Is there any technical reason to use Kh-101 missiles at night, when they are much less accurate? – Technology Org

Kh-101 missiles are used by Russian forces to fuel their invasion of Ukraine. But why are they predominantly used at night, when the performance of the rocket’s targeting system is strongly hindered?

Kx-101 (X-101) missiles mounted under the carrier aircraft. Image credit: Russian MoD

As Defense Express notes, the X-101 uses four guidance systems that supplement each other. One of them is called DSMAC – and it is the most technologically advanced targeting sub-system. Except for the fact that its performance is significantly diminished in the dark.

The Russian Federation recently started conducting its missile attacks during the night. Why?

The DSMAC navigation system which is implemented in the Kh-101 missiles uses an optical comparison of images of the surrounding area. It can detect characteristic waypoints or objects such as road junctions.

The data acquired by DSMAC is used to correct the operation of the other three sub-systems – an inertial guidance system that uses sensors and a computer, satellite navigation that receives precise coordinates, and the terrain contour matching (TERCOM) system which scans the terrain .

This diagram illustrates the operation of the DSMAC guidance system in American Tomahawk missiles. Image credit: Riedel, Frederick W. et al. “Guidance and Navigation in the Global Engagement Department.” Johns Hopkins Apl Technical Digest 29 (2010): 118-132.

The performance of DSMAC depends on the image quality and therefore on the ambient lighting conditions. At night, it operates poorly. But there are two possible reasons by the Russian army changing the timing of their missile attacks.

Optical DSMAC camera from the X-101. Image credit: ArmyInform

First, the Armed Forces of Ukraine know how to eliminate cruise missiles as they have accumulated a considerable amount of experience while defending against airborne attacks. Doing this in a daytime is, of course, the most efficient.

The second scenario is a bit more hypothetical. But it is quite possible that the Russian army cannot effectively use the DSMAC navigation system due to some kind of a technological issue (for example, incorrect operation under certain circumstances), or possibly due to the inability to constantly acquire reference topographic images of the territory in which they are conducting these missile strikes.

There could also be a third scenario – existing economic sanctions may have impacted the availability of components necessary to construct advanced electronic systems.