--- predict-2.2.1jh4.c	2006-08-05 21:11:43.317306878 -0400
+++ predict-g1yyh.c	2006-08-05 21:16:00.751348441 -0400
@@ -56,6 +56,8 @@
 #define ARRAY_SIZE(a) (sizeof(a) / sizeof(a[0]))
 #define halfdelaytime	10
 
+int PredictAt ( int iSatID, time_t ttDayNum, double dLat, double dLong );
+
 /* Constants used by SGP4/SDP4 code */
 
 #define	km2mi		0.621371		/* km to miles */
@@ -2044,6 +2046,7 @@
 
 	int i, j, n, sock;
 	socklen_t alen;
+	double dLat, dLong;           /* parameters for PredictAt */
 	struct sockaddr_in fsin;
 	char buf[80], buff[1000], satname[50], tempname[30], ok;
 	time_t t;
@@ -2199,6 +2202,34 @@
 			sendto(sock,buff,strlen(buff),0,(struct sockaddr *)&fsin,sizeof(fsin));
 			ok=1;
 		}
+  
+		// 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_TIME$",buf,9)==0) {
 			buff[0]=0;
@@ -6179,6 +6210,121 @@
 	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[];
 {