the [*NOAO Science Archive*]{} (known also as the NOAO NVO Portal) [@Miller2007] which allows VO-compliant access to imaging data taken with major American telescopes in Arizona and Chile. In 2012 we manually selected the first NVO instrument archives to ingest in [*Mega-Archive*]{}. Until today we included almost 5 million NVO images from 19 imaging instruments mounted on 10 telescopes. The NVO collection is available for searches from the NOAO Science Archive website[^12]. Two options are possible, proprietary data access (requiring login) and general search for NOAO data (available for any other user). We used the second choice with the following options in the Simple Query Form:

[**The Subaru-Mitaka-Okayama-Kiso Archive (SMOKA)**]{} was built in 2001 to store the images taken with major Japanese telescopes [@baba2002]. It requires user registration and login before providing the FITS images, but the meta-data could be retrieved without registration. The [*Mega-Archive*]{} includes more than one million images from 17 instruments installed on 4 Japanese telescopes. The SMOKA Archive Advance Search[^13] provides meta-data selected based on the instruments and date intervals, allowing an output of maximum 20,000 rows in one query. We used the following parameters to search all available SMOKA images:

Other Instrument Archives
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Additionally 