diff --git a/configure b/configure
index efc3c3c..4485af5 100755
--- a/configure
+++ b/configure
@@ -3234,9 +3234,9 @@ fi
 
 
 if test x$enable_debug = xyes; then
-  AM_CXXFLAGS="-g       -O0                      -Werror -Wextra -W -Wall -Wconversion"
+  AM_CXXFLAGS="-g       -O0                      -Wextra -W -Wall -Wconversion -std=c++11"
 else
-  AM_CXXFLAGS="-DNDEBUG -O2 -fomit-frame-pointer -Wextra -Werror -W -Wall -Wconversion"
+  AM_CXXFLAGS="-DNDEBUG -O2 -fomit-frame-pointer -Wextra -W -Wall -Wconversion -std=c++11"
 fi
 
 ac_ext=c
diff --git a/configure.ac b/configure.ac
index 4130a4f..2d6c35b 100644
--- a/configure.ac
+++ b/configure.ac
@@ -19,9 +19,9 @@ AC_ARG_ENABLE(debug,
               enable_debug=no)
 
 if test x$enable_debug = xyes; then
-  AM_CXXFLAGS="-g       -O0                      -Werror -Wextra -W -Wall -Wconversion"
+  AM_CXXFLAGS="-g       -O0                      -Wextra -W -Wall -Wconversion -std=c++11"
 else
-  AM_CXXFLAGS="-DNDEBUG -O2 -fomit-frame-pointer -Wextra -Werror -W -Wall -Wconversion"
+  AM_CXXFLAGS="-DNDEBUG -O2 -fomit-frame-pointer -Wextra -W -Wall -Wconversion -std=c++11"
 fi
 
 AC_SEARCH_LIBS([clock_gettime],
diff --git a/libsgp4/CoordGeodetic.h b/libsgp4/CoordGeodetic.h
index d7c3b14..689c000 100644
--- a/libsgp4/CoordGeodetic.h
+++ b/libsgp4/CoordGeodetic.h
@@ -79,13 +79,6 @@ public:
         altitude = geo.altitude;
     }
 
-    /**
-     * Destructor
-     */
-    virtual ~CoordGeodetic()
-    {
-    }
-
     /**
      * Assignment operator
      * @param[in] geo object to copy from
@@ -158,8 +151,8 @@ private:
 
 /**
  * Dump a Coordgeodetic to a stream
- * @params[in,out] strm stream to output to
- * @params[in] g the CoordGeodetic to print
+ * @param[in,out] strm stream to output to
+ * @param[in] g the CoordGeodetic to print
  */
 inline std::ostream& operator<<(std::ostream& strm, const CoordGeodetic& g)
 {
diff --git a/libsgp4/CoordTopocentric.h b/libsgp4/CoordTopocentric.h
index 04fd6c7..42fbeb4 100644
--- a/libsgp4/CoordTopocentric.h
+++ b/libsgp4/CoordTopocentric.h
@@ -31,17 +31,17 @@
  * Azimuth and elevation are stored in radians. Range in kilometres. Range
  * rate in kilometres/second.
  */
-struct CoordTopocentric
+struct CoordTopocentric final
 {
 public:
     /**
      * Default constructor
      */
     CoordTopocentric()
-        : azimuth(0.0), 
-        elevation(0.0),
-        range(0.0),
-        range_rate(0.0)
+        : azimuth(0.0)
+        , elevation(0.0)
+        , range(0.0)
+        , range_rate(0.0)
     {
     }
 
@@ -57,10 +57,10 @@ public:
             double el,
             double rnge,
             double rnge_rate)
-        : azimuth(az),
-        elevation(el),
-        range(rnge),
-        range_rate(rnge_rate)
+        : azimuth(az)
+        , elevation(el)
+        , range(rnge)
+        , range_rate(rnge_rate)
     {
     }
 
@@ -76,13 +76,6 @@ public:
         range_rate = topo.range_rate;
     }
 
-    /**
-     * Destructor
-     */
-    virtual ~CoordTopocentric()
-    {
-    }
-
     /**
      * Assignment operator
      * @param[in] topo object to copy from
diff --git a/libsgp4/DateTime.h b/libsgp4/DateTime.h
index 40679df..cac0ea6 100644
--- a/libsgp4/DateTime.h
+++ b/libsgp4/DateTime.h
@@ -21,6 +21,7 @@
 #include <iomanip>
 #include <iostream>
 #include <sstream>
+#include <cstdint>
 #include "TimeSpan.h"
 #include "Util.h"
 
