Juho-Pekka Virtanen

Forum Virium Helsinki

Individual tree data could offer potential uses for both forestry and landscape visualization but has not yet been realized on a large scale. Relying on 5 points/m2 Finnish national laser scanning, we present the design and implementation of a system for producing, storing, distributing, querying, and viewing individual tree data, both in a web bro...

Urban digital twins have become an interest for cities worldwide. The current urban digital twins frequently build on earlier 3D city modelling efforts, and thus also share many of the applications. At the same time, the ongoing digitalization offers potential routes for further development of urban digital twins. We present some of the ongoing dev...

The digital twins in various forms have recently drawn considerable attention in the city innovation and urban governance discourses. The core of traditional digital twins lies in describing and monitoring objects and creating mathematical simulations, e.g., for optimization and risk management purposes. In the urban context, this technological app...

Increasing interest has recently been shown towards the digital twins of cities. These urban digital twins utilize 3D city models together with other data sources, such as open data, which can be accessed, e.g., through application programming interfaces (APIs). A large amount of open geospatial data is already available through various open data p...

The Digital Twins (DT) in various forms have recently appeared in the smart city innovation and governance discussions. The definition of the digital twin is somewhat mature in industrial, non-scientific use cases. The industrial digital twin approach often is focused on describing, monitoring, and sensing objects and creating mathematical simulati...

The continuous flow of autonomous vehicle-based data could revolutionize current map updating procedures and allow completely new types of mapping applications. Therefore, in this article, we demonstrate the feasibility of using perception data of autonomous vehicles to replace traditionally conducted mobile mapping surveys with a case study focusi...

3D City information models have become established geospatial data sets in many cities globally. In addition to existing GIS data, cities are “flooded” with new potential data sources, such as IoT systems, smart mobility devices, digital services and 3D mapping methods like UAV photogrammetry. Tools are needed in the cities for translating the data...

What is a digital twin for mobility? This document explains what is meant by the concept. It provides a brief introduction to the concept, explains the data it consists of, and outlines its potential applications. It provides a snapshot of where the topical development is going and what the opportunities and barriers for further development are, es...

Remote sensing-based forest investigation and monitoring have become more affordable and applicable in the past few decades. The current bottleneck limiting practical use of the vast volume of remote sensing data lies in the lack of affordable, reliable, and detailed field references, which are required for necessary calibrations of satellite and a...

Virtual reality-based urban audit methods are gaining increasing attention; however, most virtual urban audit studies have focused on panoramic views. The 3D city model-based geovisualizations have remained until now rather unexplored in user studies for urban audits and for communicative urban planning. We explored the feasibility of a 3D geovisua...

Digital twins (DTs) have been found useful in manufacturing, construction, and maintenance. Adapting DTs to serve cities, the question arises of what an urban digital twin should contain and how it should be orchestrated to serve a city’s dynamical ecosystem, along with how to enhance the efficiency of the city. We are aligning with the commonplace...

The importance of ensuring the adequacy of urban ecosystem services and green infrastructure has been widely highlighted in multidisciplinary research. Meanwhile, the consolidation of cities has been a dominant trend in urban development and has led to the development and implementation of the green factor tool in cities such as Berlin, Melbourne,...

An efficient 3D survey of a complex indoor environment remains a challenging task, especially if the accuracy requirements for the geometric data are high for instance in building information modeling (BIM) or construction. The registration of non-overlapping terrestrial laser scanning (TLS) point clouds is laborious. We propose a novel indoor mapp...

We aim to present a method to measure 3D luminance point clouds by applying the integrated high dynamic range (HDR) panoramic camera system of a terrestrial laser scanning (TLS) instrument for performing luminance measurements simultaneously with laser scanning. We present the luminance calibration of a laser scanner and assess the accuracy, color...

