THIS SUBROUTINE COMPUTES THE GREENWICH SIDEREAL TIME (EITHER MEAN OR APPARENT) AT JULIAN DATE TJDH + TJDL.
TJDH = UT1 JULIAN DATE, HIGH-ORDER PART (IN)
TJDL = UT1 JULIAN DATE, LOW-ORDER PART (IN)
THE JULIAN DATE MAY BE SPLIT AT ANY POINT, BUT
FOR HIGHEST PRECISION, SET TJDH TO BE THE INTEGRAL
PART OF THE JULIAN DATE, AND SET TJDL TO BE THE
FRACTIONAL PART
K = TIME SELECTION CODE (IN)
SET K=0 FOR GREENWICH MEAN SIDEREAL TIME
SET K=1 FOR GREENWICH APPARENT SIDEREAL TIME
GST = GREENWICH (MEAN OR APPARENT) SIDEREAL TIME
IN HOURS (OUT)
NOTE: SEE ALSO SUBROUTINE SETDT TO SET THE VALUE OF DELTA-T (DELTA-T = TT - UT1) TO BE USED HERE.
Type | Intent | Optional | Attributes | Name | ||
---|---|---|---|---|---|---|
real(kind=wp) | :: | tjdh | ||||
real(kind=wp) | :: | tjdl | ||||
integer | :: | k | ||||
real(kind=wp) | :: | gst |