The catalogues were matched sequentially in the order listed. Selected object parameters were transferred to existing records and then new objects added.
Unless otherwise noted, only objects that matched within 2 arcseconds were retained.
| Step | GSC2 objects | Catalogue Matched | Catalogue Objects | Objects Matched | Objects Added |
|---|---|---|---|---|---|
| 1 | 945,443,930 | GAIA dr1 | 1,142,679,769 | 685,921,019 | 456,758,750 |
| 2 | 1,402,202,680 | APASS dr9 | 61,176,401 | 46,867,631 | 0 |
| 3 | 1,402,202,680 | UCAC5 | 107,758,513 | 107,758,513 | 0 |
| 4 | 1,402,202,680 | 2MASS | 496,911,362 | 449,162,648 | 47,748,714 |
| 5 | 1,449,951,394 | SDSS dr13 | 469,050,976 | 161,761,097 | 307,289,879 |
| 6 | 1,757,241,273 | VISTA VHS dr4 | 1,155,634,198 | 430,865,659 | 631,411,390 |
| 7 | 2,388,652,663 | VISTA VIKING dr2 | 46,270,162 | 5,820,583 | 40,449,939 |
| 8 | 2,429,102,602 | VST ATLAS dr3 | 105,132,174 | 49,708,717 | 55,423,457 |
| 9 | 2,484,526,059 | KIDS dr3 | 48,736,590 | 17,196,222 | 31,540,368 |
| 10* | 2,516,066,427 | PanSTARRS dr1-best | 1,919,106,885 | 1,162,635,062 | 756,604,569 |
| 11 |
GSC2411 was released at step 10 prior to matching PanSTARRS.
