YodaProfiler/inc/sgp4.h

//
// stdafx.h 
//
#ifndef sgp4_h 
#define sgp4_h
#pragma once

//#define WIN32_LEAN_AND_MEAN   // Exclude rarely-used stuff from Windows headers
#include <stdio.h>
//#include <tchar.h>

#include <string>
#include <map>
#include <vector>
#include <algorithm>
#include <assert.h>
#include <time.h>
#include <math.h>

using namespace std;
//
// globals.h
//

const double PI           = 3.141592653589793;
const double TWOPI        = 2.0 * PI;
const double RADS_PER_DEG = PI / 180.0;

const double GM           = 398601.2;   // Earth gravitational constant, km^3/sec^2
const double GEOSYNC_ALT  = 42241.892;  // km
const double EARTH_DIA    = 12800.0;    // km
const double DAY_SIDERAL  = (23 * 3600) + (56 * 60) + 4.09;  // sec
const double DAY_24HR     = (24 * 3600);   // sec

const double AE           = 1.0;
const double AU           = 149597870.0;  // Astronomical unit (km) (IAU 76)
const double SR           = 696000.0;     // Solar radius (km)      (IAU 76)
const double TWOTHRD      = 2.0 / 3.0;
const double XKMPER_WGS72 = 6378.135;     // Earth equatorial radius - km (WGS '72)
const double F            = 1.0 / 298.26; // Earth flattening (WGS '72)
const double GE           = 398600.8;     // Earth gravitational constant (WGS '72)
const double J2           = 1.0826158E-3; // J2 harmonic (WGS '72)
const double J3           = -2.53881E-6;  // J3 harmonic (WGS '72)
const double J4           = -1.65597E-6;  // J4 harmonic (WGS '72)
const double CK2          = J2 / 2.0;
const double CK4          = -3.0 * J4 / 8.0;
const double XJ3          = J3;
const double E6A          = 1.0e-06;
const double QO           = AE + 120.0 / XKMPER_WGS72;
const double S            = AE + 78.0  / XKMPER_WGS72;
const double HR_PER_DAY   = 24.0;          // Hours per day   (solar)
const double MIN_PER_DAY  = 1440.0;        // Minutes per day (solar)
const double SEC_PER_DAY  = 86400.0;       // Seconds per day (solar)
const double OMEGA_E      = 1.00273790934; // earth rotation per sideral day
const double XKE          = sqrt(3600.0 * GE /           //sqrt(ge) ER^3/min^2
                                (XKMPER_WGS72 * XKMPER_WGS72 * XKMPER_WGS72)); 
const double QOMS2T       = pow((QO - S), 4);            //(QO - S)^4 ER^4

// Utility functions
double sqr   (const double x);
double Fmod2p(const double arg);
double AcTan (const double sinx, double cosx);

double rad2deg(const double);
double deg2rad(const double);
//
// coord.h
//
// Copyright 2002-2003 Michael F. Henry
//
//////////////////////////////////////////////////////////////////////
// Geocentric coordinates.
class cCoordGeo  
{
public:
   cCoordGeo();
   cCoordGeo(double lat, double lon, double alt) :
      m_Lat(lat), m_Lon(lon), m_Alt(alt) {}
   virtual ~cCoordGeo() {};

   double m_Lat;   // Latitude,  radians (negative south)
   double m_Lon;   // Longitude, radians (negative west)
   double m_Alt;   // Altitude,  km      (above mean sea level)
};

//////////////////////////////////////////////////////////////////////
// Topocentric-Horizon coordinates.
class cCoordTopo  
{
public:
   cCoordTopo();
   cCoordTopo(double az, double el, double rng, double rate) :
      m_Az(az), m_El(el), m_Range(rng), m_RangeRate(rate) {}
   virtual ~cCoordTopo() {};

   double m_Az;         // Azimuth, radians
   double m_El;         // Elevation, radians
   double m_Range;      // Range, kilometers
   double m_RangeRate;  // Range rate of change, km/sec
                        // Negative value means "towards observer"
};

