diff --git a/Julian.cpp b/Julian.cpp
index 1e9145c..93e9c66 100755
--- a/Julian.cpp
+++ b/Julian.cpp
@@ -159,13 +159,13 @@ std::ostream & operator<<(std::ostream& stream, const Julian& julian) {
     std::stringstream out;
     struct Julian::DateTimeComponents datetime;
     julian.ToGregorian(&datetime);
-    out << std::right << std::fixed << std::setprecision(7) << std::setfill('0');
+    out << std::right << std::fixed << std::setprecision(3) << std::setfill('0');
     out << std::setw(4) << datetime.years << "-";
     out << std::setw(2) << datetime.months << "-";
     out << std::setw(2) << datetime.days << " ";
     out << std::setw(2) << datetime.hours << ":";
     out << std::setw(2) << datetime.minutes << ":";
-    out << std::setw(10) << datetime.seconds;
+    out << std::setw(6) << datetime.seconds << " UTC";
     stream << out.str();
     return stream;
 }
diff --git a/RunTest.cpp b/RunTest.cpp
index 3dae99b..2062497 100755
--- a/RunTest.cpp
+++ b/RunTest.cpp
@@ -58,8 +58,8 @@ void RunTle(Tle tle, double start, double end, double inc) {
             std::cout.width(14);
             std::cout << velocity.z << std::endl;
 
-        } catch (std::exception* ex) {
-            std::cout << ex->what() << std::endl;
+        } catch (SatelliteException& e) {
+            std::cout << e.what() << std::endl;
             running = false;
         }
         if ((first_run && current == 0.0) || !first_run) {
@@ -144,15 +144,15 @@ void RunTest(const char* infile) {
          */
         if (!got_first_line) {
 
-            if (Tle::IsValidLine(line, 1)) {
+            try {
+                Tle::IsValidLine(line, 1);
                 /*
                  * store line and now read in second line
                  */
                 got_first_line = true;
                 line1 = line;
-
-            } else {
-                std::cerr << "Error: Badly formatted first line:" << std::endl;
+            } catch (TleException& e) {
+                std::cerr << "Error: " << e.what() << std::endl;
                 std::cerr << line << std::endl;
             }
         } else {
@@ -182,12 +182,13 @@ void RunTest(const char* infile) {
             /*
              * following line must be the second line
              */
-            if (Tle::IsValidLine(line2, 2)) {
+            try {
+                Tle::IsValidLine(line2, 2);
                 Tle tle("Test", line1, line2);
                 RunTle(tle, start, end, inc);
-            } else {
-                std::cerr << "Error: Badly formatted second line:" << std::endl;
-                std::cerr << line2 << std::endl;
+            } catch (TleException& e) {
+                std::cerr << "Error: " << e.what() << std::endl;
+                std::cerr << line << std::endl;
             }
         }
     }
diff --git a/SGP4.cpp b/SGP4.cpp
old mode 100644
new mode 100755
index aaadee9..4933358
--- a/SGP4.cpp
+++ b/SGP4.cpp
@@ -43,11 +43,11 @@ void SGP4::SetTle(const Tle& tle) {
      * error checks
      */
     if (eccentricity_ < 0.0 || eccentricity_ > 1.0 - 1.0e-3) {
-        throw new SatelliteException("Eccentricity out of range");
+        throw SatelliteException("Eccentricity out of range");
     }
 
     if (inclination_ < 0.0 || eccentricity_ > kPI) {
-        throw new SatelliteException("Inclination out of range");
+        throw SatelliteException("Inclination out of range");
     }
 
     Initialize();
@@ -273,7 +273,7 @@ void SGP4::FindPositionSDP4(Eci* eci, double tsince) const {
     DeepSpaceSecular(tsince, &xmdf, &omgadf, &xnode, &e, &xincl, &xn);
 
     if (xn <= 0.0) {
-        throw new SatelliteException("Error: #2 (xn <= 0.0)");
+        throw SatelliteException("Error: #2 (xn <= 0.0)");
     }
 
     a = pow(kXKE / xn, kTWOTHIRD) * pow(tempa, 2.0);
@@ -283,7 +283,7 @@ void SGP4::FindPositionSDP4(Eci* eci, double tsince) const {
      * fix tolerance for error recognition
      */
     if (e >= 1.0 || e < -0.001) {
-        throw new SatelliteException("Error: #1 (e >= 1.0 || e < -0.001)");
+        throw SatelliteException("Error: #1 (e >= 1.0 || e < -0.001)");
     }
     /*
      * fix tolerance to avoid a divide by zero
@@ -318,7 +318,7 @@ void SGP4::FindPositionSDP4(Eci* eci, double tsince) const {
     omega = omgadf;
 
     if (e < 0.0 || e > 1.0) {
-        throw new SatelliteException("Error: #3 (e < 0.0 || e > 1.0)");
+        throw SatelliteException("Error: #3 (e < 0.0 || e > 1.0)");
     }
 
