| 1 | SUBROUTINE DSOLVER(NL,GAMA,CP,CM,CPM1,CMM1 |
|---|
| 2 | ,,E1,E2,E3,E4,BTOP,BSURF,RSF,XK1,XK2) |
|---|
| 3 | C VERSION OF SOLVER |
|---|
| 4 | c PARAMETER (NMAX=201) |
|---|
| 5 | PARAMETER (NMAX=401) |
|---|
| 6 | IMPLICIT REAL (A-H,O-Z) |
|---|
| 7 | DIMENSION GAMA(NL),CP(NL),CM(NL), |
|---|
| 8 | ,CPM1(NL),CMM1(NL),XK1(NL),XK2(NL) |
|---|
| 9 | ,,E1(NL),E2(NL),E3(NL),E4(NL) |
|---|
| 10 | DIMENSION AF(NMAX),BF(NMAX),CF(NMAX),DF(NMAX),XK(NMAX) |
|---|
| 11 | C********************************************************* |
|---|
| 12 | C* THIS SUBROUTINE SOLVES FOR THE COEFFICIENTS OF THE * |
|---|
| 13 | C* TWO STREAM SOLUTION FOR GENERAL BOUNDARY CONDITIONS * |
|---|
| 14 | C* NO ASSUMPTION OF THE DEPENDENCE ON OPTICAL DEPTH OF * |
|---|
| 15 | C* C-PLUS OR C-MINUS HAS BEEN MADE. * |
|---|
| 16 | C* NL = NUMBER OF LAYERS IN THE MODEL * |
|---|
| 17 | C* CP = C-PLUS EVALUATED AT TAO=0 (TOP) * |
|---|
| 18 | C* CM = C-MINUS EVALUATED AT TAO=0 (TOP) * |
|---|
| 19 | C* CPM1 = C-PLUS EVALUATED AT TAOSTAR (BOTTOM) * |
|---|
| 20 | C* CMM1 = C-MINUS EVALUATED AT TAOSTAR (BOTTOM) * |
|---|
| 21 | C* EP = EXP(LAMDA*DTAU) * |
|---|
| 22 | C* EM = 1/EP * |
|---|
| 23 | C* E1 = EP + GAMA *EM * |
|---|
| 24 | C* E2 = EP - GAMA *EM * |
|---|
| 25 | C* E3 = GAMA*EP + EM * |
|---|
| 26 | C* E4 = GAMA*EP - EM * |
|---|
| 27 | C* BTOP = THE DIFFUSE RADIATION INTO THE MODEL AT TOP * |
|---|
| 28 | C* BSURF = THE DIFFUSE RADIATION INTO THE MODEL AT * |
|---|
| 29 | C* THE BOTTOM: INCLUDES EMMISION AND REFLECTION * |
|---|
| 30 | C* OF THE UNATTENUATED PORTION OF THE DIRECT * |
|---|
| 31 | C* BEAM. BSTAR+RSF*FO*EXP(-TAOSTAR/U0) * |
|---|
| 32 | C* RSF = REFLECTIVITY OF THE SURFACE * |
|---|
| 33 | C* XK1 = COEFFICIENT OF THE POSITIVE EXP TERM * |
|---|
| 34 | C* XK2 = COEFFICIENT OF THE NEGATIVE EXP TERM * |
|---|
| 35 | C********************************************************* |
|---|
| 36 | L=2*NL |
|---|
| 37 | C************MIXED COEFFICENTS********** |
|---|
| 38 | C* THIS VERSION AVOIDS SINGULARITIES ASSOC. |
|---|
| 39 | C* WIRH W0=0 BY SOLVING FOR XK1+XK2, AND XK1-XK2. |
|---|
| 40 | AF(1)=0.0 |
|---|
| 41 | BF(1)=GAMA(1)+1. |
|---|
| 42 | CF(1)=GAMA(1)-1. |
|---|
| 43 | DF(1)=BTOP-CMM1(1) |
|---|
| 44 | N=0 |
|---|
| 45 | LM2=L-2 |
|---|
| 46 | C* EVEN TERMS |
|---|
| 47 | DO 10 I=2,LM2,2 |
|---|
| 48 | N=N+1 |
|---|
| 49 | AF(I)=(E1(N)+E3(N))*(GAMA(N+1)-1.) |
|---|
| 50 | BF(I)=(E2(N)+E4(N))*(GAMA(N+1)-1.) |
|---|
| 51 | CF(I)=2.*(1.-GAMA(N+1)**2) |
|---|
| 52 | DF(I)=(GAMA(N+1)-1.) * (CPM1(N+1) - CP(N)) |
|---|
| 53 | & + (1.-GAMA(N+1))* (CM(N)-CMM1(N+1)) |
|---|
| 54 | 10 CONTINUE |
|---|
| 55 | N=0 |
|---|
| 56 | LM1=L-1 |
|---|
| 57 | DO 20 I=3,LM1,2 |
|---|
| 58 | N=N+1 |
|---|
| 59 | AF(I)=2.*(1.-GAMA(N)**2) |
|---|
| 60 | BF(I)=(E1(N)-E3(N))*(1.+GAMA(N+1)) |
|---|
| 61 | CF(I)=(E1(N)+E3(N))*(GAMA(N+1)-1.) |
|---|
| 62 | DF(I)=E3(N)*(CPM1(N+1) - CP(N)) |
|---|
| 63 | & + E1(N)*(CM(N) - CMM1(N+1)) |
|---|
| 64 | 20 CONTINUE |
|---|
| 65 | AF(L)=E1(NL)-RSF*E3(NL) |
|---|
| 66 | BF(L)=E2(NL)-RSF*E4(NL) |
|---|
| 67 | CF(L)=0.0 |
|---|
| 68 | DF(L)=BSURF-CP(NL)+RSF*CM(NL) |
|---|
| 69 | CALL DTRIDGL(L,AF,BF,CF,DF,XK) |
|---|
| 70 | C***UNMIX THE COEFFICIENTS**** |
|---|
| 71 | DO 28 N=1,NL |
|---|
| 72 | XK1(N)=XK(2*N-1)+XK(2*N) |
|---|
| 73 | XK2(N)=XK(2*N-1)-XK(2*N) |
|---|
| 74 | C NOW TEST TO SEE IF XK2 IS REALLY ZERO TO THE LIMIT OF THE |
|---|
| 75 | C MACHINE ACCURACY = 1 .E -30 |
|---|
| 76 | C XK2 IS THE COEFFICEINT OF THE GROWING EXPONENTIAL AND MUST |
|---|
| 77 | C BE TREATED CAREFULLY |
|---|
| 78 | IF (XK2(N) .EQ. 0.0) GO TO 28 |
|---|
| 79 | IF (ABS (XK2(N)/XK(2*N-1)) .LT. 1.E-30) XK2(N)=0.0 |
|---|
| 80 | 28 CONTINUE |
|---|
| 81 | RETURN |
|---|
| 82 | END |
|---|
