Changeset 3371

Timestamp:

03/01/04 15:33:06 (21 years ago)

Author:

tbretz

Message:

*** empty log message ***

Location:

trunk/MagicSoft/Mars

Files:

• Changelog (modified) (2 diffs)
• mastro/MAstro.cc (modified) (5 diffs)
• mastro/MAstro.h (modified) (2 diffs)
• mbase/MTime.cc (modified) (1 diff)
• mbase/MTime.h (modified) (2 diffs)

trunk/MagicSoft/Mars/Changelog

@@ -9 +9 @@
      - now the arrival time is at the half max of the spline:
        half max = (maximum - pedestal)/2
+
+
 
  2004/03/01: Wolfgang Wittek
@@ -28 +30 @@
      - fixed a bug in determin the file-type
 
+   * mbase/MTime.[h,cc]:
+     - added GetGmst() member function
+
    * mastro/MAstro.[h,cc]:
      - added Coordinate2Angle
      - added AngularDistance
+     - implemented UT2GMST
+     - replaced defined by TMath::Pi()
 
    * mastro/MObservatory.[h,cc]:

trunk/MagicSoft/Mars/mastro/MAstro.cc

@@ -18 +18 @@
 !   Author(s): Thomas Bretz, 11/2003 <mailto:tbretz@astro.uni-wuerzburg.de>
 !
-!   Copyright: MAGIC Software Development, 2000-2003
+!   Copyright: MAGIC Software Development, 2000-2004
 !
 !
@@ -33 +33 @@
 #include <TVector3.h> // TVector3
 
+#include "MTime.h"    // MTime::GetGmst
+
 ClassImp(MAstro);
 
@@ -56 +58 @@
 {
     /* pi/(180*3600):  arcseconds to radians */
-#define DAS2R 4.8481368110953599358991410235794797595635330237270e-6
-    return Hms2Sec(deg, min, sec, sgn)*DAS2R;
+    //#define DAS2R 4.8481368110953599358991410235794797595635330237270e-6
+    return Hms2Sec(deg, min, sec, sgn)*TMath::Pi()/(180*3600)/**DAS2R*/;
 }
 
@@ -63 +65 @@
 {
     /* pi/(12*3600):  seconds of time to radians */
-#define DS2R 7.2722052166430399038487115353692196393452995355905e-5
-    return Hms2Sec(hor, min, sec, sgn)*DS2R;
+//#define DS2R 7.2722052166430399038487115353692196393452995355905e-5
+    return Hms2Sec(hor, min, sec, sgn)*TMath::Pi()/(12*3600)/**DS2R*/;
 }
 
@@ -295 +297 @@
     return v0.Angle(v1);
 }
+
+// --------------------------------------------------------------------------
+//
+// Calls MTime::GetGmst() Better use MTime::GetGmst() directly
+//
+Double_t MAstro::UT2GMST(Double_t ut1)
+{
+    return MTime(ut1).GetGmst();
+}

trunk/MagicSoft/Mars/mastro/MAstro.h

@@ -13 +13 @@
 
 public:
+    // Angle/Time conversion functions
     static Double_t Hms2Sec(Int_t deg, UInt_t min, Double_t sec, char sgn='+');
     static Double_t Dms2Rad(Int_t deg, UInt_t min, Double_t sec, Char_t sgn='+');
@@ -37 +38 @@
     static void Hor2Hm(Double_t rad, Char_t &sgn, UShort_t &deg, Double_t &min);
 
+    // Angle treatment functions
     static Bool_t String2Angle(TString &str, Double_t &ret);
     static Bool_t Coordinate2Angle(const TString &str, Double_t &ret);
 
     static Double_t AngularDistance(Double_t theta0, Double_t phi0, Double_t theta1, Double_t phi1);
- 
+
+    // Time treatment functions
     static void  Mjd2Ymd(UInt_t mjd, UShort_t &y, Byte_t &m, Byte_t &d);
     static Int_t Ymd2Mjd(UShort_t y, Byte_t m, Byte_t d);
+
+    static Double_t UT2GMST(Double_t ut1);
 
     ClassDef(MAstro, 0)

trunk/MagicSoft/Mars/mbase/MTime.cc

@@ -317 +317 @@
     return kTRUE;
 
+}
+
+// --------------------------------------------------------------------------
+//
+//  Conversion from Universal Time to Greenwich mean sidereal time,
+//  with rounding errors minimized.
+//
+//  The result is the Greenwich Mean Sidereal Time (radians)
+//
+//  There is no restriction on how the UT is apportioned between the
+//  date and ut1 arguments.  Either of the two arguments could, for
+//  example, be zero and the entire date+time supplied in the other.
+//  However, the routine is designed to deliver maximum accuracy when
+//  the date argument is a whole number and the ut argument lies in
+//  the range 0 to 1, or vice versa.
+//
+//  The algorithm is based on the IAU 1982 expression (see page S15 of
+//  the 1984 Astronomical Almanac).  This is always described as giving
+//  the GMST at 0 hours UT1.  In fact, it gives the difference between
+//  the GMST and the UT, the steady 4-minutes-per-day drawing-ahead of
+//  ST with respect to UT.  When whole days are ignored, the expression
+//  happens to equal the GMST at 0 hours UT1 each day.
+//
+//  In this routine, the entire UT1 (the sum of the two arguments date
+//  and ut) is used directly as the argument for the standard formula.
+//  The UT1 is then added, but omitting whole days to conserve accuracy.
+//
+//  The extra numerical precision delivered by the present routine is
+//  unlikely to be important in an absolute sense, but may be useful
+//  when critically comparing algorithms and in applications where two
+//  sidereal times close together are differenced.
+//
+Double_t MTime::GetGmst() const
+{
+    const Double_t ut = (Double_t)(fNanoSec/1e6+(Long_t)fTime)/kDay;
+
+    // Julian centuries since J2000.
+    const Double_t t = (ut -(51544.5-fMjd)) / 36525.0;
+
+    // GMST at this UT1
+    const Double_t r1 = 24110.54841+(8640184.812866+(0.093104-6.2e-6*t)*t)*t;
+    const Double_t r2 = 86400.0*ut;
+
+    const Double_t sum = (r1+r2)/(24*3600);
+
+    return fmod(sum, 1)*TMath::TwoPi()+TMath::TwoPi();
 }
 

trunk/MagicSoft/Mars/mbase/MTime.h

@@ -56 +56 @@
         Set(tm);
     }
-    MTime(Double_t d);
+    MTime(Double_t mjd);
     MTime(const MTime& t) : fMjd(t.fMjd), fTime(t.fTime), fNanoSec(t.fNanoSec)
     {
@@ -85 +85 @@
     void     SetMjd(Double_t m);
     Double_t GetMjd() const;
+    Double_t GetGmst() const;
     TString  GetString() const;
     TString  GetStringFmt(const char *fmt=0) const;