3D The serving discipline

Plans and maps are rapidly being replaced by spatial models. In the world of 3D geo-information, the Netherlands is doing pioneering work. A lot of it has to do with practical diplomacy.

Self-driving cars tour neighbourhoods, recording everything. Cameras in Amsterdam photograph the street every couple of days in order to check parking permits. Laser scanners transform the environment into a 3D cloud of points and a drone equipped with Lidar equipment searches the area at 80,000 pulses a second. There is certainly no lack of data in the world of 3D geo-information. The headline in an article about brontobytes in the January 2015 issue of GIM International read: ‘Help! What do we do with all these 3D points?’ To illustrate: our little Netherlands has been entirely mapped using six to ten points per square metre. The National Height Model of the Netherlands (AHN2) dataset contains no fewer than 640 billion measurement points.

Facing this dizzying amount of data is a growing list of 3D technology applications. But because every field uses its own methods and standards there is a lot of duplicate work being done and little information being shared. “When noise experts need data for a noise pollution analysis, they will hire a company to compile specific 3D data about the actual situation,” says Dr Jantien Stoter (44), Professor of 3D Geo-information in the Faculty of Architecture and the Built Environment. Still, she has no doubt that everything currently still being done with plans and maps will yield to 3D spatial models within the next 10 to 15 years. Consequently, it would help if researchers, users and lawmakers could use data more effectively than they do now.

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Happy
Stoter’s field plays a coordinating role between producers of 3D data and users of every stripe. “We are a service discipline”, she says with a friendly smile. “Solutions that we come up with must meet real needs. The experts for whom we work represent very different domains. The people in my group are happy to find solutions for 3D data that help others advance.”

This service-minded approach has proved extremely successful. In 2010, Stoter received a Vidi grant from STW for her 5D geomodelling research project, which she is continuing this year with a grant from the European Research Council under the name Urban Modelling in Higher Dimensions. As if 3D was not sufficiently complicated, Stoter is adding another two dimensions to it in her 5D research: detail level and time. She explains:

“It’s important to be able to zoom in and out in the same data set, and time is likewise important. Maps need to be current, but you should also be able to go back, say, a year ago. ”

A 5D geo model allows you to zoom in and out in a spatial model and offers the option to travel over and back in time.” The object of her research is to make 3D geographic data smart in order to make it possible to retrieve a far greater amount of relevant information from data for various applications.

Logical conditions, established in the data structure, ensure that geographic data is always accurate. An example of a logical condition is that there cannot be any overlap on a land registry map (because then you would have two owners) and that there cannot be any gaps (land that does not belong to anyone). There must be continuity time-wise, too. Buildings do not just disappear. Stoter: “When you include the concept of detail level and time as an extra dimension, you can simply command accuracy. Otherwise you have to build in separate rules in order to do so.”

Connecting
Around 2009 Stoter had a brilliant idea. She had earned a degree in Physical Geography from Utrecht University, had conducted spatial analyses for environment impact reports, had subsequently obtained her doctorate in 3D Cadastre at TU Delft (2000- 2004) and then went on to Twente University to work on map generalisation (the automatic reduction of maps at low detail level from maps with considerable detail). She noticed that a lot of academic research went unused. “We would make something beautiful, only it would not be adopted in practice because it was either too complicated or almost but not quite fit for use. Usually there was just that extra bit of research needed to bridge the gap.” This prompted her move in 2009 to both Kadaster and Geonovum (which makes government-provided geo information accessible) as well as TU Delft. By working for each of these organisations (two days at Urbanism, Faculty of Architecture and the Built Environment, two days at Kadaster, one day at Geonovum) she was able to apply the academic research to reality. She has been playing a coordinating role ever since, connecting researchers with users.

As a result, countries such as Singapore, China, Korea and Bahrain ask the Netherlands for advice. “Technology is often the driving force in the process. An entire 3D model has been made without including the users. They come to us after the fact with a request to validate the 3D data, correct or improve it for applications such as calculations about airflows or energy consumption.”

Shifting norms
During her PhD research 15 years ago, 3D design programmes were still in their infancy. Today they are the norm, especially for more complex buildings such as the railway station in Delft. For the government, in this case Kadaster, the norm is still flat maps, albeit with the option to seamlessly incorporate 3D models. Stoter expects 3D city models will be the norm within 10 to 15 years. “People currently in charge of making the decisions are not used to 3D but that’s a generational thing.”

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