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'sat_id' can now be used to list artsats within a given field of view.
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@Bill-Gray
Bill-Gray committed Nov 18, 2023
1 parent 446ada7 commit 1a3e7c0
Showing 1 changed file with 106 additions and 17 deletions.
123 changes: 106 additions & 17 deletions sat_id.cpp
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Original file line number Diff line number Diff line change
Expand Up @@ -109,7 +109,7 @@ OBSERVATION

typedef struct
{
double dist;
double dist, ra, dec, motion_rate, motion_pa;
int norad_number;
char intl_desig[9];
char text[54];
Expand Down Expand Up @@ -155,11 +155,18 @@ static bool my_tles_only = false;
#define NORMAL_VIDEO
#endif

/* Sputnik 1 was launched on 1957 Oct 4. There is no point in
checking for satellites before that date. TLEs, and therefore
this program, won't work after 2057 Jan 1. */

const double oct_4_1957 = 2436115.5;
const double jan_1_2057 = 2472364.5;

static int get_mpc_data( OBSERVATION *obs, const char *buff)
{
obs->jd = extract_date_from_mpc_report( buff, NULL);
if( !obs->jd) /* not an 80-column MPC record */
return( -1);
if( obs->jd < oct_4_1957 || obs->jd > jan_1_2057)
return( -1); /* not an 80-column MPC record */
if( get_ra_dec_from_mpc_report( buff, NULL, &obs->ra, NULL,
NULL, &obs->dec, NULL))
if( 's' != buff[14] && 'v' != buff[14]) /* satellite offsets and */
Expand All @@ -170,6 +177,49 @@ static int get_mpc_data( OBSERVATION *obs, const char *buff)
return( 0);
}

/* If we encounter 'field' data -- we're determining which artsats
are in a field, not which ones match moving objects -- the output
is very different : */

static bool field_mode = false;

/* An imaging field is specified as an image name, date/time, RA and
dec in decimal degrees, and MPC obscode, all comma-separated, such as
MyImage,2023 nov 17 03:14:15.9,271.818,-14.142,T05 */

static int get_field_data( OBSERVATION *obs, const char *buff)
{
int rval = -1;
size_t n_commas, loc[6], i;

for( i = n_commas = 0; buff[i] && n_commas < 5; i++)
if( buff[i] == ',')
loc[n_commas++] = i;
if( n_commas == 4 && strlen( buff) < 80)
{
char tbuff[80];

memcpy( tbuff, buff + loc[0] + 1, loc[1] - loc[0]);
tbuff[loc[1] - loc[0]] = '\0'; /* extract the time */
obs->jd = get_time_from_string( 0., tbuff, 0, NULL);
if( obs->jd > oct_4_1957 && obs->jd < jan_1_2057
&& 2 == sscanf( buff + loc[1] + 1, "%lf,%lf",
&obs->ra, &obs->dec))
{
memcpy( obs->text, buff, loc[0]);
obs->text[loc[0]] = '\0';
obs->ra *= PI / 180.;
obs->dec *= PI / 180.;
memcpy( obs->text + 77, buff + loc[3] + 1, 3);
obs->text[80] = '\0'; /* copy over the three-character MPC code */
field_mode = true;
rval = 0;
}
}
return( rval);
}

