The P-18 or 1RL131 Terek (also referred to by the NATO reporting name "Spoon Rest D" in the west) is a 2D VHF radar developed and operated by the former Soviet Union.

[2] The P-18 is still in service today and was widely exported, many companies offer upgrade options to improve the performance and reliability of the radar and to replace out-dated components.

[3] Also Retia, a Czech civil and military electronics company, developed its own, fundamental modernisation of the P-18 under the name ReVEAL.

The P-18PL[6][7] is a modernized Polish road-mobile, long-range, three-dimensional (3D), very high frequency (VHF) early warning radar with an active electronically scanned array (AESA) technology.

Key features: P-18ML[8] – ground-based long-range VHF surveillance radar P-18ML is offered as the modernized follow-on to its prototype, the analogue P-18.

[11] This data receiver enables use of remote control for radar using optical cable at distances from 100 to 500 meters.

The radar continues to serve in many client and third world states who received the P-18 from the Soviet Union by export.

Many P-18 have been upgraded and continue to serve in the military and air traffic control role across the world.

[24] The presence of a P-18 radar in Yugoslavia during the Kosovo War contributed to the loss of a US F-117 Nighthawk during the conflict.