Spatial Queries on Astronomic Data

PhD Qualifying Examination


Title: "Spatial Queries on Astronomic Data"

by

Miss Xiaoying JIA


Abstract:

We survey the state of the art on spatial query processing on astronomic 
catalogs.  Astronomic catalogs are produced from telescope data and 
contain position information of celestial objects in the sky. These 
celestial objects are recorded as two-dimensional points in the equatorial 
coordinate system, and each table may consist of millions to billions of 
them.

Typical spatial queries on astronomic catalogs include range search and 
cross match, or spatial join. Traditional spatial database research has 
proposed well-known techniques for both types of queries; however, due to 
the characteristics of astronomic data processing and the scientific focus 
of astronomers, astronomic spatial query processing techniques remain at a 
rather preliminary stage. Specifically, range searches are typically done 
via a Hierarchical Triangular Mesh (HTM) index, and cross-match queries 
are processed in a filter-and-refinement approach. As such, we survey 
traditional spatial query processing techniques, such as B-tree, 
Z-ordering, and R-tree for range search, and nested-loops and plane 
sweeping for joins, and discuss whether and how these techniques can be 
adapted and applied to process astronomic spatial queries.


Date:			Friday, 16 January 2015

Time:                  	10:00am - 12:00noon

Venue:                  Room 3494
                         Lifts 25/26

Committee Members:	Dr. Qiong Luo (Supervisor)
 			Dr. Lei Chen (Chairperson)
 			Dr. Raymond Wong
 			Dr. Ke Yi


**** ALL are Welcome ****