Cross-Matching Multiple Spatial Observations and Dealing with Missing Data

: Cross-match spatially clusters and organizes several astronomical point-source measurements from one or more surveys. Ideally, each object would be found in each survey. Unfortunately, the observation conditions and the objects themselves change continually. Even some stationary objects are missing in some observations; sometimes objects have a variable light flux and sometimes the seeing is worse. In most cases we are faced with a substantial number of differences in object detections between surveys and between observations taken at different times within the same survey or instrument. Dealing with such missing observations is a difficult problem. The first step is to classify misses as ephemeral – when the object moved or simply disappeared, masked – when noise hid or corrupted the object observation, or edge – when the object was near the edge of the observational field. This classification and a spatial library to represent and manipulate observational footprints help cons...

• Type: Journal
• Year: 2007
• Where: CORR
• Authors: Jim Gray, Alexander S. Szalay, Tamas Budavari, Robert Lupton, María A. Nieto-Santisteban, Ani Thakar
• Keywords: Astronomical Point-source Measurements, CORR 2007, Education, Observations, Variable Light Flux