WebSDRs are radios that are attached to the internet which can be individually operated. They are for listening only so can be operated by unlicensed individuals.

They are useful listening-posts in supporting communication with other stations when propagation conditions are difficult.

There is a video with simple demo on the sub page GLENN g0gbi.

Many thanks to those radio amateurs who generously make the WebSDRs available and to those who have developed the systems.