摘要：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 Ashtech Promark 2 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.
其他摘要：Since the creation of the NAVSTAR/GPS several sources of observational errorshave been identified and studied. They include, among others, ionospheric delayand clock offsets. The error caused by multipath, however, persists as a challenge,especially for applications that demand high accuracy. In Brazil, with thepromulgation of Law 10267/2001 creating the National Cadastre of RuralProperties (CNIR), this challenge assumes a specific feature since it influences theapplicability of the new cadastral system. The GPS receiver manufacturingcompanies have been making large investments in research to deal with multipath,especially at receiver design level. This work performs an analysis of the appliedtechnologies involved in the Ashtech Promark 2 GPS receiver in field conditions asrealistic as possible similar to the ones encountered in geodetic surveys satisfyingCNIR’s specifications. The results show the potential of using such receivers tocertification works by the Instituto Nacional de Colonização e Reforma Agrária(INCRA). It also makes evident their limitations.
