To celebrate Global Surveyors’ Day, a Distinguished Lecture jointly organized by the Department of Land Surveying & Geo-Informatics (LSGI) and Alumni Association (LSGIAA) was held on March 21, 2023. The Distinguished Lecture was in hybrid mode with over fifty participants from different parts of the world online or face to face. The name of the Distinguished Lecture is entitled as ‘Development of a Monitoring System for Power Cable Tunnels with Optic Fibre Sensors’ delivered by Emeritus Professor Yong-Qi Chen. The Lecture is a presentation that gives a discussion on the features of a power cable tunnel compared with traffic tunnels, the difficulties with the existing monitoring techniques, fiber optic sensors, and the system development for a real project. It was an honour for Professor Yong-Qi Chen to deliver a Distinguished Lecture at PolyU when he was still in Emeritus status. Professor Yong-Qi Chen first joined the University in January 1994 as the Head of Department of LSGI, and Chair Professor of Land Surveying. He had been both Chair Professor and Department Head for fourteen years until June 2008. With him at the helm, LSGI achieved exponential growth to become a leading academic department in the field of geomatics. At the start of the Distinguished Lecture, Prof. George Liu, Associate Head of LSGI, represented LSGI to introduce and greet the speaker – Emeritus Professor Yong-Qi Chen. At the end of the Distinguished Lecture, Sr Paul Tsui, Chairman of LSGI Alumni Association, presented the souvenir to Prof. Yong-Qi Chen.