Every winter, the same grim ritual plays out at Delhi's Indira Gandhi International Airport.
SkyCast is not a single gadget but a stack of instruments working together to build a live, three-dimensional picture of the air directly above the airport.
Around that core, SkyCast bundles several other remote-sensing tools.
To understand why this is news worth caring about, look at what fog does to Delhi every winter.
Delhi's main runways are equipped for CAT III operations, a category that in principle lets suitably certified aircraft land in visibility as low as around 50 metres.