@misc{MTMT:34818857,
	title = {Proceedings of the 8th International Conference on Research, Technology and Education of Space},
	url = {https://m2.mtmt.hu/api/publication/34818857},
	isbn = {9789637367342},
	editor = {Bacsárdi, László and Kovács, Kálmán},
	publisher = {Hungarian Astronautical Society},
	unique-id = {34818857},
	year = {2024},
	orcid-numbers = {Bacsárdi, László/0000-0002-7337-317X}
}

@article{MTMT:34794507,
	title = {Hazai eredmények a kvantumhálózatok fejlesztésében},
	url = {https://m2.mtmt.hu/api/publication/34794507},
	author = {Bacsárdi, László and Kis, Zsolt},
	journal-iso = {FIZIKAI SZEMLE},
	journal = {FIZIKAI SZEMLE},
	volume = {74},
	unique-id = {34794507},
	issn = {0015-3257},
	year = {2024},
	pages = {124-128},
	orcid-numbers = {Bacsárdi, László/0000-0002-7337-317X}
}

@CONFERENCE{MTMT:34519766,
	title = {National Space Education with 17 Universities},
	url = {https://m2.mtmt.hu/api/publication/34519766},
	author = {Bacsárdi, László},
	booktitle = {Winter Satellite Workshop 2024},
	unique-id = {34519766},
	year = {2024},
	pages = {1-2},
	orcid-numbers = {Bacsárdi, László/0000-0002-7337-317X}
}

@CONFERENCE{MTMT:34763430,
	title = {Analyzing a multi-satellite quantum communication network},
	url = {https://m2.mtmt.hu/api/publication/34763430},
	author = {Ifkovics, Barnabás and Bacsárdi, László},
	booktitle = {74th International Astronautical Congress, IAC 2023},
	volume = {2023-October},
	unique-id = {34763430},
	abstract = {Quantum-based satellite networks utilize the power of quantum technology to transmit and receive information globally. They are using quantum mechanics to encrypt and decrypt data, thus making it virtually impossible for someone to intercept or hack the communication. Such infrastructure can conduct highly accurate measurements, which can help precision agriculture, medical imaging, and environmental monitoring. In the future, quantum-based satellite networks can enhance distributed computing by interconnecting multiple quantum processors, significantly increasing the available computational power. In our work, we are interested in the effectiveness of different satellite topologies using two quantum key distribution (QKD) methods: prepare-and-measure and entanglement-based, examining networks operating with one, two, and three satellites. After comparing the results, we determine each case's most effective topologies and protocols. In the paper, we compare two different systems: networks using quantum entanglement (untrusted nodes-based concept) with networks using prepare-and-measure QKD (trusted nodes or reliable satellites-based system). These give us a relatively comprehensive picture of the differences between device-dependent and device-independent satellite infrastructures using available technologies. Copyright © 2023 by the International Astronautical Federation (IAF). All rights reserved.},
	year = {2023},
	orcid-numbers = {Bacsárdi, László/0000-0002-7337-317X}
}

@inproceedings{MTMT:34531269,
	title = {Routing the quantum internet in large LEO satellite constellations},
	url = {https://m2.mtmt.hu/api/publication/34531269},
	author = {Solymos, Balázs and Nepusz, Tamás and Bacsárdi, László},
	booktitle = {IEEE 23rd International Symposium on Computational Intelligence and Informatics (CINTI 2023) : Proceedings},
	doi = {10.1109/CINTI59972.2023.10382070},
	unique-id = {34531269},
	abstract = {Space is a promising medium for quantum communications, boasting potentially better link performance compared to optical fibers. A future quantum internet, therefore, may rely heavily on satellite networks, which present various open networking challenges, one of which is routing, that today lack definitive solutions, sometimes even in the case of classical networks too. Nonetheless, with ever-bigger satellite constellations, this new plane of networking is slowly becoming a reality. To address the problem of dynamically changing links and handle the unique behavior of quantum repeater protocols, we propose a simple method based on a modified variant of the standard A* graph search algorithm. We then simulate a Starlink-like LEO constellation with simplified models for the main steps of quantum repeater protocols to investigate the feasibility of our method and future quantum satellite networks.},
	keywords = {simulation; ATTENUATION; quantum communication; SATELLITES; Routing; Routing; Heuristic algorithms; protocols; Low earth orbit satellites; Quantum Internet; satellite networks; Satellite constellations},
	year = {2023},
	pages = {000397-000402},
	orcid-numbers = {Solymos, Balázs/0000-0002-5123-7548; Nepusz, Tamás/0000-0002-1451-338X; Bacsárdi, László/0000-0002-7337-317X}
}

