Open Journal Systems

Analysis of the feasible GPS L1/CA code-smoothed receiver precision under the challenge of multipath

Julio Cesar Farret, Marcelo Carvalho dos Santos, Carlito Vieira de Moraes, Rogers Ademir Drumm Pereira


Since the creation of the NAVSTAR/GPS several sources of observational errors have been identified and studied. They include, among others, ionospheric delay and clock offsets. The error caused by multipath, however, persists as a challenge,
especially for applications that demand high accuracy. In Brazil, with the promulgation of Law 10267/2001 creating the National Cadastre of Rural Properties (CNIR), this challenge assumes a specific feature since it influences the applicability of the new cadastral system. The GPS receiver manufacturing companies have been making large investments in research to deal with multipath,
especially at receiver design level. This work performs an analysis of the applied technologies involved in the Leica GS20 GPS receiver in field conditions as realistic as possible similar to the ones encountered in geodetic surveys satisfying CNIR’s specifications. The results show the potential of using such receivers to certification works by the Instituto Nacional de Colonização e Reforma Agrária (INCRA). It also makes evident their limitations.


multicaminho; GPS; multipath; Delay Lock Loop; Phase Lock Loop