@@ -57,7 +58,7 @@ public:
      * Constructor
      * @param[in] ticks raw tick value
      */
-    DateTime(unsigned long long ticks)
+    DateTime(int64_t ticks)
         : m_encoded(ticks)
     {
     }
@@ -67,9 +68,10 @@ public:
      * @param[in] year the year
      * @param[in] doy the day of the year
      */
-    DateTime(int year, double doy)
+    DateTime(unsigned int year, double doy)
     {
-        m_encoded = TimeSpan(static_cast<long long int>(AbsoluteDays(year, doy) * TicksPerDay)).Ticks();
+        m_encoded = TimeSpan(
+                static_cast<int64_t>(AbsoluteDays(year, doy) * TicksPerDay)).Ticks();
     }
 
     /**
@@ -298,10 +300,9 @@ public:
     /**
      *
      */
-    double AbsoluteDays(int year, double doy) const
+    double AbsoluteDays(unsigned int year, double doy) const
     {
-
-        int previousYear = year - 1;
+        int64_t previousYear = year - 1;
 
         /*
          * + days in previous years ignoring leap days
@@ -309,10 +310,10 @@ public:
          * - minus prior century years
          * + plus prior years divisible by 400 days
          */
-        long long daysSoFar = 365 * previousYear
-            + previousYear / 4
-            - previousYear / 100
-            + previousYear / 400;
+        int64_t daysSoFar = 365 * previousYear
+            + previousYear / 4LL
+            - previousYear / 100LL
+            + previousYear / 400LL;
 
         return static_cast<double>(daysSoFar) + doy - 1.0;
     }
@@ -441,11 +442,11 @@ public:
 
     DateTime AddMicroseconds(const double microseconds) const
     {
-        long long ticks = static_cast<long long>(microseconds * TicksPerMicrosecond);
+        int64_t ticks = static_cast<int64_t>(microseconds * TicksPerMicrosecond);
         return AddTicks(ticks);
     }
 
-    DateTime AddTicks(long long ticks) const
+    DateTime AddTicks(int64_t ticks) const
     {
         return DateTime(m_encoded + ticks);
     }
@@ -454,7 +455,7 @@ public:
      * Get the number of ticks
      * @returns the number of ticks
      */
-    long long Ticks() const
+    int64_t Ticks() const
     {
         return m_encoded;
     }
@@ -646,7 +647,7 @@ public:
     }
 
 private:
-    unsigned long long m_encoded;
+    int64_t m_encoded;
 };
 
 inline std::ostream& operator<<(std::ostream& strm, const DateTime& dt)
@@ -656,24 +657,12 @@ inline std::ostream& operator<<(std::ostream& strm, const DateTime& dt)
 
 inline DateTime operator+(const DateTime& dt, TimeSpan ts)
 {
-    long long int res = dt.Ticks() + ts.Ticks();
-    if (res < 0 || res > MaxValueTicks)
-    {
-           throw 1;
-    }
-
-    return DateTime(res);
+    return DateTime(dt.Ticks() + ts.Ticks());
 }
 
 inline DateTime operator-(const DateTime& dt, const TimeSpan& ts)
 {
-    long long int res = dt.Ticks() - ts.Ticks();
-    if (res < 0 || res > MaxValueTicks)
-    {
-        throw 1;
-    }
-
-    return DateTime(res);
+    return DateTime(dt.Ticks() - ts.Ticks());
 }
 
 inline TimeSpan operator-(const DateTime& dt1, const DateTime& dt2)
diff --git a/libsgp4/DecayedException.cpp b/libsgp4/DecayedException.cpp
new file mode 100644
index 0000000..2d344f7
--- /dev/null
+++ b/libsgp4/DecayedException.cpp
@@ -0,0 +1,5 @@
+#include "DecayedException.h"
+
+DecayedException::~DecayedException()
+{
+}
diff --git a/libsgp4/DecayedException.h b/libsgp4/DecayedException.h
index a8846e4..8dc2678 100644
--- a/libsgp4/DecayedException.h
+++ b/libsgp4/DecayedException.h
@@ -21,12 +21,13 @@
 #include "DateTime.h"
 #include "Vector.h"
 
