Our WG IV/9 events at the ISPRS congress (6-11 June 2022), Nice, France

The XXIV ISPRS Congress will take place 6-11 June 2022 in Nice, France. Our working group hosting the following sessions hosting the conference (the complete programme is available here). 


TUE 7th June, 11:00-12:30
Geovisualization and extended reality

Projective Multitexturing Of Current 3D City Models And Point Clouds With Many Historical Images, M. Brédif

Improving 3D Pedestrian Detection for Wearable Sensor Data With 2D Human Pose, V. Kamalasanan 

Virtual Element Retrieval In Mixed Reality, M. Radanovic

Pose Estimation Through Mask-R CNN And VSLAM In Large-Scale Outdoors Augmented Reality, A. Boutsi

Virtual Data Sphere: Inverse Stereographic Projection For Immersive Multi-Perspective Geovisualization, M. Spur

Interaction And Visualization Design Considerations For Gaze-Guided Communication In Collaborative Extended Reality, A. Cöltekin

Wed 8th June, 9:00-10:30
Digital twins: Vision papers

Twins For Cities, L. Thuvander

The Future Of Urban Living, N. Holliman

Panel Session

Thu 8th June, 9:00-10:30
Digital twins: Case studies

State Departments Of Transportation’s Vision Toward Digital Twins: Investigation Of Roadside Asset Data Management Current Practices And Future Requirements, A. Ammar

Visually Annotated Responsive Digital Twins for Remote Collaboration in Mixed Reality Environments, K. Koebel

Digital Twinning In The Ocean — Challenges In Multimodal Sensing And Multiscale Fusion Based On Faithful Visual Models, V. Grossmann

Exploring Digital Twin Adaptation To The Urban Environment: Comparison With Cim To Avoid Silo-Based Approaches, A. Depretre

Virtually Throwing Benchmarks Into The Ocean For Deep Sea Photogrammetry And Image Processing Evaluation, Y. Song

Hybrid Aerial Sensor Data As Basis For A Geospatial Digital Twin, U. Bacher 

Computer Vision System For Detecting Orchard Trees From UAV Images, B. Leblon


Wed 8th June, 16:00-17:30 – Digital Twins 

Wed 8th June, 16:00-17:30 – Spatial Information Science

Thu 9th June, 16:00-17:30 – Spatial Information Science



Recent PhD thesis: Exploring the cognitive processes of map users employing eye tracking and EEG

As you know, we sometimes feature recently finished PhD theses here in the blog. While 2020 has been an odd year in many ways, several PhD candidates finished up their thesis, defended their thesis remotely, basically talking to a screen. Not really the best energy but we commend them all for their resilience and congratulate them for this gigantic life event. Among those was Merve Keskin, a member of our WG, and Merve has sent us the following text that summarizes her thesis. Enjoy, and happy 2021!


Exploring the cognitive processes of map users employing eye tracking and EEG

Merve Keskin

Various research in cartography focused on how we see maps and how we derive meaning from them. When people need to perform a map related task (e.g. visuospatial search, route selection, navigation, distance estimation), they tend to memorize the relevant direct or indirect information on a map. Direct information could be about the location, name, shape, and size of objects, and indirect information is the spatial relationships among these objects. Next to the perceptual, cognitive, and visual abilities of individuals, the retrieval of a spatial information is linked with map learning. Map learning includes the processes of matching the map to the prior knowledge that already exists in memory and how map-learning task should be achieved. Each map user can develop their own strategy to approach the spatial information on maps.

To study the cognitive procedures during a map-reading task, various user-testing methods, such as sketch maps and eye tracking, contributed to understanding map users’ behavior. For instance, sketch maps represent the information extracted from a cognitive map through drawing and they reveal insights on the hierarchical structure of cognitive map processing and the amount of details of individuals’ cognitive maps. Eye tracking technique allows capturing users’ visual behavior in real-time and monitoring locations of fixations within images. Eye tracking metrics provide significant information on attention, cognitive load and task performance. On the other hand, EEG records the electrical activity along the scalp produced by the firing of neurons in the brain with high temporal resolution and relatively low cost. Eye tracking is used to detect overt attention through gaze movements, whereas EEG is more likely to detect covert attention through direct measures of the brain activity. As well as eye tracking, EEG suggests statistical and visual exploration of cognitive processes and has been commonly used in cognitive and experimental psychology. The cognitive theories and methods borrowed from psychology are very useful for cartographic usability research, especially when dealing with the issues caused by individual characteristics. However, cartographers rarely employed EEG to investigate cognitive issues of map users and cartographic products.

