The built heritage is a fundamental element of the public space. It 
		is part of the memory of places; it is the history of places represented 
		materially and often-beautiful iconic city landmark. For these reasons, 
		among others, cities that preserve this built heritage with intrinsic 
		rare value are highly pursued by the tourism industry, because they 
		constitute financial profit and economic growth. These sources of income 
		are frequently a factor in balancing public finances and support this 
		urban inherency. Today, the diversity of mobile platforms providing 
		access onsite to real-time geographic information and the possibility of 
		supporting Apps based on Augmented Reality enable, what we can call, the 
		expansion of public space and their cultural heritage value. The Apps 
		can be understood as dematerialized extension of the public space and 
		their cultural/historical value. The recreation of the public space with 
		heritage value (physical and limited) gives place to the virtual/mixed 
		public space, leading to what we can call smart public space 
		(an intergenerational interaction in the combination of paper maps or 
		other objects, with unlimited virtual information, supported on mobile 
		platforms) and as a consequence increases also the "ubiquity of cities". 
		The development of 3D models of urban objects implanted in public space, 
		using land surveys and UAV, and its incorporation in Apps for the 
		conceptualization of mixed reality environments, enhance the value of 
		urban heritage and promote the virtualization of cities. This idea will 
		support the demonstration of the prototype Lx_W App, developed for the 
		Águas Livres Aqueduct System in Lisbon, aqueduct that is one of the most 
		important landmarks of the Portuguese capital. 
		 
		1. INTRODUCTION
		The Smart City concept fills many of today's discourses on cities. 
		This concept is closely associated with Information and Communication 
		Technologies, although it is not exclusive. In fact, the concepts of 
		city efficiency, of intelligent cities, of strategic governance 
		capacity, among other concepts, are present in the discourses that we 
		can call non-technological discourses. In this circumstance, we can 
		admit that we are in the presence of political discourses. In any case, 
		whether it is technological or political speeches, what is relevant in 
		our opinion is that the concept of Smart City is insufficient, as Carlo 
		Ratti (2014) refer in a popular article, "The Smart City is not enough. 
		How could real-time data awaken the humanity in our buildings and public 
		spaces?". Within this context and considering the way we see the 
		relations between the city and the technology, we propose the following 
		idea alignment: what exists is a Smart Public Space that results from 
		the combination of "Human Sensors (HS) + Technology (Tech)" (Figure 1).
		
		
		
		Figure 1 - Smart Public Space: Human sensors (HS) 
		+ Technology (Tech) 
		There is a Smart Public Space when there is a combination of HS + 
		Tech. HS are in physical, tangible, sensitive interaction with real 
		space. Hence an internal representation of this real space. Using Tech 
		(mobile devices, Apps, AR, VR, Wi-Fi signals) the HS enrich these 
		internal representations of public space, itself enhanced by enrichment 
		with virtual data. In this context, we can admit that there is a Smart 
		Public Space when there is convergence between the physical public space 
		and the virtual public space resulting from the HS + Tech interface.
		If we accept the ideas above, we can look at the built heritage as an 
		element of the urban public space, combined in the following forms:
		