-#include <exception>
+#include <stdexcept>
+#include <string>
 
 /**
  * @brief The exception that the SGP4 class throws when a satellite decays.
  */
-class DecayedException : public std::exception
+class DecayedException : public std::runtime_error
 {
 public:
     /**
@@ -36,24 +37,16 @@ public:
      * @param[in] vel velocity of the satellite at dt
      */
     DecayedException(const DateTime& dt, const Vector& pos, const Vector& vel)
-        : _dt(dt), _pos(pos), _vel(vel)
+        : runtime_error("Satellite decayed")
+        , _dt(dt)
+        , _pos(pos)
+        , _vel(vel)
     {
     }
 
-    /**
-     * Destructor
-     */
-    virtual ~DecayedException(void) throw ()
-    {
-    }
+    DecayedException(const DecayedException&) = default;
 
-    /**
-     * @returns the error string
-     */
-    virtual const char* what() const throw ()
-    {
-        return "Error: Satellite decayed";
-    }
+    virtual ~DecayedException();
 
     /**
      * @returns the date
diff --git a/libsgp4/Eci.h b/libsgp4/Eci.h
index b3698c2..1a6bd71 100644
--- a/libsgp4/Eci.h
+++ b/libsgp4/Eci.h
@@ -54,11 +54,11 @@ public:
 
     /**
      * @param[in] dt the date to be used for this position
-     * @param[in] position
+     * @param[in] position the position
      */
     Eci(const DateTime &dt, const Vector &position)
-        : m_dt(dt),
-        m_position(position)
+        : m_dt(dt)
+        , m_position(position)
     {
     }
 
@@ -68,16 +68,9 @@ public:
      * @param[in] velocity the velocity
      */
     Eci(const DateTime &dt, const Vector &position, const Vector &velocity)
-        : m_dt(dt),
-        m_position(position),
-        m_velocity(velocity)
-    {
-    }
-
-    /**
-     * Destructor
-     */
-    virtual ~Eci()
+        : m_dt(dt)
+        , m_position(position)
+        , m_velocity(velocity)
     {
     }
 
diff --git a/libsgp4/Makefile.am b/libsgp4/Makefile.am
index 7342273..ab13685 100644
--- a/libsgp4/Makefile.am
+++ b/libsgp4/Makefile.am
@@ -7,6 +7,9 @@ libsgp4_a_SOURCES = \
 	Globals.cpp          \
 	Observer.cpp         \
 	OrbitalElements.cpp  \
+	DecayedException.cpp \
+	SatelliteException.cpp \
+	TleException.cpp     \
 	SGP4.cpp             \
 	SolarPosition.cpp    \
 	TimeSpan.cpp         \
@@ -14,7 +17,7 @@ libsgp4_a_SOURCES = \
 	Util.cpp             \
 	Vector.cpp
 
