APRÈN. Portal de la producció docent del professorat de la UPC

The Nanosatellite and Payload Laboratory (UPC NanoSat Lab) is a multidisciplinary initiative within the Barcelona School of Telecommunications Engineering. It primarily focuses on the development and design of nanosatellite missions, emphasizing the exploration of innovative concepts for small spacecraft systems, as well as the development and integration of subsystems and payloads for Earth Observation. This thesis aims to contribute to the development of 3Cat-8 mission by conducting a comprehensive mission analysis. Specifically, this analysis focuses on evaluating the nanosatellite's capabilities for advanced ionospheric observations, including nearly simultaneous ionospheric scintillation monitoring through Global Navigation Satellite System Radio Occultation (GNSS-RO) and multispectral polarized emission imaging. It begins with an examination of the satellite's operational environament, including orbital simulations, and extends to the implementation and evaluation of the ground station. Moreover, it includes a detailed calculation of the link budget and assesses the download capacity of the ground station for both S-band and X-band communications. This analysis delivers crucial information for evaluating the experimental capabilities of the satellite. It determines the number of experiments the satellite can perform, the volume of data it can generate, and its data download capacity. The most important aspect of the project is the analysis of the different operational modes: Camera and GNSS-RO. It involves evaluating the trade-offs based on the priority of the analysis, the combination of modes, and the data generated by each. The study examines whether it is feasible to implement the various cases or if there are data constraints. It also considers whether more data can be generated than the ground station is designed to download, or if fewer data are produced and, during the time the satellite has access to the ground station, all the generated data can be downloaded.

The main objective of this thesis is the understanding and characterization of the SUSIE hyperspectral camera, designed to capture the spectra of the northern lights. It will be integrated in the 3Cat-8 mission satellite, which aims to study atmospheric phenomena such as ionospheric scintillation. This project covers both the assembly of the hardware (including the integration of the sensor, rotor, lens and polarizing filter) and the verification of the camera performance through different experimental tests in the Clean room. Different methods and techniques will be used for spectral characterization, such as the study of the linearity of brightness, dark current and defective pixels. The last two chapters will deal with the study of the modulation transfer function and its possible effects on the mission, together with the testing of the communication system between the camera and the C3SatP, which will ensure that the data collected are managed correctly. Ultimately, the goal is to verify the operability of the camera in the space environment, as well as the contribution in observation techniques for future missions.

L'objectiu d'aquesta tesi és dissenyar i implementar el programari de vol que s'executa a l'Ordinador de Bord (OBC) de la missi ó satel·lital ³Cat-8 en col·laboraci ó amb UPC NanoSat Lab. L'OBC és el cor del sat èl·lit i és l'encarregat de connectar i gestionar tots els altres subsistemes. El programari és responsable de recopilar tota la informaci ó dels experiments realitzats pels c àrrecs útils del sat èl·lit i de gestionar l'estat del mateix. Aquesta tesi inclou la definici ó completa de l'entorn de desenvolupament del codi de l'apli- caci ó, desenvolupat en llenguatge C, sobre un sistema operatiu en temps real FreeRTOS. Tamb é inclou el disseny de l'entorn de multithreading i l'arquitectura del programari, així com l'enfocament al desenvolupament segur que s'ha de seguir en aquest tipus d'aplica- cions de programari embebudes.

The final work focuses on the study and design of a lunar orbit satellite mission for observation and navigation. The project is divided into theoretical and practical blocks. The theoretical block covers essential aspects of satellites in lunar orbit, while the practical block focuses on the simulation of satellites in orbit, using advanced technology for navigation and observation. The study includes a detailed analysis of the lunar environment, comparing it with the Earth and describing its terrain, temperatures and heat flow. The lunar surface, modeled by impacts and volcanism, has basins surrounded by mountains and extensive canals, with temperatures that vary dramatically. The use of the Satellite Tool Kit (STK) allows the simulation of lunar orbits and missions, addressing features such as orbit propagators, mission control sequences (MCS) and space vehicle parameters and their fuel tank, as well as lunar orbit insertion and communication links. Technologies for observing the Moon are selected, such as hyperspectral chambers, Earth penetration radars (GPR) and LiDAR (detection and light range), which allow detailed observation of the surface and lunar subsole. The satellite design is done using SolidWorks, including the central body and side components. The mission simulates the acquisition of lunar data and studies the environmental effects, such as the impact on the ozone layer, climate change and the toxicity of the ecosystem. This TFG offers a comprehensive overview of the feasibility of lunar orbit satellite missions, using advanced technologies and detailed simulations, contributing significantly to the field of space exploration and navigation

