Lecture Theodolite Systematic Errors

Lecture Theodolite Systematic Errors - Lecture/Lab Text...

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Lecture/Lab Theodolite Systematic Errors Lecture Notes Text Coverage: Wolf and Ghilani, 11 th Edition Ch 8: 13 – 19 Problems: 8:17, 20-23,25-30. This lecture introduces an in-depth view of the theodolite/total station, its construction and error sources. To test a theodolite, do the following relationships. 1. Rotation of the cross hairs – sight a point on the left limb of the horizontal cross hair. Rotate the instrument to the left, the point should stay exactly on the cross hair as it moves right in the field of view. Adjustment: loosen capstan screws and rotate crosshairs till test works Cancel Error: use only central portion of cross hairs for pointing. 2. Line of sight perpendicular with the horizontal ax is – sight a well defined point, take horizontal reading. Reverse telescope and take second reading on the same point. These should be different by 180. The “collimation” error in the line of sight is half of the amount by which the second reading missed exactly 180 difference. or DOUBLE CENTER TEST: Sight BS point Direct, flop to reverse and set point about 150 ft from instrument. Sight same BS point Reversed, flop to Direct and set a point beside the first one. Measure the distance between the two foresight points, calculate the angular content of half of this distance. This error should equal the same value of the first test. Adjustment: loosen capstan screws and move crosshair ring left or right to eliminate error. Cancel Error: measure all angles at the same vertical angle position, or measure
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This note was uploaded on 05/19/2011 for the course GEM 3330 taught by Professor Gibson during the Spring '11 term at University of Florida.

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Lecture Theodolite Systematic Errors - Lecture/Lab Text...

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