-include_HEADERS =  \
+include_HEADERS =        \
 	CoordGeodetic.h      \
 	CoordTopocentric.h   \
 	DateTime.h           \
diff --git a/libsgp4/Makefile.in b/libsgp4/Makefile.in
index e52998e..384f3e0 100644
--- a/libsgp4/Makefile.in
+++ b/libsgp4/Makefile.in
@@ -102,8 +102,10 @@ libsgp4_a_LIBADD =
 am_libsgp4_a_OBJECTS = CoordGeodetic.$(OBJEXT) \
 	CoordTopocentric.$(OBJEXT) DateTime.$(OBJEXT) Eci.$(OBJEXT) \
 	Globals.$(OBJEXT) Observer.$(OBJEXT) OrbitalElements.$(OBJEXT) \
-	SGP4.$(OBJEXT) SolarPosition.$(OBJEXT) TimeSpan.$(OBJEXT) \
-	Tle.$(OBJEXT) Util.$(OBJEXT) Vector.$(OBJEXT)
+	DecayedException.$(OBJEXT) SatelliteException.$(OBJEXT) \
+	TleException.$(OBJEXT) SGP4.$(OBJEXT) SolarPosition.$(OBJEXT) \
+	TimeSpan.$(OBJEXT) Tle.$(OBJEXT) Util.$(OBJEXT) \
+	Vector.$(OBJEXT)
 libsgp4_a_OBJECTS = $(am_libsgp4_a_OBJECTS)
 DEFAULT_INCLUDES = -I.@am__isrc@
 depcomp = $(SHELL) $(top_srcdir)/depcomp
@@ -233,6 +235,9 @@ libsgp4_a_SOURCES = \
 	Globals.cpp          \
 	Observer.cpp         \
 	OrbitalElements.cpp  \
+	DecayedException.cpp \
+	SatelliteException.cpp \
+	TleException.cpp     \
 	SGP4.cpp             \
 	SolarPosition.cpp    \
 	TimeSpan.cpp         \
@@ -337,14 +342,17 @@ distclean-compile:
 @AMDEP_TRUE@@am__include@ @am__quote@./$(DEPDIR)/CoordGeodetic.Po@am__quote@
 @AMDEP_TRUE@@am__include@ @am__quote@./$(DEPDIR)/CoordTopocentric.Po@am__quote@
 @AMDEP_TRUE@@am__include@ @am__quote@./$(DEPDIR)/DateTime.Po@am__quote@
+@AMDEP_TRUE@@am__include@ @am__quote@./$(DEPDIR)/DecayedException.Po@am__quote@
 @AMDEP_TRUE@@am__include@ @am__quote@./$(DEPDIR)/Eci.Po@am__quote@
 @AMDEP_TRUE@@am__include@ @am__quote@./$(DEPDIR)/Globals.Po@am__quote@
 @AMDEP_TRUE@@am__include@ @am__quote@./$(DEPDIR)/Observer.Po@am__quote@
 @AMDEP_TRUE@@am__include@ @am__quote@./$(DEPDIR)/OrbitalElements.Po@am__quote@
 @AMDEP_TRUE@@am__include@ @am__quote@./$(DEPDIR)/SGP4.Po@am__quote@
+@AMDEP_TRUE@@am__include@ @am__quote@./$(DEPDIR)/SatelliteException.Po@am__quote@
 @AMDEP_TRUE@@am__include@ @am__quote@./$(DEPDIR)/SolarPosition.Po@am__quote@
 @AMDEP_TRUE@@am__include@ @am__quote@./$(DEPDIR)/TimeSpan.Po@am__quote@
 @AMDEP_TRUE@@am__include@ @am__quote@./$(DEPDIR)/Tle.Po@am__quote@
+@AMDEP_TRUE@@am__include@ @am__quote@./$(DEPDIR)/TleException.Po@am__quote@
 @AMDEP_TRUE@@am__include@ @am__quote@./$(DEPDIR)/Util.Po@am__quote@
 @AMDEP_TRUE@@am__include@ @am__quote@./$(DEPDIR)/Vector.Po@am__quote@
 
diff --git a/libsgp4/Observer.h b/libsgp4/Observer.h
index a3151ea..16238f4 100644
--- a/libsgp4/Observer.h
+++ b/libsgp4/Observer.h
@@ -39,8 +39,8 @@ public:
     Observer(const double latitude,
             const double longitude,
             const double altitude)
-        : m_geo(latitude, longitude, altitude),
-        m_eci(DateTime(), m_geo)
+        : m_geo(latitude, longitude, altitude)
+        , m_eci(DateTime(), m_geo)
     {
     }
 
@@ -49,15 +49,8 @@ public:
      * @param[in] geo the observers position
      */
     Observer(const CoordGeodetic &geo)
-        : m_geo(geo),
-        m_eci(DateTime(), geo)
-    {
-    }
-
-    /**
-     * Destructor
-     */
-    virtual ~Observer()
+        : m_geo(geo)
+        , m_eci(DateTime(), geo)
     {
     }
 
diff --git a/libsgp4/OrbitalElements.h b/libsgp4/OrbitalElements.h
index 3c9d14e..e11e2c6 100644
--- a/libsgp4/OrbitalElements.h
+++ b/libsgp4/OrbitalElements.h
@@ -31,10 +31,6 @@ class OrbitalElements
 public:
     OrbitalElements(const Tle& tle);
 
-    virtual ~OrbitalElements()
-    {
-    }
-
     /*
      * XMO
      */
diff --git a/libsgp4/SGP4.cpp b/libsgp4/SGP4.cpp
index 1df622f..e8f0b50 100644
--- a/libsgp4/SGP4.cpp
+++ b/libsgp4/SGP4.cpp
@@ -215,8 +215,6 @@ void SGP4::Initialise()
     }
 }
 
-#include <iomanip>
-
 Eci SGP4::FindPosition(const DateTime& dt) const
 {
     return FindPosition((dt - elements_.Epoch()).TotalMinutes());
@@ -433,23 +431,6 @@ Eci SGP4::FindPositionSGP4(double tsince) const
 
 }
 
-/**
- * @param[in] tsince
- * @param[in] e
- * @param[in] a
- * @param[in] omega
- * @param[in] xl
- * @param[in] xnode
- * @param[in] xincl
- * @param[in] xlcof
- * @param[in] aycof
- * @param[in] x3thml
- * @param[in] x1mth2
- * @param[in] x7thm1
- * @param[in] cosio
- * @param[in] sinio
- * @returns Eci result
- */
 Eci SGP4::CalculateFinalPositionVelocity(
         const double tsince,
         const double e,
@@ -633,14 +614,6 @@ Eci SGP4::CalculateFinalPositionVelocity(
     return Eci(elements_.Epoch().AddMinutes(tsince), position, velocity);
 }
 