			- 
			Built heritage and memory of places. The built heritage 
		is a space of memory; memory in overlapping, as if structured in layers 
		(due to the passage of time) and in fusion (for example, of 
		architectural styles, forms, methods and construction materials). All 
		built heritage has a narrative, synthesizes collectively shared 
		representations. Many of these representations remain in time, they are 
		part of the cities and the public space that compose them; are 
		historically appropriate identity and identification references. It is 
		often said that "every stone speaks" when we observe a building with 
		patrimonial value. We can affirm that the "whole" of a historical 
		building contains a narrative that can be enriched with information 
		inherited (architectural description, engravings, photos, ambiences, 
		etc.) structured on mobile platforms. 
- 
			Built heritage and public space. Buildings with historical 
		value, as well as all other buildings, are part of the architectural 
		composition of the city and of the places in general. In this context, 
		the city is understood as an open landscape constituted by 
		three-dimensional pieces in an organized environment of which the open 
		spaces are part. Many of these open spaces are public: squares, farmer's 
		markets, downtown shopping malls, public parks, playgrounds, greenways, 
		waterfronts, etc. This public space is the place of sociability 
		manifestations such as walking, talking, studying, shopping, interacting 
		with others. The built heritage is a fundamental element of the public 
		space. On the one hand, as we have mentioned, it is part of the memory 
		of places; on the other hand, constitutes a dimension of the history of 
		the places represented materially. For these reasons, among others, 
		cities with rare built heritage are highly valued by the tourism 
		industry because they are sources of financial income. These sources of 
		profit are often a factor in balancing public finances.  
- Built Heritage and Augmented Reality. The decade of 
			nineties of the 20th century were marked by the emergence of Virtual 
			Reality. The second decade of this century lives the Augmented 
			Reality. The overlay in "synchronous time" of virtual images with 
			elements of tangible reality is becoming an unprecedented social, 
			cultural and tourist practice. Today, the diversity of mobile 
			platforms providing access to real-time geographic information 
			(synchronization) and the ability to support Apps (understood as 
			data and technology that supports space-time extension) built on 
			Augmented Reality enable what we can call of expansion of the public 
			space with patrimonial or other value; ease the synchronization 
			between physical public space and virtual public space. Again, we 
			emphasize that Apps can be understood as the dematerialized 
			extension of the public space with patrimonial value. The recreation 
			of the public space with patrimonial value (physical and limited) 
			also gives place to the virtual public space and leads to what we 
			can call smart public space. 
In the context we have just presented, we propose a new concept: 
		Augmented Valuation of Cultural Heritage, as a result of virtual 
		georeferenced data added to the real world applied to cultural heritage 
		using mobile technology (Figure 2). 
		
