techniques, such as through instrument improvements and compensations to the data. The results are then analyzed using statistical methods to compute data estimates and error ranges. Computer programs XParallax viu (Free application for Windows) Astrometrica (Application for Windows) Astrometry.net (Online blind astrometry) See also References Further reading External links MPC Guide to Minor Body Astrometry Astrometry Department of the U.S. Naval Observatory USNO Astrometric Catalog and related Products Planet-Like Body Discovered at Fringes of Our Solar System (2004-03-15) Mike Brown's Caltech Home Page Scientific Paper describing Sedna's discovery The Hipparcos Space Astrometry Mission — on ESA Astronomical sub-disciplines Astrological aspects Measurement