-/**
- * @param[in] x
- * @param[in] constant
- * @param[in] linear
- * @param[in] squared
- * @param[in] cubed
- * @returns result
- */
 static inline double EvaluateCubicPolynomial(
         const double x,
         const double constant,
@@ -651,18 +624,6 @@ static inline double EvaluateCubicPolynomial(
     return constant + x * (linear + x * (squared + x * cubed));
 }
 
-/**
- * Deep space initialisation
- * @param[in] eosq
- * @param[in] sinio
- * @param[in] cosio
- * @param[in] betao
- * @param[in] theta2
- * @param[in] betao2
- * @param[in] xmdot
- * @param[in] omgdot
- * @param[in] xnodot
- */
 void SGP4::DeepSpaceInitialise(
         const double eosq,
         const double sinio,
@@ -1073,15 +1034,6 @@ void SGP4::DeepSpaceInitialise(
     }
 }
 
-/*
- * Calculate lunar / solar terms
- * @param[in]  tsince
- * @param[out] pe
- * @param[out] pinc
- * @param[out] pl
- * @param[out] pgh
- * @param[out] ph
- */
 void SGP4::DeepSpaceCalculateLunarSolarTerms(
         const double tsince,
         double& pe,
@@ -1149,15 +1101,6 @@ void SGP4::DeepSpaceCalculateLunarSolarTerms(
     ph = shs + shl;
 }
 
-/*
- * Calculate lunar / solar periodics and apply
- * @param[in]     tsince
- * @param[in,out] em
- * @param[in,out] xinc
- * @param[in,out] omgasm
- * @param[in,out] xnodes
- * @param[in,out] xll
- */
 void SGP4::DeepSpacePeriodics(
         const double tsince,
         double& em,
@@ -1261,16 +1204,6 @@ void SGP4::DeepSpacePeriodics(
     }
 }
 
-/*
- * Deep space secular effects
- * @param[in]     tsince
- * @param[in,out] xll
- * @param[in,out] omgasm
- * @param[in,out] xnodes
- * @param[in,out] em
- * @param[in,out] xinc
- * @param[in,out] xn
- */
 void SGP4::DeepSpaceSecular(
         const double tsince,
         double& xll,
@@ -1372,10 +1305,6 @@ void SGP4::DeepSpaceSecular(
     }
 }
 
-/*
- * Calculate dot terms
- * @param[in,out] the integrator values
- */
 void SGP4::DeepSpaceCalcDotTerms(struct IntegratorValues& values) const
 {
     static const double G22 = 5.7686396;
@@ -1455,12 +1384,6 @@ void SGP4::DeepSpaceCalcDotTerms(struct IntegratorValues& values) const
     values.xnddt *= values.xldot;
 }
 
-/*
- * Deep space integrator for time period of delt
- * @param[in] delt
- * @param[in] step2
- * @param[in] values
- */
 void SGP4::DeepSpaceIntegrator(
         const double delt,
         const double step2,
diff --git a/libsgp4/SGP4.h b/libsgp4/SGP4.h
index f6b4e01..cd11d41 100644
--- a/libsgp4/SGP4.h
+++ b/libsgp4/SGP4.h
@@ -33,7 +33,7 @@
 /**
  * @brief The simplified perturbations model 4 propagater.
  */
-class SGP4
+class SGP4 final
 {
 public:
     SGP4(const Tle& tle)
@@ -42,10 +42,6 @@ public:
         Initialise();
     }
 
-    virtual ~SGP4()
-    {
-    }
-
     void SetTle(const Tle& tle);
     Eci FindPosition(double tsince) const;
     Eci FindPosition(const DateTime& date) const;
@@ -91,16 +87,7 @@ private:
         double gsto;
         double zmol;
         double zmos;
-        /*
-         * whether the deep space orbit is
-         * geopotential resonance for 12 hour orbits
-         */
-        bool resonance_flag;
-        /*
-         * whether the deep space orbit is
-         * 24h synchronous resonance
-         */
-        bool synchronous_flag;
+
         /*
          * lunar / solar constants for epoch
          * applied during DeepSpaceSecular()
@@ -154,6 +141,16 @@ private:
         double del1;
         double del2;
         double del3;
+        /*
+         * whether the deep space orbit is
+         * geopotential resonance for 12 hour orbits
+         */
+        bool resonance_flag;
+        /*
+         * whether the deep space orbit is
+         * 24h synchronous resonance
+         */
+        bool synchronous_flag;
     };
 
