The SIM application (Subterranean Infrastructure Map App and Service) is developed to ease construction and digging projects by visualizing underground infrastructure with augmented reality.
Augmented reality (AR) is a live direct or indirect view of a physical, real-world environment whose elements are augmented (or supplemented) by computer-generated sensory input such as sound, video, graphics or GPS data. The applications EVRY develop uses augmented reality technology to present cadastral data which is distributed by the proDataMarket platform. With a connection to proDataMarket, SIM downloads subterranean infrastructure data that exists at the user location. This data is then used to visualize the underground grid of pipes and cables as well as give information about the pipe or cable. If there are a lot of pipes in a given area there could potentially be too much information to augment at a time. The user can then filter out pipe groups (such as water, sewage, electricity) to be able to get a more relevant view.
Relevant information could be a pipes depth, the pipes owner as well as the age and material of the pipe. An issue with data like this is that it is often private. Data are also often owned by different actors, and a challenge is to give them incentive to share their data.
One of the major technical challenges the development team have been facing, is the lack of accuracy on mobile devices. The GPS receivers and built-in compass on mobile devices are not accurate enough to give an exactly correct representation of the pipe grid. It is possible however to increase the GPS accuracy by using an external GPS receiver. But even though the GPS is correct, a small error with the heading will still create unwanted results. In addition to positioning, another challenge is the data quality in a given area. To create a good augmented reality experience, the framework needs to know the height above mean sea level. This is not always given information in the data set.
To accommodate these challenges, SIM has a calibration functionality that can “move” the pipe grid according to a given heading. It also has a call to “Google Elevation Service” to get the pipe grids height so that it does not rely on elevation data. If the augmented experience is still not sufficient, SIM also includes a 2d Map so the user may get an overview of the pipe grid
If the user for some reason does not want to use the device camera (i.e. poor lightning conditions, broken lens etc.) or does not want to relocate to see the pipe grid, a Google Street View module is also implemented. This is a regular Google street view, with the pipe grid integrated so the user can stay at one location and see the pipe grid at another location.