Survey Footprint Explorer: A Browser-Based Interactive Tool for Visualizing and Cross-Matching Astronomical Survey Footprints

TL;DR

Survey Footprint Explorer is a browser-based, interactive visualization tool for astronomical survey footprints, enabling comparison, overlap analysis, and source catalog cross-matching without server infrastructure.

Contribution

It introduces a fully client-side, web-based platform for visualizing and analyzing multiple astronomical survey footprints using MOC maps, with features for source membership testing and overlap calculation.

Findings

Supports 13 major survey footprints from X-ray to near-infrared.

Performs all calculations client-side, ensuring privacy and accessibility.

Allows users to upload catalogs and determine survey memberships.

Abstract

We present the Survey Footprint Explorer (v2.5.0), a browser-based interactive tool for visualising and comparing the sky footprints of major astronomical imaging surveys. The tool is implemented entirely in client-side JavaScript and requires no server infrastructure, making it immediately accessible from any modern web browser. Thirteen survey footprints are currently included: Euclid DR1, LSST Wide-Fast-Deep, the Nancy Grace Roman HLWAS and HLTDS (full and deep tiers), DESI Legacy Imaging Survey DR9, the Dark Energy Survey (DES), the Subaru Hyper Suprime-Cam survey (HSC), the Kilo-Degree Survey (KiDS), the Ultraviolet Near-Infrared Optical Northern Survey (UNIONS), the eROSITA All-Sky Survey (eRASS1), and the Atacama Cosmology Telescope Legacy (ACT) survey spanning wavelengths from X-ray to near-infrared and covering footprints from 7.7 deg$^{2}$ to 21,524.4 deg$^{2}$. Survey footprints are encoded as Multi-Order Coverage (MOC) maps and rendered via two complementary views: an interactive globe powered by Aladin Lite v2, and a full-sky equirectangular projection. All MOC intersection calculations, including multi-survey overlap area computation and per-source membership testing, are performed client-side. Users may upload source catalogues in CSV or TSV format and download an augmented version with boolean survey membership columns appended. The link to access the tool is provided at the end of the Summary section.