     struct IntegratorValues
@@ -209,6 +206,9 @@ private:
             const double x7thm1,
             const double cosio,
             const double sinio) const;
+    /**
+     * Deep space initialisation
+     */
     void DeepSpaceInitialise(
             const double eosq,
             const double sinio,
@@ -219,6 +219,9 @@ private:
             const double xmdot,
             const double omgdot,
             const double xnodot);
+    /*
+     * Calculate lunar / solar terms
+     */
     void DeepSpaceCalculateLunarSolarTerms(
             const double tsince,
             double& pe,
@@ -226,6 +229,9 @@ private:
             double& pl,
             double& pgh,
             double& ph) const;
+    /**
+     * Calculate lunar / solar periodics and apply
+     */
     void DeepSpacePeriodics(
             const double tsince,
             double& em,
@@ -233,6 +239,9 @@ private:
             double& omgasm,
             double& xnodes,
             double& xll) const;
+    /**
+     * Deep space secular effects
+     */
     void DeepSpaceSecular(
             const double tsince,
             double& xll,
@@ -241,19 +250,20 @@ private:
             double& em,
             double& xinc,
             double& xn) const;
+    /**
+     * Calculate dot terms
+     * @param[in,out] values the integrator values
+     */
     void DeepSpaceCalcDotTerms(struct IntegratorValues& values) const;
+    /**
+     * Deep space integrator for time period of delt
+     */
     void DeepSpaceIntegrator(
             const double delt,
             const double step2,
             const struct IntegratorValues& values) const;
     void Reset();
 
-    /*
-     * flags
-     */
-    bool use_simple_model_;
-    bool use_deep_space_;
-
     /*
      * the constants used
      */
@@ -268,6 +278,12 @@ private:
      */
     OrbitalElements elements_;
 
+    /*
+     * flags
+     */
+    bool use_simple_model_;
+    bool use_deep_space_;
+
     static const struct SGP4::CommonConstants Empty_CommonConstants;
     static const struct SGP4::NearSpaceConstants Empty_NearSpaceConstants;
     static const struct SGP4::DeepSpaceConstants Empty_DeepSpaceConstants;
diff --git a/libsgp4/SatelliteException.cpp b/libsgp4/SatelliteException.cpp
new file mode 100644
index 0000000..841536c
--- /dev/null
+++ b/libsgp4/SatelliteException.cpp
@@ -0,0 +1,5 @@
+#include "SatelliteException.h"
+
+SatelliteException::~SatelliteException()
+{
+}
diff --git a/libsgp4/SatelliteException.h b/libsgp4/SatelliteException.h
index 45320ed..b1e718c 100644
--- a/libsgp4/SatelliteException.h
+++ b/libsgp4/SatelliteException.h
@@ -18,30 +18,23 @@
 #ifndef SATELLITEEXCEPTION_H_
 #define SATELLITEEXCEPTION_H_
 
-#include <exception>
+#include <stdexcept>
+#include <string>
 
 /**
  * @brief The exception that the SGP4 class throws upon an error.
  */
-class SatelliteException : public std::exception
+class SatelliteException : public std::runtime_error
 {
 public:
     SatelliteException(const char* message)
-        : message_(message)
+        : runtime_error(message)
     {
     }
 
-    virtual ~SatelliteException(void) throw ()
-    {
-    }
+    SatelliteException(const SatelliteException&) = default;
 
-    virtual const char* what() const throw ()
-    {
-        return message_.c_str();
-    }
-
-private:
-    std::string message_;
+    virtual ~SatelliteException();
 };
 
 #endif
diff --git a/libsgp4/SolarPosition.h b/libsgp4/SolarPosition.h
index f2629e5..e74c548 100644
--- a/libsgp4/SolarPosition.h
+++ b/libsgp4/SolarPosition.h
@@ -31,10 +31,6 @@ public:
     {
     }
 
