How can rescue personnel detect that a SART is transmitting in the immediate vicinity?

The DSC unit will react to the SART's signal and respond with the two-tone auto alarm.

The SART can provide an approximate location to within a two nautical mile radius, per IMO standards.

The SART signal appears as a target which comes and goes; the effect of heavy swells on a SART.

The SART's dots on the PPI will become arcs and then eventually become concentric circles.

How can rescue personnel detect that a SART...