How Tomahawk Finds Its Target

Tomahawk
Tomahawk in flight (Wikipedia)

The Tomahawk land-attack cruise missile (TLAM) is an American-made low-flying strategic guided missile launched from naval ships or submarines to strike targets on land. It flies at low altitudes to strike fixed targets, such as communication and air-defense sites, in high-risk environments where manned aircraft may be vulnerable to surface-to-air missiles. TLAM is a long-range, unmanned weapon with an accuracy of about 5 meters (16 feet). The 5.6 meters long missile ranges up to approximately 2,400 km (about 1,500 miles) and can travel as fast as 885 km (550 miles) per hour.

The missiles are approximately 21 feet long, weigh 1.5 tons, and be launched from traditional torpedo tubes and vertical launch tubes on modern submarines. Once the Tomahawk is in the air, the turbojet engine kicks in, and its wings spread, allowing it to reach speeds of 500 miles per hour.

TLAM was used extensively during Desert Storm in 1991, in Iraq in January and June 1993, in Bosnia (Deliberate Force) in 1995, and Iraq (Desert Strike) in 1996. Four hundred Block II and Block III missiles were fired on five separate occasions. Two submarines and many surface ships fired TLAM during the Gulf War. According to initial US Navy reports, 297 attempted cruise missile launches, 290 missiles fired, and 242 Tomahawks hit their targets.

TLAM is a highly survivable weapon. Radar detection is difficult because of the missile’s small cross-section, low altitude flight. The Tomahawk Block IV uses GPS navigation and a satellite data link to continue through a pre-set course. The missile can be reprogrammed in flight to a new target. The two-way satellite communications are used to perform post-launch mission changes throughout the flight. The onboard camera provides imagery of the target to the commanders before the strike.

Raytheon image

Tomahawk’s Guidance and Navigation

The sophisticated guidance system uses a combination of GPS, Terrain Contour Matching (TERCOM), Time of Arrival (TOA) control, and Digital Scene-Matching Area Correlator (DSMAC) to pinpoint their targets with better accuracy. The TERCOM radar uses a stored map reference to compare with the actual terrain to determine the missile’s position. If necessary, a course correction is then made to place the missile on course to the target. The Tactical Tomahawk Weapons Control System (TTWCS) integrated within the ship’s systems computes the path to engage targets. The system enables the planning of new missions onboard the launch vessel. TTWCS is also used to communicate with multiple missiles for reassigning the targets and redirecting the rockets in flight.

Terminal guidance in the target area is provided by the DSMAC system, which compares a stored image captured by the missile while in flight toward its target and matches them to pictures taken before the flight, during mission planning. TERCOM compares images from a previously acquired contour map and compares them with measurements that a radar altimeter makes onboard the missile. Based on input for the terrain-matching algorithm, the system can update its inertial navigation system — a set of sensors, such as accelerometers and gyroscopes to measure rotation — to reorient itself. Tomahawk missiles can also make real-time updates to their position.

The missile sends constant emails back to the controlling agency for getting updated guidance via essentially a data email back to the missile. If something in the terrain changes or the mission gets cancelled, the missile can be redirected via a simple command.

Arleigh Burke-class destroyer launching Tomahawk

The accurate navigation allows the missiles to fly low to the ground, meaning they can fly closer to other objects and evade foreign military radar detection. As it closes in on its target, the missile drops to an altitude of 100 feet or less before impact. Therefore, TLAM can be launched from great distances, with pinpoint accuracy, minimizing risk to personnel and civilians.

They can also take a nonlinear route to a target, which makes them well-suited for evading dangerous areas en route to a target. Their ability to take a nonlinear course also means multiple missiles can be launched from different locations and all land at the target at the same time.

Raytheon, which manufactures the Tomahawk missiles, is currently developing an updated version of the missile that could have two-way satellite communication with objects on the ground, such as tanks and ships, and more robust and sophisticated navigation systems. Tomahawk missile can take reconnaissance pictures after reaching a designated area and send them to the HQ via SATCOM and wait for their instructions. It can be loitered until the target is ‘clear to engage. With DSMAC, a picture of a discrete target can be uploaded in a confined region and have Tomahawks specifically find and hunt them down.

Rendering of Tomahawk Block V (Raytheon)

The Tomahawk Block V Upgrade

The Tomahawk Block IV missiles were converted and upgraded to Block V in 2017. The upgraded Tomahawk includes extended range, enhanced navigation and communication systems, and modernized datalink radio.US Navy will use the upgraded Tomahawk cruise missiles beyond 2040. Raytheon was contracted to integrate the upgraded navigation and communication systems into the Block IV Tactical Tomahawk (TACTOM) missile in March 2020. The upgraded version is known as the Block V TACTOM.            

What sets the Tomahawk apart from other types of munitions is that combination of size, speed, distance, and trajectory. Conventional saturation bombing–in which hundreds of bombs are dropped from a plane–is powerful but inaccurate. Saturation bombing also requires the use of a pilot and crew, which endangers personnel. Ballistic missiles, like the Scud, can travel greater distances at faster speeds but need much bigger launching pads and a lot more fuel, meaning they can’t be used covertly. TLAM is smaller and flies lower than other missiles, making them harder to detect and intercept.

Check out Naval Library App to find out the specifications of Tomahawk missile.

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