Summary: This technical note describes the mathematical process used to solve a least square problem in space astrometry that presents an Helmert blocking structure. We focus particularly on its implementation in ODAS. We assume that the reader is familiar with the space astrometric least square problem.

Bibtex entry for this abstract:

@UNPUBLISHED{LL:APB-002,
author = {A.~Bombrun},
title={{H}elmert blocking algebra in {O}{D}{A}{S}},
institution={Astronomisches Rechen-Institut, Heidelberg (part of ZAH, Zentrum fuer Astronomie, Heidelberg)},
year={2008},
month={December},
url={http://www.rssd.esa.int/doc_fetch.php?id=2865094},
note={GAIA-C3-TN-ARI-APB-002},
type={Technical note}
}