In my PhD research, I focused on how expert and novice maps users read, interpret and retrieve the visual information presented on digital 2D static maps from memory (i.e. spatial memory task) by conducting user experiments with sketch maps, eye tracking and EEG as synchronized and simultaneous data collection methods (Figure 1). Through the experiments, I aimed to measure the cognitive load when map users are asked to memorize and then remember the main structuring elements (i.e. roads, green areas, and hydrography) of map stimuli with varying levels of difficulty. In the retrieval stage, the participants were asked either to draw a sketch map or to choose the most suitable one from given maps (Figure 2).

Figure 1. A snapshot from an experiment

Figure 2. Spatial memory tasks in the experiments

Accordingly, visual variables used for depicting the main structuring elements in a map play an important role in spatial memory because we utilize them to design maps that can be used either with less or more cognitive load. To understand the influence of the visual variables on spatial memory, we considered the shape, size, color and location of the drawn elements on the sketch maps and their order of drawing. As reaction time and response accuracy were used as preliminary indicators of cognitive load, fixation-related eye tracking metrics (i.e. number of fixations per second, average fixation duration) and EEG power spectrum calculations (i.e. changes at alpha and theta frequency bands) were used to extract cognitive load.

Based on the results of our user experiments, we discovered that expertise is not as influential as we think when it comes to simple spatial memory tasks using maps designed for general audience like Google maps, and high cognitive load is not necessarily linked with low cognitive performance. However, experts and novices develop different strategies to approach the map-learning tasks and these needs to be researched in more depth including other individual characteristics affecting spatial cognition.

If you would like to have further information, you can read the thesis here: https://biblio.ugent.be/publication/8684280

Relevant publications:

Keskin, M., Ooms, K., Dogru, A.O., De Maeyer, P. (2020). Exploring the Cognitive Load of Expert and Novice Map Users Using EEG & Eye Tracking.  ISPRS Int. J. Geo-Inf., 9(7), 429.

Keskin, M., Ooms, K., Dogru, A.O., De Maeyer, P. (2019). EEG & Eye Tracking User Experiments for Spatial Memory Task on Maps. ISPRS Int. J. Geo-Inf., 8, 546. 

Keskin, M., Ooms, K., Dogru, A. O., & De Maeyer, P. (2018). Digital sketch maps and eye tracking statistics as instruments to obtain insights into spatial cognition. Journal of Eye Movement Research, 11(3).


The three special activities at the ISPRS2020 Nice (FR): Two theme sessions & one tutorial

An active ISPRS Congress is ahead of us! Our working group will chair several regular sessions (we are the ‘area chair’ for geovisualization, virtual and augmented reality sessions), two theme sessions and offer one tutorial. Both for regular sessions and theme sessions, you are welcome to use the congress’ interface to submit your contributions by 3rd of February, 2010 start here: http://www.isprs2020-nice.com/index.php/participate-submit/.

The tutorial does not require contributions but at some point you will need to sign up for it. What tutorial, you might ask. Below you can find the information on both the two theme sessions and the tutorial:

1) Thematic session Digital twins: Vision papers
Arzu Çöltekin, Chris Pettit, Sidonie Christophe and Victoria Rautenbach

2) Thematic session SimVisu: Visualization of complex spatio-temporal data & phenomena https://geoviz.casa.ucl.ac.uk/2020/01/13/thematic-session-ii/

3) Tutorial: An open catalogue for geospatial educational resources https://geoviz.casa.ucl.ac.uk/2020/01/13/tutorial-at-the-isprs-congress-open-content-for-geospatial-education/


Thematic session II: SimVisu

ISPRS2020/2021 Thematic session
SimVisu2020 /2021 “Visualization of complex spatio-temporal data and phenomena on earth“.
2021 deadline: 1 February 2021, submit here

Organizers: Sidonie Christophe,  Arzu Cöltekin, Christopher Pettit, Victoria Rautenbach, for the ISPRS WG IV

The purpose is to bring closer simulation, prediction, learning models to geovisualization and geovisual analytics, to ease the visuo-spatial reasoning on the complex data and phenomena we could observe, learn, predict and simulate.

