Project summary

For more specifics about the current state of the project, see the presentation by Roweis to Google Pittsburgh, available here (ppt) or here (pdf).

We are building an “astrometry engine” to create correct, standards-compliant astrometric meta data for every useful astronomical image ever taken, past and future, in any state of archival disarray.

The astrometry engine will take any image and return the astrometry world coordinate system (WCS)—ie, a standards-based description of the (usually nonlinear) transformation between image coordinates and sky coordinates—with absolutely no “false positives” (but maybe some “no answers”). It will do its best, even when the input image has no—or totally incorrect—meta-data.

We intend to install the engine for real-time operation on the web, at observatories, at plate-scanning projects, and at data archives.

Intellectual merit

The removal of astrometry as a barrier to using legacy and badly archived (or not archived) data will greatly extend astronomical time baselines into the past, and greatly increase time sampling for sources all over the sky. It facilitates work with distributed, heterogeneous data sets. It also provides a channel for professional and amateur astronomers to collaborate, as the installation of correct WCS makes currently hard-to-access amateur imaging data interoperable with professional projects.

We have elucidated and solved a fundamental computer science problem in the field of geometric hashing: the fast and efficient search for matches to patches of a two-dimensional set of points, when the patch to be matched has unknown location, scale, orientation, and completeness or contamination, as well as realistic errors. Efficient and robust algorithms for this matching problem will be the basis for attacking many highly non-trivial problems in pattern matching, data analysis, and computer vision.

Broader impacts

If there are a few thousand US ground-based observing programs anually with a person-week or so spent on astrometry, an astrometry engine would effectively pay the entire astrophysics community a few million US dollars per year in perpetuity.

The engine will be made freely mirror-able anywhere by anyone, and we will provide support for mirroring. We will also provide our algorithms and code to the public.

By setting the engine loose on historical, scanned, and amateur data, we will enlarge, test, and improve astronomy's burgeoning public data archives, for science and education.


Belorussian translation provided by Patricia Claisnitzer, hosted by fatcow.