The lowest region which is not covered by MST radar and LAWP is taken care using a multi-frequency (1600–2500 Hz) phased-array Doppler SODAR system installed recently at the NARL for the continuous observation of the lower atmosphere from near ground to the atmospheric boundary layer (ABL). The NARL sodar, developed in technical collaboration with the Society for Applied Microwave Electronics Engineering and Research (SAMEER), was built using piezoceramic tweeters (8x 8 array of antenna elements), which are capable of generating 100-W acoustic power. In favourable atmospheric conditions, the SOADAR gives wind profiles from 25 m up to 1 km. The pulse width and inter-pulse period are programmable for getting a range resolution of 10–200 m for an altitude coverage of 1500 m. Observations can be conducted in three directions (east, north, and vertical), with a tilt angle up to 22°.