@CONFERENCE{MTMT:34519786,
	title = {Report on the First Hungarian Short Range Free Space QKD Link},
	url = {https://m2.mtmt.hu/api/publication/34519786},
	author = {Galambos, Máté and Czermann, Márton and Jánosi, Gergely and Kornis, János and Papp, Zsolt and Koller, István and Holló, Csaba Tamás and Sarkadi, Tamás and Erdei, Gábor and Barócsi, Attila and Kis, Zsolt and Koppa, Pál and Imre, Sándor and Bacsárdi, László},
	booktitle = {Proceedings of the 74th International Astronautical Congress (IAC 2023)},
	unique-id = {34519786},
	abstract = {Here we report on the development of our short-range free space quantum communication system. We have built an entangled photon-pair source, based on wavefront splitting interference. We used commercially available fibre coupling ports to create a few meters long free space channel in the lab. We transmitted one half of an entangled photon-pair between two optical ground stations while the other photon was measured locally. To identify corresponding photons on the transmitter and receiver sides, we have tested multiple time synchronization and correlation peak search methods. We found that Fourier transform based correlation search-although works well in theory-has trouble finding overlap in case of low signal to noise ratio. Start-stop histograms proved feasible under realistic channel conditions, yet require longer data collection, and perform best with a reasonable guess at the propagation delay and time synchronization offset. We successfully verified that the transmission is suitable for quantum cryptography using Bell-test experiments. Our experiences show that loss has little effect on the average outcome of the Bell-test experiment but interferes with polarization correction resulting in greater variability and less consistency. We also examined the effect of optical turbulence induced fading using a heat source and observed that with properly increased integration time the fading has no effect on the Bell-test experiment. Copyright © 2023 by the International Astronautical Federation (IAF). All rights reserved.},
	keywords = {ENTANGLEMENT; quantum cryptography; QKD; free space},
	year = {2023},
	orcid-numbers = {Holló, Csaba Tamás/0000-0001-9807-7441; Erdei, Gábor/0000-0003-1584-3142; Barócsi, Attila/0000-0002-8986-1346; Imre, Sándor/0000-0002-2883-8919; Bacsárdi, László/0000-0002-7337-317X}
}

@book{MTMT:34494666,
	title = {Magyar Űrkutatási Fórum 2023 - Válogatott közlemények},
	url = {https://m2.mtmt.hu/api/publication/34494666},
	isbn = {9789637367335},
	editor = {Bacsárdi, László and Barta, Veronika and Szárnya, Csilla and Wesztergom, Viktor},
	publisher = {Hungarian Astronautical Society},
	unique-id = {34494666},
	year = {2023},
	orcid-numbers = {Bacsárdi, László/0000-0002-7337-317X; Szárnya, Csilla/0000-0002-8880-194X}
}

@inproceedings{MTMT:34157649,
	title = {Testing the First Hungarian CV-QKD System On a Real Optical Line},
	url = {https://m2.mtmt.hu/api/publication/34157649},
	author = {Márton, Botond László and Kis, Zsolt and Bacsárdi, László},
	booktitle = {2023 International Conference on Software, Telecommunications and Computer Networks (SoftCOM)},
	doi = {10.23919/SoftCOM58365.2023.10271613},
	unique-id = {34157649},
	year = {2023},
	orcid-numbers = {Bacsárdi, László/0000-0002-7337-317X}
}

@inproceedings{MTMT:34091229,
	title = {A Portable Ambient Optical Noise Measurement Station},
	url = {https://m2.mtmt.hu/api/publication/34091229},
	author = {Schranz, Ágoston and Gerhátné Udvary, Eszter and Matolcsy, Balázs and Bacsárdi, László and Nagy, András},
	booktitle = {2023 23rd International Conference on Transparent Optical Networks (ICTON)},
	doi = {10.1109/ICTON59386.2023.10207414},
	unique-id = {34091229},
	year = {2023},
	pages = {1-6},
	orcid-numbers = {Schranz, Ágoston/0000-0002-2058-9030; Gerhátné Udvary, Eszter/0000-0003-3023-7810; Bacsárdi, László/0000-0002-7337-317X}
}

@article{MTMT:34069895,
	title = {Optical transmittance based store and forward routing in satellite networks},
	url = {https://m2.mtmt.hu/api/publication/34069895},
	author = {Mihály, András and Bacsárdi, László},
	doi = {10.36244/ICJ.2023.2.2},
	journal-iso = {INFOCOMM J},
	journal = {INFOCOMMUNICATIONS JOURNAL},
	volume = {15},
	unique-id = {34069895},
	issn = {2061-2079},
	abstract = {Quantum computing will play a crucial part in our security infrastructure for the coming years. Quantum networks can consist of direct optical fiber or free-space links. With the use of satellite channels, we can create a quantum network with higher coverage than using optical fibers where the distances are limited due to the properties of the fiber. One of the highest drivers of cost for satellite networks, apart from the cost of the technology needed for such systems, are the costs of launching and maintaining said satellites. By minimizing the satellites needed for a well-functioning quantum network, we can decrease said network’s cost, thus enabling a cheaper quantum internet. In this paper, we present an optical transmittance-based routing algorithm with which it is possible to conduct successful quantum entanglement transfer between terrestrial nodes.},
	year = {2023},
	eissn = {2061-2125},
	pages = {8-13},
	orcid-numbers = {Bacsárdi, László/0000-0002-7337-317X}
}