The objective of this thematic session is to make researchers have a new perspective on their way to interpret their models and results. This thematic session aims at favoring a new dynamic of interdisciplinary research, between methodological communities based on spatial applications, for climate change issues. We expect abstract or full papers addressing:

– visualization or visual analysis and reasoning methods to support perception and interpretation of spatio-temporal data and related phenomena (..)

– analysis and interpretation of spatial data, potentially requiring additional visual and interactive methods: how could geovisualization, at any spatio-temporal scales (…)

There is a need here to bring closer spatial, topographic, physical observations and models, and approaches, models and experiments for visualization and visual reasoning, on many possible applications, such as the following, but not exhaustive ones:

  • Climate change simulation, urban climate, climate data visualization, urban heat islands;
  • Air pollution, pollutant dispersion;
  • Meteorological or weather prediction;
  • Water rising, flash flooding, marine submersion, tsunami simulation and scenarii;
  • Geosciences, earthquakes and cryosphere assessment and monitoring;
  • Spatial dynamics of land cover use or terrain on long-term scale;
  • Simulation of past or future urban morphology dynamics;
  • High temporal change detection, detection of high frequency events or weak signals;
  • Acoustic signal, microwave lengths, wind flow into streets;
  • Adaptive user interaction with learning models.

For more details: The CFP is attached to this e-mail, be careful the deadline submission is soon (1st February 2021) (3rd February 2020).

Feel free also to share this CFP in your communities and related ones, because the aim is to bring together researchers from different research communities interested into climate change issues.

Important dates: 2021 deadline: 1 February 2021, submit here
3 February 2020: Deadline for abstracts & full papers.
2 March 2020: Notification for abstracts.
30 March 2020: Notification for full papers.
14-20 June 2020: ISPRS 2020 Conference

How to proceed to submit: A specific track will be created in the Conference Managing System in order to smoothly follow the papers of each session. It will be entitled “TS_SimVisu”. The papers will be reviewed through the regular stream. If a sufficient number of (abstract or full) papers is accepted, a specific thematic session will be set up.

Tutorial at the ISPRS congress: Open content for geospatial education

An open catalogue for geospatial educational resources  
Tutorial presenters: Serena Coetzee, Victoria Rautenbach, Arzu Çöltekin, Chris Pettit, Sidonie Christophe, Marguerite Madden, Ochiroo Lkhamjav

Existing geospatial educational resources (e.g. electronic textbooks, tutorials, and quizzes) are not always easy to find and to integrate into an academic module, amongst others, because the required metadata is not available. As a consequence, simple search attempts do not bring us to these resources, and we miss out on some material that may be very useful in teaching and learning. As part of the ISPRS Education and Capacity Building Initiatives 2018, we developed a searchable catalogue of existing geospatial educational resources that can be used by communities, such as ISPRS or GeoForAll, universities and other educational institutions. The catalogue indexes geospatial educational resources so that the resources can be searched and discovered. Based on the metadata, educators can select appropriate educational resources for integration into an educational event, such as an online course or a module at university level.

During this tutorial, participants will learn how to add, edit and search for educational resources in the pilot catalogue. Subsequently, we will discuss the usability of the metadata elements selected for the prototype and come up with recommendations to improve the overall usability of the catalogue. At the moment, some of the elements are not self-explanatory and would be a barrier for wider use. Additionally, the tutorial will be used to plan the future and next phase of the catalogue.

Following topics will be covered during the tutorial:

• Overview of the pilot catalogue of geospatial educational resources, including how to add and update resources, and how to search for resources
• Review of metadata standards for describing educational resources
• Discussion of the metadata element used in the pilot catalogue
• Discussion on the future and next phase of the catalogue

Target audience: Educators at secondary and tertiary level
Expected number of participants: 40 participants
Duration: Half day session

Resources that will be distributed: The pilot catalogue (https://isprs.education/) is available online and metadata standards for describing educational resources will be made available electronically. Participants have to bring their own laptops.

Digital twins theme session in ISPRS 2020

Call for papers for a thematic session at the ISPRS 2020 / 2021

Digital twins: Vision papers

Organizers: Arzu Çöltekin, Chris Pettit, Sidonie Christophe and Victoria Rautenbach

2021 deadline: 1 February 2021, submit here

2020 Deadline: 3rd of February

As part of the “ISPRS Olympics” (the global international congress that takes place every fourth year) ISPRS2020 in Nice, we are organizing a thematic session on Digital Twins.

