successful ray (crossing reference surface), C negative - unsuccessful ray (terminating before crossing C reference surface). C IREC... Index of the receiver for a two-point ray, C otherwise zero. C YLI... Array containing the values of the quantities YL(1)-YL(6), C see C.R.T.5.5.4, describing the local properties of the C model at the initial point of the ray. See the list of C YL(1) to YL(6) in the file 'ray.for'. C YI... Array containing the quantities describing the properties C of the rays and of the travel-time field at the initial C point of the ray, see C.R.T.6.1. These quantities are C listed in the file 'init.for'. C C The storage locations of the common block /POINTC/ are defined and C redefined in the external procedure AP00 of file 'ap.for'. C The quantities describing another point along a ray can be stored C into the common block /POINTC/ by another invocation of the C subroutine AP00. C C Common block /POINTC/ is included in FORTRAN 77 source code files C 'ap.for', 'apvar.for', 'crt2p.for', 'crtout.for', 'crtpts.for', C 'crtray.for', 'inv1.for', and may also be included in any user's C subroutine processing the results of the complete ray tracing C program. C C Date: 1996, September 30 C Coded by Ludek Klimes C C======================================================================= C