// cVector.h: interface for the cVector class.
//
// Copyright 2003 (c) Michael F. Henry
//
//////////////////////////////////////////////////////////////////////

class cVector  
{
public:
   cVector(double x = 0.0, double y = 0.0, double z = 0.0, double w = 0.0) :
      m_x(x), m_y(y), m_z(z), m_w(w) {}
   virtual ~cVector() {};

   void Sub(const cVector&);     // subtraction
   void Mul(double factor);      // multiply each component by 'factor'

   double Angle(const cVector&) const;    // angle between two vectors
   double Magnitude() const;              // vector magnitude
   double Dot(const cVector& vec) const;  // dot product

// protected:
   double m_x;
   double m_y;
   double m_z;
   double m_w;
};
//
// cTle.h 
//
// This class will accept a single set of two-line elements and then allow
// a client to request specific fields, such as epoch, mean motion, 
// etc., from the set.
//
// Copyright 1996-2003 Michael F. Henry
//
/////////////////////////////////////////////////////////////////////////////
class cTle
{
public:
   cTle(string&, string&, string&);
   cTle(const cTle &tle);
   ~cTle();
   
   enum eTleLine
   {
      LINE_ZERO,
      LINE_ONE,
      LINE_TWO
   };

   enum eField
   {
      FLD_FIRST,
      FLD_NORADNUM = FLD_FIRST,
      FLD_INTLDESC,
      FLD_SET,       // TLE set number
      FLD_EPOCHYEAR, // Epoch: Last two digits of year
      FLD_EPOCHDAY,  // Epoch: Fractional Julian Day of year
      FLD_ORBITNUM,  // Orbit at epoch
      FLD_I,         // Inclination
      FLD_RAAN,      // R.A. ascending node
      FLD_E,         // Eccentricity
      FLD_ARGPER,    // Argument of perigee
      FLD_M,         // Mean anomaly
      FLD_MMOTION,   // Mean motion
      FLD_MMOTIONDT, // First time derivative of mean motion
      FLD_MMOTIONDT2,// Second time derivative of mean motion
      FLD_BSTAR,     // BSTAR Drag
      FLD_LAST       // MUST be last
   };

   enum eUnits
   {
      U_FIRST,
      U_RAD = U_FIRST,  // radians
      U_DEG,            // degrees
      U_NATIVE,         // TLE format native units (no conversion)
      U_LAST            // MUST be last
   };
   
   void Initialize();
   
   static int    CheckSum(const string&);
   static bool   IsValidLine(string&, eTleLine);
   static string ExpToDecimal(const string&);

   static void TrimLeft(string&);
   static void TrimRight(string&);
   
   double getField(eField fld,               // which field to retrieve
                   eUnits unit  = U_NATIVE,  // return units in rad, deg etc.
                   string *pstr = NULL,      // return ptr for str value
                   bool bStrUnits = false)   // 'true': append units to str val
                   const;
   string getName()  const { return m_strName; }
   string getLine1() const { return m_strLine1;}
   string getLine2() const { return m_strLine2;}

protected:
   static double ConvertUnits(double val, eField fld, eUnits units); 

private:
   string getUnits(eField) const;
   double getFieldNumeric(eField) const;

   // Satellite name and two data lines
   string m_strName;
   string m_strLine1;
   string m_strLine2;

   // Converted fields, in atof()-readable form
   string m_Field[FLD_LAST];

   // Cache of field values in "double" format
   typedef int FldKey;
   FldKey Key(eUnits u, eField f) const { return (u * 100) + f; }
   mutable map<FldKey, double>  m_mapCache;
};

