Hello. I'm Kelvin (Tsz Hei Choi).
I build AI systems that make sense of the physical world through sensing — from roads and solar panels to roller coasters and the open sea.
I'm Head of Data Science at Valerann, a startup in intelligent transportation systems, where I lead the development of real-time multimodal fusion engines, computer vision, and agentic AI controllers for road monitoring. I hold US patents in data fusion and computer vision.
Outside of Valerann, I founded Logger Labs, a studio building sensor data tools and apps — including Sensor Logger, Coaster Logger, and Ship Logger — used by researchers, engineers, and enthusiasts worldwide.
My PhD is in space and atmospheric physics from Imperial College London, focused on satellite data fusion for solar energy — combining multi-source Earth-observation datasets to produce higher-quality measurements than any single sensor could deliver. The intuitions from that work — modelling noise, bias, and uncertainty across heterogeneous sensor streams — still underpin everything I build.
In my spare time I blend my love for data and visualisation with interests like LEGO, theme parks, photography, and travel.
PhD. Research
Through my PhD research, I have furthered the atmospheric radiative transfer and remote sensing capabilities in existing retrieval schemes, such that quantities that are most pertinent for assessing solar resources worldwide are routinely generated. In this way, the optimal cell technology and design for different regions can be identified based on real, long-term observations.
Personal Interests
I enjoy fusing the beauty of science with design. This fascination has manifested itself in a wide range of expressions, including my love for physics, computing, architecture, immersive-themed design, photography, cartography, and more. I am always excited to explore new frontiers and find new and unique perspectives to see the world through traveling, exploring, and the work I do. I am actively involved in the physics community and science outreach.
I am constantly seeking exciting opportunities. Please don't hesitate to contact me for any reason.
Selected past and current education and experiences. Full CV and references are available upon request.
Education
PhD in Physics, Imperial College London and the Grantham Institute, Graduated. | 2017 - 2021
Researched the use of earth observations to improve solar panels design
Aerosol classification by fusing physical model observations, validation against ground-based observations
Studied error propagation and quantification using earth observation data for solar cell power output
Developed metrics to evaluate climate products for solar energy applications
Investigated the impact of the COVID-19 lockdown on solar energy resources
Thesis at https://spiral.imperial.ac.uk/handle/10044/1/92800
BSc (Hons) Physics, Imperial College London: Graduated, First Class | 2013 - 2016
IB Bilingual Diploma, Graduated, 44/45 | 2013
Employment & Work Experience
Head of Data Science, Valerann | 2025 - (ongoing)
Senior Data Scientist, Valerann | 2022 - 2025
Data Scientist, Valerann | 2020 - 2022
Real-Time Multimodal Data Fusion
Leads R&D of real-time multimodal fusion engines ingesting heterogeneous data for mission-critical road monitoring
Researches and tunes foundational traffic flow models for operational situational awareness
Incorporates real-time computer vision — detection, tracking, calibration, vision-language models
Designs probabilistic fusion architectures spanning geospatial ML, time-series models & knowledge graphs
Agentic Controller
Builds LLM-driven agentic control systems for real-time traffic operations with live tool orchestration
Studies emergent reasoning, operator alignment, and large-scale validation of agentic decisions
Computer Vision
Tackles alignment and cross-camera localisation for multi-camera fusion at scale
Develops PTZ camera automation systems for roadside deployment under harsh environmental constraints
Innovation & Engineering
Leads innovation activities, including multiple patents, hackathons & conferences — See Publications
Productionises and scales streaming data pipelines across edge and cloud infrastructure
Academic Visitor, Imperial College London | 2021
Earth Observation Intern, Assimila | Winter 2019
Designed algorithms to extract geophysical information from earth observation data with data assimilation
Assimilated thermal observations into a canopy temperature model in Africa and Colombia
Lead Teacher for Python, King Solomon Academy | 2019 - 2020
Physics Undergraduate Laboratory Demonstration, Imperial College London | 2017 - 2020
Laboratory demonstration in scientific Python programming
Telephone Fundraising, Imperial College London | 2016
Undergraduate Researcher, Imperial College Space & Atmospheric Physics Group | 2015
Head of Design, Squeek startup company | 2015 - 2016
Apps, Tools & Personal Projects
Sensor Logger, available on app stores | 2020 (ongoing)
Designed & developed iOS + Android app for data logging from motion, GPS, audio, video & bluetooth sensors
Grown into a commercially viable indie product with monthly recurring revenue alongside academic adoption
Conceived & built a SasS platform to support large-scale crowd-sourced data studies & research
Consulting & supporting users in academia and industries with their data needs, including medical studies, flight tracking, whale watching, geology surveys, railway monitoring, indoor localisation, insurance and more
Beyond development, assumed design, marketing, product development and commercial functionalities
Ship Logger, available on app stores | 2025 (ongoing)
Whale Watcher, for Institute of Marine Research | 2022
Coaster Logger, available on app stores | 2022 (ongoing)
Developed algorithms to fuse smartphone motion sensors to re-create roller coaster experiences
Used variety of sensor fusion, time-series mining, inertial navigation techniques
State estimation e.g. particle filter, ensemble Kalman filter, 4D variational data assimilation
ML-based analysis on heart rate and audio data from rides
Roller coaster track element identification & classification via ML-based methods (LSTM)
Developed 3D visualisation of roller coasters in AR & web
WKBrew, A popular web-based tool for geometry and map projection conversions | 2024 (ongoing)
Property Price Radar, an easy-to-use, cross-platform app that helps you explore and keep track of property prices in England and Wales based on property sales since 1995. | 2021 (discontinued)
Automated Projection Mapping on LEGO Sets | 2021
Prototyped projection mapping system for official sets inspired by remote sensing
Implemented photogrammetric 3D reconstruction (Structure from Motion, SLAM)
Watch Recorder, consulting work for Human Signals Lab, University of Texas Austin | 2022
Repositories / Open Source
Sensor Zoo, cross-platform sensor fusion algorithms for orientation, compass and pedometer
Awesome Sensor Logger, A GitHub repository of scripts and tools for analysing motion data, diagnosing data issues, data visualisation, and handling Bluetooth and streaming data
Sensor BLE, An pure javascript open-source library for decoding BLE advertisement data and streaming data from a variety of Bluetooth devices
Sensor Logger Streaming Demo App, A simple web app to demonstrate MQTT streaming and live Sensor Logger data
Publication & Patents
Choi et al. (2025). Lessons from Building an Agentic Traffic Controller: Exploring Tool Use, Emergent Reasoning Patterns, and Large-Scale Validation. Presented at Transportation Research Board Annual Meeting 2026. See https://www.tszheichoi.com/its-research
Choi (2025). Studies: A Managed Solution for Standardized, Scalable, Privacy‑First Smartphone Sensor Data Collection for Indoor Positioning Research. Workshop for Computing & Advanced Localization at the Fifteenth International Conference on Indoor Positioning and Indoor Navigation, Tampere Finland.