This final degree project focuses on the development of a GNSS (Global Navigation Satellite System) receiver block, based on a radiofrequency switching matrix. The main objective is to take the first step towards the operability of the satellite navigation system and the receiver for reflectometry and radio occultation experiments. This project is carried out in collaboration with UPC NanoSat Lab, a department of the Universitat Politècnica de Catalunya specialized in launching nanosatellites for earth observation. Specifically, within the framework of the 3CAT-8 mission, the phenomenon of ionospheric scintillation is being investigated, that is, how radiofrequency waves are affected when crossing the ionosphere. Additionally, it aims to monitor radio frequency interference (RFI) in the L and K frequency bands as a secondary objective. This project involves a deep theoretical study on GNSS concepts and their implications in reflectometry and radio occultation fields. Next, the different subsystems of the satellite are thoroughly explored for the generation of a comprehensive design that will integrate existing antennas with receivers, considering the scientific requirements of the mission and selecting components according to space standards. Furthermore, the necessary printed circuit boards are developed for efficient integration of the switching matrix with the rest of the satellite subsystems, always respecting the basic characteristics of GNSS signals and their fundamental properties. This project represents the first step towards the culmination of the satellite system responsible for conducting the scientific tests of the 3CAT-8 mission.

The aim of this final thesis is to carry out the CAD design and structural analysis of: the support of the camera, the support for the rotor of the camera and a Magnetorquer, the whole set on board the 3Cat8 mission, corresponding to one of the missions of the UPC NanoSat Lab. The 3Cat8 mission the following main objectives. Firstly, the educational component, a project carried out by students, with the help of certain companies in the sector. Secondly, the scientific component, focused on the observation of the ionosphere using GNSS-RO. The elaboration of the design of the different components has been carried out through the design software respecting the standard dimensions of the CubeSat, comprised in a maximum available space and respecting the restrictions imposed by components of the neighbouring units. Subsequently, the model has been simplified in order to be able to replicate the structural behaviour of the components by optimising the computational calculations for FEM simulations. Once the model has been simplified, a series of analyses of modal type, random vibrations, quasi-static creep and shocks in the FEM type environment have been carried out. Finally, the results obtained, the are analyzed to get the conclusions. The achieved results are considered successful. Finally, a series of recommendation are made for the projects evolution.

The goal of this Final Degree Project is to develop a payload for a drone with an L-band radiometer and techniques for the detection and mitigation of interferences. It has been carried out in collaboration with NanoSat Lab, an initiative of the Escola Tècnica Superior d'Enginyeria de Telecomunicació de Barcelona dedicated to the design and development of nanosatellites with new technologies of Earth Observation by remote sensing. This project is a continuation of the Final Grade Work titled Development of a drone-based miniaturized Flexible Microwave Payload (FMPL) for GNSS-Reflectometry and L-band radiometry. This work aimed to develop the Flexible Microwave Payload Drone (FMPL-D), similar to the FMPL-1 payload used on the 3Cat-4 NanoSat Lab mission. FMPL-D integrates two passive remote sensing systems using microwaves: reflectometry Global Navigation Satellite System (GNSS) signals (GNSS-R) and microwave radiometry (MWR) in L-band. The impact of interferences on FMPL-D, particularly in MWR, has motivated the realization of this final degree thesis. The high mobility of the drone allows for results with a spatial resolution much higher than that obtained with satellites and the detection of possible interfering sources, which can already be unintentional or intentional (jammers). The thesis begins with the characterization of the MWR used in FMPL-D, which was determined to be impaired and unusable. As a solution, the RITA MWR schematic, developed at NanoSat Lab with collaboration from other partners, was adopted, which incorporates remote sensing and interference detection instruments. This memory describes the design, implementation and characterization of the new MWR. Two techniques are developed for the detection and mitigation of Radio-Frequency Interferences (RFI) by statistical analysis of the captured signal in two different domains. The results from kurtosis applied in the time domain and the spectral kurtosis applied in the time-frequency domain are used to compute several metrics for evaluating its effectiveness in the detection and mitigation of different types of RFI. The system is then analyzed through several laboratory experiments, including the study of MWR behavior in the absence of external interference and the results obtained with both techniques for detecting RFI. Finally, a functional test is performed on board a drone to qualify the system's performance and set targets for future work. In both cases, internal interference generated by a USB connection negatively affects the operation of the system.