     /*
@@ -402,14 +402,14 @@ void SGP4::FindPositionSGP4(Eci* eci, double tsince) const {
     xl = xmp + omega + xnode + RecoveredMeanMotion() * templ;
 
     if (xl <= 0.0) {
-        throw new SatelliteException("Error: #2 (xl <= 0.0)");
+        throw SatelliteException("Error: #2 (xl <= 0.0)");
     }
 
     /*
      * fix tolerance for error recognition
      */
     if (e >= 1.0 || e < -0.001) {
-        throw new SatelliteException("Error: #1 (e >= 1.0 || e < -0.001)");
+        throw SatelliteException("Error: #1 (e >= 1.0 || e < -0.001)");
     }
     /*
      * fix tolerance to avoid a divide by zero
@@ -519,7 +519,7 @@ void SGP4::CalculateFinalPositionVelocity(Eci* eci, const double& tsince, const
     const double pl = a * temp;
 
     if (pl < 0.0) {
-        throw new SatelliteException("Error: #4 (pl < 0.0)");
+        throw SatelliteException("Error: #4 (pl < 0.0)");
     }
 
     const double r = a * (1.0 - ecose);
@@ -549,7 +549,7 @@ void SGP4::CalculateFinalPositionVelocity(Eci* eci, const double& tsince, const
     const double rfdotk = rfdot + xn * temp1 * (x1mth2 * cos2u + 1.5 * x3thm1);
 
     if (rk < 1.0) {
-        throw new SatelliteException("Error: #6 Satellite decayed (rk < 1.0)");
+        throw SatelliteException("Error: #6 Satellite decayed (rk < 1.0)");
     }
 
     /*
diff --git a/SGP4.h b/SGP4.h
old mode 100644
new mode 100755
index 3bdada0..7077899
--- a/SGP4.h
+++ b/SGP4.h
@@ -3,6 +3,7 @@
 
 #include "Tle.h"
 #include "Eci.h"
+#include "SatelliteException.h"
 
 class SGP4 {
 public:
diff --git a/Tle.cpp b/Tle.cpp
index 057e807..5c87837 100755
--- a/Tle.cpp
+++ b/Tle.cpp
@@ -5,7 +5,6 @@
 
 Tle::Tle(const std::string& line_one, const std::string& line_two) {
 
-    name_.erase();
     line_one_ = line_one;
     line_two_ = line_two;
 
@@ -57,7 +56,9 @@ std::string Tle::ExpToDecimal(const std::string& str) {
     static const int START_EXP = 6;
     static const int LENGTH_EXP = 2;
 
-    assert(8 == str.length());
+    if ((LENGTH_SIGN + LENGTH_MANTISSA + LENGTH_EXP) != str.length()) {
+        throw TleException("Invalid string length for exponential conversion.");
+    }
 
     std::string value = str.substr(START_SIGN, LENGTH_SIGN);
     value += ".";
@@ -88,16 +89,16 @@ void Tle::Initialize() {
     /*
      * check the two lines are valid
      */
-    assert(IsValidPair(line_one_, line_two_));
+    IsValidPair(line_one_, line_two_);
 
     /*
      * line 1
      */
 
-    temp = line_one_.substr(TLE1_COL_NORADNUM, TLE1_LEN_NORADNUM).c_str();
+    temp = ExtractNoradNumber(line_one_, 1);
     norad_number_ = atoi(temp.c_str());
     /*
-     * if blank use norad number
+     * if blank use norad number for name
      */
     if (name_.empty())
         name_ = temp;
@@ -113,7 +114,6 @@ void Tle::Initialize() {
         year += 2000;
     else
         year += 1900;
-
     epoch_ = Julian(year, day);
 
     if (line_one_[TLE1_COL_MEANMOTIONDT] == '-') {
@@ -164,43 +164,49 @@ void Tle::Initialize() {
 
