抄録
In the past time, “GPS” was the only one available satellite system for the global positioning. During the last decade, “GNSS” has become popular as a general term of satellite based global positioning system which includes GPS and other satellite systems such as GLONASS of Russia. Recently, as deployment plans, such as QZSS (=Quasi-Zenith Satellite System) of Japan, Chinese BeiDou, Galileo of EU, and IRNSS of India, progressed steadily and two or more global positioning systems can be used simultaneously, the multi-GNSS environment became realistic. This report expounds the effect of multi-GNSS and the latest information relating to the multi-GNSS receivers, especially the surveying instruments for which the positioning results of cm order are required.