		Figure 2 - New concept proposal: Augmented 
		Valuation of Cultural Heritage 
		This concept is outlined in the figure 2 and is composed of three 
		fundamental parts: i) the tangible cultural heritage; ii) the intangible 
		cultural heritage; both being part of the cultural heritage; and iii) 
		the augmented valuation results from the combined use of virtual data 
		and mobile platforms. This combined use increases the value that the 
		built heritage has. It extends the memory and qualities of this 
		heritage; increases its value because it introduces the possibility of 
		constructing a narrative. In what way can we answer the question: "How 
		can 3D models and augmented reality visualization based on mobile 
		platforms enhance the value of urban heritage?". Presently, we use of 
		public space resorting to mobile platforms has been a reality for some 
		years. In such a way that the urbanism of the future will consider this 
		new reality. There is no better way to answer the question, nor to 
		exemplify what we have just said, than to resort to the short story of 
		implementing a mobile App. 
		2. SCHEMATIC APPROACH TO MODELLING, REPRESENT AND VISUALISE 3D 
		OBJECTS IN AN AR ENVIRONMENT 
		Urban planning is intimately connoted with spatial relationships 
		between objects, buildings, blocks, streets, neighbourhoods, and cities, 
		and often 2D representations are considered insufficient to address real 
		3D planning problems, especially at the scale (in area and height) of 
		the modern city (Yin, 2010). 3D representations increase the engagement 
		of the user, making easier to understand and participate by visualizing 
		interactively, for example, volumes, textures, shadows, sights and their 
		relation. This principally occurs because of its high level of 
		similarity to reality and how humans perceive the world, congregating 
		detailed information and volume property, stimulating more enthusiasm 
		and simplifying creative solutions for detected problems after a 
		walk-drive-fly-through re-presentation (embodying the user in that 
		environment or presence), improving understanding and communication. 3D 
		representations and analysis tools are more adequate for volume 
		variation and enriching spatial representations.
		Allowing to collect data to generate diverse types of geographical 
		information products, and particularly very detailed 3D point clouds and 
		models, practically on demand, Unmanned Aerial Vehicles (UAV) has 
		introduced a flexible, low-cost and rapid response as an alternative to 
		other traditional methods, such as ground acquisitions and manned 
		vehicles. 3D point cloud data automatically generate 3D models, 
		including Digital Terrain Models (DTM - simple terrain), Digital Surface 
		Models (DSM - including the elevations of objects above the ground), and 
		3D models (from isolated or collective objects). 3D point clouds are 
		mostly generated directly from a laser scan or through stereo image 
		matching, processing imagery algorithms by overlapping (terrestrial or 
		airborne). This means that it is possible to acquire relevant urban 
		parameters at low-cost, from 3D point cloud data acquisition (Tenedório 
		et al., 2014).
		Unlike Virtual Reality, which provides a synthetic environment as a 
		replacement for (represented) reality to the user, Augmented Reality, 
		ensures that the user sees the real/virtual environment augmented and 
		mixed with information from the opposite environment. Thus, the frontier 
		between virtual and real worlds may be more diffuse and permeable than 
		experts had previously imagined. This Mixed Reality complements 
		reality/virtuality rather than completely replacing it, appearing to the 
		user that the virtual and real coexist in the same space. This 
		technology is becoming increasingly popular at overcoming numerous 
		issues, such as the obstacles related with the successful public 
		participation, regarding, for example, flexible solutions adapted to 
		different scenarios that may arise (e.g. public consultation meetings). 
		Augmented Reality as a tool has the potential to assist decisional 
		processes in the context of urban design and planning, adding the 
		capability to increase representational information (virtual or real) 
		into the selected environment presented (also virtual or real). These 
		characteristics are also valid to understand temporal and spatial 
		changes, manipulate geographical data and navigate through this 
		alternative space. Techniques like image matching and the use of a 
		navigational coordinate system allows linking virtual data to the real 
		environment (the device knows where the user is) as a camera permits 
		capturing real images and mixing them with virtual synthetized digital 
		representations, visualizing in real time in the device screen.nbsp; 3D 
		virtual representations of objects allow us to model and (virtual) 
		travel through time, creating new methods of special analysis and 
		visualization as we perceive them in our heads (e.g. internal 
		representations or imagination). Through technology, both the virtual 
		and the real worlds can be combined expanding the space/time dimensions, 
		human connectivity, and information/intelligence, expanding the mind.
		Augmented Reality enhances the real world instead of replacing it. The 
		users can view the real world enriched with additional 3D graphics 
		superimposed to their field of view. The possibility of combining real 
		and virtual objects will allow a huge amount of applications. In the 
		field of Cultural Heritage, AR is of the most outstanding technologies, 
		considering the possibilities to recreate 3D representations, to Virtual 
		Time Travel (fundamental for cultural elements that are often 
		historically relevant), and combine the virtual with the real world 
		(e.g. recreate some object from the past or viewing several phases of 
		construction). This is more valuable when using mobile devices since 
		these are portable and can be used on site, knowing the user’s position 
		through navigation systems. AR digital representations, restitutions and 
		simulations can offer interesting possibilities and useful applications, 
		due to their fairly good interactive capabilities and their capacity to 
		visually stimulate and engage the user, for example, when applied to 
		cultural heritage on-site visualization and exploration tools. 
		The figure 3 schematically synthesises the methodology, procedures 
		and fluxes of data used in the case study developed, concerning the 
		visualization of 3D models, gathered (internet catalogues) or produced, 
		using 3D modelling software or 3D scanning (terrestrial or aerial - UAV) 
		to be visualised in an AR environment. 
		