 /*
  * check the two lines have matching norad numbers
- * and that the lines themselves are valid
+ * and that the lines themselves are equal
  */
-bool Tle::IsValidPair(const std::string& line1, const std::string& line2) {
+void Tle::IsValidPair(const std::string& line1, const std::string& line2) {
 
-    if (!IsValidLine(line1, 1))
-        return false;
+    /*
+     * validate each line
+     */
+    IsValidLine(line1, 1);
+    IsValidLine(line2, 2);
 
-    if (!IsValidLine(line2, 2))
-        return false;
+    /*
+     * extract norad numbers
+     */
+    std::string norad_1 = ExtractNoradNumber(line1, 1);
+    std::string norad_2 = ExtractNoradNumber(line2, 2);
 
-    if (atoi(line1.substr(TLE1_COL_NORADNUM, TLE1_LEN_NORADNUM).c_str()) !=
-            atoi(line2.substr(TLE2_COL_NORADNUM, TLE2_LEN_NORADNUM).c_str()))
-        return false;
-
-
-    return true;
+    /*
+     * make sure they match
+     */
+    if (norad_1.compare(norad_2) != 0)
+        throw TleException("Norad numbers do not match.");
 }
 
 /*
  * validate a line
  */
-bool Tle::IsValidLine(const std::string& str, const unsigned char line_number) {
+void Tle::IsValidLine(const std::string& str, const unsigned char line_number) {
 
-    static const std::string line1_pattern = "1 NNNNNC XXXXXXXX NNNNN.NNNNNNNN +.NNNNNNNN +NNNNN-N +NNNNN-N N NNNNN";
+    /*
+     * validation patterns
+     */
+    static const std::string line1_pattern = "1 NNNNNC NNNNNXXX NNNNN.NNNNNNNN +.NNNNNNNN +NNNNN-N +NNNNN-N N NNNNN";
     static const std::string line2_pattern = "2 NNNNN NNN.NNNN NNN.NNNN NNNNNNN NNN.NNNN NNN.NNNN NN.NNNNNNNNNNNNNN";
 
     /*
      * validate line against the pattern
      */
     if (1 == line_number) {
-        if (!ValidateLine(str, line1_pattern))
-            return false;
+        ValidateLine(str, line1_pattern);
     } else if (2 == line_number) {
-        if (!ValidateLine(str, line2_pattern))
-            return false;
+        ValidateLine(str, line2_pattern);
     } else {
-        return false;
+        throw TleException("Invalid line number to check.");
     }
 
     /*
@@ -211,20 +217,23 @@ bool Tle::IsValidLine(const std::string& str, const unsigned char line_number) {
      * if (chk != (str[TLE_LEN_LINE_DATA - 1] - '0'))
      *   return false;
      */
+}
 
-    return true;
+bool Tle::IsValidLineLength(const std::string& str) {
+
+    return str.length() == GetLineLength() ? true : false;
 }
 
 /*
  * validate line given a pattern
  */
-bool Tle::ValidateLine(const std::string& line, const std::string& pattern) {
+void Tle::ValidateLine(const std::string& line, const std::string& pattern) {
 
     /*
-     * check length of lines match
+     * check length of line
      */
-    if (line.length() < pattern.length()) {
-        return false;
+    if (!IsValidLineLength(line)) {
+        throw TleException("Invalid line length.");
     }
 
     std::string::const_iterator pattern_itr = pattern.begin();
@@ -236,47 +245,67 @@ bool Tle::ValidateLine(const std::string& line, const std::string& pattern) {
                 *pattern_itr == '.') {
 
             /*
-             * these characters should match exactly
+             * should match exactly
              */
-            if (*pattern_itr != *line_itr)
-                return false;
+            if (*pattern_itr != *line_itr) {
+                throw TleException("Invalid character.");
+            }
 
         } else if (*pattern_itr == 'N') {
 
             /*
-             * if pattern value is 'N' then either a number or a ' '
+             * 'N' = number or ' '
              */
-            if (!isdigit(*line_itr) && *line_itr != ' ')
-                return false;
+            if (!isdigit(*line_itr) && *line_itr != ' ') {
+                throw TleException("Invalid character.");
+            }
 