This end-of-degree project focuses on the software development of a pico-satellite Attitude Determination and Control System, using MATLAB, as well as its subsequent integration in C. The software carried out will be implemented in a 5 cm sided pico-satellite, called PocketQube. The research project will form part of the IEEE Open PocketQube Kit mission developed in the NanoSat laboratory belonging to the UPC. The pico-satellite attitude system can be broken down into two distinct branches, attitude determination and attitude control. Attitude determination involves the process of determining the orientation of the satellite using the measurements acquired by its sensors (they include photodiodes, gyroscopes, and magnetometers). On the other hand, attitude control is the process by which the orientation of the pico-satellite is controlled using specific control algorithms (such as detumbling and nadir pointing) and actuators, (such as magnetorquers). To analyse and understand the attitude of the pico-satellite, a model is developed that allows simulating the environment in which the satellite is located. This model encompasses pico-satellite dynamics, a model that describes orbital dynamics, and another that represents the various perturbation forces that affect the pico-satellite. In this way, it is possible to describe the orbit followed by the pico-satellite, including its position, speed and the external forces that influence and affect its behaviour during the orbital flight. Once the modelling of the simulation environment is complete, the determination and control algorithms are implemented, as well as the mathematical models that describe the behaviour of the sensors and actuators. These algorithms and models are designed with the aim of meeting the requirements established for the Determination and Control System. Subsequently, an exhaustive analysis of the results obtained during the simulation is carried out. The purpose of this analysis is to verify if the previously established requirements for the Attitude Determination and Control System are met. The conclusion of this work allows to start the test campaigns of this system in the PocketQube hardware, as well as to check if the results obtained in the simulations correspond to reality.

The Lithosphere- Atmosphere-Ionosphere coupling models have been widely studied and applied to earthquakes and their precursors. Recently, evidence has been found that electromagnetic phenomena related to earthquakes might produce ionospheric anomalies even before their occurrence. This thesis aims to analyze the correlation between ionospheric scintillation and seismic events such as earthquake precursors, with the hypothesis that there is a positive correlation. Among all the ionospheric indicators, this study analyzes the S4 scintillation index from COSMIC-2 GNSS Radio Occultation (GNSS-RO), to estimate the ionospheric perturbation and identify anomalies. Case studies of earthquakes happening in 2022, as well as a statistical analysis centered on the Coral Sea area, are presented showing positive correlation. In some of the case studies are seen anomalies up to one week before the earthquake. Moreover, in the statistical analysis it is shown a correlation with anomalies happening between 3 and 6 days before the earthquakes and the earthquake itself. A probability of detection of 35.7% and a false alarm rate of 7.1% are obtained. This leads to the conclusion of ionospheric scintillation and seismic activity having a small positive correlation.

This project aims to develop mission-critical software that facilitates the monitoring and automation of the operations plan between the Operation Center and the CubeSats. This software will assist operators in various tasks, including scheduling satellite passes, controlling one or multiple Ground Stations to follow the satellite, preparing execution plans with contingencies for all the different steps in the communication protocol, and automating these processes. To minimize errors introduced by operators, the software will offer an interactive user interface for configuring message sets and information exchange during contact. It will also allow for the setup of conditional blocks that depend on received data, creating a seamless and error-free feedback loop. The objective is to gradually reduce the operator's workload, to the point of making their interaction unnecessary. This will enable automated communication with the satellite at any time of day. As part of the operations, all uploaded and downloaded data will be stored for posterior processing, with automated processing wherever possible. The software will be developed using the Rust programming language, known for its speed, memory safety, and thread safety. Rust compiler detects a significant amount of common errors at compile-time, this will allow the development of a highly reliable and high-performance application. While the project will initially focus on supporting the 3Cat-4 satellite, it will also create the basis to operate any other satellite in the future, such as the RITA Payload.

