461 lines
9.1 KiB
C
461 lines
9.1 KiB
C
#include <stdio.h>
|
|
#include <string.h>
|
|
#include <stdlib.h>
|
|
#include <math.h>
|
|
#include <ctype.h>
|
|
#include "cpgplot.h"
|
|
#include "sgdp4h.h"
|
|
#include "satutl.h"
|
|
#include <getopt.h>
|
|
|
|
#define LIM 128
|
|
#define XKE 0.07436680 // Guassian Gravitational Constant
|
|
#define XKMPER 6378.135
|
|
#define AE 1.0
|
|
#define XMNPDA 1440.0
|
|
#define R2D 180.0/M_PI
|
|
#define D2R M_PI/180.0
|
|
|
|
extern double SGDP4_jd0;
|
|
|
|
// Dot product
|
|
float dot(xyz_t a,xyz_t b)
|
|
{
|
|
return a.x*b.x+a.y*b.y+a.z*b.z;
|
|
}
|
|
|
|
// Return x modulo y [0,y)
|
|
double modulo(double x,double y)
|
|
{
|
|
x=fmod(x,y);
|
|
if (x<0.0) x+=y;
|
|
|
|
return x;
|
|
}
|
|
|
|
// Magnitude
|
|
double magnitude(xyz_t a)
|
|
{
|
|
return sqrt(dot(a,a));
|
|
}
|
|
|
|
// Cross product
|
|
xyz_t cross(xyz_t a,xyz_t b)
|
|
{
|
|
xyz_t c;
|
|
|
|
c.x=a.y*b.z-a.z*b.y;
|
|
c.y=a.z*b.x-a.x*b.z;
|
|
c.z=a.x*b.y-a.y*b.x;
|
|
|
|
return c;
|
|
}
|
|
|
|
// Compute Date from Julian Day
|
|
void mjd2date(double mjd,int *year,int *month,double *day)
|
|
{
|
|
double f,jd;
|
|
int z,alpha,a,b,c,d,e;
|
|
|
|
jd=mjd+2400000.5;
|
|
jd+=0.5;
|
|
|
|
z=floor(jd);
|
|
f=fmod(jd,1.);
|
|
|
|
if (z<2299161)
|
|
a=z;
|
|
else {
|
|
alpha=floor((z-1867216.25)/36524.25);
|
|
a=z+1+alpha-floor(alpha/4.);
|
|
}
|
|
b=a+1524;
|
|
c=floor((b-122.1)/365.25);
|
|
d=floor(365.25*c);
|
|
e=floor((b-d)/30.6001);
|
|
|
|
*day=b-d-floor(30.6001*e)+f;
|
|
if (e<14)
|
|
*month=e-1;
|
|
else
|
|
*month=e-13;
|
|
|
|
if (*month>2)
|
|
*year=c-4716;
|
|
else
|
|
*year=c-4715;
|
|
|
|
return;
|
|
}
|
|
|
|
// MJD to DOY
|
|
double mjd2doy(double mjd,int *yr)
|
|
{
|
|
int year,month,k=2;
|
|
double day,doy;
|
|
|
|
mjd2date(mjd,&year,&month,&day);
|
|
|
|
if (year%4==0 && year%400!=0)
|
|
k=1;
|
|
|
|
doy=floor(275.0*month/9.0)-k*floor((month+9.0)/12.0)+day-30;
|
|
|
|
*yr=year;
|
|
|
|
return doy;
|
|
}
|
|
|
|
// Clasical elements
|
|
orbit_t classel(int ep_year,double ep_day,xyz_t r,xyz_t v)
|
|
{
|
|
int i;
|
|
double rm,vm,vm2,rvm,mu=1.0;;
|
|
double chi,xp,yp,sx,cx,b,ee;
|
|
double a,ecc,incl,node,peri,mm,n;
|
|
xyz_t h,e,kk,nn;
|
|
orbit_t orb;
|
|
|
|
r.x/=XKMPER;
|
|
r.y/=XKMPER;
|
|
r.z/=XKMPER;
|
|
v.x/=(XKE*XKMPER/AE*XMNPDA/86400.0);
|
|
v.y/=(XKE*XKMPER/AE*XMNPDA/86400.0);
|
|
v.z/=(XKE*XKMPER/AE*XMNPDA/86400.0);
|
|
|
|
rm=magnitude(r);
|
|
vm2=dot(v,v);
|
|
rvm=dot(r,v);
|
|
h=cross(r,v);
|
|
chi=dot(h,h)/mu;
|
|
|
|
e.x=(vm2/mu-1.0/rm)*r.x-rvm/mu*v.x;
