Submarine Periscopes: Visibility and Identification in Modern Warfare

The visibility of submarine periscopes from above the water's surface has been a subject of interest and concern in naval strategies. This article explores the challenges and methods of detecting and identifying submarine periscopes in modern warfare, focusing on the role of periscopes, photonic masts, and radar technologies.

Understanding Periscopes and Their Challenges

Periscopes were traditionally used by submarines to observe and communicate visually while underwater. However, these mechanical devices leave a visible wake and are prone to detection by various means. One notable observation is the difficulty in identifying periscopes while they are submerged at periscope depth. This depth is typically between 6 and 10 meters, where the periscope can provide clear visual data but is also more vulnerable to detection.

Here are a few images of submarines operating at periscope depth. Notable problems include the periscope wake, which can alert opposing vessels or aircraft to the submarine's presence. These wakes are often visible as a trail of disturbed seawater left behind by the periscope as it moves.

The radar signature of a periscope wake is also an indicator of the potential threat it poses. This signature can be detected by various radar systems, highlighting the need for silent, modern means of observation.

Technological Advances: Photonic Masts

Modern submarines are increasingly equipped with photonic masts. These advanced observation devices use fiber optics to transmit images and data from above the water's surface, significantly reducing the likelihood of detection. A photonic mast from a U.S. Virginia-class submarine is depicted in the following image:

Photonic Mast from a U.S. Virginia-class submarine.

While periscopes are still used in certain scenarios, the use of photonic masts is becoming more prevalent due to their stealth capabilities. However, the fact that something is now above the water's surface means that identification is still possible. The visibility of photonic masts depends on a variety of factors such as sea state, weather conditions, and the angle at which they are observed. Modern patrol aircraft primarily rely on radar systems to detect periscopes, while electronic and infrared (EO/IR) sensors can also be used to identify them. The installation of periscope detection modes in radar systems further complicates the potential for detection.

Radar Detection and Image Recognition

Modern patrol aircraft and ship-based radars have developed advanced periscope detection capabilities. For instance, the MH-60R’s AN/APS-153V Multi-Mode Radar has a Periscope Detection mode that specifically targets small targets, including periscopes. Additionally, image recognition software can automate the process of identifying periscopes from EO/IR sensor data. This technology could significantly reduce the time and effort required to detect and identify periscopes, making them a more reliable tool for submarines operating in modern conflict zones.

Ship-based radars, such as the AN/SPQ-9B Surface Search Radar, also feature periscope detection modes, further enhancing the submarine's ability to avoid detection.

Submarine-Launched Drones and Future Developments

In the future, submarines may rely on drones to augment their observation capabilities. These drones can be launched from existing flare dispensers, allowing for silent and independent surveillance above the water's surface. Silent drone launches could make these systems both stealthier alternatives to traditional periscopes and provide a much larger field of view for the submarine.

Police and military vessels have been using similar technology for many years, where after a submarine is detected, a drone is launched by the attacker as a countermeasure. These drones can use EO/IR sensors to confirm the presence of the periscope and provide real-time reconnaissance data.

{Your name} served on a submarine where an encounter with a periscope was observed. The encounter is a critical reminder of the continuing development and importance of stealth technology in submarine warfare. These technological advancements not only provide submarines with an extended field of view but also reduce the risks associated with traditional observation methods.