Sammanfattning I varje flygfas av en kommersiell flygrutt krävs att navigations- och inflygningshjälpmedlen klarar högt ställda krav på noggrannhet, kontinuitet, tillgänglighet och integritet. Befintliga ILS-landningssystem klarar inte alla de kraven. GBAS, som är en modern teknik, kan däremot ppfylla uppställda krav med hjälp av GPS-satellitsignaler och ge stöd för alla faser av precisionsinflygningskategorier. GBAS-teknik kan ersätta ILS-tekniken och göra flygtrafiken säkrare under olika flygfaser. Systemet tillämpar konceptet "differentiella korrigeringar" för att förstärka GPS-satellitsignaler och överföra korrigeringar från GNSS-data till utrustade flygplan i närheten av en flygplats. Detta möjliggör att angränsade flygplatser kan förses med behövligt stöd och möjliggöra precisionsinflygningar upp till CAT III. Syftet med examensarbetet har varit att analysera GBAS-system och dess effekter på en flygplats och jämföra det med ILS-system för att bedöma vilket som är bäst. Sedan om möjligt ge förslag på hur man kan rädda små flygplatser med hjälp av GBAS-teknik. Arbetet inleddes med informationsinsamling om systemets tekniska och operativa kriterier. Utifrån denna information skapades ett analysschema för att analysera skillnaderna mellan landningssystemen. Resultaten av arbetet och analysschemat visar att GBAS-systemet bedöms vara mer ändamålsenligt med avseende på ekonomiska, tekniska och operativa förhållanden jämfört med ILS-systemet. Analyserna tyder också på att GBAS är ett bättre alternativ än ILS på små flygplatser och att man kan använda resultaten som verktyg för att identifiera olika problem med ILS-systemet. / Abstract Nowadays we have two general rules for flight: VFR (Visual Flight Rules) and IFR (Instrument Flight Rules). VFR can only be used according to visual flight rules, where the pilot always has visual contact with the ground. In low visibility conditions (such as fog, snow, low clouds level, rain and darkness) the pilot uses ILS (Instrument Landing System) to position the aircraft for approach and landing. Those situations at ILS are categorized into three different stages: CAT I, CAT II and CAT III. The categories are based on the sight (visibility conditions). ILS is sensitive to nearby radio signals from other devices and to buildings around the airport and cannot guide multiple aircraft simultaneously. At the same time the critical and sensitive areas of the ILS result in a reduction of the throughput under low-visibility conditions. In addition, the system is expensive and requires great maintenance. Another important disadvantage of this system is that it allows only straight approach (Not curved flying within landing and approach). Most of the airports’ landing systems have some inaccuracy and unreliability. It is due to older models and systems. Systems like ILS, VOR, TLS, MLS, GPS, GNSS, etc., have been constantly modernized and are used to reduce the risk of incidents and accidents during approach and landing phases which are crucial steps in the flight. However, the GPS (Global Position System) precision method cannot alone meet ICAO’s (International Civil Aviation Organization) requirements when additional accuracy, integrity, accessibility and continuity are required. In order to meet the ICAO requirements, one needs to strengthen the GNSS’s performance by using the GBAS system and guaranteeing very high performance in a given coverage area such as, an airport. The current GBAS has already been certified for CAT1 and can be improved to ICAO requirements. CAT II / III has already been developed by the ICAO Navigation System Panel (NSP) but not yet appended to Annex 10 as an alternative to ILS. Annex 10 is an ICAO regulation that contains all standards and practices for aviation telecommunications. This thesis study provides an overall overview of the aircraft’s performance with different aids and specifies new landing system and compares with some of the existing systems. Limitations are studied in order to analyze the best available new system that can be achieved.

