Differential Precise Positioning by using Low Cost GPS

• Main Authors: Atunggal, Dedi, Widjajanti, Nurrohmat, Cahyono, Bambang Kun, Matori, Abdul Nasir
• Format: Conference or Workshop Item PeerReviewed
• Language: English
• Published: 2008
• Subjects: Geomatic Engineering; Geodesy; Surveying (incl. Hydrographic Surveying); Engineering
• Online Access: https://repository.ugm.ac.id/276014/1/_SIP6.pdf; https://repository.ugm.ac.id/276014/
• Institution: Universitas Gadjah Mada

The use of Global Positioning System (GPS) for positioning, mapping and navigation has been rapidly developed. Different application scenarios and accuracy levels require different receiver classes, from a high-end geodetic receiver to a low-cost handheld receiver. Handheld GPS receiver has been employed only for recreational purposes where low-accuracy will suffice. This is because handheld GPS only provides real-time position which utilizes C/A code (Coarse Acquisition) where the accuracy is commonly at a few meters. Some handheld GPS receivers use carrier-smoothed code to produce more precise position. Theoretically, the use of either P code or L1 carrier phase for differential postprocessed positioning will provide higher accuracy up to decimeter or centimeter level. For this current experiment, a low-cost handheld GPS receiver, Garmin eTrex Vista, was applied as the main equipment and was compared to a set of standard geodetic GPS receiver. The L1 carrier phase and the P code data of the handheld receivers are downloaded and transferred to a notebook in real-time due to the lack of memory within the GPS receiver. The stored raw data are converted to RINEX file and are processed using commercial GPS software. The result reveals that a 30-minutes period of static positioning gives a fine result of centimeter accuracy.