		
		Figure 3 - Schematic approach to gather/model and 
		visualise 3D objects in an AR environment
		Considering the fluxes of data, simple multimedia images/videos might 
		be visualised within mixed reality environments through mobile 
		platforms. In the case of built 3D models (e.g. internet catalogues), it 
		may be necessary to convert or adapt these to other formats, compatible 
		with the AR application to be used in the mobile device. Based on 
		digital cartography, in the case of the 2D vector, the volume associated 
		with alphanumerical “z” values can been created (beside the z value, in 
		the case of a building having, for example, the number of floors, the 
		user can assign a medium height and multiply to calculate an estimation 
		of the building’s volume), while on raster documents (e.g. satellite 
		imagery or ancient cartography) the process requires 2D/3D drawing and 
		eventually adding texture (e.g. building façades) or other features 
		(e.g. audio or video) (Marques et. al., 2016). A 3D scan can be made 
		using several techniques, geomatics, sensors and terrestrial or aerial 
		platforms, taking into consideration scale and object availability. The 
		UAV become extremely relevant considering fast data acquisition based on 
		low cost platforms (when compared with traditional methods). 
		Photogrammetric applications and point cloud extraction by 
		image-matching overlapped images generates rapid data acquisition and 
		processing results. LiDAR might be applied to collect three dimensional 
		point clouds of cities and buildings. High levels of detail and 
		considering large amounts of data retrieved in the models produced, it 
		is frequently necessary to convert, filter and down sample these to 
		further improve the performance of the model, especially in mobile 
		platforms (considering the graphics and processor capacity). The models 
		produced required some adjustments regarding graphic correction, scale 
		and positioning. Once the 3D model has been imported to the AR 
		application, a marker can be defined through image matching recognition 
		(e.g. satellite imagery, ancient map or a touristic map, as in 
		previously to examples) or visualised over a certain chosen surface. 
		However, in the case of not using AR markers, the visualisation in the 
		field may be associated with real coordinates (a georeferenced 3D model) 
		and eventually enable the possibility to access more information about 
		the object.  
		3. CASE STUDY: LISBON AQUEDUCT SYSTEM 
		3.1. Identifying the Lisbon Aqueduct System (LAS) 
		The “Águas Livres” Aqueduct System was projected as one of the 
		boldest hydraulic engineering  structures  built  in  Portugal,  
		crossing  the  municipalities  of  Loures,  Sintra, Amadora, and Lisbon. 
		The works for the construction of this complex system were initiated in 
		the 18th century. Built in limestone, the Águas Livres Aqueduct System, 
		which has been deactivated for 50 years, is presently an important 
		historical and cultural heritage landmark in Lisbon. The Lisbon aqueduct 
		collected, transported, accumulated, and distributed water by gravity 
		(with a descent of ~3mm/m); it included the general aqueduct (14km), the 
		subsidiary extensions, reservoirs, underground galleries and fountains, 
		which in total extended for a length of approximately 58km. The aqueduct 
		was classified as a National Monument in 1910 and its most remarkable 
		section is located in the Alcântara Valley. The existence of this 
		structure in the city is not obvious, especially because it is not 
		visible (it is mostly underground), although it has contributed to 
		define in part the evolution of the territory (with regard to water 
		supply, but especially considering the impact of the implementation of 
		the aqueduct system). 
		The use of technology applied to cultural heritage has enormous 
		advantages to better visualise and understand the importance of such 
		elements, recognising the connection between the structural elements 
		(visible) and areas (known by its path). In view of the importance of 
		the Lisbon Aqueduct monument, research was undertaken for the 
		elaboration of a mobile device App (Android) that enables the 
		visualisation of the GIS information and 3D modelling in the AR 
		environment on site. The GIS data collected and project, consisted in 
		the georeferencing of several sets of ancient cartography 
		contemporaneous to the LAS (to identify and vectorise the entire system 
		and associated elements: Reservoirs, fountains, vents, etc.) and several 
		other datasets, (such as terrain, water lines, roads, building) 
		supported the system comprehension and identification. Example of that 
		is the Digital Terrain Model, which helped to better comprehend the 
		water distribution through gravity and the system galleries and 
		aqueducts. The identification of the Lisbon Aqueduct System structure 
		and associated elements within the GIS project, produced new 
		georeferenced datasets, consisting mainly in segments and dots (X, Y). 
		The several sets of ancient cartography used (from the years 1856, 1858, 
		1868, 1968), required procedural processes of scanning, colour and 
		geometry correction and built mosaics of parts of charts. The 
		cartography, during the procedure of georeferencing, reveal to be highly 
		accurate being extremely useful for the identification of much of the 
		path of the main aqueduct, adductors, distribution galleries and 
		associated elements, enabling the delimitation of traces on the 
		territory, as well as missing objects, displaced or projected but never 
		executed. 
		
		
		Figure 4 - Identification of the Lisbon Aqueduct 
		System using ancient cartography (Planta Geral da Cidade de Lisboa, 
		1868), GIS georeferencing (transparent) over satellite imagery 
		3.2. 3D Data Modelling 
		There are several internet catalogues and warehouses with 3D models 
		available to use. Besides that, the creation of 3D models could be 
		carried out with common software (e.g. 3D Studio Max, Blender, Sketchup, 
		or City Engine), with a high level of detail and without losing 
		performance while inserting them into the augmented reality application. 
		However, the use of a survey point cloud based on a collection of 
		fieldwork photographs proved to be surprising, taking into account its 
		rapid acquisition and processing capabilities with the additional 
		advantage of being authentic. The processing stages of the workflow, 
		besides being very organised and intuitive for the user, allow for the 
		adjustment of several specific tasks and adequate different types and 
		sources of data (multiple scales, objects, environments and/or using 
		different devices and techniques). The software generates 3D models 
		extremely quickly, with regard to the procedures of inserting and 
		aligning photos, and building dense clouds, meshes and textures (with a 
		wide variety of output formats), as refered already in the Figure 3, 
		image processing from terrestrial/aerial scan (Figure 5). 
		
