Added DecayedException. Removed premature check.

libsgp4/DecayedException.h

@@ -0,0 +1,47 @@
+#ifndef DECAYEDEXCEPTION_H_
+#define DECAYEDEXCEPTION_H_
+
+#include <exception>
+#include <iostream>
+#include "Julian.h"
+#include "Vector.h"
+
+class DecayedException : public std::exception
+{
+public:
+    DecayedException(const Julian& dt, const Vector& pos, const Vector& vel)
+        : _dt(dt), _pos(pos), _vel(vel)
+    {
+    }
+
+    virtual ~DecayedException(void) throw ()
+    {
+    }
+
+    virtual const char* what() const throw ()
+    {
+        return "Error: Satellite decayed";
+    }
+
+    Julian GetDate() const
+    {
+        return _dt;
+    }
+
+    Vector GetPosition() const
+    {
+        return _pos;
+    }
+
+    Vector GetVelocity() const
+    {
+        return _vel;
+    }
+
+private:
+    Julian _dt;
+    Vector _pos;
+    Vector _vel;
+};
+
+#endif

libsgp4/SGP4.cpp

@@ -3,6 +3,7 @@
 #include "Util.h"
 #include "Vector.h"
 #include "SatelliteException.h"
+#include "DecayedException.h"
 
 #include <cmath>
 #include <iomanip>
@@ -267,11 +268,6 @@ Eci SGP4::FindPositionSDP4(const Julian& dt, double tsince) const
     xl = xmam + omgadf + xnode;
     omega = omgadf;
 
-    if (a < 1.0)
-    {
-        throw SatelliteException("Error: (a < 1.0)");
-    }
-
     /*
      * fix tolerance for error recognition
      */
@@ -373,11 +369,6 @@ Eci SGP4::FindPositionSGP4(const Julian& dt, double tsince) const
     e = elements_.Eccentricity() - tempe;
     xl = xmp + omega + xnode + elements_.RecoveredMeanMotion() * templ;
 
-    if (a < 1.0)
-    {
-        throw SatelliteException("Error: (a < 1.0)");
-    }
-
     /*
      * fix tolerance for error recognition
      */
@@ -538,11 +529,6 @@ Eci SGP4::CalculateFinalPositionVelocity(const Julian& dt, const double& e,
     const double rdotk = rdot - xn * temp42 * x1mth2 * sin2u;
     const double rfdotk = rfdot + xn * temp42 * (x1mth2 * cos2u + 1.5 * x3thm1);
 
-    if (rk < 1.0)
-    {
-        throw SatelliteException("Error: Satellite decayed (rk < 1.0)");
-    }
-
     /*
      * orientation vectors
      */
@@ -572,6 +558,11 @@ Eci SGP4::CalculateFinalPositionVelocity(const Julian& dt, const double& e,
     const double zdot = (rdotk * uz + rfdotk * vz) * kXKMPER / 60.0;
     Vector velocity(xdot, ydot, zdot);
 
+    if (rk < 1.0)
+    {
+        throw DecayedException(dt, position, velocity);
+    }
+
     Eci eci(dt, position, velocity);
 
     return eci;

libsgp4/SGP4.h

@@ -5,6 +5,7 @@
 #include "OrbitalElements.h"
 #include "Eci.h"
 #include "SatelliteException.h"
+#include "DecayedException.h"
 
 class SGP4
 {

runtest/runtest.cpp

@@ -27,31 +27,59 @@ void RunTle(Tle tle, double start, double end, double inc)
 
     while (running)
     {
+        bool error = false;
+        Vector position;
+        Vector velocity;
+        double tsince;
+
         try
         {
-            double val;
             if (first_run && current != 0.0) 
             {
                 /*
                  * make sure first run is always as zero
                  */
-                val = 0.0;
+                tsince = 0.0;
             }
             else
             {
                 /*
                  * otherwise run as normal
                  */
-                val = current;
+                tsince = current;
             }
-            Eci eci = model.FindPosition(val);
 
-            Vector position = eci.GetPosition();
+            Eci eci = model.FindPosition(tsince);
-            Vector velocity = eci.GetVelocity();
+            position = eci.GetPosition();
+            velocity = eci.GetVelocity();
+        }
+        catch (SatelliteException& e)
+        {
+            std::cerr << e.what() << std::endl;
+            error = true;
+            running = false;
+        }
+        catch (DecayedException& e)
+        {
+            std::cerr << e.what() << std::endl;
 
+            position = e.GetPosition();
+            velocity = e.GetVelocity();
+
+            if (!first_run)
+            {
+                // print out position on first run
+                error = true;
+            }
+
+            running = false;
+        }
+
+        if (!error)
+        {
             std::cout << std::setprecision(8) << std::fixed;
             std::cout.width(17);
-            std::cout << val << " ";
+            std::cout << tsince << " ";
             std::cout.width(16);
             std::cout << position.x << " ";
             std::cout.width(16);
@@ -65,12 +93,8 @@ void RunTle(Tle tle, double start, double end, double inc)
             std::cout << velocity.y << " ";
             std::cout.width(14);
             std::cout << velocity.z << std::endl;
+        }
 
-        }
-        catch (SatelliteException& e)
-        {
-            running = false;
-        }
         if ((first_run && current == 0.0) || !first_run)
         {
             if (current == end)
@@ -87,7 +111,6 @@ void RunTle(Tle tle, double start, double end, double inc)
             }
         }
         first_run = false;
-
     }
 }