aeroReadIERSData

File containing current International Astronomical Union (IAU) 2000A Earth orientation data

Syntax

file = aeroReadIERSData(foldername)

file = aeroReadIERSData(foldername,'url',urladdress)

Description

file = aeroReadIERSData(foldername) creates a MAT file, file, based on IAU 2000A Earth orientation data from the International Earth Rotation and Reference Systems Service (IERS). It saves the file to foldername. file name has the format aeroiersdataYYYYMMDD.mat, where:

• YYYY - Year

• MM - Month

• DD - Day

file = aeroReadIERSData(foldername,'url',urladdress) creates the MAT file based on Earth orientation data from a specific web site or data file.

Examples

Create File from IERS Data

This example shows how to create the Earth orientation file for the current day or a specified website.

Create File from Specified Website

Create the Earth orientation file for the current day, in the current folder, using data from the default https://maia.usno.navy.mil/ser7/finals2000A.data website.

aeroReadIERSData(pwd)

ans = 
'C:\Users\peters\OneDrive - MathWorks\Documents\MATLAB\ExampleManager\peters.Bdoc25b.j2988169\aero-ex20368314\aeroiersdata20250812.mat'

Create File from Specified Website

Create the Earth orientation file for the current day, in the current folder, using data from the alternate https://datacenter.iers.org/data/latestVersion/10_FINALS.DATA_IAU2000_V2013_0110.txt website.

aeroReadIERSData(pwd,'url','https://datacenter.iers.org/data/latestVersion/10_FINALS.DATA_IAU2000_V2013_0110.txt')

ans = 
'C:\Users\peters\OneDrive - MathWorks\Documents\MATLAB\ExampleManager\peters.Bdoc25b.j2988169\aero-ex20368314\aeroiersdata20250812.mat'

Create File from Specified File

Create the Earth orientation file for the current day, in the current folder, using data from a specified file file:///C:\Documents\final2000A.data.

aeroReadIERSData(pwd,'url','file:///C:\Documents\finals2000A.data')

Input Arguments

foldername — Folder for IERS data file

folder name

Folder for IERS data file, specified as a character array or string. Before running this function, create foldername with write permission.

Data Types: char | string

'url',urladdress — Optional web site or Earth orientation data file

https://maia.usno.navy.mil/ser7/finals2000A.data (default) | web site address | file name

Optional web site or file containing the IAU 2000A Earth orientation data, specified as a web site address or file name.

Note

If you receive an error message while accessing the default site, use one of these alternate sites:

• https://datacenter.iers.org/data/latestVersion/10_FINALS.DATA_IAU2000_V2013_0110.txt

• ftp://ftp.iers.org/products/eop/rapid/standard/finals2000A.data

Example: https://datacenter.iers.org/data/latestVersion/10_FINALS.DATA_IAU2000_V2013_0110.txt

Data Types: char | string

Output Arguments

file — Location of Earth orientation data MAT file

character array

Location of Earth orientation data MAT file, specified as a character array.

More About

International Astronomical Union (IAU) 2000A Earth Orientation Data Format

The function expects the International Astronomical Union (IAU) 2000A Earth orientation data to use the format referenced here https://maia.usno.navy.mil/ser7/finals2000A.data:

Column	Description
1 to 2	Year (to get true calendar year, add 1900 for MJD<=51543 or add 2000 for MJD>=51544)
3 to 4	Month number
5 to 6	Day of month
7	Blank
8 to 15	Fractional modified Julian date (MJD UTC)
16	Blank
17	IERS (I) or Prediction (P) flag for Bull. A polar motion values*
18	Blank
19 to 27	Bull. A PM-x (sec. of arc)*
28-36	Error in PM-x (sec. of arc)*
37	Blank
38-46	Bull. A PM-y (sec. of arc)*
47-55	Error in PM-y (sec. of arc)*
56-57	Blank
58	IERS (I) or Prediction (P) flag for Bulletin A UT1-UTC values*
59-68	Bull. A UT1-UTC (sec. of time)*
69-78	Error in UT1-UTC (sec. of time)*
79	Blank
80-86	Bull. A LOD (msec. of time) -- not always filled*
87-93	Error in LOD (msec. of time) -- not always filled*
94-95	Blank
96	IERS (I) or Prediction (P) flag for Bull. A nutation values*
97	Blank
98-106	Bull. A dX wrt IAU2000A nutation (msec. of arc), free core nutation not removed*
107-115	Error in dX (msec. of arc)
116	Blank
117-125	Bull. A dY wrt IAU2000A nutation (msec. of arc), free core nutation not removed*
126-134	Error in dY (msec. of arc)
135-144	Bull. B PM-x (sec. of arc)*
145-154	Bull. B PM-x (sec. of arc)*
155-165	Bull. B UT1-UTC (sec. of time)*
166-175	Bull. B dX wrt IAU2000A nutation (msec. of arc)*
176-185	Bull. B dY wrt IAU2000A nutation (msec. of arc)*

* Abbreviated terms:

• Bull. — Bulletin

• LOD — Length of day

• wrt — With regard to

• pm — Polar motion

Version History

Introduced in R2017b