		
		Figure 5 – 3D modelling process of the Armada 
		fountain (Tie points, Dense Cloud, Mesh, Texture, Anaglyph) 
		However, the technical challenge is to simplify these 3D models (with 
		the elimination of faces for example) without losing the realism of 
		urban elements. With the 3D modelling software (Agisoft Photoscan), it 
		is possible to draw masks in the pictures taken to reduce the area of 
		the image that the software has to process, identifying common pixels. 
		The position of the pictures (cameras) made by the software (alignment) 
		is commonly amazingly accurate and very near the reality. During the 
		modelling process, it is possible to eliminate data that could introduce 
		unnecessary noise to the final result. The parameters used depend on 
		computer capacity and final results objective, considering the limited 
		resources of the current most commonly used mobile devices. The Águas 
		Lives aqueduct system has several elements that permit the collection of 
		data by using simply terrestrial images (on site) and creating point 
		cloud meshes. 
		
		
		Figure 6 – 3D modelling using UAV collected data 
		for the “Mãe de Água” water reservoir 
		Otherwise, considering the dimension and volume of objects such as 
		“Mãe de Água das Amoreiras” (37x33m com 17m height building), it is very 
		difficult to conduct a survey without using high or aerial platforms. 
		After having all the authorisations and subsequently performing the 
		necessary flight tests and security, it was decided to use UAV to 
		collect data for the “Mãe de Água” water reservoir. Thus, the usage of a 
		UAV greatly simplifies the assignment of collecting data and processing 
		them, although these data are authentic with an impressive level of 
		detail. 
		In the technical-scientific field, there is a growing interest among 
		technicians for the usage of 3D virtual models, taking advantage of 
		their enormous potential for pedagogical, documentary, and exploratory 
		activities, as well as of their predictive power. This is especially 
		relevant for urban studies since it facilitates interventions in 
		historical sites, rehabilitation and planning of buildings, 
		neighbourhoods and cities, providing opportunities to simulate past, 
		present, or future interventions, and their respective evolution and 
		management, where people can move through and interact with the space 
		within a virtual/mixed environment. This emergent interest is associated 
		with the very fast process of urban sprawl, also tied with the tendency 
		of cities to growth in terms of height (Z axis) and consequently 
		elevating the level of complexity of the urban processes that take place 
		in the third dimension. Mixed Reality environments have the potential to 
		assist decisional processes in the context of urban and environmental 
		planning, cultural and natural heritage modelling, adding the capability 
		to increase (virtual or real) representational information to the 
		selected environment presented (also virtual or real). Realistic 3D 
		environments offer the user interesting possibilities of immersing 
		in/combining with the real world, e.g. convincing reconstructions of 
		events and contexts particularly to raise historical awareness. Virtual 
		environments and especially Augmented Reality have, thus, a clear 
		potential to support cultural heritage, highlighting and enriching its 
		value in a dynamically and interactive form. It also allows users, 
		especially the general public, to learn, intervene, and experience with 
		higher engagement innovative approaches to the promotion, operation, and 
		dissemination of cultural heritage. 
		3.3. Building a mobile App (Lx_W App) 
		The research about the development of one mobile App to visualise the 
		LAS within an Augmented Reality (AR) environment developed several tests 
		consisting in the use of the mobile device camera to visualise the 
		elements of the LAS in virtual data over the real environment. Using the 
		segments and dots of the structure collected previously was possible to 
		understand, in place, the location of the structure and the azimuth of 
		any other element of this monument and the respective distance (from the 
		place of the user and using the device position system – GNSS). However, 
		the most interesting capability revealed to be the possibility to enrich 
		a free and accessible city official plan in paper, with virtual sets of 
		2D/3D produced data within an AR environment. To accomplish that, it was 
		developed the mobile App Lx_W (Lisbon Water), which  was divided in two 
		main Apps, consisting in the AR component: AqueductAR; and the LAS 
		contents: AqueductGPS (ancient and actual pictures, texts, possibility 
		to visit, costs of entrance, google map thematic representation, 
		proximity alert and navigation). The Lx_W App was developed having in 
		mind the idea of using the paper city plan (Official Lisbon Plan), 
		extremely accessible and available for free, as a AR marker (Marques et. 
		al., 2017). The combination between the paper maps (analogue) with the 
		digital virtual data at 3D/4D, superimposed within an Augmented Reality 
		environment is a very interesting capability that might be useful to 
		endless applications (for example, in this project, it was though to use 
		as case study the ancient Fernandina Wall or the Lisbon 3D recreation 
		before the 1755 Lisbon earthquake). The limited base information printed 
		in paper can in this way support innumerous datasets of geographical 
		information, transforming this simple paper map into any thematic 
		cartography required by the user and properly developed. This idea has 
		several exciting approaches while thinking in: the combined 
		intergenerational use (between the older people preferring the paper and 
		younger generation visualising the virtual data through the mobile 
		device); or the portable unfindable thematic proposes; higher number of 
		possibilities for visitors exploration (e.g. touristic/visitor paths 
		with monuments/restaurants/university campus highlighted in 3D 
		visualisation); new forms of sites and brands promotion or publicity; 
		support for navigation; alerting for proximity of objects; among others. 
		Superimposing the representation of the LAS structure over the Lisbon 
		Official Plan, the users are able to simply open the App, point the 
		camera to the paper city map and visualise the digital information 
		within an AR environment and then, interact with and access to more data 
		for each object (e.g. visualise ancient pictures of that object, read 
		the text about its engineer/architect, or identify their position on map 
		and the relation to the rest of the LAS structure). 
		
