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SURFEX v7.3
General documentation of Surfex
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SURFEX v7.3
General documentation of Surfex
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00001 ! ######### 00002 SUBROUTINE LATLONTOXY1D(PLAT0,PLON0,PRPK,PBETA,PLATOR,PLONOR, & 00003 PXHATM,PYHATM,PLAT,PLON,KN,PRADIUS) 00004 ! ################################################ 00005 ! 00006 !!**** *SM_LATLONTOXY1D * - Routine to compute conformal coordinates 00007 !! 00008 !! 00009 !! PURPOSE 00010 !! ------- 00011 ! This routine computes the cartesian conformal coordinates 00012 ! of an array given in latitude-longitude coordinates 00013 ! Three map projections are available: 00014 ! - polar-stereographic (PRPK=1), 00015 ! - lambert conformal (0<PRPK<1), 00016 ! - mercator (PRPK=0). 00017 ! 00018 ! 00019 !!** METHOD 00020 !! ------ 00021 !! Spherical earth approximation is used. Longitude origin is 00022 !! set in Greenwich, and is positive eastwards. An anticlockwise 00023 !! rotation of XBETA degrees is applied to the conformal frame 00024 !! with respect to the geographical directions. 00025 !! 00026 !! WARNING: ALL INPUT AND OUTPUT ANGLES ARE IN DEGREES... 00027 !! 00028 !! EXTERNAL 00029 !! -------- 00030 !! None 00031 !! 00032 !! EXPLICIT ARGUMENTS 00033 !! ------------------ 00034 !! PXHAT,PYHAT(:) : 1D arrays of the "velocity" gridpoints 00035 !! cartesian conformal coordinates (meters,input). 00036 !! PLATOR : Latitude of the (1,1) point of the "mass" grid 00037 !! (degrees,input); 00038 !! PLONOR : Longitude of the (1,1) point of the "mass" grid 00039 !! (degrees,input); 00040 !! PXHATM : conformal coordinate x (meters, mass-grid, input) 00041 !! PYHATM : conformal coordinate y (meters, mass-grid, input) 00042 !! PLAT : latitude (degrees, mass-grid, output) 00043 !! PLON : longitude (degrees, mass-grid, output) 00044 !! 00045 !! IMPLICIT ARGUMENTS 00046 !! ------------------ 00047 !! Module MODD_CST : contains Physical constants 00048 !! XPI : Pi; 00049 !! XRADIUS : Earth radius (meters); 00050 !! 00051 !! 00052 !! REFERENCE 00053 !! --------- 00054 !! Asencio N. et al., 1994, "Le projet de modele non-hydrostatique 00055 !! commun CNRM-LA, specifications techniques", 00056 !! Note CNRM/GMME, 26, 139p, (Chapter 2). 00057 !! Ducrocq V., 1994, "Generation de la grille dans le modele", 00058 !! Note interne MNH, 5 mai, 3p. 00059 !! Joly A., 1992, "Geographic parameters for ARPEGE/ALADIN", 00060 !! Internal note ARPEGE/ALADIN, february 27,28p. 00061 !! Levallois J., 1970, "Geodesie generale", Tome 2, Collection 00062 !! de l'IGN, Eyrolles, Paris, 408p. 00063 !! 