With the advent of better functioning and more affordable extended reality displays (virtual, augmented, mixed reality) than before, and real time ‘spatial computing’, we might be at a turning point where the Digital Earth vision from decades ago is closer to becoming a reality. Driven by the same technological developments, the term digital twins gained popularity in recent years.

As a concept, the term ‘digital twin’ appears to be somewhat flexibly used. What is clearly established is that a digital twin of any object must have a visual representation; thus a virtual object must exist  whether it is included in virtual, augmented or mixed reality. Ideally, these virtual objects (digital twins) mimic their physical counterpart in controllable ways (and can impact their physical twins too). Adding big data, IoT, 3D modelling, machine learning and artificial intelligence in the mix, the digital twin concept becomes enticing as it promises a  plethora of very meaningful use cases from manufacturing through surgeries to digital preservation which  may eventually be our ticket to time travel.

Given the rising popularity of the concept (and the term) in recent years, its clear connections to photogrammetry, and obvious links to the concept of Digital Earth; we propose that we hold a theme session on visionary papers. As such we expect statements, commentary and position papers that examine where we are now and what the future directions are.

We welcome a broad range of papers such as, but not limited to, the following;

• critical reflections on the digital twin concept
• discussing the implications of digital twins in real world
adoption (opportunities, threats, ethics, security, privacy)
• discussing their possible societal and cognitive impact in
various domains (education, asset management, city planning,
manufacturing, cultural documentation, crime scene analysis,
entertainment, etc.) and for various user groups (children, older
adults, professionals, etc.)
• proposing methodological procedure(s) for e.g., automating the
creation of digital twins

• identifying gaps in our current practices

• outlining solutions

• presenting real-world case studies

Submission information can be found here:

Note that both ISPRS Archives (where the short papers would go) and ISPRS Annals (where the long papers would go) are both open access and are indexed by Scopus (if this matters to your institution). You can submit short or long contributions in this track. Papers will go through the standard review process of the ISPRS. We are looking forward to your submissions.

2021 deadline: 1 February 2021, submit here

IJGI Journal Special Issue: “Human-Centered Geovisual Analytics and Visuospatial Display Design”

A few of us are involved in organizing a journal special issue, loosely linked to the three events (see the previous post) this year. If you work on geovisual analytics/geovisualization and modern cartographic considerations for visual analytics/geovis (from a “display design” perspective), this may be for you. Note that this is an open access publication, this means there’s an article processing charge of CHF1000. This is nothing to do with the guest editorial team, it’s completely managed by the journal. However, the journal was willing to hear waiver/discount requests, so if you do not have the funds from your department/library/funding agency, and you still want to play, we still encourage you to consider.

Everything you need to know is here:


Also important to note that:

  • An expression of interest with a 200-word abstract should be sent to the editorial team latest by 15th of August 2018 at the email address human.isprs.ijgi@gmail.com. Please also mention if you will need a discount or waiver on the open access fees. If your institution has funds for open access publications, please consider that others might not, before asking for the waiver or discount.
  • Deadline for full paper submissions: 15 November 2018

The three events of 2018

Our working group is involved in organizing three events this year. Below you will find a summary and links to relevant event pages. Feel free to spread the word!

1) Workshop on Reproducibility in Cartography
Led by ICA’s CogViz Commission. April 27th 2018, Olomouc, Czech Republic

2) Workshop on Virtual environments as geo/spatial labs
At the Spatial Cognition Conference. September 5th 2018, Tuebingen,

3) Theme session on Virtual & Augmented Reality: Technology, Design &
Human Factors http://www.geo.uzh.ch/~arzu/arvr2018/
At the ISPRS Midterm symposium by the Spatial Information Sciences commission.  October 3rd, 2018, WED 09:00-12:30 Delft
(+two regular conference sessions on geovis/AR/VR)

New Master of City Analytics

I am pleased to announce the enrolment for the first intake into UNSW’s Master of City Analytics  (MCA) is now open. Core courses include Programmable Cities, GIS and Urban Informatics, Digital Cities, Geodesign, Geocomputation and Urban Data Visualisation.

Please circulate this to your students and colleagues you think might be interested.




