Kamil Krasuski

Determination of reliability parameters of HPL and VPL technical safety in the procedure of a non-precision landing approach NPA GNSS with using GPS and GLONASS navigation systems in air transport

Published: 30 June 2018 The paper presents the results of determining the HPL and VPL safety parameters used to evaluate the reliability of aircraft positioning in air transport. The HPL and VPL security level parameters were determined using GPS and GLONASS systems for the NPA GNSS nonprecision landing approach. The work also compares the HPL and VPL values with the technical standards published by ICAO.

Application of IGS Products for Air Navigation

Abstract Single Point Positioning (SPP) method is widely used in air, marine, and land navigation to determine the user’s position in real time and post factum. A typical accuracy for this method of determining the user’s position in the static mode is approximately 10 meters. In air operations, the SPP method accuracy can be several times lower and that may cause problems with precise positioning of an aircraft. The authors of this article presented preliminary results of research concerning aircraft positioning in the kinematic mode based on GPS observations. For this purpose, an in-flight experiment, in which a Cessna 172 aircraft was used, was performed at the airport in Mielec, Poland. The aircraft was equipped with a dual-frequency Topcon TPS HiperPro receiver, which was recording satellite observations with 1-second interval. The aircraft position was determined using the least-squares method (LSM) in the RTKLIB (RTKPOST module) software. Two research tests were performed within the scope of the experiment, i.e. in test I the aircraft position was determined on the basis of raw GPS observations and the broadcast ephemeris data whereas in test II precision products of the IGS were used, such as: precise ephemeris SP3, DCB hardware delay, clock bias data of GPS satellites and receivers in the CLK format, data of the ionosphere maps based on IONEX format, and phase center calibration of GPS satellites and receivers in the ANTEX format. The use of the IGS precision products improved the accuracy of the X coordinate to 1 m, Y to 0.7 m and Z to 1.3 m. On the basis of tests I and II, an additional RMS-3D parameter was determined, whose mean value was 4 m.

Utilization PPP method in aircraft positioning in post-processing mode

Purpose The purpose of this paper is to study the implementation of GNSS technique in aviation for recovery of aircraft’s position using Precise Point Positioning (PPP) method. Design/methodology/approach The aircraft’s coordinates in ellipsoidal frame were obtained based on GPS code and phase observations for PPP method. The numerical computations were executed in post-processing mode in the CSRS-PPP and magicPPP online services. The mathematical scheme of PPP method was development using indifference equations of Ionosphere-Free linear combination. In the experiment, airborne test using Cessna 172 aircraft on June 01, 2010 in the military airport in Deblin was realized. The aircraft’s position was determined using data from GNSS receiver (Topcon HiperPro with interval of 1 s). Findings In this paper, the accuracy of aircraft’s position is better than 0.07 m for CSRS-PPP service and better than 0.27 m for magicPPP service. In case of the Mean Radial Spherical Error parameter, the average value for CSRS-PPP service equals to 0.01 m, whereas for magicPPP, it is about 0.38 m. The values of vertical coordinate of Cessna 172 aircraft were also checked with results of Real Time Kinematic–On The Fly technique. Research limitations/implications In this paper, the analysis of aircraft positioning is focused on the application of the PPP method in post-processing mode. In near real time, the PPP method still has limitations, especially in the area of ambiguity resolution and also instrumental biases (e.g. Narrow Lane Hardware Delays). Practical implications The PPP method can be applied in aviation in post-processing mode for verification of true aircraft coordinates and elimination of blunder errors from adjustment processing of GNSS observations. The Zenith Wet Delay term as a product of troposphere delay and receiver clock bias as a product of precise time transfer can be obtained in the PPP method. Originality/value The paper presents that the PPP method is an alternative solution for the recovery of aircraft’s position in aviation, and this method can be also applied in the positioning of aircraft based on GLONASS or GPS/GLONASS data.

Wykorzystanie techniki GPS do wyznaczenia kątów heading, pitch i roll – część I

This article presents an experiment concerning the designation of heading, pitch and roll angles using GPS technology. For this purpose, authorial HPR_GPS software has been created, the code source of which was written in Scilab 5.4.1 language. Operation of application was presented and an algorithm of estimation of heading, pitch, and roll angles was showed. Additionally, final results of angles from HPR_GPS software were compared with raw INS data. Based on comparison, mean difference for heading angle is equal to 0.29° with standard deviation of 5.96°, for pitch angle it is equal to 4.98° with standard deviation of 1.62°, and for roll angle it is about 0.06° with standard deviation of 2.31°, respectively.