【GNSS】【GAMP】观测数据obs的读取

1.readobsnav(ts,te,ti,fopt->inf,index,MAXINFILE,popt,&obss,&navs,stas))

首先存储观测数据，结构体，有两个，obs_t     obsd_t

typedef struct {        /* observation data */

    int n,nmax;         /* number of obervation data/allocated */

    obsd_t *data;       /* observation data records */

} obs_t;

 

typedef struct {        /* observation data record */

    gtime_t time;       /* receiver sampling time (GPST) */

    unsigned char sat,rcv; /* satellite/receiver number */

    unsigned char SNR [NFREQ+NEXOBS]; /* signal strength (0.25 dBHz) */

    unsigned char LLI [NFREQ+NEXOBS]; /* loss of lock indicator */

    unsigned char code[NFREQ+NEXOBS]; /* code indicator (CODE_???) */

       char *type[NFREQ];

    double L[NFREQ+NEXOBS]; /* observation data carrier-phase (cycle) */

    double P[NFREQ+NEXOBS]; /* observation data pseudorange (m) */

    float  D[NFREQ+NEXOBS]; /* observation data doppler frequency (Hz) */

} obsd_t;

 

 

---

 

2.     if (!readobsnav(ts,te,ti,fopt->inf,index,MAXINFILE,popt,&obss,&navs,stas))

​obs的初始化

---

3.

nep=readrnxt(infile[i],rcv,ts,te,ti,prcopt->rnxopt,obs,nav,rcv<=2?sta+rcv-1:NULL);

//读取文件。

---

4. stat=readrnxfile(file,ts,te,tint,opt,0,rcv,&type,obs,nav,sta);

建立指针，打开文件。

FILE *fp;

fp=fopen(file,"r");

---

5.

 stat=readrnxfp(fp,ts,te,tint,opt,flag,index,type,obs,nav,sta);

 

---

6.      /* read rinex header */

    if (!readrnxh(fp,&ver,type,&sys,&tsys,tobs,nav,sta)) return 0;

    /* flag=0:except for clock,1:clock */

    if ((!flag&&*type=='C')||(flag&&*type!='C')) return 0;

    /* read rinex body */

    switch (*type)
{

        case 'O': return readrnxobs(fp,ts,te,tint,opt,index,ver,tsys,tobs,obs);

        case 'N': return readrnxnav(fp,opt,ver,sys    ,nav);

        case 'G': return readrnxnav(fp,opt,ver,SYS_GLO,nav);

        case 'J': return readrnxnav(fp,opt,ver,SYS_QZS,nav); /* extension */

        case 'L': return readrnxnav(fp,opt,ver,SYS_GAL,nav); /* extension */

        case 'C': return readrnxclk(fp,opt,index,nav);

    }

case 'O': return readrnxobs(fp,ts,te,tint,opt,index,ver,tsys,tobs,obs); 

---

7.   obs_t  *obs

    obs是指针

  obsd_t *data;

     data也是指针

 if (!(data=(obsd_t *)malloc(sizeof(obsd_t)*MAXOBS))) return 0;

    /* read rinex obs data body */

    while ((n=readrnxobsb(fp,opt,ver,tobs,&flag,data))>=0&&stat>=0)

//读取单个历元进行循环。

    {

        for (i=0;i

        {

            /* utc -> gpst */

            if (tsys==TSYS_UTC) data[i].time=utc2gpst(data[i].time);

            /* save cycle-slip */

            saveslips(slips,data+i);

        }

        /* screen data by time */

        if (n>0&&!screent(data[0].time,ts,te,tint)) continue;

        for (i=0;i

        {

            /* restore cycle-slip */

            restslips(slips,data+i);

            data[i].rcv=(unsigned char)rcv;

            /* save obs data */

            if ((stat=addobsdata(obs,data+i))<0) break;

        }

 

//完成单个历元的叠加 

  }

//完成整个文件的diej叠加