/* This loads up the file 'ObsCodes.html' into memory on its first call.
Then, given an MPC code, it finds the corresponding line and copies
it into 'station_code_data'. It looks in several places for the file;
Expand Down Expand Up @@ -388,8 +438,8 @@ static OBSERVATION *get_observations_from_file( FILE *ifile, size_t *n_found,
assert( ades_context);
memset( &obs, 0, sizeof( OBSERVATION));
while( fgets_with_ades_xlation( buff, sizeof( buff), ades_context, ifile))
if( !get_mpc_data( &obs, buff) && obs.jd > t_low
&& obs.jd < t_high
if( (!get_mpc_data( &obs, buff) || !get_field_data( &obs, buff))
&& obs.jd > t_low && obs.jd < t_high
&& (!_target_desig || strstr( buff, _target_desig)))
{
if( buff[14] == 's' || buff[14] == 'v')
Expand Down Expand Up @@ -1061,7 +1111,10 @@ static int add_tle_to_obs( object_t *objects, const size_t n_objects,
temp_array[5] = optr1->dec;
temp_array[6] = optr2->ra; /* ending point (observed) */
temp_array[7] = optr2->dec;
motion_diff = relative_motion( temp_array);
if( !dt)
motion_diff = 0.;
else
motion_diff = relative_motion( temp_array);
motion_diff *= 3600. * 180. / PI; /* cvt to arcseconds */
if( motion_diff < motion_mismatch_limit)
{
Expand Down Expand Up @@ -1127,22 +1180,29 @@ static int add_tle_to_obs( object_t *objects, const size_t n_objects,
dist_to_satellite, radius);
/* "Speed" is displayed in arcminutes/second,
or in degrees/minute */
printf( "%s\n", optr1->text);
printf( "%s", obuff);
if( verbose || !field_mode)
{
printf( "%s\n", optr1->text);
printf( "%s", obuff);
#ifdef SHOW_RA_DEC_OFFSETS
printf( "dRA = %.3f dDec = %.3f\n",
printf( "dRA = %.3f dDec = %.3f\n",
(ra - optr1->ra) * 180. / PI,
(dec - optr1->dec) * 180. / PI);
#endif
}
motion_rate = angular_sep( ra - ra2, dec, dec2, &motion_pa);
motion_rate *= arcminutes_per_radian;
if( dt)
motion_rate /= dt * minutes_per_day;
else
motion_rate /= min_dt * minutes_per_day;
printf( " motion %7.4f\"/sec at PA %5.1f (computed)\n",
if( verbose || !field_mode)
printf( " motion %7.4f\"/sec at PA %5.1f (computed)\n\n",
motion_rate, motion_pa);
printf( "\n");
obj_ptr->matches[i].ra = ra;
obj_ptr->matches[i].dec = dec;
obj_ptr->matches[i].motion_rate = motion_rate;
obj_ptr->matches[i].motion_pa = motion_pa;
}
}
}
Expand Down Expand Up @@ -1368,8 +1428,8 @@ int main( const int argc, const char **argv)
artsat. We don't even bother to check those (unless the -z
option is used to reset this limit). */
double speed_cutoff = 0.001;
double t_low = 2435839.5; /* no satellites before 1957 Jan 1 */
double t_high = 3000000.5;
double t_low = oct_4_1957;
double t_high = jan_1_2057;
int rval, i, j, prev_i;
bool show_summary = false;

Expand Down Expand Up @@ -1493,13 +1553,14 @@ int main( const int argc, const char **argv)
shellsort_r( obs, n_obs, sizeof( obs[0]), compare_obs, NULL);

for( n_objects = i = 0; (size_t)i < n_obs; i++)
if( !i || id_compare( obs + i - 1, obs + i))
if( !i || id_compare( obs + i - 1, obs + i) || field_mode)
n_objects++;
objects = (object_t *)calloc( n_objects, sizeof( object_t));
assert( objects);
printf( "%d objects\n", (int)n_objects);
if( !field_mode)
printf( "%d objects\n", (int)n_objects);
for( n_objects = i = prev_i = 0; (size_t)i < n_obs; i++)
if( !i || id_compare( obs + i - 1, obs + i))
if( !i || id_compare( obs + i - 1, obs + i) || field_mode)
{
objects[n_objects].obs = obs + i;
if( n_objects)
Expand All @@ -1520,7 +1581,10 @@ int main( const int argc, const char **argv)
}
}
n_objects = j;
printf( "%u objects after removing slow ones\n", (unsigned)n_objects);
if( !field_mode)
printf( "%u objects after removing slow ones\n", (unsigned)n_objects);
else
max_revs_per_day = 20.; /* for field-finding, list everything */
rval = add_tle_to_obs( objects, n_objects, tle_file_name, search_radius,
max_revs_per_day);
if( rval)
Expand Down Expand Up @@ -1552,6 +1616,31 @@ int main( const int argc, const char **argv)
printf( "\n%d matched of %d tracklets (%.1f%%)\n", n_matched, (int)n_objects,
(double)n_matched * 100. / (double)n_objects);
}
else if( field_mode)
{
size_t j;
const char *header =
"Field RA (J2000) dec '/min PA NORAD Int'l desig Name";

printf( "%s", header);
for( i = 0; (size_t)i < n_objects; i++)
for( j = 0; j < objects[i].n_matches; j++)
{
double ra = objects[i].matches[j].ra;
double dec = objects[i].matches[j].dec;
char buff[30];

epoch_of_date_to_j2000( objects[i].obs->jd, &ra, &dec);
printf( "\n%-12.12s %7.3f %7.3f %7.2f %5.1f", objects[i].obs->text,
ra * 180. / PI, dec * 180. / PI,
objects[i].matches[j].motion_rate,
objects[i].matches[j].motion_pa);
printf( " %05d %-11s", objects[i].matches[j].norad_number,
unpack_intl( objects[i].matches[j].intl_desig, buff));
printf( "%s", strchr( objects[i].matches[j].text, ':') + 1);
}
printf( "\n%s", header);
}
if( output_astrometry_filename)
{
FILE *ofile = fopen( output_astrometry_filename, "wb");
Expand Down

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