This master’s thesis deals with technologies intended for flight control during approach and landing. The main focus is on perspective approach systems, including differential technology systems. The thesis is to serve as a study aid for pilots and students of Air Traffic study programme. The main aim of this thesis is to create a qualified whole of perspective and used approach systems. Individual systems include basic characteristics and assessment of their future use. The thesis also includes an analysis of the possibility of implementing the DGNSS system at the airport with multiple runways. Prague-Ruzyně airport was chosen for this purpose. The implementation of this system is compared to other precision approach systems.

This diploma thesis is focused to systems used for automatic control of civil aircraft along an precision approach trajectory. It describes precision approach systems used in the past and their evolutional steps leading to their current and future configuration. The thesis does not put the goal to be a detailed study but to be a publication providing to pilots and students of Aeronautical traffic the introduction to the field of precision approach systems in context to another fields of aeronautical traffic, describing its current status and infer its further development.

This thesis deals with the problem of GNSS. The document will attempt to illustrate some possible sources of error and their corrections. The main characteristics of SBAS and GBAS are described. The aim of this work is to design GBAS interconnection

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<p>  </p> <p>Concrete is the second most consumed material in the world after water and is an essential element of constructed infrastructure. Over 14 billion m3 of concrete are being produced annually, resulting in a serious impact on the environment. The production of cement, which is the main component of concrete, is responsible for 5 – 8 % of global CO2 emissions. As a result, several global initiatives have been undertaken to achieve carbon neutrality by 2050. This carbon neutrality target coincides with the Paris Agreement's goal to limit global warming to 1.5 °C. A well-known, and successful strategy to reduce CO2 emissions in the concrete industry is to use supplementary cementitious materials (SCMs) as a partial replacement for cement. However, it is projected that in 2030 the demand for two of the most commonly used SCMs, fly ash and slag cement, will exceed their supply. Using nontraditional and natural pozzolans (NNPs) can help to close this supply gap, but there is a lack of knowledge regarding the reactivity and long-term performance of these materials.</p> <p>The purpose of this research was to perform experiments on several NNPs, some of which can be supplied in commercially viable quantities with the objective of evaluating their performance in cementitious systems (mortars and concretes) with the goal of accurately assessing their potential for use as alternative SCMs. The mortar study was performed using a total of 11 different NNPs, belonging to 4 distinctive groups and distributed as follows: 3 from the group of calcined clays (CCs) - CC1, CC2, and CC3, 3 from the group of natural pozzolans (NPs) - NP1, NP2 and NP3, 2 from the group of fluidized bed combustion (FBCs) ashes - FBC1 and FBC2, and 3 from the group of bottom ashes (GBAs) - GBA1, GBA2, and GBA3.</p> <p>The concrete study was performed on 4 different materials, one from each of the previously mentioned groups. The materials selected for concrete study were the worst-performing members of each group, as determined by the analysis of the test results obtained from mortars. These included CC2, NP3, FBC1, and GBA3 materials. This approach was adopted under the assumption that achieving adequate concrete characteristics with lowest-quality materials will all but assure satisfactory performance of concretes with higher-quality materials. </p> <p>The findings generated from this research indicate that several of the NNPs used in this study present a viable alternative to traditional SCMs. As an example, out of the 11 NNPS, 9 were found to conform to the requirements of the ASTM C618-19, the standard specification currently used to assess the suitability of coal fly ash and raw or calcined natural pozzolans for use in concrete. Results obtained from tests performed on mortars demonstrated that, when used at the replacement level of 25%, all 11 NNPs produced mixtures with characteristics similar to those obtained from the plain cement (OPC) mortar. For that reason, this level of replacement was selected to prepare concrete specimens. The results collected from concrete specimens showed that, when compared to plain concrete, mixtures with all 4 NNPs attained comparable (or improved) mechanical (compressive and flexural strength), durability (freeze-thaw resistance), and transport (formation factor and rate of water absorption) properties. As in the case of traditional SCMs, the mixtures with NNPs were found to require extended curing times to fully realize their property-enhancing potential associated with pozzolanic reactions. Overall, the best performing materials were those from the CCs group, followed by those belonging to, respectively, NPs, GBAs, and FBCs groups. </p>