1.5  Verification of Surveying Instruments

The surveying instruments used in 1999, as listed below in Table 8, have been verified and calibrated by the authorized verification bodies listed in Table 9, prior to the survey. (Refer to g3. Reference Materialsh for the details regarding the results of the verification.)

 

Table 8  Surveying instruments used

Model type

S/N

Performance of the instrument

Total Station

 NET2B : Sokkia

31481

 

31788

Precision of the surveying range:

0.8mm+1ppm * observation range

Precision of the surveying angle:

2 seconds (Minimum readable unit:

1 second)

Total Station

 TC2002 : Leica

359698

Precision of the surveying range:

1.0mm+1ppm * observation range

Precision of the surveying angle:

0.5 seconds (Minimum readable unit: 0.1 seconds)

Level

 DiNi11:Carl Zeiss

100312

First class level

Verified by Japanese Association of Surveyors

Staff

 Invar staff : Carl Zeiss

12562

12564

First class staff

Verified by Japanese Association of Surveyors

GPS receivers

 4000SSI : Trimble

01693

01741

 

01746

 

06732

First class GPS receivers

Precision of the surveying range:

5mm+1ppm * range

Verified by Japanese Association of Surveyors

 


Table 9  Verification method

instrument type

Verification method

Verification body

NET2B

Measuring apparatus   :    Laser length-measuring instrument SL-2000

Base line                      :    100m underground base line

Sokkia Co. Ltd

TC2002

Base line                      :    1km outdoor base line

Sokkia Co. Ltd

DiNi11

Observation value check

Compensator functional check

Japanese Association of Surveyors

Invar staff

Scale error check

Japanese Association of Surveyors

GPS receivers

Base line

GPS relative base line field at Geographical Survey Institute

Japanese Association of Surveyors