tdbjuliandate

Convert from Barycentric Dynamical Time Estimate to Julian date

Syntax

jdtdb = tdbjuliandate(terrestrial_time)

[jdtdb,tttdb] = tdbjuliandate(terrestrial_time)

Description

jdtdb = tdbjuliandate(terrestrial_time) returns an estimate of the Julian date for Barycentric Dynamical Time (TDB). These estimations are valid for the years 1980 to 2050.

[jdtdb,tttdb] = tdbjuliandate(terrestrial_time) additionally returns an array of Julian dates for the Barycentric Dynamical Time (TDB) based on the Terrestrial Time (TT).

Examples

Estimate Julian Date for Barycentric Dynamical Time

Estimate the Julian date for the Barycentric Dynamical Time for the Terrestrial Time 2014/10/15 16:22:31.

jdtdb = tdbjuliandate([2014,10,15,16,22,31])

jdtdb =

   2.4569e+06

Estimate Julian Dates for the Barycentric Dynamical Time and TT-TDB

Estimate the Julian dates for the Barycentric Dynamical Time and TT-TDB in seconds for the terrestrial time 2014/10/15 16:22:31 and 2010/7/22 1:57:17.

[jdtdb,tttdb] = tdbjuliandate([2014,10,15,16,22,31;2010,7,22,1,57,17])

JDTDB =

   1.0e+06 *

    2.4569
    2.4554


TTTTDB =

    0.0016
    0.0005

Input Arguments

terrestrial_time — Terrestrial Time

1-by-6 array | M-by-6 array

Terrestrial Time (TT) in year, month, day, hour, minutes, and seconds for which the function calculates the Julian date for Barycentric Dynamical Time. M is the number of Julian dates, one for each TT date. Specify values for year, month, day, hour, and minutes as whole numbers.

Output Arguments

jdtdb — Julian date

M-by-1 array

Julian date for the Barycentric Dynamical Time, returned as an M-by-1 array. M is the number of rows, one for each Terrestrial Time input.

tttdb — Difference in seconds

M-by-1 array

Difference in seconds between Terrestrial Time and Barycentric Dynamical Time (TT-TDB), returned as an M-by-1 array. M is the number of rows, one for each Terrestrial Time input.

Limitations

Fundamentals of Astrodynamics and Applications[1] indicates an accuracy of 50 microseconds, which this function cannot achieve due to numerical issues with the values involved.

References

[1] Vallado, D. A., Fundamentals of Astrodynamics and Applications, New York: McGraw-Hill, 1997.