Technical Visit to Hong Kong West Drainage Tunnel A technical visit to the Hong Kong West Drainage Tunnel was jointly organized by the HKIS LSD and the Department of Land Surveying & Geo-Informatics of the Hong Kong Polytechnic University on 17 April 2010. It was a great pleasure to let our members and university students to visit one of the major drainage improvement projects. We were warmly welcomed by Ir Kenny Wong and his site staff followed by an informative presentation on the double shields Tunnel Boring Machines (TBMs) operating at the eastern and western portals. The multi-functional TBM performs drilling, excavation as well as removal of soils. Other tunneling methods to suit various site situations were also discussed. We took a walking tour in the western portal site area. The students expressed that it was a valuable experience to understand the contribution of our profession in an engineer project. The technical visit ended with discussion among the participants and the site staff. Our sincere thanks to Ove Arup & Partner (Hong Kong) Ltd for arranging such an impressive event. Trends and Challenges of Photogrammetry Professor Ralf Schroth of University of Hannover, Germany, delivered a very thought-provoking CPD on 20 April 2010. He gave a comprehensive review of the development of digital photogrammetry, aerial camera and airborne sensors such as LiDAR, Bathymetry and thermal sensors. He explained current trends in geo-referencing, image processing, digital terrain / surface models, ortho photo and the latest techniques using oblique photo imagery (the Pictometry). On the application aspects, he talked about Geo-portal, 3D city models and the most exciting technology which integrates 3D models into desktop, web, mobile devices and navigation application. Finally he introduced the unmanned airborne systems which can acquire low altitude imagery with great efficiency and at extremely low cost.