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 | Release |
|---|---|---|---|---|---|---|
| 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 | 524,222,808 | 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 | GSC2411 |
| 10 | 2,516,066,427 | PanSTARRS dr1-best | 1,919,106,885 | 1,162,502,316 | 756,604,569 | |
| 11 | 3,272,670,996 | ALLWISE | 747,634,026 | 577,692,464 | 169,941,562 | |
| 12 | 3,442,612,558 | SkyMapper dr1 | 285,159,194 | 278,372,291 | 6,786,903 | |
| 13 | 3,449,399,461 | GALEX AIS | 82,992,086 | 45,629,534 | 37,376,932 | GSC2412 |
| 14 | 3,486,776,393 |
GSC2411 was released at step 10 prior to matching PanSTARRS.
