Physics Practical Magic

There’s now a way to map exactly how much sky you can actually see from any street corner in a city full of skyscrapers.

March 30, 2026

Original Paper

The Skyline Process: Quantifying Sky Visibility in 3D Urban Environments

Junse Lee, François Baccelli

arXiv · 2603.26072

The Takeaway

In the era of 6G and satellite-based internet, 'sky visibility' is a disappearing resource in urban canyons. This new statistical geometry framework allows engineers to predict exactly how many satellites will be visible at any given moment by treating a city's jagged skyline as a measurable mathematical process.

From the abstract

Non-terrestrial networks (NTNs) are considered a promising technology for seamless, universal communication in the 6G era. However, signals from NTN elements to ground users are often blocked by high-rise buildings in dense urban environments. To quantify this blocking effect, in this paper, we propose a novel analytical framework by modeling the location of buildings as a 3D skyline process based on stochastic geometry and we derive closed-form expressions for the distribution of the blockage e