Conrad Tang is associate professor at the land surveying and geo-informatics department at the Hong Kong Polytechnic University. He talks about the development of a citywide spatial data infrastructure, a key technology in the transformation of Hong Kong into a smart city. What is spatial data infrastructure? A spatial data infrastructure is a collaborative, multisource database where all geospatial information and metadata converge. Many aspects of our daily life contain some sort of spatial dimension, such as the location of a building or height of a built structure. Its development is important to the transformation of Hong Kong into a smart city. With the high penetration of GPS-enabled smartphones, people are used to using Google Maps, which helps you pinpoint your location, or helps you to plan your journey by calculating the shortest route. But so far, what these map service providers have done is mainly based on 2D maps. Last year, the government said it would seek to develop a common spatial data infrastructure in the long run. To put it simply, it is envisioned as a robust 3D geographical information system while serving as a geo-platform for the public and private sectors to integrate and exchange geographical spatial data. What is its progress in Hong Kong so far? The Hong Kong government has a complete set of geodetic data and grid systems, consisting of latitudes and longitudes, covering the entire city. Based on the geographical information system data provided by the Survey and Mapping Office, the positioning of GPS- and 3G-enabled smartphones is accurate to a few metres. Purpose-built GPS receivers can achieve 2cm accuracy anywhere in Hong Kong. Besides geographical information system data, the government also provides 2D maps online. Digital and paper maps in greater detail are not free, though they are not expensive. But given that free online maps are easily accessible, I doubt that many people use government maps these days. It’s now the right time for our government to think about how to make the most out of its geospatial and mapping data, and most importantly, how to integrate that data with spatial data held by different government departments, such as the Lands Department, Buildings Department, Transport Department, and so on. In the absence of concerted efforts to co-ordinate data integration and consolidation, each of these government departments collects and maintains its own geographical information system data, which is not cost-effective or efficient. Perhaps we can learn from Singapore’s success in the building of spatial data infrastructure. The city state has done a good job in the creation of a high-resolution 3D map of the country – in a highly cost-effective way. The project involved capturing large amounts of data, creating 2D and 3D data sets in different data formats, and supporting the interoperability of the data and management of data sets in a single repository. How does it benefit Hong Kong as a whole and in our daily lives? When the spatial data infrastructure becomes available to professionals and the public, it can harness the power of big data. It not only can help you pinpoint more accurately the location of a building in real-time, but can also facilitate urban planning, infrastructure development, architectural design, transportation systems, car navigation, and so on. It is shareable, interoperable, cost-effective, and sustainable. It will play an important role in the building of smart city with the strategic deployment of sensors, big data analytics and the internet of things.