		
		Figure 7 – LAS structure 3D visualization within 
		an Augmented Reality environment through mobile platforms over a simple 
		paper city plan (accessible and available for free). Image from the 
		authors (Marques et. al., 2017) 
		The case study of LAS was preferred, considering  the  especial 
		 feature  that  the  remains  of  this important landmark are mostly 
		underground and are not known by visitors or even by some inner 
		residents. It is also relevant to verify that some parts of these 
		underground galleries can be visited, having an enormous potential for 
		tourism and consequently functioning as sources of income for its 
		management entities.
		Nevertheless, the main research idea that outcomes from the 
		development of this App was to increase the intrinsic value of this 
		cultural heritage object; in this case, considering not only the 
		individual elements of the aqueduct, but also the wider delimitation of 
		the entire system (over years of constant construction), identifying the 
		most relevant path and associated elements, starting from several 
		springs, subsidiaries and distribution aqueducts and galleries, vents, 
		connections with the exterior and culminating in the fountains, spread 
		throughout some of the most relevant and growing locations within the 
		city (18th to 20th centuries). Most of these places are within the most 
		touristic and visited areas of Lisbon, which could not be detached from 
		cultural heritage knowledge and dissemination, considering the potential 
		interest of a tourist to discover the city.
		4. FINAL REMARKS 
		The buildings with heritage value, as is the case of the Lisbon 
		Aqueduct System (Águas Livres), are part of the city as outstanding 
		elements of the urban space. Often, these elements are so iconic that 
		they form a relevant part of the city identification itself (as is the 
		case of the Colosseum in Rome, the Eiffel Tower in 
		Paris, the Cathedral of the Sagrada Familia in Barcelona, the
		Tower Bridge in London, just to name a few examples). These 
		cultural heritage elements have a substantial power of attraction, 
		particularly for tourists. Tourists somehow endorse these “attractions” 
		since they are systematically preferred for their visits, as circular 
		causality. It is the unique value of this heritage with “global 
		influence” to shape the image of the cities. 
		Technology has always been at the service of promoting and enhancing 
		heritage. Photography, for example, is one of the technologies that has 
		most contributed to record what we might call “memory extension”, i.e., 
		it has been used throughout the ages as a means to record moments of a 
		tourist visit, to remember later (this is what we refer to as “extension 
		of memory”); sharing with other the experience they have lived. 
		Augmented Reality is an enriched view of the physical world that 
		empowers users to experience virtual data superimposed on real 
		environments that function interactively in three or four dimensions 
		(3D+time) in real time. The emergence of mobile devices such as 
		smartphones anticipated a huge potential field request for Augmented 
		Reality applications. When appropriately conducted, the application of 
		three or four dimensional Digital Representations of Cultural Heritage 
		superimposed on the real world, within an Augmented Reality environment, 
		using mobile platforms has the power to improve temporal understanding, 
		map the uncertain, verify the limitations of human perceptual reasoning, 
		and create systems to form collaborative solutions, envisioning 
		processes, simulations, and results. These external affordances enhance 
		human cognition and help to understand societal and anthropologic 
		behaviour besides their symbolism, considering the bases of cultural and 
		heritage conceptions. This is highly relevant for human knowledge, 
		enhancing and augmenting the intrinsic value of the object in analysis. 
		The value attributed to Cultural Heritage might be increased by the use 
		of digital representations, which disclose, explain and promote its 
		symbolic significance, technical-scientific importance, unicity, or 
		other relevant assets, disclosing what could be considered as an 
		Augmented Valuation of Cultural Heritage. 
		
