Height determination is a main task for any engineering project. And it is necessary to determine the height within the required accuracy levels for different tasks. Mostly, in Sri Lanka, automatic Leveling method is used for determining the heights of points in construction projects such as roads, railways, bridges, cannels, dams and drainages etc. However, currently, height determination can be done by using different instruments with different methods such as GPS, Auto Level, Total Station, Theodolites. The purpose of this study is to compare the accuracy of relative height differences using Hand held GPS with Auto level instrument. Pambahinna pipe line construction project area was selected for this study. Further, 13 points were recognized for height determination and one point was selected as the base point to determine the relative heights of other points. The height of the base point was determined using GPS (GS15) instrument and Hand held GPS (Leica Zeno 20) instrument was used to determine the height of other points. These data were collected with different modes such as Streaming, SBAS OFF and SBAS ON. Further the collected data were processed with the DGPS and without DGPS approaches. The height differences of the control points were assumed as true values and they compared with the hand held GPS approach. Finally, the result of this study indicated that 77% accuracy can be obtained through the SBAS ON mode of DGPS in hand held GPS system. This level of accuracy level is enough for some aspects in engineering projects.
Relative Height, Handheld GPS, Auto level
DS Munasinghe , PGRNI Pussella "Accuracy Comparison of Relative Height Determination using Handheld GPS Approach and Automatic Level in Engineering Projects in Sri Lanka" Iconic Research And Engineering Journals Volume 4 Issue 8 2021 Page 67-75
DS Munasinghe , PGRNI Pussella "Accuracy Comparison of Relative Height Determination using Handheld GPS Approach and Automatic Level in Engineering Projects in Sri Lanka" Iconic Research And Engineering Journals, 4(8)