GlobalTop does not provide sub-meter accuracy GPS that are typically found in expensive survey equipment.

Generally, GPS accuracy can be increased by insuring the GPS module is used in an open sky environment. It is best if the GPS module is not used beside a large water body such as lake or ocean, or other tall constructions to lower the chance of multi-path signals.

User can also use DGPS (WAAS, EGNOS) and RTCM (on selected models) to increase GPS accuracy. By comparing the GPS signal received to a precisely known location, it is possible to increase the accuracy to around 2.5M. It is not sub-meter quality, but it is the best GlobalTop can offer for now.