		
		Figure 8 – Visualising the 
		LAS structure within a AR environment over the city official plan 
		
		The concept of Augmented Valuation of Cultural Heritage (Marques, 2017) 
		is clearly inspired by the concept of Augmented Reality, being capable 
		of identifying, analysing, and increasing/augmenting the intrinsic value 
		that is already present in the notion of cultural heritage. This concept 
		brings about the opportunity to recognize that, besides the idea of 
		enriching the physical environment with virtual synthetized data, 
		Augmented Reality technology can simultaneously increase the intrinsic 
		value of cultural heritage. This concept presupposes the process of 
		augmenting the value of cultural heritage. This valuation is dynamic 
		since the user experience mixed reality environments as the process of 
		dynamically augmenting cultural heritage valuation. 
		ACKNOWLEDGEMENT
		We would like to express our deepest gratitude to: Teresa Romão, 
		Fernando Birra and Antero Pires from the NOVA Laboratory for Computer 
		Science and Informatics (NOVA LINCS), unit of the national Science & 
		Technology network in the area of Computer Science and Engineering, 
		hosted at the Departamento de Informática of Faculdade de Ciências e 
		Tecnologia of Universidade NOVA de Lisboa – Portugal (DI-NOVA), for 
		the conception and implementation of the App. To the startup company 
		GEODRONE and its founder João Marques for the UAV survey. To Josep Roca 
		from UPC – BarcelonaTECH and CPSV for suggestions and critics. 
		
		REFERENCES
		MARQUES, L., 2017. Augmented Valuation of Cultural Heritage 
		Representations based upon Geographic Information Technologies: the case 
		study of Lisbon Aqueduct System within an Augmented Reality environment. PhD 
		Thesis. Departament de Tecnologia de l'Arquitectura, Universitat 
		Politècnica de Catalunya, Barcelona, Spain.
		
		http://upcommons.upc.edu/handle/2117/111501
		
		MARQUES, L.; CLADERA, J. R., TENEDÓRIO, J. A., 2017. Valorisation 
		of urban elements through 3D models generated from image matching point 
		clouds and augmented reality visualization based in mobile platforms, 
		Proc. SPIE 10431, Remote Sensing Technologies and Applications in 
		Urban Environments II, 104310P (4 October 2017); doi: 
		10.1117/12.2278065. 
		http://dx.doi.org/10.1117/12.2278065 
		
		MARQUES, L.; TENEDÓRIO, J. A., BURNS, M. C., ROMÃO, T.; BIRRA, F.; 
		MARQUES, J.; PIRES, A. 2016. Cultural Heritage 3d Modelling and 
		Visualisation Within an Augmented Reality Environment, Based on 
		Geographic Information Technologies and Mobile Platforms in ACE 
		Arquitectura, Ciudad y Entorno.
		
