Availability Analysis of an Free Space Optical Communication Link in Delft, Netherlands
Contributed to analyzing optical turbulence data for free‑space optical communication (FSOC) link availability, using rooftop measurements of Rytov variance and other parameters from TU Delft's optical ground station. I authored the Atmospheric Turbulence section and introduction for the literature review, synthesizing complex research into concise summaries, and created Python visualizations including seasonal/daily availability graphs and multi‑year Rytov variance comparisons. The work highlighted real‑world applications in satellite and horizontal optical links, strengthening my skills in data analysis, scientific writing, and group collaboration.
Project Details
Technologies
Python, Research, Data Analysis
Category
Aerospace Engineering
Status
In Progress
Institution
TU Delft
Key Features
- 650+GB of data analysed from TU Delft's optical ground station
- Data from 1km horizontal link and Polaris vertical link
- 1500+ lines of Python code for data processing and visualization
- Research paper produced, aiming to publish in a peer-reviewed journal
Project Overview
This study addresses the critical challenge of limited radio frequency (RF) spectrum capacity by evaluating free-space optical communication (FSOC) as a high-bandwidth alternative. While optical frequencies offer immense potential for high-speed data transfer, their performance is significantly hindered by atmospheric turbulence—specifically refractive index fluctuations that cause scintillation and beam wander.
The project aims to quantify FSOC link availability in Delft, the Netherlands, by analyzing turbulence data collected from ground-based sensors on the TU Delft Aerospace Engineering faculty building.
FSOC Performance and Atmospheric Turbulence
RF technology is traditionally preferred due to its long wavelengths, which are less susceptible to atmospheric disturbances than the shorter wavelengths used in optical systems. In contrast, optical frequencies (0.5–5 µm) are highly sensitive to temperature, humidity, and density fluctuations, which generate small-scale eddies that severely distort beam propagation. Overcoming these turbulence-induced outages is essential to unlocking the 100 THz of bandwidth offered by optical communication for Earth-to-space links.
Methodology and Measurement Setup
To establish reliable, region-specific FSOC availability data, the study utilizes two complementary measurement methods. A horizontal link spanning 1 km to Delftechpark employs a scintillometer to derive the atmospheric structure constant (Cn2) and the Rytov variance (σR2), providing a direct measure of scintillation strength. Concurrently, vertical link data is obtained using infrared cameras to observe Polaris, allowing for the calculation of the Fried parameter (r0)—a critical indicator of atmospheric coherence and link stability.
The horizontal scintillometer data was collected over the period November 2022 to November 2025 with a measurement every 10 minutes. The vertical link data was collected over the year 2025 with measurements every minute. This gives a total of 16,687,432 data points to work with and analyse.
Data Analysis and Link Availability
The research evaluates the probability and cumulative density functions of both horizontal and vertical turbulence measurements to establish month-by-month and time-of-day performance rankings. By correlating these metrics, the study identifies the optimal operational windows for reliable FSOC transmission in mid-latitude European environments. Additionally, it investigates the feasibility of deriving supplementary optical parameters from existing rooftop instrumentation to further improve the understanding of satellite and horizontal link availability.