-    virtual ~SolarPosition()
-    {
-    }
-
     Eci FindPosition(const DateTime& dt);
 
 private:
diff --git a/libsgp4/TimeSpan.h b/libsgp4/TimeSpan.h
index 2cde2c8..671bc26 100644
--- a/libsgp4/TimeSpan.h
+++ b/libsgp4/TimeSpan.h
@@ -22,22 +22,23 @@
 #include <sstream>
 #include <iomanip>
 #include <cmath>
+#include <cstdint>
 
 namespace
 {
-    static const long long TicksPerDay =  86400000000LL;
-    static const long long TicksPerHour =  3600000000LL;
-    static const long long TicksPerMinute =  60000000LL;
-    static const long long TicksPerSecond =   1000000LL;
-    static const long long TicksPerMillisecond = 1000LL;
-    static const long long TicksPerMicrosecond =    1LL;
+    static const int64_t TicksPerDay =  86400000000LL;
+    static const int64_t TicksPerHour =  3600000000LL;
+    static const int64_t TicksPerMinute =  60000000LL;
+    static const int64_t TicksPerSecond =   1000000LL;
+    static const int64_t TicksPerMillisecond = 1000LL;
+    static const int64_t TicksPerMicrosecond =    1LL;
 
-    static const long long UnixEpoch = 62135596800000000LL;
+    static const int64_t UnixEpoch = 62135596800000000LL;
 
-    static const long long MaxValueTicks = 315537897599999999LL;
+    static const int64_t MaxValueTicks = 315537897599999999LL;
 
     // 1582-Oct-15
-    static const long long GregorianStart = 49916304000000000LL;
+    static const int64_t GregorianStart = 49916304000000000LL;
 }
 
 /**
@@ -50,7 +51,7 @@ namespace
 class TimeSpan
 {
 public:
-    TimeSpan(long long ticks)
+    TimeSpan(int64_t ticks)
         : m_ticks(ticks)
     {
     }
@@ -130,7 +131,7 @@ public:
         return static_cast<int>(m_ticks % TicksPerSecond / TicksPerMicrosecond);
     }
 
-    long long Ticks() const
+    int64_t Ticks() const
     {
         return m_ticks;
     }
@@ -194,7 +195,7 @@ public:
     }
 
 private:
-    long long m_ticks;
+    int64_t m_ticks;
 
     void CalculateTicks(int days,
             int hours,
diff --git a/libsgp4/Tle.cpp b/libsgp4/Tle.cpp
index 599d1a9..b7f6cd3 100644
--- a/libsgp4/Tle.cpp
+++ b/libsgp4/Tle.cpp
@@ -25,9 +25,9 @@ namespace
     static const unsigned int TLE1_LEN_NORADNUM = 5;
     static const unsigned int TLE1_COL_INTLDESC_A = 9;
     static const unsigned int TLE1_LEN_INTLDESC_A = 2;
-    static const unsigned int TLE1_COL_INTLDESC_B = 11;
+//  static const unsigned int TLE1_COL_INTLDESC_B = 11;
     static const unsigned int TLE1_LEN_INTLDESC_B = 3;
-    static const unsigned int TLE1_COL_INTLDESC_C = 14;
+//  static const unsigned int TLE1_COL_INTLDESC_C = 14;
     static const unsigned int TLE1_LEN_INTLDESC_C = 3;
     static const unsigned int TLE1_COL_EPOCH_A = 18;
     static const unsigned int TLE1_LEN_EPOCH_A = 2;
@@ -39,10 +39,10 @@ namespace
     static const unsigned int TLE1_LEN_MEANMOTIONDDT6 = 8;
     static const unsigned int TLE1_COL_BSTAR = 53;
     static const unsigned int TLE1_LEN_BSTAR = 8;
-    static const unsigned int TLE1_COL_EPHEMTYPE = 62;
-    static const unsigned int TLE1_LEN_EPHEMTYPE = 1;
-    static const unsigned int TLE1_COL_ELNUM = 64;
-    static const unsigned int TLE1_LEN_ELNUM = 4;
+//  static const unsigned int TLE1_COL_EPHEMTYPE = 62;
+//  static const unsigned int TLE1_LEN_EPHEMTYPE = 1;
+//  static const unsigned int TLE1_COL_ELNUM = 64;
+//  static const unsigned int TLE1_LEN_ELNUM = 4;
 
     static const unsigned int TLE2_COL_NORADNUM = 2;
     static const unsigned int TLE2_LEN_NORADNUM = 5;
@@ -147,6 +147,7 @@ void Tle::Initialize()
         year += 2000;
     else
         year += 1900;
+
     epoch_ = DateTime(year, day);
 }
 
