As populations increase and urban sprawls rapidly expand outwards, the demand for 3D City Modeling – a system in which cameras capture aerial images of a targeted area – is becoming essential as planners seek to develop smarter and effective urban planning.
Aerial solutions for 3D city modeling include multi-perspective desktop viewers, visualization of buildings roofs and façades from a 360-degree perspective, realistic texturing of 3D City models, and measurement of building heights in monoplotting mode.
Today urban planners and decision-makers rely on 3D City models to support a wide variety of initiatives and actions.
3D city models are used to prepare for changes in city structures, population growth and urban planning, preventative measures for natural and industrial disasters, inhibiting overuse of finite resources, incorporating sustainable practices, and more.
City planners require a reliable database that can be easily modified over time to gain a holistic look at the urban environment. An immediate advantage of acquiring oblique images is the possibility to view elements that are generally occluded or not visible in the vertical views.
Historic architecture can also be digitized and modeled for conservation, preservation, and protection of the structures and their cultural heritage. Today, with the development of smaller and lighter aerial platforms, such as UAVs and cameras, surveying complex structures in a populated environment is becoming easier, faster, affordable, and more efficient.
Images can be utilized for inspection, monitoring, 2D/3D image rectification, and dense point cloud creation. Even smaller municipalities can now achieve cost-effective, high-quality 3D city models as well as orthophotos with an accuracy of two to ten centimeters.
Multi-perspective aerial imaging opens many new opportunities in geodata-based applications. Aerial imaging with qualified cameras offers the fastest way to reproduce a digital 3D representation of reality for all kinds of planning, surveying, or visualization.
One such project was the complex aerial survey and documentation of the historic neo-Gothic church St. Mauritius in Frankfurt /Main. The church, built-in 1901, is located in a populated area and attracts many visitors.
The challenge was not only documenting the structure but also allowing the traffic of people around it uninterrupted. The four facades of the church tower – 42 meters high – were documented by 2D rectified images in the scale 1:20 and 300 dpi resolution.
With image rectification and mapping, as well as quantity survey and analysis, true-to-scale image plans enabled planners and conservators to document damage and estimate quantities, costs, and time estimations, for conservation projects.
As well as 3D City modelling, aerial solutions are also proving to be exceptionally useful for leading energy companies who want to acquire high-definition 3D IR data on a city scale using thermal sensors and specialist cameras.
In such an example, an airship platform was equipped with the latest technology to enable UAV remote sensing over cities, crowds, and beyond visual line of sight (BVLOS) missions for the first time.
With a maximum payload of 10kg and flying at 60km/h, an airship is ideal for 3D mapping on a city scale at low altitudes for data acquisition at a high GSD. The aerial thermal imagery was used by ‘energy optimizers’ to detect sources of heat loss in buildings and homes.
But the new high-definition imagery opens up new uses and opportunities for other 3D Modelling uses for the likes of firefighters, police; administrations for monitoring, architects, and safety bodies.
Such specialists are increasingly finding their cameras, drones, platforms, and software in constant demand from imaging companies who want to achieve the best in 3D City Modelling.