00064 !! AUTHOR 00065 !! ------ 00066 !! P.M. *LA* 00067 !! 00068 !! MODIFICATION 00069 !! ------------ 00070 !! Original PM 24/05/94 00071 !! Updated PM 27/07/94 00072 !! Updated VD 23/08/94 00073 !! Updated VM 24/10/95 projection from north pole (PRPK<0) and 00074 !! longitudes set between PLON0-180. and PLON0+180. 00075 !! 00076 !------------------------------------------------------------------------------- 00077 ! 00078 !* 0. DECLARATIONS 00079 ! ------------ 00080 ! 00081 USE MODD_CSTS 00082 ! 00083 ! 00084 USE YOMHOOK ,ONLY : LHOOK, DR_HOOK 00085 USE PARKIND1 ,ONLY : JPRB 00086 ! 00087 IMPLICIT NONE 00088 ! 00089 !* 0.1 Declarations of arguments and results 00090 ! 00091 INTEGER, INTENT(IN) :: KN 00092 REAL, INTENT(IN) :: PLAT0 00093 REAL, INTENT(IN) :: PLON0 00094 REAL, INTENT(IN) :: PRPK 00095 REAL, INTENT(IN) :: PBETA 00096 REAL, INTENT(IN) :: PLATOR ! Latitude of the origine point 00097 REAL, INTENT(IN) :: PLONOR ! Longitude of the origine point 00098 REAL, DIMENSION(KN), INTENT(IN) :: PLAT,PLON 00099 REAL, DIMENSION(KN), INTENT(OUT):: PXHATM,PYHATM 00100 REAL, OPTIONAL, INTENT(IN) :: PRADIUS 00101 ! 00102 !* 0.2 Declarations of local variables 00103 ! 00104 REAL,DIMENSION(KN) :: ZLAT,ZLON 00105 REAL :: ZRPK,ZLAT0,ZLON0,ZLATOR,ZLONOR 00106 REAL :: ZRDSDG,ZCLAT0,ZSLAT0,ZCLATOR,ZSLATOR 00107 REAL :: ZRO0,ZGA0,ZBETA,ZCGAM,ZSGAM 00108 REAL :: ZXP,ZYP,ZRACLAT0,ZXE,ZYE 00109 REAL :: ZRADIUS 00110 ! 00111 REAL,DIMENSION(KN) :: ZCLAT,ZSLAT,ZRO,ZGA,ZXPR,ZYPR 00112 REAL(KIND=JPRB) :: ZHOOK_HANDLE 00113 ! 00114 ! 00115 !------------------------------------------------------------------------------- 00116 ! 00117 !* 1. PRELIMINARY CALCULATION FOR ALL PROJECTIONS 00118 ! ------------------------------------------- 00119 ! 00120 IF (LHOOK) CALL DR_HOOK('LATLONTOXY1D',0,ZHOOK_HANDLE) 00121 ZRDSDG = XPI/180. ! Degree to radian conversion factor 00122 ! 00123 ! By definition, (PLONOR,PLATOR) are the geographical 00124 ! coordinates, and (ZXBM0,ZYBM0) the conformal cartesian 00125 ! coordinates of the (1,1) point of the "mass" grid. 00126 ! 00127 ! 00128 ZLON(:)=PLON(:) 00129 ZLON(:)=ZLON(:)+NINT((PLON0-ZLON(:))/360.)*360. 00130 ! 00131 ZLONOR=PLONOR 00132 ZLONOR=ZLONOR+NINT((PLON0-ZLONOR)/360.)*360. 00133 ! 00134 ZRADIUS = XRADIUS 00135 IF (PRESENT(PRADIUS)) ZRADIUS = PRADIUS 00136 ! 00137 !------------------------------------------------------------------------------ 00138 ! 00139 !