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Even for a simple amateur astrophotographer [1] the SDSS data is invaluable. It powers most of the target selection, and provides accurate coordinates for most

Even for a simple amateur astrophotographer [1] the SDSS data is invaluable. It powers most of the target selection, and provides accurate coordinates for most astronomical objects. Combined with Plate Solving, it makes my life much easier [2]. Take for example a well known tool "Sequence Generator Pro", I only have to type in a name and I can start imaging [3]. I can't thank the people enough who worked on this. I'm soon upgrading the telescope with a set of Sloan photometric filters (used in the survey) [4], and particularly interested in expanding my images with Near Infrared data. Which can also give very pretty pictures [5] [1]: my 2017 images https://www.flickr.com/photos/joelkuiper/38496747325/ https://www.flickr.com/photos/joelkuiper/38496747325/ [2]: http://cosmo.nyu.edu/hogg/research/2006/09/28/astrometry_google.pdf http://cosmo.nyu.edu/hogg/research/2006/09/28/astrometry_goo... [3]: https://www.flickr.com/photos/joelkuiper/24582661547 https://www.flickr.com/photos/joelkuiper/24582661547 [4]: http://astrodon.com/store/p12/Astrodon_Photometrics_Sloan_Filters.html http://astrodon.com/store/p12/Astrodon_Photometrics_Sloan_Fi... [5] http://trappedphotons.com/files/tmp/Making%20Pretty%20Pictures%20from%20Scientific%20Data.pdf http://trappedphotons.com/files/tmp/Making%20Pretty%20Pictur...

geokon 9y ago
The second link is fascinating. I've never come across this algorithm. What a clever solution! I'm a bit unclear on how the "quads" are chosen (ie. which 4 stars are grouped together). I assume your image and the sky-survey database you're comparing to are at a completely different detail-level. Choosing every combination of 4 stars seems not practical. If you just choose groups of 4 that are next to each other then you may find the database has dozens of stars in between your quad's stars (b/c it's at a higher detail level) The slides acknowledge this by saying " Finally, there is the additional problem of distractor & dropout stars", but I don't see their solution :) Maybe this is a clue "Cycle through all possible valid* quads (brightest first) and compute their corresponding codes" but there are no details.

geokon 9y ago

The second link is fascinating. I've never come across this algorithm. What a clever solution! I'm a bit unclear on how the "quads" are chosen (ie. which 4 stars are grouped together). I assume your image and the sky-survey database you're comparing to are at a completely different detail-level. Choosing every combination of 4 stars seems not practical. If you just choose groups of 4 that are next to each other then you may find the database has dozens of stars in between your quad's stars (b/c it's at a higher detail level) The slides acknowledge this by saying " Finally, there is the additional problem of distractor & dropout stars", but I don't see their solution :) Maybe this is a clue "Cycle through all possible valid* quads (brightest first) and compute their corresponding codes" but there are no details.