As of 2017, there are three operational DOWs of a total of eight constructed since 1995. All three are dual-polarization dual-frequency quick-scanning Doppler weather radars. Several instrumented mobile mesonet pickup trucks host in situ weather instrumentation on masts to complement the remote sensing radars. These mobile mesonets also carry approximately twenty instrumented "PODS", which are ruggedized quickly deployable weather stations designed to survive inside tornadoes, tropical cyclones, and other adverse environments. The DOW fleet is sometimes accompanied by a Mobile Operations and Repair Center (MORC), a large van containing workstations for in-field coordination, data management, and equipment repair.