         } else if (*pattern_itr == '+') {
 
             /*
-             * if pattern value is '+' then either a '+' or '-' or ' ' or '0'
+             * '+' = '+' or '-' or ' ' or '0'
              */
-            if (*line_itr != '+' && *line_itr != '-' && *line_itr != ' ' && *line_itr != '0')
-                return false;
+            if (*line_itr != '+' && *line_itr != '-' && *line_itr != ' ' && *line_itr != '0') {
+                throw TleException("Invalid character.");
+            }
 
         } else if (*pattern_itr == '-') {
 
             /*
-             * if pattern value is '+' or '-'
+             * '-' = '+' or '-'
              */
-            if (*line_itr != '+' && *line_itr != '-')
-                return false;
+            if (*line_itr != '+' && *line_itr != '-') {
+                throw TleException("Invalid character.");
+            }
+
+        } else if (*pattern_itr == 'C') {
+
+            /*
+             * 'C' = 'U' or 'S'
+             */
+            if (*line_itr != 'U' && *line_itr != 'S') {
+                throw TleException("Invalid character.");
+            }
+
+        } else if (*pattern_itr == 'X') {
+
+            /*
+             * 'X' = A-Z or ' '
+             */
+            if (!(*line_itr >= 'A' || *line_itr <= 'Z') && *line_itr != ' ') {
+                throw TleException("Invalid character.");
+            }
         }
 
         pattern_itr++;
         line_itr++;
     }
-
-    return true;
 }
 
 /*
  * compute checksum
  */
-int Tle::CheckSum(const std::string& str) {
+int Tle::CheckSum(const std::string & str) {
 
     size_t len = str.size() - 1;
     int xsum = 0;
@@ -294,3 +323,28 @@ int Tle::CheckSum(const std::string& str) {
 
     return (xsum % 10);
 }
+
+std::string Tle::ExtractNoradNumber(const std::string& str, const unsigned char line_number) {
+
+    std::string norad_number;
+
+    /*
+     * check length
+     */
+    if (!IsValidLineLength(str)) {
+        throw TleException("Invalid line length.");
+    }
+
+    /*
+     * extract string
+     */
+    if (1 == line_number) {
+        norad_number = str.substr(TLE1_COL_NORADNUM, TLE1_LEN_NORADNUM);
+    } else if (2 == line_number) {
+        norad_number = str.substr(TLE2_COL_NORADNUM, TLE2_LEN_NORADNUM);
+    } else {
+        throw TleException("Invalid line number to check.");
+    }
+
+    return norad_number;
+}
diff --git a/Tle.h b/Tle.h
index b6e1609..fa9107a 100755
--- a/Tle.h
+++ b/Tle.h
@@ -3,6 +3,7 @@
 
 #include "Globals.h"
 #include "Julian.h"
+#include "TleException.h"
 
 #include <iostream>
 
@@ -101,8 +102,8 @@ public:
     static unsigned int GetLineLength() {
         return TLE_LEN_LINE_DATA;
     }
-    static bool IsValidPair(const std::string& line1, const std::string& line2);
-    static bool IsValidLine(const std::string& str, unsigned char line_number);
+    static void IsValidPair(const std::string& line1, const std::string& line2);
+    static void IsValidLine(const std::string& str, unsigned char line_number);
 
 private:
     /*
@@ -116,12 +117,16 @@ private:
     /*
      * validate a line against a pattern
      */
-    static bool ValidateLine(const std::string& line, const std::string& pattern);
+    static void ValidateLine(const std::string& line, const std::string& pattern);
     /*
      * compute checksum
      */
     static int CheckSum(const std::string& str);
 
+    static std::string ExtractNoradNumber(const std::string& str, const unsigned char line_number);
+
+    static bool IsValidLineLength(const std::string& str);
+
 private:
     /*
      * raw tle data
diff --git a/TleException.h b/TleException.h
new file mode 100755
index 0000000..e047f33
--- /dev/null
+++ b/TleException.h
@@ -0,0 +1,25 @@
+#ifndef TLEEXCEPTION_H_
+#define TLEEXCEPTION_H_
+
+#include <exception>
+#include <iostream>
+
+class TleException : public std::exception {
+public:
+
+    TleException(const char* message)
+    : message_(message) {
+    }
+
+    virtual ~TleException(void) throw () {
+    }
+
+    virtual const char* what() const throw () {
+        return message_.c_str();
+    }
+
+private:
+    std::string message_;
+};
+
+#endif
\ No newline at end of file