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Showing result 1 - 5 of 20 essays matching the above criteria.

  1. 1. Assisted GNSS Positioning using State Space Corrections

    University essay from Linköpings universitet/Institutionen för systemteknik

    Author : Oskar Philipsson; [2023]
    Keywords : positioning; GNSS; SSR; EKF; sensor fusion;

    Abstract : Classical GNSS based positioning has accuracy limitations due to many sources oferror. The error sources range from clock errors and orbit errors toerrors due to variations in atmospheric propagation delays. One way to improve GNSSpositioning is to generate real time corrections using a GNSS reference network. READ MORE

  3. 2. Estimation of dissolved organic carbon from inland waters using remote sensing data and machine learning

    University essay from Lunds universitet/Institutionen för naturgeografi och ekosystemvetenskap

    Author : Lasse Harkort; [2022]
    Keywords : dissolved organic carbon; machine learning; remote sensing; inland waters; water quality; open source data; Earth and Environmental Sciences;

    Abstract : This thesis presents the first attempt to estimate Dissolved Organic Carbon (DOC) in inland waters over a large-scale area using satellite data and machine learning (ML) methods. Four ML approaches, namely Random Forest Regression (RFR), Support Vector Regression (SVR), Gaussian Process Regression (GPR), and a Multilayer Backpropagation Neural Network (MBPNN) were tested to retrieve DOC using a filtered version of the recently published open source AquaSat dataset with more than 16 thousand samples across the continental US matched with satellite data from Landsat 5, 7 and 8 missions. READ MORE

  4. 3. Fragmentation in graupel snow collisions

    University essay from Lunds universitet/Institutionen för naturgeografi och ekosystemvetenskap

    Author : Martanda Gautam; [2022]
    Keywords : Ecosystem Analysis; Clouds; Snow; Graupel; SIP; Fragmentation; CKE; Rime Fraction; Earth and Environmental Sciences;

    Abstract : Aircraft observations of precipitating clouds with cloud top temperatures higher than -38°C have revealed that Secondary Ice Production (SIP) is responsible for presence of majority of ice particles. One such SIP mechanism is fragmentation via collisions between ice particles. READ MORE

  5. 4. Data-driven Dynamic Baseline Calibration Method for Gas Sensors

    University essay from KTH/Skolan för elektroteknik och datavetenskap (EECS)

    Author : Cheng Yang; [2021]
    Keywords : CO2 gas sensing; drift; dynamic baseline calibration; time series analysis; data-driven modeling; clustering; classification; CO2 gasavkänning; drift; dynamisk baslinjekalibrering; tidsserieanalys; datadriven modellering; kluster; klassificering;

    Abstract : Automatic Baseline Correction is the state-of-the-art calibration method of non-dispersive infrared CO2 sensing, which is the standard CO2 gas monitoring method. In this thesis, we improve it by introducing the dynamic baseline based on environmental data. READ MORE

  6. 5. Risk computation for atmospheric re-entry

    University essay from KTH/Rymdteknik

    Author : Florian Teilhard; [2021]
    Keywords : Spacecraft Dynamics; Atmospheric re-entry; Rymdfarkosters dynamik; Atmosfäriska återinträdet;

    Abstract : In the present work, two numerical tools are under scrutiny. Both were made to study the atmospheric re-entry of a spacecraft: DEBRISK computes the trajectory and the survivability of the spacecraft as well as its fragments, and ELECTRA calculates the trajectory of the spacecraft and its fragments, as well as the associated on-ground risk of human casualty. READ MORE