PERFORMANCE TEST OF GEODETIC GNSS RECEIVER WITH MEMS AND IMU SENSORS USING NETWORK-BASED GNSS RTK METHOD

Abstract

This article aims to study and test the performance of the geodetic GNSS receiver equipped with MEMS and IMU sensors for determining horizontal and vertical positions. The antenna tilt was measured at 15°, 25°, 35° and 45° using Network-based GNSS RTK method. It was firstly tested in controlled environment in which the GNSS receiver was set up in an open space and on the roof that the points were two meters away from the wall. For the second case, the GNSS receiver was directly set up on the land boundary pins. This test was divided into three sub-cases: (1) near the wall with clear obstacle environment (2) near the wall with densely obstructed environment and (3) densely planted trees environment. The third case was tested on VRS survey marks of the Department of Lands. Data was collected up to twenty points per case with a total of one hundred twenty points using a purposive sampling technique. By comparing between the reference coordinates and the GNSS receiver with MEMS and GNSS receiver with IMU, the accuracy comparison was made in both horizontal and vertical components. This study found that GNSS receiver with IMU produced the more accurate positioning results than GNSS receiver with MEMS for both the open area with clear signal and the obstructed environment. The GNSS receiver with IMU yielded the horizontal positioning accuracy better than 4 centimeters when the pole was tilted at 15° and 25°. In addition, it was found that the measurement angle when the pole is tilted affects the horizontal positioning accuracy however has no direct impact on the vertical positioning accuracy. Moreover, the horizontal and vertical positioning accuracy depends on obstacles around the test points. Finally, the future researches will focus on a comparison of horizontal and vertical positioning accuracy while the pole is tilted with different GNSS receiver brands.