|
|
e.y=(vm2/mu-1.0/rm)*r.y-rvm/mu*v.y;
|
|
e.z=(vm2/mu-1.0/rm)*r.z-rvm/mu*v.z;
|
|
|
|
a=pow(2.0/rm-vm2/mu,-1);
|
|
ecc=magnitude(e);
|
|
incl=acos(h.z/magnitude(h))*R2D;
|
|
|
|
kk.x=0.0;
|
|
kk.y=0.0;
|
|
kk.z=1.0;
|
|
nn=cross(kk,h);
|
|
if (nn.x==0.0 && nn.y==0.0)
|
|
nn.x=1.0;
|
|
node=atan2(nn.y,nn.x)*R2D;
|
|
if (node<0.0)
|
|
node+=360.0;
|
|
|
|
peri=acos(dot(nn,e)/(magnitude(nn)*ecc))*R2D;
|
|
if (e.z<0.0)
|
|
peri=360.0-peri;
|
|
if (peri<0.0)
|
|
peri+=360.0;
|
|
|
|
// Elliptic motion
|
|
if (ecc<1.0) {
|
|
xp=(chi-rm)/ecc;
|
|
yp=rvm/ecc*sqrt(chi/mu);
|
|
b=a*sqrt(1.0-ecc*ecc);
|
|
cx=xp/a+ecc;
|
|
sx=yp/b;
|
|
ee=atan2(sx,cx);
|
|
n=XKE*sqrt(mu/(a*a*a));
|
|
mm=(ee-ecc*sx)*R2D;
|
|
}
|
|
if (mm<0.0)
|
|
mm+=360.0;
|
|
|
|
// Fill
|
|
orb.satno=0;
|
|
orb.eqinc=incl*D2R;
|
|
orb.ascn=node*D2R;
|
|
orb.argp=peri*D2R;
|
|
orb.mnan=mm*D2R;
|
|
orb.ecc=ecc;
|
|
orb.rev=XKE*pow(a,-3.0/2.0)*XMNPDA/(2.0*M_PI);
|
|
orb.bstar=0.0;
|
|
orb.ep_year=ep_year;
|
|
orb.ep_day=ep_day;
|
|
orb.norb=0;
|
|
|
|
return orb;
|
|
}
|
|
|
|
orbit_t rv2el(int satno,double mjd,xyz_t r0,xyz_t v0)
|
|
{
|
|
int i,imode;
|
|
orbit_t orb[5],orb1[5];
|
|
xyz_t r,v;
|
|
kep_t kep;
|
|
char line1[70],line2[70];
|
|
int ep_year;
|
|
double ep_day;
|
|
|
|
// Epoch
|
|
ep_day=mjd2doy(mjd,&ep_year);
|
|
|
|
// Initial guess
|
|
orb[0]=classel(ep_year,ep_day,r0,v0);
|
|
orb[0].satno=satno;
|
|
|
|
for (i=0;i<4;i++) {
|
|
// Propagate
|
|
imode=init_sgdp4(&orb[i]);
|
|
imode=satpos_xyz(mjd+2400000.5,&r,&v);
|
|
|
|
// Compute initial orbital elements
|
|
orb1[i]=classel(ep_year,ep_day,r,v);
|
|
|
|
// Adjust
|
|
orb[i+1].rev=orb[i].rev+orb[0].rev-orb1[i].rev;
|
|
orb[i+1].ascn=orb[i].ascn+orb[0].ascn-orb1[i].ascn;
|
|
orb[i+1].argp=orb[i].argp+orb[0].argp-orb1[i].argp;
|
|
orb[i+1].mnan=orb[i].mnan+orb[0].mnan-orb1[i].mnan;
|
|
orb[i+1].eqinc=orb[i].eqinc+orb[0].eqinc-orb1[i].eqinc;
|
|
orb[i+1].ecc=orb[i].ecc+orb[0].ecc-orb1[i].ecc;
|
|
orb[i+1].ep_year=orb[i].ep_year;
|
|
orb[i+1].ep_day=orb[i].ep_day;
|
|
orb[i+1].satno=orb[i].satno;
|
|
orb[i+1].norb=orb[i].norb;
|
|
orb[i+1].bstar=orb[i].bstar;
|
|
|
|
// Keep in range
|
|
if (orb[i+1].ecc<0.0)
|
|
orb[i+1].ecc=0.0;
|
|
if (orb[i+1].eqinc<0.0)
|
|
orb[i+1].eqinc=0.0;
|
|
}
|
|
|
|
orb[i].mnan=modulo(orb[i].mnan,2.0*M_PI);
|
|
orb[i].ascn=modulo(orb[i].ascn,2.0*M_PI);
|
|
orb[i].argp=modulo(orb[i].argp,2.0*M_PI);
|
|
|
|
return orb[i];
|
|
}
|
|
|
|
// Format TLE
|
|
void format_tle(orbit_t orb,char *line1,char *line2)
|
|
{
|
|
