Table 9.
Number of ICRF3 defining sources at each frequency band and statistics about coordinate uncertainties, correlation coefficients between right ascension and declination, and the error ellipse size (semi-major axis) for these sources.
| Statistics for all defining sources |
Statistics for the common defining sources |
||||||||
|---|---|---|---|---|---|---|---|---|---|
| Frequency | Number of | Coordinate uncertainty | Correlation | Error ellipse | Coordinate uncertainty | Correlation | Error ellipse | ||
| band | sources | α cos δ | δ | coeff. | (μas) | α cos δ | δ | coeff. | (μas) |
| (μas) | (μas) | (μas) | (μas) | ||||||
| S/X | 303 | 36 | 41 | 0.07 | 41 | 33 | 35 | 0.06 | 35 |
| K | 193 | 63 | 120 | 0.28 | 122 | 60 | 113 | 0.27 | 115 |
| X/Ka | 176 | 62 | 92 | 0.40 | 98 | 62 | 92 | 0.40 | 97 |
Notes. Statistics are provided for all defining sources in each catalog and for the 171 defining sources common to the three catalogs. All values reported in columns 3–10 are median values.
Current usage metrics show cumulative count of Article Views (full-text article views including HTML views, PDF and ePub downloads, according to the available data) and Abstracts Views on Vision4Press platform.
Data correspond to usage on the plateform after 2015. The current usage metrics is available 48-96 hours after online publication and is updated daily on week days.
Initial download of the metrics may take a while.