///////////////////////////////////////////////////////////////////////////
//
// TLE data format
//
// [Reference: T.S. Kelso]
//
// Two line element data consists of three lines in the following format:
//
//  AAAAAAAAAAAAAAAAAAAAAA
//  1 NNNNNU NNNNNAAA NNNNN.NNNNNNNN +.NNNNNNNN +NNNNN-N +NNNNN-N N NNNNN
//  2 NNNNN NNN.NNNN NNN.NNNN NNNNNNN NNN.NNNN NNN.NNNN NN.NNNNNNNNNNNNNN
//  
//  Line 0 is a twenty-two-character name.
// 
//   Lines 1 and 2 are the standard Two-Line Orbital Element Set Format identical
//   to that used by NORAD and NASA.  The format description is:
//      
//     Line 1
//     Column    Description
//     01-01     Line Number of Element Data
//     03-07     Satellite Number
//     10-11     International Designator (Last two digits of launch year)
//     12-14     International Designator (Launch number of the year)
//     15-17     International Designator (Piece of launch)
//     19-20     Epoch Year (Last two digits of year)
//     21-32     Epoch (Julian Day and fractional portion of the day)
//     34-43     First Time Derivative of the Mean Motion
//               or Ballistic Coefficient (Depending on ephemeris type)
//     45-52     Second Time Derivative of Mean Motion (decimal point assumed;
//               blank if N/A)
//     54-61     BSTAR drag term if GP4 general perturbation theory was used.
//               Otherwise, radiation pressure coefficient.  (Decimal point assumed)
//     63-63     Ephemeris type
//     65-68     Element number
//     69-69     Check Sum (Modulo 10)
//               (Letters, blanks, periods, plus signs = 0; minus signs = 1)
//
//     Line 2
//     Column    Description
//     01-01     Line Number of Element Data
//     03-07     Satellite Number
//     09-16     Inclination [Degrees]
//     18-25     Right Ascension of the Ascending Node [Degrees]
//     27-33     Eccentricity (decimal point assumed)
//     35-42     Argument of Perigee [Degrees]
//     44-51     Mean Anomaly [Degrees]
//     53-63     Mean Motion [Revs per day]
//     64-68     Revolution number at epoch [Revs]
//     69-69     Check Sum (Modulo 10)
//        
//     All other columns are blank or fixed.
//          
// Example:
//      
// NOAA 6
// 1 11416U          86 50.28438588 0.00000140           67960-4 0  5293
// 2 11416  98.5105  69.3305 0012788  63.2828 296.9658 14.24899292346978

//
// cJulian.h
//
// Copyright (c) 2003 Michael F. Henry
//
//
// See note in cJulian.cpp for information on this class and the epoch dates
//
const double EPOCH_JAN1_00H_1900 = 2415019.5; // Jan 1.0 1900 = Jan 1 1900 00h UTC
const double EPOCH_JAN1_12H_1900 = 2415020.0; // Jan 1.5 1900 = Jan 1 1900 12h UTC
const double EPOCH_JAN1_12H_2000 = 2451545.0; // Jan 1.5 2000 = Jan 1 2000 12h UTC

//////////////////////////////////////////////////////////////////////////////
class cJulian  
{
public:
   cJulian() { Initialize(2000, 1); }
   explicit cJulian(time_t t);              // Create from time_t
   explicit cJulian(int year, double day);  // Create from year, day of year
   explicit cJulian(int year,               // i.e., 2004
                    int mon,                // 1..12
                    int day,                // 1..31
                    int hour,               // 0..23
                    int min,                // 0..59
                    double sec = 0.0);      // 0..(59.999999...)
   ~cJulian() {};

   double toGMST() const;           // Greenwich Mean Sidereal Time
   double toLMST(double lon) const; // Local Mean Sideral Time
   time_t toTime() const;           // To time_t type - avoid using

   double FromJan1_00h_1900() const { return m_Date - EPOCH_JAN1_00H_1900; }
   double FromJan1_12h_1900() const { return m_Date - EPOCH_JAN1_12H_1900; }
   double FromJan1_12h_2000() const { return m_Date - EPOCH_JAN1_12H_2000; }

   void getComponent(int *pYear, int *pMon = NULL, double *pDOM = NULL) const;
   double getDate() const { return m_Date; }

   void addDay (double day) { m_Date += day;                 }
   void addHour(double hr ) { m_Date += (hr  / HR_PER_DAY ); }
   void addMin (double min) { m_Date += (min / MIN_PER_DAY); }
   void addSec (double sec) { m_Date += (sec / SEC_PER_DAY); }

   double spanDay (const cJulian& b) const { return m_Date - b.m_Date;        }
   double spanHour(const cJulian& b) const { return spanDay(b) * HR_PER_DAY;  }
   double spanMin (const cJulian& b) const { return spanDay(b) * MIN_PER_DAY; }
   double spanSec (const cJulian& b) const { return spanDay(b) * SEC_PER_DAY; }

   static bool IsLeapYear(int y)
      { return (y % 4 == 0 && y % 100 != 0) || (y % 400 == 0); }

