@Jessica summarize https://www.researchgate.net/publication/325121858_A_Hierarchical_Vision-Based_UAV_Localization_for_an_Open_Landing/fulltext/5af992e50f7e9b026bf742e7/A-Hierarchical-Vision-Based-UAV-Localization-for-an-Open-Landing.pdf?_tp=eyJjb250ZXh0Ijp7ImZpcnN0UGFnZSI6InB1YmxpY2F0aW9uIiwicGFnZSI6InB1YmxpY2F0aW9uIn19
2
