A hands-on hackathon focused on ground-based LiDAR and close-range sensing for urban trees is scheduled for June 1–5, 2026, in Bratislava, Slovakia. The event is designed to merge rapid field data collection, open-source processing, and stakeholder engagement. The primary goal is to transform state-of-the-art methods into practical, implementable workflows for effective city tree management.
Program Aim and Deliverables
The central aim is to develop and document end-to-end, open workflows for capturing and processing close-range 3D data from various LiDAR sources to derive individual-tree metrics relevant to urban inventories and management. Expected outputs from the hackathon include:
• Open-source workflows for data collection and processing, published as a documented workflow for practical implementation.
• Training materials, including short videos and written guides.
• A policy brief on the use of ground-based LiDAR for monitoring individual urban trees.
• A scientific manuscript benchmarking LiDAR sensors and processing solutions, with an emphasis on usability for operational city inventories.
• A catalogue of “tree blueprints” suitable for broader public communication.
• Engagement with stakeholders through a roundtable with municipal bodies and outreach to local media to increase public visibility.
Hackathon Activities
The week will be divided into two main phases. The first two to three days will be dedicated to fieldwork, involving data collection across multiple urban sites using a range of close-range sensing systems. The indicative list of equipment includes:
• RIEGL VZ-series TLS (e.g., VZ-600i)
• Hovermap STX
• FARO (e.g., Orbis / Focus-class TLS)
• GeoSLAM mobile scanner
• Prototype mobile laser scanning (MLS) systems
• iPhone/iPad LiDAR scanning
Ground-based data collection will also involve using GNSS to determine tree positions and identify species. The latter part of the week will focus on processing, where teams will implement and compare pipelines to extract individual-tree parameters such as:
• Tree location / stem map
• Diameter(s) (e.g., DBH)
• Tree height
• Crown metrics
• Above-ground biomass proxies
• Data quality and uncertainty notes
Provisional Schedule
• Monday: Devices overview, study sites, team formation, and field planning in the morning, followed by data collection in the afternoon.
• Tuesday: Data collection, training video capture, and an evening keynote/social session.
• Wednesday: Data collection, start of processing, and an evening keynote/social session.
• Thursday: Processing sprint and workflow write-up.
• Friday: Team presentations and synthesis in the morning and early afternoon, with departures scheduled for the evening.
Ideal Candidate Profile
Applications are encouraged from individuals with experience in one or more of the following areas:
• Close-range sensing / point clouds: TLS/MLS/handheld scanning, acquisition design, and field protocols.
• Point cloud processing: Registration, SLAM outputs, denoising, segmentation, stem detection, and tree metric extraction.
• Coding: Deploying tools and plugins using Python, R, or Matlab for reproducible workflows.
• Urban forestry / inventories: Understanding of operational constraints, target variables, and quality assurance.
• Science communication / training content: Creating clear video or written guides.
• Policy translation: Turning technical outcomes into implementable guidance for public bodies.
Participant Benefits
Participants will gain several benefits, including:
• Intensive, hands-on collaboration with an international group of practitioners and researchers.
• Access to a diverse set of sensors and datasets collected under comparable conditions.
• Contribution and co-authorship opportunities in the resulting workflow publications, policy brief, and manuscript, based on role and contribution.
• Direct interaction with municipal stakeholders, providing valuable insight for impactful research and implementation.
• A follow-up opportunity for one selected participant to undertake a Short-Term Scientific Mission (STSM) for 1-2 months to finalize hackathon outputs.
Participation Costs and Support
There is no registration fee to participate in the hackathon. For selected participants from COST countries, the COST action INTUF will reimburse the costs of travel, accommodation, and subsistence after the event is completed. Applicants from outside these countries are welcome to apply but must secure their own funding.
Application Process
To apply, interested individuals must complete the application form available at https://forms.gle/GbJqFSXWWHias1MG8. Applicants will be required to provide:
• A short abstract, a motivation statement, and a CV (PDF).
• A list of tools they can work with (software packages, languages, pipelines).
• A description of what they want to contribute during the week.
• Information on whether they can bring or support any hardware/software setups (optional).
Evaluation Criteria
Applications will be evaluated by the organizing committee based on scientific relevance, motivation, and technical experience. Specific attention will be given to the motivation letter, research relevance, and experience with close-range sensing, point cloud data processing, and urban tree monitoring. Additional criteria include career stage (with priority for early-stage researchers), interdisciplinarity, and ensuring a balance of countries, institutions, and expertise. Applicants from COST countries will be prioritized for reimbursement. The scoring is weighted as follows:
• Motivation Letter: 10 points
• CV: 3 points
• Abstract: 5 points
• Research interest: 5 points
• Position: 3 points
• Close-range tech experience: 5 points
• Point cloud processing: 5 points
• Tools & implementations: 5 points
• Urban tree monitoring: 5 points
Key Dates and Contact Information
• Call opens: February 2026
• Application deadline: 31st March 2026
• Notification of results: No later than 7th April 2026
For any questions regarding the program or application, please contact Tomáš Goga at tomas.goga@savba.sk or Martin Mokroš at m.mokros@ucl.ac.uk.
This hackathon presents a unique opportunity for researchers and practitioners to collaborate on developing tangible solutions for urban forestry. By focusing on open-source workflows and direct stakeholder engagement, the event aims to bridge the gap between advanced 3D sensing technology and its practical application in managing city trees, with outcomes designed to have a lasting impact on the field.