Low-cost CTD sensor using OpenCTD and OSBK

Context

Access to oceanographic measurements is unevenly distributed. CTD data (conductivity, temperature, depth) are fundamental for marine research, yet dedicated instruments remain expensive and technically inaccessible for many research groups, citizen science initiatives, and practitioners — particularly in regions with limited infrastructure or funding.

Open initiatives such as OpenCTD and the SOOP platform address this gap by lowering technical and financial barriers to data collection. This project builds on these efforts by exploring how open hardware, modular computing platforms, and reproducible workflows can be combined into a practical, low-cost CTD system suitable for research and citizen science applications.

Project focus

The project aims to develop a low-cost CTD sensor based on the OpenCTD design, using the Open Source Building Kit (OSBK) from SOOP as the central computing and integration platform.

The focus lies on adapting an open CTD concept to a modular and reusable system that lowers technical and financial barriers to marine data collection. This includes sensor integration, calibration considerations, and reproducible data handling workflows.

While the project contributes to broader efforts toward the democratization of ocean data collection, it also serves as a practical entry point into hands-on sensor development and as a foundation for future citizen science deployments, including small-scale measurements from private sailing vessels.

Collaboration

The project is developed in collaboration with Katharina Petersen and Martin Petri from the SOOP platform, who provide technical guidance on OSBK integration and access to the OSBK infrastructure. SOOP serves as both a technical backbone and a strategic context for the project, enabling future integration into larger open ocean observation efforts.

My role

I design and build the CTD sensor kit and integrate the sensors into the OSBK platform. My work includes hardware assembly, sensor integration, and implementation of data handling workflows.

I conduct practical tests in real marine environments and iteratively refine the system with the goal of using it as a reusable tool for future citizen science data collection activities.

Implementation

• Adaptation of the OpenCTD design to the OSBK hardware platform
• Integration of conductivity, temperature, and pressure sensors
• Hands-on electronics prototyping and low-level hardware integration
• Development and testing of data acquisition and storage workflows
• Practical field testing under real deployment conditions

Stack

Expected outcomes

• A functional low-cost CTD sensor kit based on OpenCTD and OSBK, suitable for repeated field use
• A documented build guide covering hardware components, assembly steps, and system integration
• Adaptations of the OpenCTD design to metric standards and components commonly available in Europe
• A contribution-ready documentation base that can be shared with the OpenCTD community
• A reusable technical and methodological foundation for future citizen science data collection activities