SOFA - Online
SOFA - Standards Of Fundamental Astronomy
The SOFA software library is a collection of routines which implement official IAU algorithms for fundamental astronomical calculations. The SOFA library is written in FORTRAN 77 and comprises 108 astronomical routines which are facilitated by 52 vector/matrix routines. These algorithms have been worked out and reviewed by an international panel, the SOFA Reviewing Board, appointed through IAU Division 1.
The SOFA product distribution service is coordinated from the Space Science & Technology Department, STFC Rutherford Appleton Laboratory, Harwell Science and Innovation Campus, DIDCOT, Oxfordshire OX11 0QX, United Kingdom.
Further information on SOFA:
Examplary applications
Some of the SOFA routines are available as interactive applications on this web site. For this purpose a few simple astronomical/geodetic calculations have been chosen. This offer will be extended if necessary.
To use these application JAVA script has to be activated and pup-up windows must be allowed. Every application starts with its own window so that multiple applications can be started parallel.
Calendar Functions:
- Conversion from Gregorian Calendar zu Julian Date
- Conversion from Julian Date to Gregorian Calendar
- Conversion from Julian Date to Julian Epoch
- Conversion from Julian Epoch to Julian Date
- Conversion from Julian Date to Besselian Epoch
- Conversion from Besselian Epoch to Julian Date
Time Scales:
- Calculation of Greenwich Sidereal Time with IAU 2000 model
- Calculation of Greenwich Sidereal Time with IAU 2006 model
Ephemerides:
Reference Systems (precession and nutation)
- Conversion from celestial to terrestrial coordinates with IAU 2000 model
- Conversion from celestial to terrestrial coordinates with IAU 2006 model
- Nutation and Precession (different time-dependent transformation matrices), IAU 2000 model
- Nutation und Precession (different time-dependent transformation matrices), IAU 2006 model