SMART-S Mk2 (Signaal Multibeam Acquisition Radar for Tracking, S band Mk2) is a naval medium to long-range air and surface surveillance multibeam passive electronically scanned array 3D radar designed by Thales Nederland, formerly Hollandse Signaalapparaten (Signaal). While the original SMART-S radar was only produced in small numbers, SMART-S Mk2 is more successful with 30 systems were sold to navies all over the world within six years after being introduced. The radar transmitter/receiver (T/R) modules for the radar are purchased by Thales from the Turkish defence company Aselsan.