3D-models of the Human Habitat for the Internet

The Internet has inspired an enormous appetite for 3-dimensional geo-data of the urban environment to support location-aware applications. This has in fact become the surprising „killer application“ of such 3-dimensional data. In March 2005, at the occasion of his 50th birthday, Bill Gates went public with his “Virtual Earth Vision” for local search in the Internet and stated: "You'll be walking around in downtown London and be able to see the shops, the stores, see what the traffic is like. Walk in a shop and navigate the merchandise. Not in the flat, 2D interface that we have on the web today, but in a virtual reality walkthrough.” The key words are „walk in a shop“. This implies the need for an enormous detail, and the associated computing power, communications bandwidth, miniaturization of computing, increase of storage capacity and in the ability to model the human habitat (the Earth) in great detail in 3 dimensions. This paper seeks to evangelize the current capabilities of the Virtual Earth system, focuses on the creation of 3D data, but also points to some pieces of new science in the 3D-analysis of overlapping imagery of the human habitat at sub-pixel accuracies. 1. FROM 2-DIMENSIONAL NAVIGATION TO 3DIMENSIONAL SEARCH The Internet-use of geographic information dates back to the mid-1990s in the form of navigational support for cars and trucks. Digital street maps have made it into car navigation systems. Microsoft offered Streets and Trips, later MapPoint, as stand-alone PC-based solutions for travel planning, and when augmented by GPS, also supporting the navigation application. Subsequently, digital street maps have also appeared on the Web by various vendors to support travel plans and online routing as well as navigation via the Internet. Some of the more prominent global offerings are by MapQuest, in the form of an Internet-enabled MapPoint by Microsoft, as mapping service by Google, Yahoo, Ask and other search services (maps.google.com, maps.yahoo.com, maps.ask.com, maps.live.com). In nearly every industrialized country, one or even multiple regional systems have come into existence, oftentimes on the basis of an existing telephone directory business. Under http://www.klicktel.de/routenplaner/ one finds one sample solution for Germany. These 2-D navigation and route planning systems were soon augmented by an aerial and satellite photography backdrop in the form of socalled ortho-photos. Google may have been the pioneering provider of imagery via its acquisition of Keyhole Inc in 2004 and the subsequent release of Google Earth in 2005. Microsoft released its Virtual Earth website in June 2005, also augmenting MapPoint by aerial imagery, to include bird’s eye aerial coverage as collected by Pictometry Inc. under an exclusive contract with Microsoft. 3-D building models were first introduced into Virtual Earth by Microsoft in November 2006 and grew to a coverage of all major US cities and some cities outside North America. The media response was enormous. Google followed suit by initially providing its own data sets consisting of Lego-type building blocks without photo texture. The third dimension reflects the idea of a human experience of our environment – we see a 3D world, not the flat mapping version of the world. As we navigate urban spaces we interact with buildings, building floors, vegetation, billboards, interior spaces and other items defining the world around us. We search in 3D. From a From Proceedings of Visigrapp-2009, Lisbon, Portugal; 5th – 8th Feb. Publ. by INSTCC-Portugal, ISBN 978-989-8111-69-2, Volume IS, pp 7 –15. P a g e | 8 Table 1: UltraCam-evolution via an exploitation of advances in CCD-technology. „Level 1“ are raw data from a total of 13 area array CCD-sensors @ 2 byte per pixel; „Level 2“ are the 9 panchromatic image tiles merged into one large format panchromatic image, plus the 4 separate color bands in red-green-blue and near-infrared, geometrically matched to the panchromatic image, but at a geometric resolution that is 3 times reduced. . „Level-3“ consists of the 4 high resolution color bands resulting from fusing the panchromatic and color bands („pansharpened“). From the 4 Level-3 component images one can create a true color (red-green-blue) as well as a false color infrared image (red-green-infrared). Figure 1: Image formats of the UltraCam-versions D, X und XP. Obviously, a larger format will increase the efficiency of image collection resulting in fewer aircraft flight miles and fewer individual images and data files. Figure 2: Illustrating an image coverage with 80% forward and 60% side-lap, resulting in a building being imaged 10 times. Form these 10 inputs, a single output is being generated in the form of a 2-D ortho-photo. From Proceedings of Visigrapp-2009, Lisbon, Portugal; 5th – 8th Feb. Publ. by INSTCC-Portugal, ISBN 978-989-8111-69-2, Volume IS, pp 7 –15. P a g e | 9 Virtual Earth we move into a digital model of the spaces we live in -a Virtual Habitat. 2. LOCATIONAL AWARENESS IN THE INTERNET? One may want to denote the internet-based mapping and search services as “locationally aware”. We see a marriage between geo-data and the Internet with its vast locationally unorganized data repository. “Geodata” have come a long way in the last 2 decennia with a transition from 2-D paper maps to, initially, the 2-D geographical information system GIS. We now see a slow emergence of the third dimension in geo-data production. As a result the GIS transits from 2D data with a third dimension encoded as an attribute to the GIS-elements, to a true 3-D model of the world. The main source of such 3D geo-data is the field of photogrammetry. One may be able to track the evolution via the quadrennial scientific-technical Congresses of the International Society for Photogrammetry and Remote Sensing ISPRS as follows (ISPRS, 2008): 1992 (Baltimore) -first film scanning systems get introduced, thereby supporting the digital processing of images in photogrammetric geo-data processing, but based on film sources; 1996 (Vienna) – first digital stereo (also called softcopy stereo) systems come online and start the demise of the 100-year optical stereo-technology relying on the human stereo viewing ability; 2000 (Amsterdam) -the first digital aerial cameras get announced but have yet to get introduced into the application in photogrammetry; 2004 (Istanbul) – first reports of the systematic application of digitally collected imagery and its advantages in reducing cost and increasing quality; the end of the film-based geo-data creation is near; 2008 (Beijing) – this is the Congress celebrating the marriage of the Interent with geo-data in 2 and 3 dimensions. The Internet changes the geo-data user’s paradigm. It moves from the realm of the expert users into everyday live. At all places one can interact with all places and do so at all times. The idea of interacting “with all places” may include the galaxy, as demonstrated by Microsoft’s „Worldwide Telescope“ and http://www.google.com/sky/. These Internet data systems thereby evolve into a societal force by providing the global geographic knowledge to all of humanity in an easy and intuitive manner. The business model initially relies on advertisement. But we can expect that this model will broaden into computer games, ecommerce, the Internet-of-things, the so-called „Ambient Living“ and others. 3. SIX CHALLENGES TO MEET