protected:
   void Initialize(int year, double day);

   double m_Date; // Julian date
};
//
// cEci.h
//
// Copyright (c) 2003 Michael F. Henry
//
//////////////////////////////////////////////////////////////////////
// class cEci
// Encapsulates an Earth-Centered Inertial position, velocity, and time.
class cEci
{
public:
   cEci() { m_VecUnits = UNITS_NONE; }
   cEci(const cCoordGeo &geo, const cJulian &cJulian);
   cEci(const cVector &pos, const cVector &vel, 
        const cJulian &date, bool IsAeUnits = true);
   virtual ~cEci() {};

   cCoordGeo toGeo(); 

   cVector getPos()  const { return m_pos;  }
   cVector getVel()  const { return m_vel;  }
   cJulian getDate() const { return m_date; }

   void setUnitsAe() { m_VecUnits = UNITS_AE; }
   void setUnitsKm() { m_VecUnits = UNITS_KM; }
   bool UnitsAreAe() const { return m_VecUnits == UNITS_AE; }
   bool UnitsAreKm() const { return m_VecUnits == UNITS_KM; }
   void ae2km();  // Convert position, velocity vector units from AE to km

protected:
   void MulPos(double factor) { m_pos.Mul(factor); }
   void MulVel(double factor) { m_vel.Mul(factor); }

   enum VecUnits
   {
      UNITS_NONE, // not initialized
      UNITS_AE,
      UNITS_KM,
   };

