Calculate difference between principal Universal Time (UT1) and Coordinated Universal Time (UTC) according to International Astronomical Union (IAU) 2000A reference system
Utilities / Axes Transformations
The Delta UT1 block calculates the difference between principal UT1 and UTC according to the IAU 2000A reference system and Earth orientation data. By default, this block uses a prepopulated list of International Astronomical Union (IAU) 2000A Earth orientation (IERS) data. This list contains measured and calculated (predicted) data supplied by the IERS. The IERS measures and calculates this data for a set of predetermined dates. For dates after those listed in the prepopulated list, Delta UT1 calculates the data using this equation, limiting the values to +/- .9s:
ΔUT1— Difference between UT1 and UTC
Difference between UT1 and UTC.
IERS data file— Earth orientation data
aeroiersdata.mat(default) | MAT-file
Custom list of Earth orientation data, specified in a MAT-file.
Action for out-of-range input— Out-of-range action
Out-of-range action, specified as a string.
Action to take in case of out-of-range or predicted value dates, specified as a string:
Warning — Displays warning and indicates that the dates were out-of-range or predicted values.
Error — Displays error and indicates that the dates were out-of-range or predicted values.
None — Does not display warning or error.
IERS data URL— Website or Earth orientation data file
http://maia.usno.navy.mil/ser7/finals2000A.data(default) | website address | file name
Website or Earth orientation data file containing the Earth orientation data according to the IAU 2000A, specified as a website address or file name.
Destination folder— Folder for IERS data file
Folder for IERS data file, specified as a character array or string. Before running this function, create foldername with write permission.
To create the IERS data file in the destination folder, click the Create button.