* 2. POLAR SEREOGRAPHIC AND LAMBERT CONFORMAL CASES 00140 ! ---------------------------------------------- 00141 ! (PRPK=1 P-stereo, 0<PRPK<1 Lambert) 00142 ! 00143 IF(PRPK /= 0.) THEN 00144 ! 00145 IF (PRPK<0.) THEN ! projection from north pole 00146 ZRPK=-PRPK 00147 ZBETA=-PBETA 00148 ZLAT0=-PLAT0 00149 ZLON0=PLON0+180. 00150 ZLATOR=-PLATOR 00151 ZLONOR=ZLONOR+180. 00152 ZLAT(:)=-PLAT(:) 00153 ZLON(:)=ZLON(:)+180. 00154 ELSE ! projection from south pole 00155 ZRPK=PRPK 00156 ZBETA=PBETA 00157 ZLAT0=PLAT0 00158 ZLON0=PLON0 00159 ZLATOR=PLATOR 00160 ZLONOR=ZLONOR 00161 ZLAT(:)=PLAT(:) 00162 ZLON(:)=ZLON(:) 00163 ENDIF 00164 ! 00165 !* 2.1 Preliminary calculations 00166 ! 00167 ZCLAT0 = COS(ZRDSDG*ZLAT0) 00168 ZSLAT0 = SIN(ZRDSDG*ZLAT0) 00169 ZCLATOR = COS(ZRDSDG*ZLATOR) 00170 ZSLATOR = SIN(ZRDSDG*ZLATOR) 00171 ZRO0 = (ZRADIUS/ZRPK)*(ABS(ZCLAT0))**(1.-ZRPK) & 00172 * ((1.+ZSLAT0)*ABS(ZCLATOR)/(1.+ZSLATOR))**ZRPK 00173 ZGA0 = (ZRPK*(ZLONOR-ZLON0)-ZBETA)*ZRDSDG 00174 ZXP = -ZRO0*SIN(ZGA0) 00175 ZYP = ZRO0*COS(ZGA0) 00176 ! 00177 !* 2.2 Conformal coordinates in meters 00178 ! 00179 ZCLAT(:) = COS(ZRDSDG*ZLAT(:)) 00180 ZSLAT(:) = SIN(ZRDSDG*ZLAT(:)) 00181 ZRO(:) = (ZRADIUS/ZRPK)*(ABS(ZCLAT0))**(1.-ZRPK) & 00182 * ((1.+ZSLAT0)*ABS(ZCLAT(:))/(1.+ZSLAT(:)))**ZRPK 00183 ZGA(:) = (ZRPK*(ZLON(:)-ZLON0)-ZBETA)*ZRDSDG 00184 ! 00185 PXHATM(:) = ZXP+ZRO(:)*SIN(ZGA(:)) 00186 PYHATM(:) = ZYP-ZRO(:)*COS(ZGA(:)) 00187 ! 00188 IF (PRPK<0.) THEN ! projection from north pole 00189 PYHATM(:)=-PYHATM(:) 00190 ENDIF 00191 ! 00192 !------------------------------------------------------------------------------- 00193 ! 00194 !* 3. MERCATOR PROJECTION WITH ROTATION 00195 ! --------------------------------- 00196 ! (PRPK=0) 00197 ! 00198 ELSE 00199 ! 00200 !* 3.1 Preliminary calculations 00201 ! 00202 ZCGAM = COS(-ZRDSDG*PBETA) 00203 ZSGAM = SIN(-ZRDSDG*PBETA) 00204 ZRACLAT0 = ZRADIUS*COS(ZRDSDG*PLAT0) 00205 ZXE = - ZRACLAT0*(PLONOR-PLON0)*ZRDSDG 00206 ZYE = - ZRACLAT0*LOG(TAN(XPI/4.+PLATOR*ZRDSDG/2.)) 00207 ! 00208 !* 3.2 Conformal coordinates 00209 ! 00210 ZXPR(:) = ZRACLAT0*(ZLON(:)-PLON0)*ZRDSDG+ZXE 00211 ZYPR(:) = ZRACLAT0*LOG(TAN(XPI/4.+PLAT(:)*ZRDSDG/2.))+ZYE 00212 ! 00213 PXHATM = ZXPR(:)*ZCGAM-ZYPR(:)*ZSGAM 00214 PYHATM = ZXPR(:)*ZSGAM+ZYPR(:)*ZCGAM 00215 ! 00216 !------------------------------------------------------------------------------- 00217 ! 00218 !* 4. EXIT 00219 ! ---- 00220 ! 00221 END IF 00222 IF (LHOOK) CALL DR_HOOK('LATLONTOXY1D',1,ZHOOK_HANDLE) 00223 !------------------------------------------------------------------------------- 00224 END SUBROUTINE LATLONTOXY1D
1.8.0
