The Nizhny Novgorod Research Institute of Radio Engineering (NNIIRT) is a Russian electronics company specializing in the development and manufacturing of radar equipment.

[2] Beginning in 1975, NNIIRT developed the first VHF 3D radar capable of measuring height, range, and azimuth to a target.

[3] In the post–Cold War era, NNIIRT developed the 55Zh6 Nebo U 'Tall Rack' radar, which has been integrated with the SA-21 anti-aircraft weapons system.

[5][6] The Nizhny Novgorod Research Institute of Radio Engineering (Russian acronym: NNIIRT) has since 1948 developed a number of radars.

[7] Other innovations were radars with frequency hopping; the P-10 Volga A (NATO: KNIFE REST B) in 1953, radars with transmitter signal coherency and special features like moving target indicator (MTI); the P-12 Yenisei (NATO: SPOON REST) in 1955, as well as the P-70 Lena-M with chirp signal modulation in 1968.