int i,csum;
|
|
char sbstar[]=" 00000-0",bstar[13];
|
|
|
|
// Format Bstar term
|
|
if (fabs(orb.bstar)>1e-9) {
|
|
sprintf(bstar,"%11.4e",10*orb.bstar);
|
|
sbstar[0] = bstar[0]; sbstar[1] = bstar[1]; sbstar[2] = bstar[3]; sbstar[3] = bstar[4];
|
|
sbstar[4] = bstar[5]; sbstar[5] = bstar[6]; sbstar[6] = bstar[8]; sbstar[7] = bstar[10]; sbstar[8] = '\0';
|
|
}
|
|
// Print lines
|
|
sprintf(line1,"1 %05dU %-8s %2d%012.8f .00000000 00000-0 %8s 0 0",orb.satno,orb.desig,orb.ep_year-2000,orb.ep_day,sbstar);
|
|
sprintf(line2,"2 %05d %8.4f %8.4f %07.0f %8.4f %8.4f %11.8f 0",orb.satno,DEG(orb.eqinc),DEG(orb.ascn),1E7*orb.ecc,DEG(orb.argp),DEG(orb.mnan),orb.rev);
|
|
|
|
// Compute checksums
|
|
for (i=0,csum=0;i<strlen(line1);i++) {
|
|
if (isdigit(line1[i]))
|
|
csum+=line1[i]-'0';
|
|
else if (line1[i]=='-')
|
|
csum++;
|
|
}
|
|
sprintf(line1,"%s%d",line1,csum%10);
|
|
for (i=0,csum=0;i<strlen(line2);i++) {
|
|
if (isdigit(line2[i]))
|
|
csum+=line2[i]-'0';
|
|
else if (line2[i]=='-')
|
|
csum++;
|
|
}
|
|
sprintf(line2,"%s%d",line2,csum%10);
|
|
|
|
return;
|
|
}
|
|
|
|
// Present nfd
|
|
void nfd_now(char *s)
|
|
{
|
|
time_t rawtime;
|
|
struct tm *ptm;
|
|
|
|
// Get UTC time
|
|
time(&rawtime);
|
|
ptm=gmtime(&rawtime);
|
|
|
|
sprintf(s,"%04d-%02d-%02dT%02d:%02d:%02d",ptm->tm_year+1900,ptm->tm_mon+1,ptm->tm_mday,ptm->tm_hour,ptm->tm_min,ptm->tm_sec);
|
|
|
|
return;
|
|
}
|
|
|
|
// Compute Julian Day from Date
|
|
double date2mjd(int year,int month,double day)
|
|
{
|
|
int a,b;
|
|
double jd;
|
|
|
|
if (month<3) {
|
|
year--;
|
|
month+=12;
|
|
}
|
|
|
|
a=floor(year/100.);
|
|
b=2.-a+floor(a/4.);
|
|
|
|
if (year<1582) b=0;
|
|
if (year==1582 && month<10) b=0;
|
|
if (year==1582 && month==10 && day<=4) b=0;
|
|
|
|
jd=floor(365.25*(year+4716))+floor(30.6001*(month+1))+day+b-1524.5;
|
|
|
|
return jd-2400000.5;
|
|
}
|
|
|
|
// nfd2mjd
|
|
double nfd2mjd(char *date)
|
|
{
|
|
int year,month,day,hour,min,sec;
|
|
double mjd,dday;
|
|
|
|
sscanf(date,"%04d-%02d-%02dT%02d:%02d:%02d",&year,&month,&day,&hour,&min,&sec);
|
|
dday=day+hour/24.0+min/1440.0+sec/86400.0;
|
|
|
|
mjd=date2mjd(year,month,dday);
|
|
|
|
return mjd;
|
|
}
|
|
|
|
void usage(void)
|
|
{
|
|
printf("propagate c:i:t:m:\n\nPropagates orbital elements to a new epoch using the SGP4/SDP4 model.\nDefault operation propagates classfd.tle to now,\n\n-c input catalog\n-i Satellite number\n-t New epoch (YYYY-MM-DDTHH:MM:SS)\n-m New epoch (MJD)\n");
|
|
|
|
return;
|
|
}
|
|
|
|
|
|
int main(int argc,char *argv[])