   cVector  m_pos;
   cVector  m_vel;
   cJulian  m_date;
   VecUnits m_VecUnits;
};
#endif
1	mocchiut	1.1	//
2			// stdafx.h
3			//
4			#ifndef sgp4_h
5			#define sgp4_h
6			#pragma once
7
8			//#define WIN32_LEAN_AND_MEAN // Exclude rarely-used stuff from Windows headers
9			#include <stdio.h>
10			//#include <tchar.h>
11
12			#include <string>
13			#include <map>
14			#include <vector>
15			#include <algorithm>
16			#include <assert.h>
17			#include <time.h>
18			#include <math.h>
19
20			using namespace std;
21			//
22			// globals.h
23			//
24
25			const double PI = 3.141592653589793;
26			const double TWOPI = 2.0 * PI;
27			const double RADS_PER_DEG = PI / 180.0;
28
29			const double GM = 398601.2; // Earth gravitational constant, km^3/sec^2
30			const double GEOSYNC_ALT = 42241.892; // km
31			const double EARTH_DIA = 12800.0; // km
32			const double DAY_SIDERAL = (23 * 3600) + (56 * 60) + 4.09; // sec
33			const double DAY_24HR = (24 * 3600); // sec
34
35			const double AE = 1.0;
36			const double AU = 149597870.0; // Astronomical unit (km) (IAU 76)
37			const double SR = 696000.0; // Solar radius (km) (IAU 76)
38			const double TWOTHRD = 2.0 / 3.0;
39			const double XKMPER_WGS72 = 6378.135; // Earth equatorial radius - km (WGS '72)
40			const double F = 1.0 / 298.26; // Earth flattening (WGS '72)
41			const double GE = 398600.8; // Earth gravitational constant (WGS '72)
42			const double J2 = 1.0826158E-3; // J2 harmonic (WGS '72)
43			const double J3 = -2.53881E-6; // J3 harmonic (WGS '72)
44			const double J4 = -1.65597E-6; // J4 harmonic (WGS '72)
45			const double CK2 = J2 / 2.0;
46			const double CK4 = -3.0 * J4 / 8.0;
47			const double XJ3 = J3;
48			const double E6A = 1.0e-06;
49			const double QO = AE + 120.0 / XKMPER_WGS72;
50			const double S = AE + 78.0 / XKMPER_WGS72;
51			const double HR_PER_DAY = 24.0; // Hours per day (solar)
52			const double MIN_PER_DAY = 1440.0; // Minutes per day (solar)
53			const double SEC_PER_DAY = 86400.0; // Seconds per day (solar)
54			const double OMEGA_E = 1.00273790934; // earth rotation per sideral day
55			const double XKE = sqrt(3600.0 * GE / //sqrt(ge) ER^3/min^2
56			(XKMPER_WGS72 * XKMPER_WGS72 * XKMPER_WGS72));
57			const double QOMS2T = pow((QO - S), 4); //(QO - S)^4 ER^4
58
59			// Utility functions
60			double sqr (const double x);
61			double Fmod2p(const double arg);
62			double AcTan (const double sinx, double cosx);
63
64			double rad2deg(const double);
65			double deg2rad(const double);
66			//
67			// coord.h
68			//
69			// Copyright 2002-2003 Michael F. Henry
70			//
71			//////////////////////////////////////////////////////////////////////
72			// Geocentric coordinates.
73			class cCoordGeo
74			{
75			public:
76			cCoordGeo();
77			cCoordGeo(double lat, double lon, double alt) :
78			m_Lat(lat), m_Lon(lon), m_Alt(alt) {}
79			virtual ~cCoordGeo() {};
80
81			double m_Lat; // Latitude, radians (negative south)
82			double m_Lon; // Longitude, radians (negative west)
83			double m_Alt; // Altitude, km (above mean sea level)
84			};
85
86			//////////////////////////////////////////////////////////////////////
87			// Topocentric-Horizon coordinates.
88			class cCoordTopo
89			{
90			public:
91			cCoordTopo();
92			cCoordTopo(double az, double el, double rng, double rate) :
93			m_Az(az), m_El(el), m_Range(rng), m_RangeRate(rate) {}
94			virtual ~cCoordTopo() {};
95
96			double m_Az; // Azimuth, radians
97			double m_El; // Elevation, radians
98			double m_Range; // Range, kilometers
99			double m_RangeRate; // Range rate of change, km/sec
100			// Negative value means "towards observer"
101			};
102
103			// cVector.h: interface for the cVector class.
104			//
105			// Copyright 2003 (c) Michael F. Henry
106			//
107			//////////////////////////////////////////////////////////////////////
108
109			class cVector
110			{
111			public:
112			cVector(double x = 0.0, double y = 0.0, double z = 0.0, double w = 0.0) :
113			m_x(x), m_y(y), m_z(z), m_w(w) {}
114			virtual ~cVector() {};
115
116			void Sub(const cVector&); // subtraction
117			void Mul(double factor); // multiply each component by 'factor'
118
119			double Angle(const cVector&) const; // angle between two vectors
120			double Magnitude() const; // vector magnitude
121			double Dot(const cVector& vec) const; // dot product
122
123			// protected:
124			double m_x;
125			double m_y;
126			double m_z;
127			double m_w;
