Performance Evaluation of MADOCA PPP with Existing Positioning Techniques for UAV Altitude Determination

Global Navigation Satellite Systems (GNSS) are vital for Unmanned Aerial Vehicle (UAV) operations, particularly where precise altitude estimation is critical for applications such as surveillance, target tracking, and weapons testing. Traditional methods like Single Point Positioning (SPP) offer simplicity and cost-efficiency but provide limited accuracy, generally suitable only for broad, low-precision tasks. Real Time Kinematic (RTK) techniques significantly enhance positioning precision to the centimetre level but require dedicated base stations and continuous communication, which may not be feasible in remote or restricted environments. To overcome these limitations, this study explores the potential of Precise Point Positioning (PPP) using Multi-GNSS Advanced Demonstration tool for Orbit and Clock Analysis (MADOCA) technique. MADOCA PPP leverages real-time corrections via QZSS, eliminating the need for local ground-based infrastructure. Using SWaP-C GNSS modules suitable for UAV integration, the study compares SPP, RTK, and MADOCA PPP in terms of positioning accuracy. Experimental results show that SPP achieves 3D precision of 2.614 m, RTK improves it to 0.070 m, and MADOCA PPP offers superior performance with 0.017 m 3D precision and 0.011 m 2D precision. These findings highlight MADOCA PPP’s suitability for UAV missions requiring high-accuracy, infrastructure-free navigation.