Remote sensing has a strong relationship to the concept of ecological building. Unlike green building and sustainable architecture which are more directly oriented to building performance and efficiency, ecological building is based on ecology. For geospatial applications this involves the relationship of the building itself with the surrounding environment. While building design will usually involve vectors, the surrounding environment will likely extend to include rasters or imagery.
It is important to differentiate between green building design and ecological building. While ecological building approaches may have green goals in mind, they are usually oriented to agree with concepts of ecology and ecological approaches. These will often include both the green building design and the management of surrounding land base. How much land base is another question, since, we can talk about the ecological environment of the immediate building area, the block, a series of blocks or an entire city. In some cases we might be interested in groups of green buildings and their relationships to larger and larger areas.
While remotely sensed imagery is more often associated with spatial analysis across the landscape, it is important to recognise that raster-to-vector or extraction, involves the creation of building models from lidar data and remotely sensed imagery. ERDAS Imagine Objective, for example, can extract objects from a wide variety of Infoterra imagery. This is an example of the raster-to-vector conversion process at a high level. For this very reason, archived imagery has value that is yet to be realised in many cases.
It is the interface between an individual building and it’s surrounding area that continues to intrigue and interest researchers and application developers. That is due to the fact that CAD and GIS tools are used markedly more or less on each side of that line - the tools to model buildings being different from the tools to spatially organise and manage land area. Yet, even that division is not as definitive as it once was. ESRI, Bentley, Autodesk and others each provide tools that criss-cross this line and offer integrated functionality optimised for either side of it. In practice that means remotely sensed imagery also integrates across the divide.
Remotely sensed imagery also plays an important role in services offered by Google Earth, Bing, WorldWind and others. Although the imagery is mostly to provide a visual presentation environments, the inclusion of GIS layers or colored polygons into these environments means that they can display information pertianing to ecological building.
At a recent course in Finland, the concept of single tree 3D forest inventory was discussed and data provided together with lecture notes. The idea here was to analyse individual trees from imagery, thereby to provide an accurate forest inventory. In the Bavarian state of Bayern, scientists are now using lidar in a vertical fashion, on the ground to estimate tree inventory for every individual tree in a forest.
At this resolution, the information processing needs are high and efficient systems for handling the information are needed. But the idea is clear, if individual trees can be assessed and monitored, then the resolution at which spatial analysis takes place within buildings is likely to extend to surrounding areas. Collectively then, aren’t we speaking about one continuous digital model? A model that transcends buildings to land area.
The drivers to see a continuous model appearing within the near future are slowly coming into place. These include both more efficient computing, higher resolution data, development of tools that integrate CAD-GIS and the launching of new satellites that will continuously (or almost) provide the imagery. At the same time vertically acquired imagery, the kind millions of people are collecting through mobile phones with referencing from GPS are also becoming integrated into the data work flow.This is a very exciting time to be in the geospatial industry.
Remotely sensed imagery has a key role in the future as ecological building progresses. The key questions of sustainable communities, energy balance and efficiency through performance are all significantly tied to imagery and image analysis.
Jeff Thurston is editor of V1 Magazine and V1 Energy Magazine for Europe, Middle East and Africa. This column alternates weekly.