128			};
129			//
130			// cTle.h
131			//
132			// This class will accept a single set of two-line elements and then allow
133			// a client to request specific fields, such as epoch, mean motion,
134			// etc., from the set.
135			//
136			// Copyright 1996-2003 Michael F. Henry
137			//
138			/////////////////////////////////////////////////////////////////////////////
139			class cTle
140			{
141			public:
142			cTle(string&, string&, string&);
143			cTle(const cTle &tle);
144			~cTle();
145
146			enum eTleLine
147			{
148			LINE_ZERO,
149			LINE_ONE,
150			LINE_TWO
151			};
152
153			enum eField
154			{
155			FLD_FIRST,
156			FLD_NORADNUM = FLD_FIRST,
157			FLD_INTLDESC,
158			FLD_SET, // TLE set number
159			FLD_EPOCHYEAR, // Epoch: Last two digits of year
160			FLD_EPOCHDAY, // Epoch: Fractional Julian Day of year
161			FLD_ORBITNUM, // Orbit at epoch
162			FLD_I, // Inclination
163			FLD_RAAN, // R.A. ascending node
164			FLD_E, // Eccentricity
165			FLD_ARGPER, // Argument of perigee
166			FLD_M, // Mean anomaly
167			FLD_MMOTION, // Mean motion
168			FLD_MMOTIONDT, // First time derivative of mean motion
169			FLD_MMOTIONDT2,// Second time derivative of mean motion
170			FLD_BSTAR, // BSTAR Drag
171			FLD_LAST // MUST be last
172			};
173
174			enum eUnits
175			{
176			U_FIRST,
177			U_RAD = U_FIRST, // radians
178			U_DEG, // degrees
179			U_NATIVE, // TLE format native units (no conversion)
180			U_LAST // MUST be last
181			};
182
183			void Initialize();
184
185			static int CheckSum(const string&);
186			static bool IsValidLine(string&, eTleLine);
187			static string ExpToDecimal(const string&);
188
189			static void TrimLeft(string&);
190			static void TrimRight(string&);
191
192			double getField(eField fld, // which field to retrieve
193			eUnits unit = U_NATIVE, // return units in rad, deg etc.
194			string *pstr = NULL, // return ptr for str value
195			bool bStrUnits = false) // 'true': append units to str val
196			const;
197			string getName() const { return m_strName; }
198			string getLine1() const { return m_strLine1;}
199			string getLine2() const { return m_strLine2;}
200
201			protected:
202			static double ConvertUnits(double val, eField fld, eUnits units);
203
204			private:
205			string getUnits(eField) const;
206			double getFieldNumeric(eField) const;
207
208			// Satellite name and two data lines
209			string m_strName;
210			string m_strLine1;
211			string m_strLine2;
212
213			// Converted fields, in atof()-readable form
214			string m_Field[FLD_LAST];
215
216			// Cache of field values in "double" format
217			typedef int FldKey;
218			FldKey Key(eUnits u, eField f) const { return (u * 100) + f; }
219			mutable map<FldKey, double> m_mapCache;
220			};
221
222			///////////////////////////////////////////////////////////////////////////
223			//
224			// TLE data format
225			//
226			// [Reference: T.S. Kelso]
227			//
228			// Two line element data consists of three lines in the following format:
229			//
230			// AAAAAAAAAAAAAAAAAAAAAA
231			// 1 NNNNNU NNNNNAAA NNNNN.NNNNNNNN +.NNNNNNNN +NNNNN-N +NNNNN-N N NNNNN
232			// 2 NNNNN NNN.NNNN NNN.NNNN NNNNNNN NNN.NNNN NNN.NNNN NN.NNNNNNNNNNNNNN
233			//
234			// Line 0 is a twenty-two-character name.
235			//
236			// Lines 1 and 2 are the standard Two-Line Orbital Element Set Format identical
237			// to that used by NORAD and NASA. The format description is:
238			//
239			// Line 1
240			// Column Description
241			// 01-01 Line Number of Element Data
242			// 03-07 Satellite Number
243			// 10-11 International Designator (Last two digits of launch year)
244			// 12-14 International Designator (Launch number of the year)
245			// 15-17 International Designator (Piece of launch)
246			// 19-20 Epoch Year (Last two digits of year)
247			// 21-32 Epoch (Julian Day and fractional portion of the day)
248			// 34-43 First Time Derivative of the Mean Motion
249			// or Ballistic Coefficient (Depending on ephemeris type)
250			// 45-52 Second Time Derivative of Mean Motion (decimal point assumed;
251			// blank if N/A)
252			// 54-61 BSTAR drag term if GP4 general perturbation theory was used.
253			// Otherwise, radiation pressure coefficient. (Decimal point assumed)
254			// 63-63 Ephemeris type
255			// 65-68 Element number
256			// 69-69 Check Sum (Modulo 10)
257			// (Letters, blanks, periods, plus signs = 0; minus signs = 1)
258			//
259			// Line 2