Choi et al. (2025). Is More Better? Measuring the Value of Data Fusion in Search of the Optimal Data Source Combination for Road Incident Monitoring. Presented at Transportation Research Board Annual Meeting 2025. See https://www.tszheichoi.com/its-research
Choi et al. (Dec, 2023) System and Method for Providing Consolidated Events in a Traffic Management Control Centre Using Situational Awareness (US Patent No. 12,118,881)
Choi et al. (Jan, 2023) System and Method for Determining a Viewpoint of a Traffic Camera (US Patent No. 11,557,089)
Choi et al. (2021). Developing Automated Methods to Estimate Spectrally Resolved Direct Normal Irradiance for Solar Energy Applications. Renewable Energy. https://doi.org/10.1016/j.renene.2021.03.127
Choi et. al. (2020). COVID-19 lockdown air quality change implications for solar energy generation over China. Environ. Res. Lett. https://doi.org/10.1088/1748-9326/abd42f
Choi, K. T. (2019). The role of climate services in handling climate change risks: Contributions of UKCP18. Weather, 74(7), 255-256. doi:10.1002/wea.3526
Choi, K. T. (2018). Essential climate variables and the future of climate monitoring from space. Weather,73(12), 390-391. doi:10.1002/wea.3306
Student Scholarship & Awards
Grantham Institute for Climate Change and the Environment DTP Scholar | 2017 - 2021
Best Presentation at the NCEO Researchers' Forum 2020 | Mar 2020
Best Presentation at the NCEO Researchers' Forum 2018 | Feb 2018
Imperial College Alumni Association Hong Kong Endowment Fund Scholar | 2013
Training & Summer Schools
Deep Learning for Computer Vision | by NVIDIA at Plymouth Marine Laboratory | Mar 2020
Data Assimilation Training Course | by NCEO & DARS at University of Reading | Feb 2020
SOlar Radiation Based Established Techniques for aTmospheric Observations Summer School | CNR and Sapienza University, Rome | Jul 2018
Presentations
Join DTP Conference 2020; Implications of Air Quality Change Over China During COVID-19 for Solar Energy Generation | Sep 2020
NCEO Conference 2020; Implications of Air Quality Change Over China During COVID-19 for Solar Energy Generation | Jun 2020
Researching Software & Atmospheric Physics: Coping with Data & Models for Imperial College Research Software Engineering | May 2019
EGU 2019; Session ESSI1.16 Earth Observations for Sustainable Development | Apr 2019
A Changing Planet Joint DTP Conference 2018; Session 4B Novel Measurements and Solar | Sep 2018
UK National Earth Observation Conference 2018; Session 6A Satellite ECV data asset and climate services | Sep 2018
Imperial Space & Atmospheric Physics Group Talk | Mar 2018
Space, Satellites & Solutions, Royal Meteorological Society | Mar 2018
NCEO Researchers' Forum 2018, National Centre for Earth Observation | Feb 2018
Public Engagement
Brick-ing Down the Global Solar Energy Resources with LEGOs, Research as Art Installation & Exhibition at the Blyth Gallery, Imperial College | Jul 2019
Earth Observation Detective, NCEO at the Farnborough International Airshow I Jul 2018
Raising awAIRness: The Board Game, Imperial Festival I Apr 2018
Debate Panellist on Are Humans Responsible For Climate Change?, UCL Life Ethics Society I Mar 2018
Imperial Fringe: Air, Imperial College Space & Atmospheric Physics Group | Nov 2017
Authorship
Dispatches from the Climate Debate: Thoughts on Engaging with Climate Deniers, Article on the Grantham Institute Blog I Apr2018
Iconic Iceland, digital photo book | published in 2015
Leadership & Volunteering
GCSE Mathematics Tutoring, The Access Project | Summer 2020
Visual Communications Officer (Elected), Imperial College Design Collective | 2015 - 2016
PhySoc Committee Member (Elected), Imperial College Physics Society | 2014 - 2015
Head of Content (Elected), Imperial College Student Television | 2014 - 2015
International Association for Physics Students appointed designer | 2014 - 2015
i, Science Magazine appointed designer | 2014 - 2015
Welsh Highland Railway Volunteering | 2014, 2015
Language Skills
Fluent in English and Cantonese
Computer Skills
Proficient in Python and the data science and scientific computing ecosystem
Javascript, React, React Native, Expo
Experience working with UNIX systems
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