		http://upcommons.upc.edu/handle/2117/101733
		
		TENEDÓRIO, J. A., REBELO, C., ESTANQUEIRO, R., HENRIQUES, C. D., 
		MARQUES, L., & GONÇALVES, J. A. 2016. New Developments in 
		Geographical Information Technology for Urban and Spatial Planning. In 
		I. Management Association (Ed.), Geospatial Research: Concepts, 
		Methodologies, Tools, and Applications (pp. 1965-1997). Hershey, 
		PA: IGI Global. doi:10.4018/978-1-4666-9845-1.ch094.
		
		https://www.igi-global.com/chapter/new-developments-in-geographical-information-technology-for-urban-and-spatial-planning/149585
		
		PINTO, N.N.; TENEDÓRIO, J.A.; ANTUNES, A.P.; ROCA, J., Eds. 2014. 
		Technologies in Urban and Spatial Planning: Virtual Cities and 
		Territories. Hershey/Pennsylvania, IGI Global, pp. 342. DOI: 
		10.4018/978-1-4666-4349-9 
		
		https://www.igi-global.com/book/technologies-urban-spatial-planning/75471
		
		RATTI, Carlo (2014). The "Sensing" City Is the Future of 
		Urbanism:
		
		http://www.metropolismag.com/cities/the-sensing-city-is-the-future-of-urbanism/
		
		Yin, L. 2010. Integrating 3D Visualization and GIS in Planning 
		Education. Journal of Geography in Higher Education, 34(3), 
		419–438. 
		https://doi.org/10.1080/03098260903556030
		BIOGRAPHICAL NOTES
		José António TENEDÓRIO 
		Geographer, Associate Professor at Universidade NOVA de Lisboa (UNL), 
		Faculty of Social Sciences and Humanities (FCSH) and Researcher at 
		CICS.NOVA - Interdisciplinary Centre of Social Sciences, RG4, Lisbon, 
		Portugal. He is a Visiting Professor at Polytechnic University of 
		Catalonia, BarcelonaTech (UPC), Faculty of Architecture, CPSV, Spain. He 
		was Director of Centre for Geographical and Regional Planning Studies 
		(e-GEO, FCSH, UNL), between 2003 and 2008, member of the Executive 
		Committee of the Department of Geography and Regional Planning of 
		FCSH-UNL (2008-2013), Director of M.Sc. in Territorial Management at 
		UNL-FCSH (2008-2013) and Director of M.Sc. in Spatial Planning & GIS 
		(e-Learning) at UNL-FCSH (2010-2013). Graduated in Geography and 
		Regional Planning (1984) at UNL-FCSH. He attended Sorbonne-Universités, 
		University of Paris VI-Pierre et Marie Curie, Faculty of Sciences, where 
		he post-graduate (DESS in 1991) in Remote Sensing and the University of 
		Paris XII, Urbanism Institute, to obtained Ph.D. (1998) in Urbanism. His 
		main scientific area of research is Remote Sensing, GIS, Spatial 
		Analysis, and Geographical Modeling. He has published more than one 
		hundred papers (book chapters, papers in periodic with scientific 
		refereeing, papers in conference proceedings with scientific 
		refereeing). In 2013 he received the (first prize) SANTANDER Award for 
		the Internationalization of the FCSH Scientific Production 2013. In 
		2015, for the second time, he received the (first prize) SANTANDER Award 
		for the Internationalization of the FCSH Scientific Production 2015 (ex 
		aequo). 
		Luís Filipe MARQUES 
		PhD (2017) in Urban and Architectonic Management and Valuations at 
		Barcelona School of Architecture of the Polytechnic University of 
		Catalonia – BarcelonaTech (ETSAB/UPC). Master (pre-Bologna, 2010) and 
		Post-Graduate (pre-Bologna, 2002) in “Land Use Management and 
		Environmental Planning” at the Faculty of Science and Technology of the 
		New University of Lisbon (FCT/UNL), Portugal. Degree (pre-Bologna – four 
		years) in Geography and Regional Planning at the Faculty of Human and 
		Social Sciences of the New University of Lisbon (FCSH/UNL), Portugal 
		(1997-2001). Senior technician at IGAMAOT – General Inspection for 
		Agriculture, Sea, Environment and Spatial Planning (Portugal). Has been 
		collaborating with several organizations of the public administration 
		(at central, regional and local level) and private companies, mainly in 
		research projects related to the themes of spatial planning and 
		environment (commonly with the use of Geographic Information 
		Technologies).