WASHINGTON --- Anti-access, area-denial, also known as A2AD, methods are used by enemy forces to slow or stop an invasion through such things as the placement of mines in the seabed near shore and concealment of forces inland.

New littoral and inland mapping tools are being developed by Army researchers to breach some of the A2AD threats. Experts spoke about these developments at the 2017 Annual Meeting and Exposition of the Association of the U.S. Army in October.

LITTORAL MAPPING

Soldiers and Marines will often travel from ship-to-shore in small landing craft.

Surf zones can be extremely dangerous places to navigate, with unseen sandbars that can ground vessels, large waves that can overturn them and strong currents that can affect navigation, according to Dr. Katherine Brodie, a research oceanographer with the U.S. Army Corps of Engineers' Engineer Research and Development Center.

The current method for littoral entry, she said, relies on charts that indicate water depths and underwater contours.

The problem with charts, Brodie said, is that they can become outdated within just hours -- for example, when a storm hits, sandbars form or disappear, along with beach erosion.

ERDC has developed a suite of inexpensive littoral imaging sensors that use video and radar to quickly map the underwater terrain, she said, explaining that they measure speed, direction and shapes of waves to accurately infer water depths, currents and underwater contours.

The methods used are so accurate, she said, that they can detect mines hidden under the water.

The sensors can also operate at night and during storms, she added.

Data is collected using unmanned aerial vehicles, which may have one or multiple cameras, as well as radar. In this manner, she said whole sections of coastline can be scanned in just minutes and the data can then be presented in the form of a map to the landing force commander.

She said the system was tested earlier this year at Camp Pendleton, California. It is still in the research and development stage at this time.

A second effort associated with this littoral mapping technology, she said, is building forecasting models and algorithms that can predict what the seabed will look like hours and days in the future. That effort involves collaboration between ERDC, the Naval Research Laboratory and the National Oceanic and Atmospheric Administration.

INLAND MAPPING

Damon Conover, an electronics engineer at the Army Research Laboratory, said his team is developing a 3-dimensional terrain visualization system that will help guide Soldiers over the safest land route to their objective.

The system relies on two types of sensors for collecting data: Light Detection and Ranging, more commonly called LIDAR, and video, which can be mounted on a small UAV, he said.

In just minutes, the imagery from the UAV can be captured and a stereoscopic map can be produced, he said.

With LIDAR, the resolution is just one meter across, Conover said. That means a small, mountain trail would be invisible. However, the photo imagery from the video produces pixels that are 10 centimeters across, allowing Soldiers to see minute detail such as the trail. Both LIDAR and the photo imagery are blended onto the 3-D map.

In addition to LIDAR and video, Conover said his team has incorporated other sensors, such as acoustic and seismic, into the mapping process.

Once these sensors are placed in the terrain by a reconnaissance unit or dropped by UAV and activated, they send signals directly to the same 3-D map, providing additional information about such things as enemy movement, he said.

During testing over the summer at Fort Huachuca, Arizona, Conover said that while watching the 3-D map at his command outpost, he could track the movement of Soldiers, who unknowingly set off the acoustic and seismic sensors on the desert floor.

Although the 3-D mapping is considered still in the research stage, Conover said "we are actively trying to get it in the hands of Soldiers."