Virtual reality is a computer-simulated environment that can simulate physical presence in places in the real world or imagined worlds. Mychilo Cline expressed a future trend of virtual reality in 2004. Virtual reality is the technology that makes users feel in a Virtual Environment by using computer hardware and software. High density point cloud makes the street view much closer to a virtual realistic environment. The 3D scalable data and vivid texture reconstruct the real street environment for the users. The users can watch the street buildings from different directions and measure any distances or angles for the street view objects.
Based on the accuracy 3D model, the close range photogrammetry can reach to a sub-centimetre level in favourable circumstances. Therefore, the Geo-referenced street view can be used for surveying. The CAD map can be extracted directly for the street view. The surveying work is simplified as checking the changes of street view data.
The American Land Service company Millman has developed their Virtual Surveyor System. It is an interactive web-based tool to do the virtual cadastral survey without charge to the clients. It has many advantages compared with the conventional surveying methods－easily review property information, mark up documents online, save and share surveys in multiple locations at once etc. Figure 29 shows the user interface of the virtual surveyor system.
With the widely using of Closed-circuit television (CCTV), the street view images could be captured by the CCTVs. Based on this, a future trend can be inferred that the ‘real-time 3D Street View’ should be established for the city security surveillance. It will be definitely beneficial for controlling crimes and reducing traffic accidents.