@@ -176,7 +177,7 @@ void Tle::ExtractInteger(const std::string& str, unsigned int& val)
         if (isdigit(*i))
         {
             found_digit = true;
-            temp = (temp * 10) + (*i - '0');
+            temp = (temp * 10) + (static_cast<unsigned char>(*i) - '0');
         }
         else if (found_digit)
         {
@@ -335,7 +336,7 @@ void Tle::ExtractExponential(const std::string& str, double& val)
                 throw TleException("Invalid sign");
             }
         }
-        else if (i == str.begin() + str.length() - 2)
+        else if (i == str.end() - 2)
         {
             if (*i == '-' || *i == '+')
             {
diff --git a/libsgp4/Tle.h b/libsgp4/Tle.h
index 408799a..60122bc 100644
--- a/libsgp4/Tle.h
+++ b/libsgp4/Tle.h
@@ -37,8 +37,8 @@ public:
      */
     Tle(const std::string& line_one,
             const std::string& line_two)
-        : line_one_(line_one),
-        line_two_(line_two)
+        : line_one_(line_one)
+        , line_two_(line_two)
     {
         Initialize();
     }
@@ -52,9 +52,9 @@ public:
     Tle(const std::string& name,
             const std::string& line_one,
             const std::string& line_two)
-        : name_(name),
-        line_one_(line_one),
-        line_two_(line_two)
+        : name_(name)
+        , line_one_(line_one)
+        , line_two_(line_two)
     {
         Initialize();
     }
@@ -84,13 +84,6 @@ public:
         orbit_number_ = tle.orbit_number_;
     }
 
-    /**
-     * Destructor
-     */
-    virtual ~Tle()
-    {
-    }
-
     /**
      * Get the satellite name
      * @returns the satellite name
@@ -322,7 +315,6 @@ private:
     std::string line_one_;
     std::string line_two_;
 
-    unsigned int norad_number_;
     std::string int_designator_;
     DateTime epoch_;
     double mean_motion_dt2_;
@@ -334,6 +326,7 @@ private:
     double argument_perigee_;
     double mean_anomaly_;
     double mean_motion_;
+    unsigned int norad_number_;
     unsigned int orbit_number_;
 
     static const unsigned int TLE_LEN_LINE_DATA = 69;
diff --git a/libsgp4/TleException.cpp b/libsgp4/TleException.cpp
new file mode 100644
index 0000000..06c5c52
--- /dev/null
+++ b/libsgp4/TleException.cpp
@@ -0,0 +1,5 @@
+#include "TleException.h"
+
+TleException::~TleException()
+{
+}
diff --git a/libsgp4/TleException.h b/libsgp4/TleException.h
index 607e620..034ae5b 100644
--- a/libsgp4/TleException.h
+++ b/libsgp4/TleException.h
@@ -18,14 +18,15 @@
 #ifndef TLEEXCEPTION_H_
 #define TLEEXCEPTION_H_
 
-#include <exception>
+#include <stdexcept>
+#include <string>
 
 /**
  * @brief The exception that the Tle class throws on an error.
  *
  * The exception that the Tle decoder will throw on an error.
  */
-class TleException : public std::exception
+class TleException : public std::runtime_error
 {
 public:
     /**
@@ -33,29 +34,13 @@ public:
      * @param message Exception message
      */
     TleException(const char* message)
-        : m_message(message)
+        : runtime_error(message)
     {
     }
 
-    /**
-     * Destructor
-     */
-    virtual ~TleException(void) throw ()
-    {
-    }
+    TleException(const TleException&) = default;
 
-    /**
-     * Get the exception message
-     * @returns the exception message
-     */
-    virtual const char* what() const throw ()
-    {
-        return m_message.c_str();
-    }
-
-private:
-    /** the exception message */
-    std::string m_message;
+    virtual ~TleException();
 };
 
 #endif
diff --git a/libsgp4/Util.h b/libsgp4/Util.h
index 2b7e6ff..fd79bc6 100644
--- a/libsgp4/Util.h
+++ b/libsgp4/Util.h
@@ -38,7 +38,7 @@ namespace Util
      */
     inline double Mod(const double x, const double y)
     {
-        if (y == 0)
+        if (y == 0.0)
         {
             return x;
         }
diff --git a/libsgp4/Vector.h b/libsgp4/Vector.h
index 525b7d7..111c5a7 100644
--- a/libsgp4/Vector.h
+++ b/libsgp4/Vector.h
@@ -80,13 +80,6 @@ public:
         w = v.w;
     }
 
-    /**
-     * Destructor
-     */
-    virtual ~Vector()
-    {
-    }
-
     /**
      * Assignment operator
      * @param v value to copy from