Positioning Accuracy Comparison of GNSS Receivers Used for Mapping and Guidance of Agricultural Machines

Abstract

Global Navigation Satellite Systems (GNSS) allow the determination of the 3D position of a point on the Earth’s surface by measuring the distance from the receiver antenna to the orbital position of at least four satellites. Selecting and buying a GNSS receiver, depending on farm needs, is the first step for implementing precision agriculture. The aim of this work is to compare the positioning accuracy of four GNSS receivers, different for technical features and working modes: L1/L2 frequency survey-grade Real-Time Kinematic (RTK)-capable Stonex S7-G (S7); L1 frequency RTK-capable Stonex S5 (S5); L1 frequency Thales MobileMapper Pro (TMMP); low-cost L1 frequency Quanum GPS Logger V2 (QLV2). In order to evaluate the positioning accuracy of these receivers, i.e., the distance of the determined points from a reference trajectory, different tests, distinguished by the use or not of Real-Time Kinematic (RTK) differential correction data and/or an external antenna, were carried out. The results show that all satellite receivers tested carried out with the external antenna had an improvement in positioning accuracy. The Thales MobileMapper Pro satellite receiver showed the worst positioning accuracy. The low-cost Quanum GPS Logger V2 receiver surprisingly showed an average positioning error of only 0.550 m. The positioning accuracy of the above-mentioned receiver was slightly worse than that obtained using Stonex S7-G without the external antenna and differential correction (maximum positioning error 0.749 m). However, this accuracy was even better than that recorded using Stonex S5 without differential correction, both with and without the external antenna (average positioning error of 0.962 m and 1.368 m).

Feasibility of Using Low-Cost Dual-Frequency GNSS Receivers for Land Surveying

“…Very few studies on the performance of a low-cost receiver combined with a low-cost antenna, used for precise relative and absolute positioning in static and kinematic mode, are available [ 28 ]. Although the manufacturers declare that their receivers enable a reliable positioning in RTK mode with a short convergence time, such a performance is limited to a favorable environment [ 24 ].…”

NRTK, PPP or Static, That Is the Question. Testing Different Positioning Solutions for GNSS Survey

“…In the last few years, the UNIPA GNSS CORS network has been involved for scientific applications in different fields, including the electromagnetic pollution monitoring via a GPS-GIS integrated system [36], the trajectories calculation of Mobile Mapping System (MMS) [37,38], the dams monitoring with integrated InSAR and GNSS techniques [39,40], the geodetic measurements of the stalactite elevation in geological analyses [41], the use of unmanned aerial vehicles for soil moisture characterization [42], the positioning and guidance of agricultural machines via GNSS [43], the monitoring of active faulting, with integrated geodetic and InSAR techniques [44,45].…”

Validation of Real-Time Kinematic (RTK) Devices on Sheep to Detect Grazing Movement Leaders and Social Networks in Merino Ewes

“…With RTK GNSS which is a normal GNSS operation improved for carrier phase tracking of the satellite signals and differential correction, the errors are reduced to the order of tens of centimeters in open environments with good satellite visibility. The accuracy achieved will depend on the exact technology that is used [ 37 ]. Under challenging conditions, the RTK correction signal may be blocked to varying degrees by buildings, dense tree coverage, or other animals and may require additional data collection such as IMU (inertial measurement unit) to improve geo-spatial data accuracy.…”