COMMENTARY

It’s time for a tactical LiDAR satellite

• By David R. Shedd
• Jan 14, 2021

Confronting potential threats emerging from the rise of great-power competition dictates new approaches to collecting intelligence, surveillance and reconnaissance (ISR). The U.S. is on the right path by making large new investments in conventional long-range precision weapons. If it does become necessary to use these advanced weapons, however, will they be effective? That is the critical question.

Throughout the Cold War, America’s national security focused on the former Soviet Union as the strategic threat. The U.S. intelligence community (IC) and the Air Force developed and fielded collection systems to monitor vast geographic areas. By maintaining large repositories of potential military targets, policymakers and military leaders could count on getting early indications and warnings of threats emanating from the USSR.

At that time, much of the ISR collection came from high-altitude aircraft, providing us invaluable “eyes and ears” over the Soviet Union. To counter this advantage, the USSR developed air defenses capable of shooting down America’s ISR aircraft, including the most famous incident – the 1960 downing of Francis Gary Powers and his U2.  This event drove the U.S. to field new intelligence satellite systems beyond the reach of enemy missiles. 

Not until after the 9/11 terrorist attacks and combat operations in Afghanistan and Iraq did American airborne systems once again become a predominant ISR source. U.S. manned and unmanned aircraft could fly with virtual impunity. 

An entire generation of military leaders came to rely on persistent collection from the new generation of sensors on aircraft.  Amazing new electro-optical, infrared, radar and LiDAR – Light Detection and Ranging — sensors delivered crucial and timely information to the warfighter and the IC.  LiDAR sensors use lasers that can effectively operate from far distances to map terrain and structures, offering both superb resolution and absolute geolocational accuracy – critical elements to direct precision guided munitions to their intended target.  LiDAR also permitted field-deployed analysts and operators alike to see through dense forests and build 3D scenes of a target.

While no one can dispute the effectiveness of airborne collection, advanced anti-aircraft weaponry put these platforms at risk.  With the U.S. national security strategy refocused on China, Russia, Iran and North Korea, America’s ISR would be vulnerable to improved air defenses, should surveillance aircraft need to enter an adversary’s airspace. These advanced air defense systems are known within defense circles and the IC as “anti-access/anti-denial” systems. This means U.S. aircraft (and even ships) require a “stand off” distance to operate without coming into harm’s way. To mitigate for A2/AD, collection capabilities must be incorporated into satellites. Simultaneously, the U.S. is building a new generation of weapons systems that can provide conventional (non-nuclear) strikes on targets at great distances with great precision. For instance, the Army is developing a new generation of long-range precision fires, including a new cannon, missile and hypersonic missile. In each case, the weapons can travel much further than any U.S. airborne ISR system can see, requiring satellites to effectively use these new weapons. 

Supporting the new weapons such as strategic hypersonic missiles depends on delivering high-quality ISR in tactically relevant timelines. The good news is that a NASA science mission called ICESAT2 proved the U.S. can collect space-based LiDAR. The bad news is that the NASA LiDAR doesn’t deliver the high-resolution, 3D, foliage-penetration imagery or even tactical timelines the military needs. Intelligence and military planners along with field operators need a space-based LiDAR capable of rapidly surveying large areas at very high resolution in a single pass. For example, they must scan areas that range from 100,000 to 400,000 square meters with resolutions of 1 meter, .5 meter and .2 meter. 

But the news is not all bad for America’s military planners. There is a promising new concept, based on proven technology, for a multi-aperture, space-based LiDAR satellite system with multiple telescope receiver modules observing a single target. This approach, which would solve the intelligence and defense problem relies on a laser pulse from a single-photon LiDAR system that reflects from the target. The signal photons propagate not only back to the transmitter but also in other directions. These results could provide unmatched visibility of a denied area of interest alongside the data necessary for more effective and accurate use of advanced weapon systems.

What is needed? First is a feasibility study by the Army partnering with the appropriate IC element focused on building space capabilities. We need confirmation that any system in development will work with detailed modeling and simulations. If those tests prove a system effective, it’s urgent we move to deployment of a demonstration satellite.

Our national decision-makers must do all they can to prevent war. However, if war is necessary, the U.S. must win and do so decisively. The nation’s precision guidance weapons require investments in new ISR satellites. LiDAR is a combat-proven sensor technology that must now be deployed in space. Such a space-based capability will assure decision-makers in and out of uniform that reliable and precise information is available when and where needed.