*** ../dfsg/predict-2.2.2/predict.c	Tue Jun 24 15:52:12 2003
--- predict.c	Mon Sep  1 17:51:31 2003
***************
*** 45,50 ****
--- 45,51 ----
  #include <termios.h>
  
  #include "predict.h"
+ int PredictAt ( int iSatID, time_t ttDayNum, double dLat, double dLong );
  
  /* Constants used by SGP4/SDP4 code */
  
***************
*** 2048,2053 ****
--- 2049,2055 ----
  	/* This is the socket server code */
  
  	int i, j, n, sock, alen;
+ 	double dLat, dLong;           /* parameters for PredictAt */
  	struct sockaddr_in fsin;
  	char buf[80], buff[1000], satname[50], tempname[30];
  	time_t t;
***************
*** 2228,2233 ****
--- 2230,2263 ----
  			sendto(sock,buff,strlen(buff),0,(struct sockaddr *)&fsin,sizeof(fsin));
  		}
  
+ 		// calculate the satellite position at a given moment in time...
+ 		if ( strncmp ( "GET_SAT_AT", buf, 10 ) == 0 ) {
+ 		  // get the parameters...
+ 		  sscanf ( &buf[10], "%s %ld %lf %lf", satname, (unsigned long *) &t, &dLat, &dLong );
+ 
+ 		  // find the satellite id
+ 		  for ( i=0; i<24; i++ ) {
+ 		    if ( strcmp ( sat[i].name, satname ) == 0) {
+ 		      //syslog ( LOG_INFO, "%s | %ld\n", sat[i].name, (unsigned long) t );
+ 
+ 		      // get the position
+ 		      PredictAt ( i, t, dLat, dLong );
+ 			       
+ 		      // print out the info...
+ 		      sprintf ( buff, "GOT_SAT_AT %ld %f %f %f %f %ld %f %f\n",   \
+ 				(unsigned long)t,                \
+ 				long_array[i],                   \
+ 				lat_array[i],                    \
+ 				az_array[i],                     \
+ 				el_array[i],                     \
+ 				aos_array[i],                    \
+ 				range_array[i],                  \
+ 				doppler[i] );
+ 		      sendto(sock,buff,strlen(buff),0,(struct sockaddr *)&fsin,sizeof(fsin));
+ 		    }
+ 		  }
+ 		}
+ 
  		if (strncmp("GET_SAT_POS",buf,11)==0)
  		{
  			/* Parse "buf" for satellite name and arguments */
***************
*** 6051,6056 ****
--- 6081,6201 ----
  	return 0;
  }
  
+ double GetDayNum ( struct timeval *tv )
+ {
+   /* used by PredictAt */
+   return ( ( ( (double) (tv->tv_sec) - 0.000001 * ( (double) (tv->tv_usec) ) ) / 86400.0) - 3651.0 );
+ }
+ 
+ /*
+  void PredictAt ( int iSatID, time_t ttDayNum, double dLat, double dLong )
+  
+     Computes the satellites possition at the given time...
+     ... so that we can report it via a socket.
+  
+     Returns:
+        TRUE if successful.
+  
+     Author/Editor:
+        February 2003
+        Glenn Richardson
+        glenn@spacequest.com
+ */
+ 
+ int PredictAt ( int iSatID, time_t ttDayNum, double dLat, double dLong )
+ {
+   double dDayNum;               /* time of prediction */
+   double dOldRange, dOldClock;  /* range / time of pre-prediction position */
+   double dDoppler = 0.0;        /* doppler calculation */
+   double dDeltaTime, dDeltaPos; /* used in doppler calc */
+   double dQLat, dQLong;         /* remember the groundstation lat/long */
+   int iInRange;                 /* is the satellite in view? */
+   struct timeval tv;            /* time structure... */
+ 
+   /* remember... */
+   dQLat = qth.stnlat;
+   dQLong = qth.stnlong;
+   qth.stnlat = dLat;
+   qth.stnlong = dLong;
+ 
+   /* are the keps ok? */
+   if ( ( sat[iSatID].meanmo == 0.0) || ( Decayed ( iSatID, 0.0 ) == 1 ) || ( Geostationary ( iSatID ) ) || !( AosHappens ( iSatID ) ) )
+     {
+       qth.stnlat = dQLat;
+       qth.stnlong = dQLong;
+ 
+       /* !!!! NOTE: we only compute LEOs !!!! */
+       /* syslog ( LOG_INFO, "PredictAT() can't do this one..."); */
+       return FALSE;
+     }
+ 
+   /* syslog ( LOG_INFO, "PredictAT: ttDayNum... %ld, %s", (unsigned long) ttDayNum, ctime ( &ttDayNum ) ); */
+   /* first, prepare for doppler by computing pos 5 sec ago */
+   indx = iSatID;
+   tv.tv_sec = ttDayNum - 5;
+   tv.tv_usec = 0;
+   daynum = GetDayNum ( &tv );
+   PreCalc ( iSatID );
+   Calc ();
+ 
+   dOldClock = 86400.0 * daynum;
+   dOldRange = sat_range * 1000.0;
+ 
+   /* now, recompute at current position */
+   tv.tv_sec = ttDayNum;
+   daynum = GetDayNum ( &tv );
+   PreCalc ( iSatID );
+   Calc ();
+ 
+   dDayNum = daynum;
+ 
+   /* setup for doppler... */
+   dDeltaTime = dDayNum * 86400.0 - dOldClock;
+   dDeltaPos = (sat_range * 1000.0) - dOldRange;
+ 
+   if ( sat_azi >= 0.0 )
+     {
+       iInRange = 1;
+ 
+       /* compute the doppler */
+       dDoppler = - ( ( dDeltaPos / dDeltaTime ) / 299792458.0 );
+       dDoppler = dDoppler * 100.0e6;
+     }
+   else
+     {
+       /* compute the doppler */
+       iInRange = 0;
+     }
+ 
+   /* printf ("InRange? %d, doppler: %f, Az: %f, El: %f, %s",
+               iInRange, dDoppler, azimuth, elevation, ctime ( &ttDayNum ) ); */
+   /* remember values for socket connection... */
+   az_array[iSatID] = sat_azi;
+   el_array[iSatID] = sat_ele;
+   lat_array[iSatID] = sat_lat;
+   long_array[iSatID] = 360.0 - sat_lon;
+   footprint_array[iSatID] = fk;
+   range_array[iSatID] = sat_range;
+   altitude_array[iSatID] = sat_alt;
+   velocity_array[iSatID] = sat_vel;
+   orbitnum_array[iSatID] = rv;
+   doppler[iSatID] = dDoppler;
+ 
+ 
+   /* Calculate Next Event (AOS/LOS) Times */
+   if ( iInRange )
+     nextevent[iSatID] = FindLOS2();
+   else
+     nextevent[iSatID] = FindAOS();
+ 
+ 
+   /* restore... */
+   qth.stnlat = dQLat;
+   qth.stnlong = dQLong;
+ 
+   return TRUE;
+ }
+ 
  int main(argc,argv)
  char argc, *argv[];
  {