A portable and inexpensive semi-differential GPS is developed. Some investigations are carried out for its practical use. The total weight of this system is about 500g including GPS receiver, data logger and their interface which can be easily taken out to field experiments. It costs only 150, 000 Japanese yen for a series of development which is as one tenth to one hundredth as the presently available differential GPS. With this system, relative positions from a fixed reference station can be measured within ±3 m as a root mean square difference, which is as accurate as the operational ones. The measured positions can be plotted on a computer map if a topographical or a digital map is available. This system is fully practical, for example, for getting ground truth data of a remote sensing or for developing a car navigation system in a town.
View full abstract