Plain English Meaning

It is the en route radar used by air traffic controllers, but with most of the weather echoes filtered out so aircraft show up clearly. The trade-off is that controllers using it can only see very basic weather information, not detailed storm intensity.

Full Definition

A long-range Air Route Surveillance Radar (ARSR) that has been digitally processed to filter out most weather returns, leaving a cleaner display of aircraft targets. Because precipitation echoes are largely removed, narrowband ARSR provides only limited weather information to the controller — typically shown as one or two basic intensity levels rather than the detailed weather depiction available on broadband or .