GravityEngine2.SGP4utils Class Reference

Classes
class	MDHMS

Static Public Member Functions
static MDHMS	Days2mdhms (int year, double days)
static string	EpochDateString (ref SGP4SatData satData)
static double[]	InvJday (double jd)
static double	JulianDate (int year, int mon, int day, int hr, int minute, double sec)
static bool	TLEtoSatData (string tleData, ref SGP4SatData satrec)

Static Public Attributes
static char	OPSMODE_AFSPC = 'a'
static char	OPSMODE_IMPROVED = 'i'
const double	pi = System.Math.PI

Detailed Description

19 June 2009

Author

Shawn E. Gano, shawn.nosp@m.@gan.nosp@m.o.nam.nosp@m.e

Member Function Documentation

InvJday()

static double[] GravityEngine2.SGP4utils.InvJday ( double jd )

static

---

                     procedure invjday

this procedure finds the year, month, day, hour, minute and second given the julian date. tu can be ut1, tdt, tdb, etc.

algorithm : set up starting values find leap year - use 1900 because 2000 is a leap year find the elapsed days through the year in a loop call routine to find each individual value

author : david vallado 719-573-2600 1 mar 2001

inputs description range / units jd - julian date days from 4713 bc

outputs : year - year 1900 .. 2100 mon - month 1 .. 12 day - day 1 .. 28,29,30,31 hr - hour 0 .. 23 min - minute 0 .. 59 sec - second 0.0 .. 59.999

locals : days - day of year plus fractional portion of a day days tu - julian centuries from 0 h jan 0, 1900 temp - temporary double values leapyrs - number of leap years from 1900

coupling : days2mdhms - finds month, day, hour, minute and second given days and year

references :

vallado 2007, 208, alg 22, ex 3-13

Parameters

jd

Returns

[year,mon,day,hr,minute,sec]

JulianDate()

static double GravityEngine2.SGP4utils.JulianDate ( int year, int mon, int day, int hr, int minute, double sec )

static

---

                     procedure jday

this procedure finds the julian date given the year, month, day, and time. the julian date is defined by each elapsed day since noon, jan 1, 4713 bc.

algorithm : calculate the answer in one step for efficiency

author : david vallado 719-573-2600 1 mar 2001

inputs description range / units year - year 1900 .. 2100 mon - month 1 .. 12 day - day 1 .. 28,29,30,31 hr - universal time hour 0 .. 23 min - universal time min 0 .. 59 sec - universal time sec 0.0 .. 59.999

outputs : jd - julian date days from 4713 bc

locals : none.

coupling : none.

references : vallado 2007, 189, alg 14, ex 3-14

---

Parameters

year
mon
day
hr
minute
sec

Returns

TLEtoSatData()

static bool GravityEngine2.SGP4utils.TLEtoSatData ( string tleData, ref SGP4SatData satrec )

static

Reads the data from the TLE and initializes the SGP4 propogator variables and stores them in the SGP4unit.Gravconsttype object DOES NOT PERFORM ANY INTERNAL CHECK BEYOND BASICS OF THE TLE DATA use other methods to do that if desired.

Parameters

satName
line1	TLE line 1
line2	TLE line 2
opsmode
whichconst	which constants to use in propogation
satrec	object to store the SGP4 data

Returns

if the sgp4 propogator was initialized properly

---

The documentation for this class was generated from the following file:

• ge2/GE2/Assets/GravityEngine2/Runtime/Core/Propagators/SGP4/SGP4utils.cs