Matthieu Baumann

Software Engineer at CDS

Affiliation – CNRS - Observatoire Astronomique de Strasbourg/CDS Position – Research Engineer Github ID – bmatthieu3


Aladin Lite v3: behind the scenes of a major overhaul

Since its first version in 2013, Aladin Lite has gained significant traction and usage as an HiPS viewer running in the browser. Designed to be easy to embed, it is now used in more than fifty websites and portals in the professional astronomy community. Aladin Lite has been adopted as the sky visualisation component of popular applications: ESA Sky, ESO Science Archive or ALMA Science Archive.

We present a major overhaul of Aladin Lite taking advantage of the GPU with WebGL, and which responds to requests of users, developers and integrators in a context where browser-based applications and science analysis platforms are increasingly important.

While keeping the strengths of the original code, Aladin version 3 will introduce several new features: support of multiple projections (Aitoff, Mollweide, Orthographic, Mercator), support of FITS tiles, display of FITS images, heatmaps visualisation of catalogue data, improved rendering pipeline and coordinates grids.
We will give an overview on the architecture used to develop these new functionalities, based on existing Rust code transpiled to WebAssembly, a portable high-performance low-level bytecode for the web supported in all modern browsers. We will also outline the technical challenges and limitations we encountered.
Short video footage sequences will demonstrate the existing prototype throughout the presentation.

These improvements have been partially supported by the ESCAPE project and will also benefit to ipyaladin, the widget enabling the usage of Aladin Lite in Jupyter notebooks.