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‘LiDAR tech more effective in battlefield’

US: The light detection and ranging (LiDAR), an optical remote sensing technology proved quicker, more accurate than traditional mapping tools in the battlefield, observed a report published on DEFENSESYSTEMS.com.
According to the report, LiDAR bounces pulsed lasers, as opposed to the electromagnetic radio waves of radar and sonar, off target objects and surrounding areas of interest to detect their properties. Because it can detect much smaller particles in the atmosphere than radar, which can’t detect things smaller than cloud particles, LiDAR can even be used for aerosol detection.
Some laser radar systems can perform multiple sequential scans over a scene. Others create images in target or mapping modes. In targeting, the sensor continually focuses, saturating a target with laser pulses to generate a high-resolution product. Mapping is wide-area collection, where the laser pans to collect data along a set path.
The National Geospatial-Intelligence Agency (NGA) has been deploying LiDAR in aircraft to map Afghanistan’s entire 647,500 square kilometres. NGA described its ALIRT LIDAR program as “an airborne 3-D imaging laser radar system optimised for wide-area terrain mapping.” LIDAR mapping was used in the aftermath of Haiti’s 2010 earthquake.
Defense Advanced Research Projects Agency Director Regina Dugan called LiDAR’s photon-detecting arrays “so sensitive it’s now possible to make range measurements with fewer than 10 photons received, versus tens of thousands,” which means that at times, the technology is capable of locating hidden objects and penetrating tree canopies.
LiDAR can complement, interface with or fuse with conventional maps, tactical computer modelling, full-motion video, hyperspectral imagery and ISR platforms.
Mathias Kolsch, assistant professor of computer science at the Naval Postgraduate School, stated, “The most advanced LiDAR sensors for critical depth measurements are called Flash LIDAR, and they do more or less what a flashlight does: send out a big broad pulse of laser light with multiple receivers” for the returns, he said. “Instead of the traditional LIDAR with its single receptor, these sensors have a whole detection array — banks of digital charge-coupled device cameras — so they simultaneously get multiple depths.”
Current-generation LiDAR can be configured to cover specific structures, vehicles, roadways or terrain. The light it pulses from an aircraft’s sensor can, by some estimates, collect as many as 150,000 data points per second. The data provides location on an X-Y-Z axis, referred to as a point cloud, with millions of individual ground data points. According to Kolsch, wavelengths range from ultraviolet to visible and infrared, which is at least 1,000 times smaller than radar. By comparison, Canada’s Radarsat satellite has a wavelength of 5.6 cm. Here, smaller is better.