This project is the continuation of two previous TFGs about the mechanical design and mechanisms of a Fresnel Zone Plate Antenna developed in the NanoSat Lab. An in-house developed antenna that wants to test and prove the viability of an innovative design for CubeSats deployable antennas. This work tackles two main topics from the design process of this deployable antenna. The first is some of the design changes of the antenna and the reasoning behind them as well as the design of the deployment mechanism. The second one is the structural analysis of the 3Cat8 6U structure with the required changes to host the antenna as well as the antenna¿s structural simulation

The objective of this bachelors thesis is to conduct a comprehensive analysis of the communication subsystems in the UHF, S, and X bands of the 3Cat-8 mission. This mission aims to develop a satellite under the CubeSat standard that allows the study of different physical phenomena, such as the effects of auroral emissions on wave propagation through the ionosphere. Furthermore, this project also includes the design of an S-band patch antenna, both to understand the design of a space application antenna and to implement it on the same satellite and compare it with other commercial options. In addition, the polar orbit described by the satellite results in limited opportunities for data downlink, making it necessary to design and dimension magnetic actuators to enable the satellite to point towards the ground station. This document addresses the study, design, and manufacturing of these elements in order to enable the satellite to aim its antennas at the ground station. Overall, this work represents a significant contribution to the 3Cat-8 mission. Throughout this project, various activities encompassing the fields of aerospace engineering and telecommunications have been carried out.

This Final Degree Project aims at developing a telecommunications link using LoRa technology to interconnect a PocketQube (pico-satellites with a form factor of 5 x 5 x 5 cm^3) with a ground station from the TinyGS network. This long-range low-bandwidth link can be used to download the telemetry, the payload or the configuration data, and to send telecommands from the ground station to the PocketQube, such as the execution of orders as activate the payload, do a soft reset, perform an ADCS calibration etc. In this Final Degre Project, the communication protocols will be implemented, using COTS LoRa TTGO T-Display ESP32 WiFi module (Arduino based), and a PocketQube developed at the UPC NanoSat Lab, which uses an STM 32 (to be programmed in C-language) as On-Board Computer.

Due to an increasing entry barrier to both universities and researchers in conventional small satellites initiatives, there has been an emergence of smaller and cheaper spacecrafts like PocketQubes, a much more affordable option for public entities. Considering all that, this thesis has been developed as part of a project undertaken by the UPC NanoSat Lab which started as an IEEE GRSS initiative named PoCat. The objective of the PoCat project is to design, develop and test three single unit picosatellites with each featuring the following different payloads, a Video Graphics Array (VGA) camera, a Radio Frequency Interference (RFI) monitoring system at L-band and an RFI monitoring system at K-Band. The three satellites, however, contain the same avionics core composed of the On-Board Computer (OBC), Communication System (COMMS), Attitude Determination and Control System (ADCS) and Electrical Power Supply System (EPS). Given this scenario, the purpose of this report is to give insights regarding the on-board software development for PocketQubes, which as of writing this report there is still room for debate concerning their standardization. Conceptually, the OBC system acts as the brain of the satellite. As for the technology, the OBC is build upon the STM32L476 microcontroller due to its memory storage, power efficiency and processing power. Performing the power management as well as giving response to events are the main objectives of the OBC. In order to do the latter, the flight software is based on a Real-Time Operating System (RTOS) called FreeRTOS which has been selected above other Operating System (OS) due to its predictability, compliance with the required deadlines, support, available documentation, compatibility with previous projects, licensing costs, and certifications. According to FreeRTOS, the program is structured into independent tasks where each one features a priority in line with their criticality. Then, the project is constituted by eight tasks, with five designed to operate the subsystems of the satellite, one for memory writing purposes and the remaining two are devoted to implement FreeRTOS software timers. Furthermore, tasks can communicate with each other by means of task notifications or event groups, both being software tools provided by the operating system.

