To measure the depth of water easily with high accuracy by combining the GPS with a staff.
GPS antennas 2, 3 are installed at the upper part of a staff body 1 having lower end provided with a ground sensor 4. A fixed station 10 is installed on the ground. The staff 1 is lowered to the bottom of water and the grounding sensor 4 is grounded. When a measurement start switch is turned on and the grounding sensor 4 is grounded with a specified pressure, a measurement is carried out. In the measurement, the position of GPS antenna 2, 3 is determined kinematically with reference to the position of fixed station 10. After determining the positional coordinates of GPS antenna 2, 3, the line connecting the positions is extended to the grounding sensor 4 thus determining the position of grounding sensor 4 and thereby, the position of measuring point on the bottom of the water.
MATSUMOTO TSUGIO
HIRAYAMA ISAMU
FURUNO ELECTRIC CO
| JPH0771960A | 1995-03-17 | |||
| JPH0694456A | 1994-04-05 | |||
| JPH0381511U | 1991-08-20 |