Radar planning, preparation and employment of 3-tiered coverage: LCMR, Q-36 and Q-37

FA Journal, Sept-Oct, 2004 by Daniel W. Caldwell

Rarely does a day go by without news of US casualties in Iraq or Afghanistan. Anti-coalition forces employ asymmetrical strategies, such as using improvised explosive devices (IEDs), to frustrate our efforts to bring stability to these areas and are representative of the contemporary operational environment (COE). While these attacks are tactical, they are aimed at achieving strategic effects.

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This new enemy perceives the United States as a global power with a huge advantage in technology and warfighting capability but also with very exploitable vulnerabilities. (See Figure 1.)

At the same time, the target acquisition (TA) mission remains unchanged: to sense enemy fire, warn the force and respond to suppress or destroy the fire. The best way to accomplish this mission is to plan and prepare properly and employ a three-tiered approach to radar coverage that also encompasses complementary systems. Emerging technologies promise improvements in the future.

Radar Planning. Tracking incoming rounds in complex terrain or an urban environment is extremely difficult due to the way the radar operates. Therefore, site selections of forward operating bases (FOBs) and radars must be planned carefully.

High "clutter" environments cause significant problems for the radar. The term "radar clutter" refers to any objects that cause unwanted reflections of a radar's electromagnetic energy to be returned to the radar receiver. These unwanted returns compete with valid returns of interest and cause the radar receiver and displays to become more cluttered and difficult to decipher.

Sources of clutter include land surfaces, vegetation, buildings, complex terrain, aircraft (particularly rotary wing) and particulate matter kicked up by wind or aircraft. In some cases, alternative sites may be limited, but if the sensor site planning process considers avoiding all possible sources of clutter, it can yield huge benefits.

The radar site analyses also can serve as input for risk assessment, patrol areas and patrolling activities, force protection plans, radar positioning and search sectors.

Radar Preparation. After securing the optimum site for radar emplacement, the radar section limits the enemy's ability to determine the radar's search sector and time of operation. A fully supported radar deception plan is a low-cost, low-tech solution that pays big dividends.

The enemy understands that the radar acquires in the direction it is pointing. He also is aware that our patterns of activity and generator noise indicate when the radar is active. He seeks sanctuary by firing when the generator is off and attempting to fire from outside the perceived search sector. Random patterns of activity and decoy radar systems easily can disrupt the enemy's ability to determine a radar's collection orientation or even if a radar is operational.

Aggressively patrolling helps to shape enemy operations. Patrolling can limit access to areas that are difficult for the radar to search electronically and minimize the impact of not having a 360-degree search capability.

Three-Tiered Employment. Protecting the force is contingent upon the ability to sense incoming rounds and provide timely warning. Judicious employment of today's fielded TA systems augmented by complementary systems can accomplish the mission. Based on the threat and environmental challenges, there is no "one size fits all" solution to TA.

A tiered approach to radar coverage provides a holistic means to protect personnel and assets from mortar, rocket and cannon artillery attacks while maximizing detections of enemy fire for engagement.

First Tier: Short-Range Lightweight Countermortar Radar (LCMR). Short-range mortars firing from all angles can be a challenge for the Q-36 radars to track and calculate a firing solution for. The Q-37 has a minimum range of 3,000 meters, and neither the Q-37 nor Q-37 has a 360-degree capability. The LCMR solves these problems.

The LCMR was developed to meet the requirements of Special Operations Forces (SOF). Transportation constraints dictated the system be much smaller and lighter than the Army's existing counterfire radars. Currently, LCMRs have been fielded to selected Army and Marine units in the Central Command (CENTCOM) theater of operations.

The LCMR fielded prototype electronically searches 360 degrees, detects and tracks mortar fire beyond the ranges of most mortar weapons and locates a firing weapon with accuracy sufficient to service that target with combat air support or counterfire. The radar weighs approximately 120 pounds and disassembles for transport. It requires only 300 watts of prime power that can be provided by generator, vehicle or commercial power. It also can operate for a few hours from a battery pack.

The radar electronics, excluding control and display, are self-contained inside the antenna. The only external connection is to a power source.

The radar reports target locations to a personal digital assistant (PDA) that communicates with the radar wirelessly, so the radar operator need not remain with the radar. The PDA also provides radar control and receives and displays the system's status and fault messages.