Ultra-Wide Band Radio Links Boost Indirect Fire Simulation.

• Jurisdiction: United States
• Date: 01 November 2000
• Author: Erwin, Sandra I.

Live fire exercises currently are the best option that Army soldiers have for conducting realistic training drills with indirect fire weapons, such as artillery and grenade launchers. But the high cost of munitions and environmental restrictions on live fires have sparked interest in developing technologies that can simulate non-line-of-sight firings in field exercises.

One of the most promising technologies--currently in the early stages of development--is part of the so-called tactical engagement simulations (ATES) program. The project's success is tied to an emerging form of radio communications called ultra-wide band.

Current force-on-force training systems rely on lasers to pair and determine the result of shooter-target engagements. The most widely used today is MILES, which stands for multiple integrated laser engagement system. The MILES 2000 is a laser-based training system in which soldiers fire infrared "bullets" from the same weapons and vehicles that they would use in actual combat. The exercise events and casualties are recorded, replayed and analyzed.

When MILES-equipped soldiers train in a simulated close-combat engagement, laser pulses are sent from a rifle-mounted transmitter to a detection device worn by a soldier from the opposing force. That pulse follows a straight line. MILES, however, has limited use in non-line-of-sight firings--and its capability is degraded by dust and smoke, Army and industry experts said.

The planned development of an advanced dual-mode infantry rifle for the Army, called the objective individual combat weapon (OICW), means that new training capabilities will be needed, beyond what MILES provides, these experts said. The OICW--which could be fielded as early as 2008--has a ranged air-burst capability for 20 mm high energy rounds, in addition to being a conventional rifle. The long-range air-bursting capability is not represented in the MILES system and shooting live OICW rounds will he expensive, at $30 or so apiece. The Army's Simulation, Training and Instrumentation Command (STRI-COM) is looking at the ATES technology as a possible training solution.

The ATES science and technology effort will continue until 2002, said Troy Dere, principal investigator for the ATES project. "The goal is to complete the research and development necessary to prove a new way of training," he said in an interview.

"In the current way of training, we have no adequate means of training soldiers to use weapons when you can't see the opponent, meaning indirect fire weapons," said Dere. "The MILES program can only do direct-fire weapons. They have some methods by which they can artificially simulate but, in my opinion, simulate poorly, indirect fire weapons.

A laser beam is a direct-energy weapon. "If you can't see your opponent, it doesn't work very well," Dere said. With indirect fire, explosive rounds or over-the-horizon shooting, he added, "we need to he able to train soldiers how to use those weapons other than through live firings.

"So far, our modeling has been limited to laboratory exercises, simulations on computers," he said. "But we are getting very close to starring some hardware demonstrations."

The OICW weapon can be programmed to explode at a distance, "so you could program it to shoot into the window of a building, for instance, where you couldn't see your opponent but you could program the round to explode after it goes through the window," explained Dere. In an urban environment, "you have all sorts of problems," he added, such as reflection of radio signals. "Sometimes you can see your opponents, sometimes you can't. It's the toughest environment."

STRICOM is working with the developers of OICW on how the training equipment would be integrated with the weapon. "But we are a long way away from that," Dere noted. "The Marine Corps will be fielding OICW too, so they are interested in the trainer."

The ultra-wide band (UWB) technology is the foundation of ATES. "Something like the UWB approach holds the most promise to give us that type of training," said Dere.

The provider of the UWB communications and position-location links for ATES is Time Domain, based in Huntsville, Ala.

"Our technology is a completely different approach to doing radio and position location tracking," said Kevin Davis, head of Time Domain's government and defense group. "It is fundamentally different in that we use very short pulses of energy instead of a continuous wave," he said in an interview.

Frequency domain radios--typically used by military operators and in AM/FM broadcasts--are continuous wave. "We are not using a frequency or continuous wave system, but an ultra-wide band impulse communication," Davis said. That approach involves firing extremely short-duration pulses at a very high rate. Those pulses are spread over large amounts of bandwidth. The UWB underlies the spectrum currently used by frequency domain systems that are found in today's military and commercial radios.

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