|
|
{
|
|
int imode,satno=0,arg,usecatalog=0,satnomin,flag=0;
|
|
FILE *file;
|
|
orbit_t orb;
|
|
xyz_t r,v,n,m,nm,r0,v0,mr,mv;
|
|
char tlefile[LIM],catalog[LIM],nfd[32];
|
|
char line1[80],line2[80],desig[20];
|
|
double mjd,ra,de,dr,drmin,dmr,dmv;
|
|
char *env;
|
|
int at_epoch=0;
|
|
|
|
// Get environment variable
|
|
env=getenv("ST_TLEDIR");
|
|
sprintf(tlefile,"%s/classfd.tle",env);
|
|
|
|
// Set date
|
|
nfd_now(nfd);
|
|
mjd=nfd2mjd(nfd);
|
|
|
|
// Decode options
|
|
while ((arg=getopt(argc,argv,"C:c:i:t:m:he"))!=-1) {
|
|
switch (arg) {
|
|
|
|
case 't':
|
|
strcpy(nfd,optarg);
|
|
mjd=nfd2mjd(nfd);
|
|
break;
|
|
|
|
case 'm':
|
|
mjd=(double) atof(optarg);
|
|
break;
|
|
|
|
case 'c':
|
|
strcpy(tlefile,optarg);
|
|
break;
|
|
|
|
case 'C':
|
|
strcpy(catalog,optarg);
|
|
usecatalog=1;
|
|
break;
|
|
|
|
case 'e':
|
|
at_epoch=1;
|
|
break;
|
|
|
|
case 'i':
|
|
satno=atoi(optarg);
|
|
break;
|
|
|
|
case 'h':
|
|
usage();
|
|
return 0;
|
|
break;
|
|
|
|
default:
|
|
usage();
|
|
return 0;
|
|
}
|
|
}
|
|
|
|
// Reloop stderr
|
|
freopen("/tmp/stderr.txt","w",stderr);
|
|
|
|
// Open file
|
|
file=fopen(tlefile,"r");
|
|
while (read_twoline(file,satno,&orb)==0) {
|
|
format_tle(orb,line1,line2);
|
|
|
|
// Propagate
|
|
imode=init_sgdp4(&orb);
|
|
if (at_epoch==1)
|
|
mjd=SGDP4_jd0-2400000.5;
|
|
imode=satpos_xyz(mjd+2400000.5,&r0,&v0);
|
|
|
|
// Compute normal
|
|
n=cross(r0,v0);
|
|
ra=modulo(atan2(n.y,n.x)*R2D,360.0);
|
|
de=asin(n.z/magnitude(n))*R2D;
|
|
|
|
if (usecatalog==0)
|
|
printf("%05d %14.8lf %10.6f %10.6f %10.2f %10.2f %10.2f %10.2f\n",orb.satno,mjd,ra,de,magnitude(n),n.x,n.y,n.z);
|
|
|
|
}
|
|
fclose(file);
|
|
|
|
// Match against a catalog
|
|
if (usecatalog==1) {
|
|
// Open file
|
|
file=fopen(catalog,"r");
|
|
while (read_twoline(file,0,&orb)==0) {
|
|
format_tle(orb,line1,line2);
|
|
|
|
// Propagate
|
|
imode=init_sgdp4(&orb);
|
|
imode=satpos_xyz(mjd+2400000.5,&r,&v);
|
|
|
|
|
|
// Compute normal
|
|
m=cross(r,v);
|
|
|
|
// Normal difference
|
|
nm.x=n.x-m.x;
|
|
nm.y=n.y-m.y;
|
|
nm.z=n.z-m.z;
|
|
dr=magnitude(nm);
|
|
|
|
// Position/velocity difference
|
|
mr.x=r0.x-r.x;
|
|
mr.y=r0.y-r.y;
|
|
mr.z=r0.z-r.z;
|
|
mv.x=v0.x-v.x;
|
|
mv.y=v0.y-v.y;
|
|
mv.z=v0.z-v.z;
|
|
|
|
if (flag==0 || dr<drmin) {
|
|
drmin=dr;
|
|
dmr=magnitude(mr);
|
|
dmv=magnitude(mv);
|
|
satnomin=orb.satno;
|
|
flag=1;
|
|
}
|
|
}
|
|
printf("%05d %05d %8.2f km %8.2f km %10.6f km/s\n",satno,satnomin,drmin,dmr,dmv);
|
|
}
|
|
|
|
return 0;
|
|
}
|