SYSTEM OF MEASURING WITH GPS FOR UNDERGROUND MAP

摘要

PURPOSE: A GPS base geodetic surveying system for manufacturing a map of underground facilities is provided to accurately record location information and topographic information of the underground facilities and to renew the location information and the topographic information of the underground facilities when topography is changed. CONSTITUTION: An underground detecting unit(1310) comprises an RFID sensor(1311), a first flux gate sensor(1312), and a second flux gate sensor(1313). The RFID sensor wirelessly detects an ID or a unique number which is wirelessly outputted from an RFID included in a magnetic marker unit. The first flux gate sensor and the second flux gate sensor respectively measure a magnetic field generated in the magnetic marker unit in its own location. A digital gradient meter(1320) digitally mixes a magnetic field wave form inputted from the first flux gate sensor and the second flux gate sensor.