260			// Column Description
261			// 01-01 Line Number of Element Data
262			// 03-07 Satellite Number
263			// 09-16 Inclination [Degrees]
264			// 18-25 Right Ascension of the Ascending Node [Degrees]
265			// 27-33 Eccentricity (decimal point assumed)
266			// 35-42 Argument of Perigee [Degrees]
267			// 44-51 Mean Anomaly [Degrees]
268			// 53-63 Mean Motion [Revs per day]
269			// 64-68 Revolution number at epoch [Revs]
270			// 69-69 Check Sum (Modulo 10)
271			//
272			// All other columns are blank or fixed.
273			//
274			// Example:
275			//
276			// NOAA 6
277			// 1 11416U 86 50.28438588 0.00000140 67960-4 0 5293
278			// 2 11416 98.5105 69.3305 0012788 63.2828 296.9658 14.24899292346978
279
280			//
281			// cJulian.h
282			//
283			// Copyright (c) 2003 Michael F. Henry
284			//
285			//
286			// See note in cJulian.cpp for information on this class and the epoch dates
287			//
288			const double EPOCH_JAN1_00H_1900 = 2415019.5; // Jan 1.0 1900 = Jan 1 1900 00h UTC
289			const double EPOCH_JAN1_12H_1900 = 2415020.0; // Jan 1.5 1900 = Jan 1 1900 12h UTC
290			const double EPOCH_JAN1_12H_2000 = 2451545.0; // Jan 1.5 2000 = Jan 1 2000 12h UTC
291
292			//////////////////////////////////////////////////////////////////////////////
293			class cJulian
294			{
295			public:
296			cJulian() { Initialize(2000, 1); }
297			explicit cJulian(time_t t); // Create from time_t
298			explicit cJulian(int year, double day); // Create from year, day of year
299			explicit cJulian(int year, // i.e., 2004
300			int mon, // 1..12
301			int day, // 1..31
302			int hour, // 0..23
303			int min, // 0..59
304			double sec = 0.0); // 0..(59.999999...)
305			~cJulian() {};
306
307			double toGMST() const; // Greenwich Mean Sidereal Time
308			double toLMST(double lon) const; // Local Mean Sideral Time
309			time_t toTime() const; // To time_t type - avoid using
310
311			double FromJan1_00h_1900() const { return m_Date - EPOCH_JAN1_00H_1900; }
312			double FromJan1_12h_1900() const { return m_Date - EPOCH_JAN1_12H_1900; }
313			double FromJan1_12h_2000() const { return m_Date - EPOCH_JAN1_12H_2000; }
314
315			void getComponent(int pYear, int pMon = NULL, double *pDOM = NULL) const;
316			double getDate() const { return m_Date; }
317
318			void addDay (double day) { m_Date += day; }
319			void addHour(double hr ) { m_Date += (hr / HR_PER_DAY ); }
320			void addMin (double min) { m_Date += (min / MIN_PER_DAY); }
321			void addSec (double sec) { m_Date += (sec / SEC_PER_DAY); }
322
323			double spanDay (const cJulian& b) const { return m_Date - b.m_Date; }
324			double spanHour(const cJulian& b) const { return spanDay(b) * HR_PER_DAY; }
325			double spanMin (const cJulian& b) const { return spanDay(b) * MIN_PER_DAY; }
326			double spanSec (const cJulian& b) const { return spanDay(b) * SEC_PER_DAY; }
327
328			static bool IsLeapYear(int y)
329			{ return (y % 4 == 0 && y % 100 != 0) \|\| (y % 400 == 0); }
330
331			protected:
332			void Initialize(int year, double day);
333
334			double m_Date; // Julian date
335			};
336			//
337			// cEci.h
338			//
339			// Copyright (c) 2003 Michael F. Henry
340			//
341			//////////////////////////////////////////////////////////////////////
342			// class cEci
343			// Encapsulates an Earth-Centered Inertial position, velocity, and time.
344			class cEci
345			{
346			public:
347			cEci() { m_VecUnits = UNITS_NONE; }
348			cEci(const cCoordGeo &geo, const cJulian &cJulian);
349			cEci(const cVector &pos, const cVector &vel,
350			const cJulian &date, bool IsAeUnits = true);
351			virtual ~cEci() {};
352
353			cCoordGeo toGeo();
354
355			cVector getPos() const { return m_pos; }
356			cVector getVel() const { return m_vel; }
357			cJulian getDate() const { return m_date; }
358
359			void setUnitsAe() { m_VecUnits = UNITS_AE; }
360			void setUnitsKm() { m_VecUnits = UNITS_KM; }
361			bool UnitsAreAe() const { return m_VecUnits == UNITS_AE; }
362			bool UnitsAreKm() const { return m_VecUnits == UNITS_KM; }
363			void ae2km(); // Convert position, velocity vector units from AE to km
364
365			protected:
366			void MulPos(double factor) { m_pos.Mul(factor); }
367			void MulVel(double factor) { m_vel.Mul(factor); }
368
369			enum VecUnits
370			{
371			UNITS_NONE, // not initialized
372			UNITS_AE,
373			UNITS_KM,
374			};
375
376			cVector m_pos;
377			cVector m_vel;
378			cJulian m_date;
379			VecUnits m_VecUnits;
380			};
381			#endif