3D city models and their browser-based applications have become an increasingly applied tool in the cities. One of their applications is the analysis views and visibility, applicable to property valuation and evaluation of urban green infrastructure. We present a near real-time semantic view analysis relying on a 3D city model, implemented in a web...

Technological development towards increased visual quality and accessibility has made photorealistic 3D geo-visualizations an interesting tool for communication in urban planning. Particularly the ability to support perception is important in assessing 3D geovisualizations' effectiveness for communication. We applied both the concept of sense of pr...

Three-dimensional city models are an increasingly common data set maintained by many cities globally. At the same time, the focus of research has shifted from their production to their utilization in application development. We present the implementation of a demonstrator application combining the online visualization of a 3D city information model...

Computer-aided 3D modelling is the standard design method in the architecture, engineering, construction, owner, operator (AECOO) industry and in lighting design. Applying a photogrammetric process, a sequence of images is used to reconstruct the geometry of a space or an object in a 3D model. Likewise, a calibrated digital camera is utilized to me...

Visualization applications are an increasingly significant component in the field of 3D geo-information. In them, the utilization of consumer grade virtual reality (VR) head mounted displays (HMD) has become a topical research question. It is notable, that in most presented implementations, the VR visualization is accomplished by a game engine. As...

This paper investigated building data from multispectral and single-photon Lidar systems. The multispectral datasets from the individual channels and fused channels were explored. The multispectral and single-photon Lidar data were compared across multiple aspects: the data acquisition geometry, number of echoes, intensity, density, resolution, dat...

Terrestrial laser scanning (TLS) enables the efficient production of high-density colored 3D point clouds of real-world environments. An increasing number of applications from visual and automated interpretation to photorealistic 3D visualizations and experiences rely on accurate and reliable color information. However, insufficient attention has b...

The automated 3D modeling of indoor spaces is a rapidly advancing field, in which recent developments have made the modeling process more accessible to consumers by lowering the cost of instruments and offering a highly automated service for 3D model creation. We compared the performance of three low-cost sensor systems; one RGB-D camera, one low-e...

The integration of the 3D measurement techniques with luminance imaging has increased the potential for mapping night-time road lighting conditions. In this study, we present selected static and mobile approaches for the purpose. The measurement methods include conventional 2D imaging luminance photometry and the integration of the luminance imagin...

Roadside vegetation can affect the performance of installed road lighting. We demonstrate a workflow in which a car-mounted measurement system is used to assess the light-obstructing effect of roadside vegetation. The mobile mapping system (MMS) includes a panoramic camera system, laser scanner, inertial measurement unit, and satellite positioning...

Surveying and robotic technologies are converging, offering great potential for robotic-assisted data collection and support for labour intensive surveying activities. From a forest monitoring perspective, there are several technological and operational aspects to address concerning under-canopy flying unmanned airborne vehicles (UAV). To demonstra...

With the development of 3D measurement systems, dense colored point clouds are increasingly available. However, up to now, their use in interactive applications has been restricted by the lack of support for point clouds in game engines. In addition, many of the existing applications for point clouds lack the capacity for fluent user interaction an...

It is well-established how visual stimuli and self-motion in laboratory conditions reliably elicit retinal-image-stabilizing compensatory eye movements (CEM). Their organization and roles in natural-task gaze strategies is much less understood: are CEM applied in active sampling of visual information in human locomotion in the wild? If so, how? And...

Forest inventories rely on field plots, the measurement of which is costly and time consuming by manual means. Thus, there is a need to automate plot-level field data collection. Mobile laser scanning has yet to be demonstrated for deriving stem curve and volume from standing trees with sufficient accuracy for supporting forest inventory needs. We...

The importance of being able to separate the semantics from the actual (X,Y,Z) coordinates in a point cloud has been actively brought up in recent research. However, there is still no widely used or accepted data layout paradigm on how to efficiently store and manage such semantic point cloud data. In this paper, we present a simple data layout tha...

