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#include <stdio.h>
#include <string.h>
#include <math.h>
#include "norad.h"
#include "norad_in.h"
#define PI \
3.1415926535897932384626433832795028841971693993751058209749445923
/* Example code to add BSTAR data using Ted Molczan's method. It just
reads in TLEs, computes BSTAR if possible, then writes out the
resulting modified TLE.
Add the '-v' (verbose) switch, and it also writes out the orbital
period and perigee/apogee distances. Eventually, I'll probably
set it up to dump other data that are not immediately obvious
just by looking at the TLEs... */
int main( const int argc, const char **argv)
{
FILE *ifile;
const char *filename;
char line0[100], line1[100], line2[100];
int i, verbose = 0;
const char *norad = NULL, *intl = NULL;
bool legend_shown = false;
for( i = 2; i < argc; i++)
if( argv[i][0] == '-')
switch( argv[i][1])
{
case 'v':
verbose = 1;
break;
case 'n':
norad = argv[i] + 2;
if( !*norad && i < argc - 1)
norad = argv[++i];
printf( "Looking for NORAD %s\n", norad);
break;
case 'i':
intl = argv[i] + 2;
if( !*intl && i < argc - 1)
intl = argv[++i];
printf( "Looking for international ID %s\n", intl);
break;
default:
printf( "'%s': unrecognized option\n", argv[i]);
return( -1);
break;
}
filename = (argc == 1 ? "all_tle.txt" : argv[1]);
ifile = fopen( filename, "rb");
if( !ifile)
{
fprintf( stderr, "Couldn't open '%s': ", filename);
perror( "");
return( -1);
}
if( !fgets( line0, sizeof( line0), ifile)
|| !fgets( line1, sizeof( line1), ifile))
perror( "Couldn't read from input file");
else while( fgets( line2, sizeof( line2), ifile))
{
if( *line1 == '1' && (!norad || !memcmp( line1 + 2, norad, 5))
&& (!intl || !memcmp( line1 + 9, intl, 5))
&& *line2 == '2')
{
tle_t tle;
if( parse_elements( line1, line2, &tle) >= 0)
{
char obuff[200];
double params[N_SGP4_PARAMS], c2;
if( verbose && !legend_shown)
{
legend_shown = true;
printf(
"1 NoradU COSPAR Epoch.epoch dn/dt/2 d2n/dt2/6 BSTAR T El# C\n"
"2 NoradU Inclina RAAscNode Eccent ArgPeri MeanAno MeanMotion Rev# C\n");
}
SGP4_init( params, &tle);
c2 = params[0];
if( c2 && tle.xno)
tle.bstar = tle.xndt2o / (tle.xno * c2 * 1.5);
write_elements_in_tle_format( obuff, &tle);
if( strlen( line0) < 60)
printf( "%s", line0);
printf( "%s", obuff);
if( verbose)
{
const double a1 = pow(xke / tle.xno, two_thirds); /* in Earth radii */
printf( "Inclination: %8.4f ", tle.xincl * 180. / PI);
printf( " Perigee: %.4f km\n",
(a1 * (1. - tle.eo) - 1.) * earth_radius_in_km);
printf( "Asc node: %8.4f ", tle.xnodeo * 180. / PI);
printf( " Apogee: %.4f km\n",
(a1 * (1. + tle.eo) - 1.) * earth_radius_in_km);
printf( "Arg perigee: %8.4f ", tle.omegao * 180. / PI);
printf( " Orbital period: %.4f min\n",
2. * pi / tle.xno);
printf( "Mean anom: %8.4f ", tle.xmo * 180. / PI);
printf( " Epoch: JD %.5f\n", tle.epoch);
}
}
}
strcpy( line0, line1);
strcpy( line1, line2);
}
fclose( ifile);
return( 0);
}
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