/*------------------------------------------------------------------------------ * tides.c : tidal displacement corrections * * Copyright (C) 2015-2017 by T.TAKASU, All rights reserved. * * options : -DIERS_MODEL use IERS tide model * * references : * [1] D.D.McCarthy, IERS Technical Note 21, IERS Conventions 1996, July 1996 * [2] D.D.McCarthy and G.Petit, IERS Technical Note 32, IERS Conventions * 2003, November 2003 * [3] D.A.Vallado, Fundamentals of Astrodynamics and Applications 2nd ed, * Space Technology Library, 2004 * [4] J.Kouba, A Guide to using International GNSS Service (IGS) products, * May 2009 * [5] G.Petit and B.Luzum (eds), IERS Technical Note No. 36, IERS * Conventions (2010), 2010 * * version : $Revision:$ $Date:$ * history : 2015/05/10 1.0 separated from ppp.c * 2015/06/11 1.1 fix bug on computing days in tide_oload() (#128) * 2017/04/11 1.2 fix bug on calling geterp() in timdedisp() *-----------------------------------------------------------------------------*/ #include "rtklib.h" #define SQR(x) ((x)*(x)) //#define AS2R (D2R/3600.0) /* arc sec to radian */ #define GME 3.986004415E+14 /* earth gravitational constant */ #define GMS 1.327124E+20 /* sun gravitational constant */ #define GMM 4.902801E+12 /* moon gravitational constant */ /* function prototypes -------------------------------------------------------*/ #ifdef IERS_MODEL extern int dehanttideinel_(double *xsta, int *year, int *mon, int *day, double *fhr, double *xsun, double *xmon, double *dxtide); #endif /* solar/lunar tides (ref [2] 7) ---------------------------------------------*/ #ifndef IERS_MODEL static void tide_pl(const double *eu, const double *rp, double GMp, const double *pos, double *dr) { const double H3=0.292,L3=0.015; double r,ep[3],latp,lonp,p,K2,K3,a,H2,L2,dp,du,cosp,sinl,cosl; int i; trace(4,"tide_pl : pos=%.3f %.3f\n",pos[0]*R2D,pos[1]*R2D); if ((r=norm(rp,3))<=0.0) return; for (i=0;i<3;i++) ep[i]=rp[i]/r; K2=GMp/GME*SQR(RE_WGS84)*SQR(RE_WGS84)/(r*r*r); K3=K2*RE_WGS84/r; latp=asin(ep[2]); lonp=atan2(ep[1],ep[0]); cosp=cos(latp); sinl=sin(pos[0]); cosl=cos(pos[0]); /* step1 in phase (degree 2) */ p=(3.0*sinl*sinl-1.0)/2.0; H2=0.6078-0.0006*p; L2=0.0847+0.0002*p; a=dot(ep,eu,3); dp=K2*3.0*L2*a; du=K2*(H2*(1.5*a*a-0.5)-3.0*L2*a*a); /* step1 in phase (degree 3) */ dp+=K3*L3*(7.5*a*a-1.5); du+=K3*(H3*(2.5*a*a*a-1.5*a)-L3*(7.5*a*a-1.5)*a); /* step1 out-of-phase (only radial) */ du+=3.0/4.0*0.0025*K2*sin(2.0*latp)*sin(2.0*pos[0])*sin(pos[1]-lonp); du+=3.0/4.0*0.0022*K2*cosp*cosp*cosl*cosl*sin(2.0*(pos[1]-lonp)); dr[0]=dp*ep[0]+du*eu[0]; dr[1]=dp*ep[1]+du*eu[1]; dr[2]=dp*ep[2]+du*eu[2]; trace(5,"tide_pl : dr=%.3f %.3f %.3f\n",dr[0],dr[1],dr[2]); } /* displacement by solid earth tide (ref [2] 7) ------------------------------*/ static void tide_solid(const double *rsun, const double *rmoon, const double *pos, const double *E, double gmst, int opt, double *dr) { double dr1[3],dr2[3],eu[3],du,dn,sinl,sin2l; trace(3,"tide_solid: pos=%.3f %.3f opt=%d\n",pos[0]*R2D,pos[1]*R2D,opt); /* step1: time domain */ eu[0]=E[2]; eu[1]=E[5]; eu[2]=E[8]; tide_pl(eu,rsun, GMS,pos,dr1); tide_pl(eu,rmoon,GMM,pos,dr2); /* step2: frequency domain, only K1 radial */ sin2l=sin(2.0*pos[0]); du=-0.012*sin2l*sin(gmst+pos[1]); dr[0]=dr1[0]+dr2[0]+du*E[2]; dr[1]=dr1[1]+dr2[1]+du*E[5]; dr[2]=dr1[2]+dr2[2]+du*E[8]; /* eliminate permanent deformation */ if (opt&8) { sinl=sin(pos[0]); du=0.1196*(1.5*sinl*sinl-0.5); dn=0.0247*sin2l; dr[0]+=du*E[2]+dn*E[1]; dr[1]+=du*E[5]+dn*E[4]; dr[2]+=du*E[8]+dn*E[7]; } trace(5,"tide_solid: dr=%.3f %.3f %.3f\n",dr[0],dr[1],dr[2]); } #endif /* !IERS_MODEL */ /* displacement by ocean tide loading (ref [2] 7) ----------------------------*/ static void tide_oload(gtime_t tut, const double *odisp, double *denu) { const double args[][5]={ {1.40519E-4, 2.0,-2.0, 0.0, 0.00}, /* M2 */ {1.45444E-4, 0.0, 0.0, 0.0, 0.00}, /* S2 */ {1.37880E-4, 2.0,-3.0, 1.0, 0.00}, /* N2 */ {1.45842E-4, 2.0, 0.0, 0.0, 0.00}, /* K2 */ {0.72921E-4, 1.0, 0.0, 0.0, 0.25}, /* K1 */ {0.67598E-4, 1.0,-2.0, 0.0,-0.25}, /* O1 */ {0.72523E-4,-1.0, 0.0, 0.0,-0.25}, /* P1 */ {0.64959E-4, 1.0,-3.0, 1.0,-0.25}, /* Q1 */ {0.53234E-5, 0.0, 2.0, 0.0, 0.00}, /* Mf */ {0.26392E-5, 0.0, 1.0,-1.0, 0.00}, /* Mm */ {0.03982E-5, 2.0, 0.0, 0.0, 0.00} /* Ssa */ }; const double ep1975[]={1975,1,1,0,0,0}; double ep[6],fday,days,t,t2,t3,a[5],ang,dp[3]={0}; int i,j; trace(3,"tide_oload:\n"); /* angular argument: see subroutine arg.f for reference [1] */ time2epoch(tut,ep); fday=ep[3]*3600.0+ep[4]*60.0+ep[5]; ep[3]=ep[4]=ep[5]=0.0; days=timediff(epoch2time(ep),epoch2time(ep1975))/86400.0+1.0; t=(27392.500528+1.000000035*days)/36525.0; t2=t*t; t3=t2*t; a[0]=fday; a[1]=(279.69668+36000.768930485*t+3.03E-4*t2)*D2R; /* H0 */ a[2]=(270.434358+481267.88314137*t-0.001133*t2+1.9E-6*t3)*D2R; /* S0 */ a[3]=(334.329653+4069.0340329577*t-0.010325*t2-1.2E-5*t3)*D2R; /* P0 */ a[4]=2.0*PI; /* displacements by 11 constituents */ for (i=0;i<11;i++) { ang=0.0; for (j=0;j<5;j++) ang+=a[j]*args[i][j]; for (j=0;j<3;j++) dp[j]+=odisp[j+i*6]*cos(ang-odisp[j+3+i*6]*D2R); } denu[0]=-dp[1]; denu[1]=-dp[2]; denu[2]= dp[0]; trace(5,"tide_oload: denu=%.3f %.3f %.3f\n",denu[0],denu[1],denu[2]); } /* iers mean pole (ref [7] eq.7.25) ------------------------------------------*/ static void iers_mean_pole(gtime_t tut, double *xp_bar, double *yp_bar) { const double ep2000[]={2000,1,1,0,0,0}; double y,y2,y3; y=timediff(tut,epoch2time(ep2000))/86400.0/365.25; if (y<3653.0/365.25) { /* until 2010.0 */ y2=y*y; y3=y2*y; *xp_bar= 55.974+1.8243*y+0.18413*y2+0.007024*y3; /* (mas) */ *yp_bar=346.346+1.7896*y-0.10729*y2-0.000908*y3; } else { /* after 2010.0 */ *xp_bar= 23.513+7.6141*y; /* (mas) */ *yp_bar=358.891-0.6287*y; } } /* displacement by pole tide (ref [7] eq.7.26) --------------------------------*/ static void tide_pole(gtime_t tut, const double *pos, const double *erpv, double *denu) { double xp_bar,yp_bar,m1,m2,cosl,sinl; trace(3,"tide_pole: pos=%.3f %.3f\n",pos[0]*R2D,pos[1]*R2D); /* iers mean pole (mas) */ iers_mean_pole(tut,&xp_bar,&yp_bar); /* ref [7] eq.7.24 */ m1= erpv[0]/AS2R-xp_bar*1E-3; /* (as) */ m2=-erpv[1]/AS2R+yp_bar*1E-3; /* sin(2*theta) = sin(2*phi), cos(2*theta)=-cos(2*phi) */ cosl=cos(pos[1]); sinl=sin(pos[1]); denu[0]= 9E-3*sin(pos[0]) *(m1*sinl-m2*cosl); /* de= Slambda (m) */ denu[1]= -9E-3*cos(2.0*pos[0])*(m1*cosl+m2*sinl); /* dn=-Stheta (m) */ denu[2]=-33E-3*sin(2.0*pos[0])*(m1*cosl+m2*sinl); /* du= Sr (m) */ trace(5,"tide_pole : denu=%.3f %.3f %.3f\n",denu[0],denu[1],denu[2]); } /* tidal displacement ---------------------------------------------------------- * displacements by earth tides * args : gtime_t tutc I time in utc * double *rr I site position (ecef) (m) * int opt I options (or of the followings) * 1: solid earth tide * 2: ocean tide loading * 4: pole tide * 8: elimate permanent deformation * double *erp I earth rotation parameters (NULL: not used) * double *odisp I ocean loading parameters (NULL: not used) * odisp[0+i*6]: consituent i amplitude radial(m) * odisp[1+i*6]: consituent i amplitude west (m) * odisp[2+i*6]: consituent i amplitude south (m) * odisp[3+i*6]: consituent i phase radial (deg) * odisp[4+i*6]: consituent i phase west (deg) * odisp[5+i*6]: consituent i phase south (deg) * (i=0:M2,1:S2,2:N2,3:K2,4:K1,5:O1,6:P1,7:Q1, * 8:Mf,9:Mm,10:Ssa) * double *dr O displacement by earth tides (ecef) (m) * return : none * notes : see ref [1], [2] chap 7 * see ref [4] 5.2.1, 5.2.2, 5.2.3 * ver.2.4.0 does not use ocean loading and pole tide corrections * 计算因地球潮汐而引起的站点位移校正值 dr * 函数参数，6个： gtime_t tutc I time in utc double *rr I 站点位置 (ecef) (m) int opt I 选项（指定包含哪些潮的影响） 1: solid earth tide 2: ocean tide loading 4: pole tide 8: elimate permanent deformation double *erp I 地球自转参数 double *odisp I 海潮负荷参数 odisp[0+i*6]: consituent i amplitude radial(m) odisp[1+i*6]: consituent i amplitude west (m) odisp[2+i*6]: consituent i amplitude south (m) odisp[3+i*6]: consituent i phase radial (deg) odisp[4+i*6]: consituent i phase west (deg) odisp[5+i*6]: consituent i phase south (deg) (i=0:M2,1:S2,2:N2,3:K2,4:K1,5:O1,6:P1,7:Q1,8:Mf,9:Mm,10:Ssa) double *dr O 因地球潮汐而引起的站点位移校正值 (ecef) (m) 返回类型: 无 *-----------------------------------------------------------------------------*/ extern void tidedisp(gtime_t tutc, const double *rr, int opt, const erp_t *erp, const double *odisp, double *dr) { gtime_t tut; double pos[2],E[9],drt[3],denu[3],rs[3],rm[3],gmst,erpv[5]={0}; int i; #ifdef IERS_MODEL double ep[6],fhr; int year,mon,day; #endif trace(3,"tidedisp: tutc=%s\n",time_str(tutc,0)); if (erp) { //1、若有erp，调用 geterp 获取erp参数。 geterp(erp,utc2gpst(tutc),erpv); } tut=timeadd(tutc,erpv[2]); dr[0]=dr[1]=dr[2]=0.0; if (norm(rr,3)<=0.0) return; pos[0]=asin(rr[2]/norm(rr,3)); pos[1]=atan2(rr[1],rr[0]); xyz2enu(pos,E); if (opt&1) { /* solid earth tides */ /* sun and moon position in ecef */ sunmoonpos(tutc,erpv,rs,rm,&gmst); #ifdef IERS_MODEL time2epoch(tutc,ep); year=(int)ep[0]; mon =(int)ep[1]; day =(int)ep[2]; fhr =ep[3]+ep[4]/60.0+ep[5]/3600.0; /* call DEHANTTIDEINEL */ dehanttideinel_((double *)rr,&year,&mon,&day,&fhr,rs,rm,drt); #else //2、若有选项，调用 tide_solid 计算固体潮 tide_solid(rs,rm,pos,E,gmst,opt,drt); #endif for (i=0;i<3;i++) dr[i]+=drt[i]; } if ((opt&2)&&odisp) { /* ocean tide loading 3、若有选项，调用 tide_oload 计算海潮负荷*/ tide_oload(tut,odisp,denu); matmul("TN",3,1,3,1.0,E,denu,0.0,drt); for (i=0;i<3;i++) dr[i]+=drt[i]; } if ((opt&4)&&erp) { /* pole tide 4、若有选项，调用 tide_pole 计算极潮*/ tide_pole(tut,pos,erpv,denu); matmul("TN",3,1,3,1.0,E,denu,0.0,drt); for (i=0;i<3;i++) dr[i]+=drt[i]; } trace(5,"tidedisp: dr=%.3f %.3f %.3f\n",dr[0],dr[1],dr[2]); }