Data collection for street-level mapping is currently executed with terrestrial (TLS) or mobile laser scanners (MLS). However, these methods have disadvantages such as TLS requiring a lot of time and MLS being dependent on the global navigation satellite system (GNSS) and an inertial measurement unit (IMU). These are not problems if we use simultan...

Background: Lately, terrestrial point clouds have drawn attention as a new data source for in situ forest investigations. So far, terrestrial laser scanning (TLS) has the highest data quality among all terrestrial point cloud data in terms of geometric accuracy and level of detail (IEEE Transact Geosci Remote Sens 53: 5117–5132, 2015). The TLS poin...

As data acquisition technology continues to advance, the improvement and upgrade of the algorithms for surface reconstruction are required. In this paper, we utilized multiple terrestrial Light Detection And Ranging (Lidar) systems to acquire point clouds with different levels of complexity, namely dynamic and rigid targets for surface reconstructi...

By combining additive manufacturing with 3D measurement techniques, tailored production work-flows that include the digitizing of existing components, computer-aided design, and tool-free manufacturing of the customized parts can be envisioned, potentially reducing the costs of mass customization. The introduction of affordable depth cameras has gr...

The Internet has become a major dissemination and sharing platform for 3D content. The utilization of 3D measurement methods can drastically increase the production efficiency of 3D content in an increasing number of use cases where 3D documentation of real-life objects or environments is required. We demonstrated a developed, highly automated and...

Digital 3D geometric models have become a central tool for geo-information. For many participatory and collaborative applications, distributing these models easily is essential. Several technical solutions exist for creating online systems that facilitate the study of 3D models in the context of the built environment. To provide an overview on brow...

The measurement of 3D geometry for road environments is one of the main applications of mobile mapping systems (MMS). We present mobile mapping applied to a night-time road environment. We integrate the measurement of luminances into a georeferenced 3D point cloud. The luminance measurement and the 3D point cloud acquired with an MMS are used in as...

Maatiloille on jo tarjolla digitaalisia ratkaisuja, mutta uusia digitalisaatiota ja älyteknologiaa hyödyntäviä innovaatioita tarvitaan lisää. Peltojen täsmäviljelyn lisäksi yksi selkeä kokonaisuus uuden teknologian hyödyntämisessä on tuotantoeläinten seuranta maatiloilla. "3D-mittaukseen perustuva karjantarkkailu" on esiselvityshanke, jonka tavoitt...

By combining game engines with indoor mapping, it is possible to create interactive virtual environments that represent the real world. In this paper a virtual version of an audio installation in a historic building is produced, where the user freely explores the building and experiences a set of audio clips, creating a virtual radio play. A depth...

3D city models have become common geospatial data assets for cities that can be utilized in numerous fields, in tasks related to planning, visualization, and decision-making among others. We present a study of 3D city modeling focusing on the six largest cities in Finland. The study portrays a contradiction between the realized 3D city modeling pro...

In this paper, we demonstrate the feasibility of using the Microsoft Kinect and Google Tango frame-based depth sensors for individual tree stem measurements and reconstruction for the purpose of forest inventory. Conventionally field reference data in forest inventory are collected at tree and sample plot level by means of manual measurements (e.g....

Road lighting measurements are executed with stationary imaging luminance photometry. In these measurements, a digital camera is utilized to create 2D luminance data maps of the scenery. We consider the third dimension to be a meaningful advancement for luminance data presentation and analysis. Hence, we present the preparation for a digital camera...

Topographic databases maintained by national mapping agencies are currently the most common nationwide data sets in geo-information. The application of laser scanning as source data for surveying is increasing. Along with this development, several analysis methods that utilize dense point clouds have been introduced. We present the concept of produ...

Accurate three-dimensional (3D) data from indoor spaces are of high importance for various applications in construction, indoor navigation and real estate management. Mobile scanning techniques are offering an efficient way to produce point clouds, but with a lower accuracy than the traditional terrestrial laser scanning (TLS). In this paper, we fi...

