/* initizlize ionosphere parameter --------------------------------------------*/
static void init_iono(const obsd_t *obs, const double *azel, double *x,
double *P, int nx)
{
double map,iono;
if (obs->P[0]==0||obs->P[1]==0) return;
map=ionmapf(pos,azel);
iono=(obs->P[0]-obs->P[1])/map;
initx(x,P,nx,II(obs->sat),iono,VAR_IONO);
}
/* ionosphere residuals ------------------------------------------------------*/
static int res_iono(const obsd_t *obs, int n, const double *azel,
const double *x, int nx, double *v, double *H, double *R)
{
double *sig,L1,L2,P1,P2,map;
int i,j,nv=0,sat;
sig=mat(1,2*n);
for (i=0;i<n;i++) {
sat=obs[i].sat;
L1=obs->L[0]*lam[0];
L2=obs->L[1]*lam[1];
P1=obs->P[0];
P2=obs->P[1];
if (L1==0||L2==0||P1==0||P2==0) continue;
/* ionosphere mapping function */
map=ionmapf(pos,azel+i*2);
/* residuals of ionosphere (geometriy-free) LC */
v[nv ]=(L1-L2)+map*x[II(sat)]-x[IB(sat)];
v[nv+1]=(P1-P2)-map*x[II(sat)];
/* partial derivatives */
for (j=0;j<nx;j++) H[nx*nv+j]=0.0;
H[nx*nv +II(sat)]=-map;
H[nx*nv +IB(sat)]=1.0;
H[nx*(nv+1)+IB(sat)]=map;
/* standard deviation of error */
sig[nv ]=std_err(azel);
sig[nv+1]=sig[nv]*RATIO_ERR;
nv+=2;
}
for (i=0;i<nv;i++) for (j=0;j<nv;j++) {
R[i+j*nv]=i==j?SQR(sig[i]):0.0;
}
free(sig);
return nv;
}
/* generate simulated observation data ---------------------------------------*/
static int simobs(gtime_t ts, gtime_t te, double tint, const double *rr,
nav_t *nav, obs_t *obs, int opt)
{
gtime_t time;
obsd_t data[MAXSAT]={{{0}}};
double pos[3],rs[3*MAXSAT],dts[MAXSAT],r,e[3],azel[2];
double ecp[MAXSAT][NFREQ]={{0}},epr[MAXSAT][NFREQ]={{0}};
double snr[MAXSAT][NFREQ]={{0}},ers[MAXSAT][3]={{0}};
double iono,trop,fact,cp,pr,dtr=0.0,rref[3],bl;
int i,j,k,n,ns,amb[MAXSAT][NFREQ]={{0}},sys,prn;
char s[64];
double pref[]={36.106114294,140.087190410,70.3010}; /* ref station */
trace(3,"simobs:nnav=%d ngnav=%d\n",nav->n,nav->ng);
for (i=0;i<2;i++) pref[i]*=D2R;
pos2ecef(pref,rref);
for (i=0;i<3;i++) rref[i]-=rr[i];
bl=norm(rref,3)/1E4; /* baseline (10km) */
srand(0);
/* ephemeris error */
for (i=0;i<MAXSAT;i++) {
data[i].sat=i+1;
data[i].P[0]=2E7;
for (j=0;j<3;j++) ers[i][j]=randn(0.0,erreph);
}
srand(tickget());
ecef2pos(rr,pos);
n=(int)(timediff(te,ts)/tint+1.0);
for (i=0;i<n;i++) {
time=timeadd(ts,tint*i);
time2str(time,s,0);
for (j=0;j<MAXSAT;j++) data[j].time=time;
for (j=0;j<3;j++) { /* iteration for pseudorange */
satpos(time,data,MAXSAT,nav,rs,dts);
for (k=0;k<MAXSAT;k++) {
if ((r=geodist(rs+k*3,rr,e))<=0.0) continue;
data[k].P[0]=r+CLIGHT*(dtr-dts[k]);
}
}
satpos(time,data,MAXSAT,nav,rs,dts);
for (j=ns=0;j<MAXSAT;j++) {
/* add ephemeris error */
for (k=0;k<3;k++) rs[k+j*3]+=ers[j][k];
if ((r=geodist(rs+j*3,rr,e))<=0.0) continue;
satazel(pos,e,azel);
if (azel[1]<minel*D2R) continue;
iono=ionmodel(time,nav->ion,pos,azel);
trop=tropmodel(pos,azel,0.3);
/* add ionospheric error */
iono+=errion*bl*ionmapf(pos,azel);
snrmodel(azel,snr[j]);
errmodel(azel,snr[j],ecp[j],epr[j]);
sys=satsys(data[j].sat,&prn);
for (k=0;k<NFREQ;k++) {
data[j].L[k]=data[j].P[k]=0.0;
data[j].SNR[k]=0;
data[j].LLI[k]=0;
if (sys==SYS_GPS) {
if (k>=3) continue; /* no L5a/L5b in gps */
if (k>=2&&!gpsblock[prn-1]) continue; /* no L5 in block II */
}
else if (sys==SYS_GLO) {
if (k>=3) continue;
}
else if (sys==SYS_GAL) {
if (k==1) continue; /* no L2 in galileo */
}
else continue;
/* generate observation data */
fact=lam[k]*lam[k]/lam[0]/lam[0];
cp=r+CLIGHT*(dtr-dts[j])-fact*iono+trop+ecp[j][k];
pr=r+CLIGHT*(dtr-dts[j])+fact*iono+trop+epr[j][k];
if (amb[j][k]==0) amb[j][k]=(int)(-cp/lam[k]);
data[j].L[k]=cp/lam[k]+amb[j][k];
data[j].P[k]=pr;
data[j].SNR[k]=(unsigned char)snr[j][k];
data[j].LLI[k]=data[j].SNR[k]<slipthres?1:0;
}
if (obs->nmax<=obs->n) {
if (obs->nmax==0) obs->nmax=65532; else obs->nmax+=65532;
if (!(obs->data=(obsd_t *)realloc(obs->data,sizeof(obsd_t)*obs->nmax))) {
fprintf(stderr,"malloc error\n");
return 0;
}
}
obs->data[obs->n++]=data[j];
ns++;
}
fprintf(stderr,"time=%s nsat=%2d\r",s,ns);
}
fprintf(stderr,"\n");
return 1;
}