Chris Pettit

Professor of Urban Science

Director, City Analytics Program

Associate Director, City Futures Research Centre

PLuS Alliance Fellow

PhD project: Using 3D geovisualisations for urban design: The case of informal settlement upgrading in South Africa

We are starting a new thread in our blog! We will be featuring interesting scientific work done by our members or in our extended community once in a while. We begin by a recently completed PhD thesis, by our working group secretary Dr. Victoria Rautenbach. Victoria (relatively recently, and very successfully) completed her PhD at the University of Pretoria, South Africa. In this post, we provide a summary of Victoria’s PhD project, and link to some of the related publications for those who wish to dig deeper.

ps. On a side note, here’s a lovely moment of cultural fusion in Victoria’s graduation ceremony: https://www.youtube.com/watch?v=zsruVtBrf0s&feature=youtu.be&t=2145


Using 3D geovisualisations for urban design: The case of informal settlement upgrading in South Africa

Informal settlements are a common occurrence in South African due to housing backlogs and shortage of housing subsidies, and are often located on disputed land. To improve in-situ circumstances of these communities, informal settlement upgrades and urban design is required. Spatial data and maps are essential throughout the entire upgrading and urban design process in order to understand the current environment, plan new developments and communicate planned developments. All stakeholders need to understand maps to ensure active participation in the urban design process. Many researchers proclaimed that because 3D visualisations resemble the real environment more than traditional maps, and are more intuitive, therefore 3D geovisualisations are easier to interpret. The question arises whether 3D geovisualisations can support and even benefit the urban design process, in the context of this thesis, specifically for upgrading of South African informal settlements.

To investigate the use of 3D geovisualisation, the following topics needs to be investigated: modelling processes (manual and procedural); visual design (visual characteristics, visual complexity and visual variables); and cognition related to spatial tasks on 3D geovisualisations and comparable alternatives (i.e. topographic maps, aerial photographs, 2D maps) when performing basic map reading tasks. They found that procedural modelling was found to be a feasible alternative to time-consuming manual modelling and has the capabilities to produce high-quality models. The results of four user studies and expert interviews contributed to understanding the impact of various levels of complexity in 3D city models and map literacy of future geoinformatics and planning professionals when using aerial photographs, 2D maps and 3D models. The research results could assist planners in designing suitable 3D models for use throughout the entire urban design process.

Relevant publications to this project:

Rautenbach, V., Coetzee, S. & Çöltekin, A. (2017) Development and evaluation of a specialized task taxonomy for spatial planning – A map literacy experiment with topographic maps. ISPRS Journal of Photogrammetry and Remote Sensing, In press. DOI: 10.1016/j.isprsjprs.2016.06.013.

Rautenbach, V., Coetzee, S. & Çöltekin, A. (2016) Investigating the use of 3D geovisualisations for urban design in informal settlement upgrading in South Africa. The International Archives of the Photogrammetry, Remote Sensing and Spatial Information Sciences (ISPRS Archives), Volume XLI-B2, 2016 XXIII ISPRS Congress, 12–19 July 2016, Prague, Czech Republic.

Rautenbach, V., Bevis, Y., Coetzee, S. & Combrinck, C. (2015) Evaluating procedural modelling for 3D models of informal settlements in urban design activities. South African Journal of Science, 111(11/12), DOI: 10.17159/sajs.2015/20150100.

Rautenbach, V., Coetzee, S. Schiewe, J. & Çöltekin, A. (2015) An Assessment of Visual Variables for the Cartographic Design of 3D Informal Settlement Models. 27th International Cartographic Conference. 23–28 August 2015, Rio de Janeiro, Brazil.

Rautenbach, V., Çöltekin, A. & Coetzee, S (2015) Exploring the Impact of Visual Complexity Levels in 3D City Models on the Accuracy of Individuals’ Orientation and Cognitive Maps, ISPRS Annals of the Photogrammetry, Remote Sensing and Spatial Information Sciences, Volume II-3/W5, 2015 ISPRS Geospatial Week 2015, 28 Sep–03 Oct 2015, La Grande Motte, France

Rautenbach, V., Coetzee, S. & Çöltekin, A. (2014) Towards evaluating the map literacy of planners in 2D maps and 3D models in South Africa. AfricaGEO 2014 Conference Proceedings. 1–3 July 2014, Cape Town, South Africa.

The thesis itself is here.