This article discusses various aspects of outdoor lighting energy efficiency by means of new light sources and smart lighting systems. We will also discuss visibility, traffic flow, safety, and environmental and economic aspects. The use of an optimum level of road lighting maximizes the contrast between the background and the object to be seen. Th...

We extend the concept of intrinsic localization from a theoretical one-dimensional (1D) solution onto a 2D manifold that is embedded in a 3D space, and then recover the full six degrees of freedom for a mobile laser scanner with a simultaneous localization and mapping algorithm (SLAM). By intrinsic localization, we mean that no reference coordinate...

The 3D measurement technique of terrestrial laser scanning (TLS) in forest inventories has shown great potential for improving the accuracy and efficiency of both individual tree and plot level data collection. However, the effect of wind has been poorly estimated in the error analysis of TLS tree measurements although it causes varying deformation...

The 3D measurement technique of terrestrial laser scanning (TLS) in forest inventories has shown great potential for improving the accuracy and efficiency of both individual tree and plot level data collection. However, the effect of wind has been poorly estimated in the error analysis of TLS tree measurements although it causes varying deformation...

The stakeholders of a built environment can attain several benefits by digitalizing the existing built environment. To highlight these benefits, this article presents a prototype of a digitalized built environment using 3D Internet technologies. To utilize existing data reserves and various measuring techniques, models of different levels of detail...

Following the pioneering work introduced in [Lehtola et al., ISPRS J. Photogramm. Remote Sens. 99, 2015, pp. 25–29], we extend the state-of-the-art intrinsic localization solution for a single two-dimensional (2D) laser scanner from one into (quasi) three dimensions (3D). By intrinsic localization, we mean that no external sensors are used to local...

Modern facilities management in digital systems requires user-friendly tools for visualization and decision making, and improved data. To help achieve this, 3D models can operate as a platform for integrating sensor data and other documentation for a building. If 3D models are not readily available for a specific building, measuring methods can be...

Value chain analyses are utilized to study the value process production of companies. For the construction industry, several change agents are affecting the value chains in usage. To address this development, this article reviews what is considered to be the state of art in additive manufacturing methods and 3D measuring technology. Consequently, a...

Personal laser scanners (PLS) fill this void and are now evolving towards compact, agile and flexible solutions for mapping complex environments. Researchers explain the new Akhka R2 PLS and illustrate its use in various applications. The current production version of the Akhka PLS, Akhka R2 has a much lighter scanner unit and a more robust solutio...

A novel approach to evaluating night-time road and street environment lighting conditions through 3D point clouds is presented. The combination of luminance imaging and 3D point cloud acquired with a terrestrial laser scanner was used for analyzing 3D luminance on the road surface. A calculation of the luminance (cd/m2) was based on the RGB output...

Three-dimensional (3D) maps have many potential applications, such as navigation and urban planning. In this article, we present the use of a 3D virtual world platform Meshmoon to create intelligent open data 3D maps. A processing method is developed to enable the generation of 3D virtual environments from the open data of the National Land Survey...

Abstract We use a single 2D laser scanner to 3D scan indoor environments, without any inertial measurement units or reference coordinates. The localization is done directly from the point cloud in an intrinsic manner compared to other state-of-the-art mobile laser scanning methods where external inertial or odometry sensors are employed and synchro...

Detailed modeling of floodplain flows and associated processes requires data on mixed, heterogeneous vegetation at river reach scale, though the collection of vegetation data is typically limited in resolution or lack spatial information. This study investigates physically-based characterization of mixed floodplain vegetation by means of terrestria...

Detailed modeling of floodplain flows and associated processes requires data on mixed, heterogeneous vegetation at river reach scale, though the collection of vegetation data is typically limited in resolution or lack spatial information. This study investigates physically-based characterization of mixed floodplain vegetation by means of terrestria...