Study on the Positioning Accuracy of the GNSS/INS System Supported by the RTK Receiver for Railway Measurements

Abstract

Currently, the primary method for determining the object coordinates is positioning using Global Navigation Satellite Systems (GNSS) supported by Inertial Navigation Systems (INS). The main goal of this solution is to ensure high positioning availability, particularly when access to satellite signals is limited (in tunnels, areas with densely concentrated buildings and in forest areas). The aim of this article is to determine whether the GNSS/INS system supported by the RTK receiver is suitable for the implementation of selected geodetic and construction tasks in railway engineering, such as determining the place and extent of rail track deformations (1 cm (p = 0.95)), the process of a rapid stocktaking of existing rail tracks (3 cm (p = 0.95)) and for design and construction works (10 cm (p = 0.95)), as well as what the impact of various terrain obstacles have on the obtained positioning accuracy of the tested system. During the research, one INS was used, the Ekinox2-U by the SBG Systems, which was supported by the Real-Time Kinematic (RTK) receiver. GNSS/INS measurements were conducted on three representative sections varying in terms of terrain obstacles that limit the access to satellite signals during mobile railway measurements in Tricity (Poland). The acquired data allowed us to calculate the basic position accuracy measures that are commonly used in navigation and transport applications. On this basis, it was concluded that the Ekinox2-U system can satisfy the positioning accuracy requirements for rapid stocktaking of existing rail tracks (3 cm (p = 0.95)), as well as for design and construction works (10 cm (p = 0.95)). On the other hand, the system cannot be used to determine the place and extent of rail track deformations (1 cm (p = 0.95)).

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“…After rearranging equation (10), the transmitter-receiver distance d estimate can be determined according to the following formula:…”

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Testing and Analysis of Selected Navigation Parameters of the GNSS/INS System for USV Path Localization during Inland Hydrographic Surveys

“…In order to reduce the position measurement error, inertial and satellite systems are supported by additional devices such as LiDAR, odometry and vision sensors [ 32 , 33 ]. GNSS/INS systems are used primarily in navigation and transport applications, which include mobile phone tracking [ 34 , 35 ]; indoor [ 36 ], land [ 37 ] and space [ 38 ] navigation; geodetic [ 39 , 40 ] and hydrographic [ 41 , 42 ] measurements; driving autonomous ground vehicles [ 43 , 44 ]; as well as car [ 45 , 46 ] and rail transport [ 47 , 48 ].…”