This paper presents the performance of the real-time kinematic (RTK) technique in very severe conditions. The measurements were conducted in forest conditions during two different experiments. Two Global Positioning System receivers were used: an Ashtech Z-Surveyor and a Z-Xtreme. Radiomodems were used for transmitting RTK corrections from a reference station to a rover. The RTK measurements were performed during quite good satellite configuration. The use of RTK technology, based on the Ashtech Z-Xtreme receiver as a rover in forest terrain, allowed centimeter accuracy to be obtained. However, practical experiments showed that there is a need for redundant independent RTK solutions based on repeated independent ambiguity reinitializations. Although gross errors might occur, the RTK technique can be very helpful technology for centimeter positioning in woodland areas.

The Satellite Base Augmentation System (SBAS) - EGNOS (European Geostationary Navigation Overlay Service) has been certified for Safety of Life (SoL) service for aircraft navigation since 2nd of March 2011. Unfortunately for the territory of Poland, located at the edge of EGNOS service area, the quality of the service corrections are still not sufficient for aircraft navigation requirements. Years 2012 and 2013 are forecasted as a maximum of solar activity in a 11-year solar cycle. This time period will be the chance to perform the first tests for the EGNOS Safety of Life service quality in disturbed ionospheric conditions. During the previous maximum of solar activity, the storm on 30 October 2003 resulted in the inability to use WAAS corrections for more than 12 hours. This was caused by a very large gradient of disturbances and its’ very sharp boundaries - vertical TEC (VTEC) varied from ~ 40 to ~ 120 TECU (TEC units) within an hour (over ~ 150 km distance). These circumstances gave the opportunity to carry out the test flights to examine the navigation parameters obtained for EGNOS SoL service in disturbed ionospheric conditions. The paper presents project proposal of study and analyses of such fundamental navigation parameters as: accuracy of determined position, availability, continuity and integrity, determined for selected disturbances in relation to quiet conditions. It can give a possibility to estimate of the quality of EGNOS SoL service in Polish airspace during the different phases of flight and its resistance to critical ionospheric conditions.

This study compared CO₂ emissions during a WLTP (Worldwide Harmonized Light-Duty Vehicles Test Procedure) test performed on a chassis dynamometer for the same flex-fuel vehicle, fuelled sequentially with E10 gasoline and E85 fuel. Based on the test data, a CO₂ emissions map was created, describing its dependence on speed and acceleration. The use of a 3D surface enabled the visualisation of the whole dynamics of emissions as a function of engine load in the WLTP cycle, including the identification of distinct emission peaks in areas of high positive acceleration. Analysis of the emission surface enabled the identification of structural differences between the fuels. For E85, more pronounced emission increases are observed in areas of intense acceleration, a consequence of the higher fuel demand resulting from the lower calorific value of bioethanol. In steady-state and moderate-load driving, CO₂ emissions for both fuels are similar. The results confirm that the main differences between E10 and E85 are not simply a shift in emission levels per se, but stem from variations in engine load during the dynamic cycle. Although E85 emits measurable CO₂ emissions, its carbon is not of fossil origin, highlighting the importance of biofuels in the context of greenhouse gas emission reduction strategies and the pursuit of climate neutrality. The presented methodology, combining chassis dynamometer tests with analysis of the speed-acceleration emission map, provides a tool for clearly identifying emission zones and can serve as a basis for further optimisation of engine control strategies and assessing the impact of fuel composition on emissions under dynamic conditions.

This paper presents the results of a study on the heat deflection temperature (HDT) and Vicat softening temperature (VST) of the LH285 MGS aerospace polymer resin, used as a matrix in ablative shielding composites. This topic is particularly relevant because, during ablative testing, the...

The article discusses the method of reconstructing the ejection process. Measurement data were obtained during field tests on an actual object. These data served as the basis for validating the mathematical model of the seat-pilot system’s motion. This model describes the spatial motion of the K-36DM ejection seat. The article includes a description of the mathematical model and a comparison of the measured motion parameters with the calculation results. It also presents computed parameters that were not recorded during the tests. Particular attention was paid to the reconstruction of the flight trajectory and seat rotation and the determination of the G-forces acting on the pilot. The primary objective of the research was to develop a mathematical model of the pilot ejection process using the K-36DM ejection seat. In addition to classical equations of motion, such as linear motion of the seat along the guide rails and motion of the seat along the rails with rotation around the lower pair of rollers, the model also considered the free motion of the seat-autopilot system, taking into account the forces acting on the seat-autopilot system. In this work, four phases of the chair movement were modeled, i.e. phase 1: After activation of the first pyrotechnic charge, the seat moves in a straight line along the guide rails until the two upper pairs of rollers disengage from the rails; phase 2: The seat continues moving along the guide rails using the lower pair of rollers until it exits the cockpit. Simultaneously, the seat begins to rotate relative to this pair of rollers; phase 3: The seat moves through the air; initially, it is propelled by the second pyrotechnic charge, providing the necessary flight altitude; phase 4: The pilot separates from the seat and descends under a parachute.