This final degree thesis describes the development and implementation of an ADCS simulator for the 3Cat-8 mission of the UPC NanoSat Lab, which enables the calculation of the actuators and controller variables. Additionally, based on the ADCS simulator, specially focuses on the ATHENA ionic thruster control analysis ensuring the proper ADCS actuators sizing of the spacecraft. The control is solely achieved by magnetic actuators. It is shown that the satellite can maintain the desired orientation with low angular rates, required during the orbital raising maneuver. A new configuration of the control stability with linear attitude dynamics for satellite thruster, based on a control algorithm using attitude quaternion and angular velocity feedback is also described. To conclude, the presented numerical results prove the efficiency of the applied method based on initial theoretical considerations and the design measurements of the satellite and the thruster.

The remote sensing and interference detector with RadIometry and vegeTation Analysis (RITA), is a payload of 1U that will fly onboard Alainsat-1 a 3U CubeSat. Among other tests and experiments, it will perform a proof of concept of a LoRa custom module for space-to-Earth communications between the satellite and a terrestrial network of Internet of Things sensors. The LoRa communications experiment proof-of-concept has been performed using several ground IoT nodes and a miniaturized drone-based payload. The communications have been performed using two MAC protocols which are compatible with an IoT scenario: pure ALOHA and CSMA/CA with RTS/CTS. In both protocols, the useful information to be sent is the data contained in the Data Packet. In this packet, the data obtained by the capacitive soil moisture sensor and the temperature sensor are stored. In order to perform LoRa communications experiment proof-of-concept, two measurement campaigns have been realized. In the first measurement campaign, the correct functioning of the LoRa modules and sensors has been tested. In the second measurement campaign, several experiments have been performed in which pure ALOHA and CSMA/CA protocols have been tested. In order to test different experiments with different configurations of the protocols, a general code structure has been designed where both the ground nodes and the drone payload are controlled by a command sent by the user. Therefore, the choice of the protocol to be used as well as the configurable parameters of each protocol are sent through a remote command. Finally, the results obtained in both protocols are analyzed and it is concluded which of the two has better performance against an IoT communications scenario.

Aquest treball conté l'anàlisi i les millores pel que fa als procediments de prova de nano satèl·lits d'actitud. Un sistema completament nou per mesurar velocitats angulars ha sigut dissenyat des de zero per aplicar-lo a les campanyes de proves de Cubesat. Aquest sis- tema ajudarà a seguir les rotacions del nano satel·lit en les diferents proves. Con `eixer la velocitat angular del nano satel·lit mentre es realitzen les proves és molt important, ja que permet calibrar els giroscopis així com establir unes condicions perfectes i conegudes al satèl·lit.

This project has been developed in collaboration with the NanosatLab UPC, which develops CubeSats for educational and scientific purposes and in-orbit technology demonstration. More specifically, the laboratory is focused on remote sensing systems. In recent years, the NanosatLab UPC has been developing the Flexible Microwave PayLoad (FMPL), the integration of different microwave remote sensing equipment in a single system: reflectometry Global Navigation Satellite System (GNSS) signals (GNSS-R) and microwave radiometry (MWR) in L-band. In 2022, the second version of this system, FMPL-2, is in orbit on board the CubeSat 3Cat5, which has provided precious scientific data on the climate of the earth and the evolution of climate change. The first version, FMPL-1, will be launched in the coming months aboard CubeSat 3Cat4. The third version, FMPL-3, is now ready for launch on board the CubeSat GNSSaS. From space, FMPL has proven to be a very useful tool for studying climate change. This work aims to design, build and test the first FMPL for drones, the FMPL-D. This new platform will be used to evaluate new versions of FMPL. It will also be a valuable tool to study the characteristics of soil, water, ice and vegetation locally and with a spatial resolution much greater than that which can be obtained from a satellite. The results presented in this thesis put the complexity of these systems into perspective. Firstly, in the results of the radiometer, an effect of distortion and destruction of the data obtained due to the radio frequency interference received during the measurement campaigns has been observed, highlighting the need for detection and mitigation systems interference for ground observation missions. For the GNSS reflectometry instrument, multiple flights were conducted in which large amounts of data were collected, the processing of which is still in progress. Preliminary results indicate good characteristics of the radio frequency chain. This Final Degree Project (TFG) is the first version of the FMPL-D, culminating in the system's first version and many lessons learned.

This project is a study of the effects the radiation environment has on the electronic components in a spacecraft. It also explores the estimation of these effects via the help of a simulation tool.