title: On the Helmert-blocking technique: its acceleration by block Choleski decomposition and formulae to insert observations into an adjusted network.
abstract: The Helmert-blocking technique is a common approach to adjust large geodetic networks like Europeans and Brazilians. The technique is based upon a division of the network into partial networks called blocks. This way, the global network adjustment can be done by manipulating these blocks. Here we show alternatives to solve the block system that arises from the application of the technique. We show an alternative that optimizes its implementation as the elapsed processing time is decreased by about 33%. We also show that to insert observations into an adjusted network it is not necessary to readjust the whole network. We show the formulae to insert new observations into an adjusted network that are more efficient than simply readjusting the whole new network.
authors.affiliation: Geodesy Laboratory, Department of Geophysics, Graduate School of Science , Kyoto University , 1/252 Kyoto, Japan ; Instituto Militar de Engenharia, Programa de Pós-graduação em Engenharia de Defesa , Seção de Engenharia Cartográfica, SE/6, Rio de Janeiro, Brazil ; Pontifícia Universidade Católica do Rio de Janeiro, Programa de Pós-graduação em Metrologia para Qualidade e Inovação , Rio de Janeiro, Brazil.
authors.forename: Eduardo
authors.identifier: 0000-0002-0084-0574
authors.initials: E
authors.lastname: Del Rio
authors.affiliation: Instituto Militar de Engenharia, Programa de Pós-graduação em Engenharia de Defesa , Seção de Engenharia Cartográfica, SE/6, Rio de Janeiro, Brazil.
authors.forename: Leonardo
authors.initials: L
authors.lastname: Oliveira
keywords: Helmert-blocking; block Choleski decomposition; block system; insertion of new observations; large geodetic networks