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Measurements of height differences can be obtained by two approaches namely levelling and trigonometric methods. Both methods have advantages and disadvantages. The levelling methode produce accurate height differences while trigonometric method offers practically and rapidness for field surveys with varied terrain topography. The question are how big the height difference deviation yielded by both methods and what is the pattern of the difference?. Can the trigonometric method produce height difference accuration closing to the Levelling method result? This research aims to get pattern or model of deviation of height difference from measurement result using both methods. Furthermore, this research aims at evaluating the result of Total Station TS NIKON DTM 352 measurements which have been corrected using the model of deviation of height difference.Research excuted on a designed path of distances ranging from 20m up to 400m for the measurements of height difference. The Total Station TS NIKON DTM 352 and Levelling Electronic Leica Sprinter 100 are the instruments used. The model of deviation of height differences constructed based on relation between distance and height differences measured by both instruments. To evaluate the model, a set of levelling network in varied topography area were measured in LC classification using both instruments. Evaluation was done by adding height difference corrections calculated based on the model to the measurement resulted by the TS NIKON DTM 352. In addition the corrected TS NIKON DTM 352 measurements then were compared with the result of Levelling Electronic Leica Sprinter 100 measurements.Based on the scater diagram, it can be indicated that height differences deviation come to near linear pattern with equation of y=0.000126x + 0.0014. Evaluation result indicated that giving correction using model to height differences measured by TS NIKON DTM 352 can improve the measurements accuracy although not significant furthermore it does not always improve the measurement class. |
