Nippon Telegraph and Telephone Corporation

Panasonic Intellectual Property Management Co., Ltd.

Yoshihiro Iriyama

Suguru Oguchi

Norihiro Fujimoto

Yasuhisa Yamazaki

Masashi Shintaku

Keisuke Kakimoto

Kenji Hiyoshi

Mamoru Kanayama

An absolute coordinate acquisition method is an absolute coordinate acquisition method for acquiring absolute coordinates of an underground pipeline, the method including: a marking step Sof setting a plurality of reference points on a road surface and setting a measurement point on a pipeline installed inside an excavated ditch; a measurement step Sof measuring absolute coordinates of the reference points; a relative position calculation step (Sto S) of calculating relative positions of the reference points and the measurement point to a reference position; and an absolute coordinate calculation step Sof calculating absolute coordinates of the measurement point based on the absolute coordinates of the reference points and the relative positions of the reference points and the measurement point.

Absolute coordinate acquisition method

A conduit inspection method includes a first specifying step (S) of specifying, as a normal section of a conduit, a section from a first end (Pa) of the conduit that is connected to one manhole to a first position (P1) in the conduit at which airtightness can be confirmed, a second specifying step (S) of specifying, as a normal section of the conduit, a section from a second end (Pb) of the conduit that is connected to another manhole to a second position (P2) in the conduit at which airtightness can be confirmed, and a third specifying step (S) of specifying a section from the first position (P1) to the second position (P2) as an abnormal section of the conduit.

Pipeline inspection method for carrying out an airtightness inspection on a conduit

A positioning terminal is provided and identifies, as appropriate, a satellite to be excluded, thereby improving positioning accuracy. A processor acquires a signal-to-noise ratio (SNR) and an angle of elevation for each satellite. The processor next identifies a satellite for which the SNR is less than a shielding SNR mask as a multipath satellite and selects the satellite to be excluded. The processor next generates positioning terminal positioning data using a positioning signal from satellites other than the satellite to be excluded. The processor next uses reference station positioning data and positioning terminal positioning data of the selected satellite to execute an RTK calculation.

Positioning method and positioning terminal

An inspection method of the present invention includes supplying water from a tank to an interior of a conduit through a hose provided at one end of the conduit, releasing air from the interior of the conduit to an outside of the conduit through an air vent tube provided at another end of the conduit, determining whether or not water that does not contain air is drained from the air vent tube, when it is determined in the determining that water that does not contain air is drained from the air vent tube, stopping supplying water to the interior of the conduit, closing a valve of an air vent portion, and blocking both ends of the conduit, and performing pressurization by increasing a pressure of the interior of the conduit whose both ends are blocked and whose interior is filled with water, and measuring a pressure value of the interior of the conduit when the pressurization ends and a pressure value of the interior of the conduit when a predetermined period of time elapses.

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Tokyo, Japan

Yoshihiro Iriyama