Tag Archives: unmanned systems

Capability Analysis, Drones

What’s the Buzz? Ship-Based Unmanned Aviation and its Influence on Littoral Navies during Combat Operations

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By Ben Ho Wan Beng

Introduction

“Unmanned aviation” has been a buzzword in the airpower community during recent years with the growing prevalence of unmanned systems to complement and in some cases replace peopled ones in key roles like intelligence, surveillance and reconnaissance (ISR). Insofar as unmanned aerial vehicles (UAVs) are increasingly used for strike, their dominant mission is still ISR because of the fledging state of pilotless technology. This is especially the case for sea-based drones, which are generally less capable than their brethren ashore. That said, several littoral navies have jumped on the shipborne UAV bandwagon owing to its relative utility and cost-effectiveness.[1] And with access to such platforms, how would these entities be affected during combat?

For littoral nations without an aerial maritime ISR capability in the form of maritime patrol aircraft (or only having a limited MPA capability), the sea-based drone can make up for this lacuna and improve battlespace/domain awareness. On the other hand, for littoral nations with a decent maritime ISR capability, the shipborne UAV can still play a valuable, albeit, complementary role. The naval drone also offers the prospect of coastal forces amassing more lethality as it refines the target-acquisition process, enabling its mother ship to attack the adversary more accurately.

The Littoral Combat Environment

Littoral operations are likely to be highly complex affairs. As esteemed naval commentator Geoffrey Till said: “The littoral is a congested place, full of neutral and allied shipping, oil-rigs, buoys, coastline clutter, islands, reefs and shallows, and complicated underwater profiles.”[2] One key reason behind the labyrinthine nature of littoral warfare is that it involves clutter not only at sea, but also on land and in the air. Especially troublesome is the presence of numerous ships in the littorals. To illustrate, almost 78,000 ships transited the Malacca Strait, one of the world’s busiest waterways, in 2013.[3]

Such a complex operating milieu would place a premium on the importance of battlespace awareness, which could make or break a campaign. As fabled ancient Chinese military philosopher Sun Tzu asserted: “With advance information, costly mistakes can be avoided, destruction averted, and the way to lasting victory made clear.” This statement was made over 2,000 years ago and is still as relevant today, especially when considered against the intricacies of littoral combat that hinder sensor usage. Indeed, shipborne radar performance during littoral operations can be significantly degraded by land clutter. For instance, the 1982 Falklands conflict manifested the problems sea-based sensors had in detecting and identifying low-flying aircraft with land clutter in the background.[4] Campaigning in congested coastal waters would also necessitate the detection and identification of hostile units in the midst of numerous other sea craft, which is by no means an easy task. All in all, the clutter common to littoral operations presents a confusing tactical picture to naval commanders, and the side with a better view of the situation ­– read greater battlespace awareness – would have a distinct edge over its adversary. Sea-based UAVs can provide multispectral disambiguation of threat contacts from commercial shipping by virtue of onboard sensor suites, yielding enhanced situational awareness to the warfare commander.

Improved Battlespace Awareness         

Traditional manned maritime patrol aircraft (MPA) would be the platform of choice to perform maritime ISR that helps in raising battlespace awareness in a littoral campaign. However, not all coastal states own such assets, which can be relatively expensive[5], or have enough of them to maintain persistent ISR over the battlespace, a condition critical to the outcome of a littoral operation. This is where the sea-based drone would come in handy. Unmanned aviation has a distinct advantage over its manned equivalent, as UAVs can stay airborne much longer than piloted aircraft. To illustrate, the ScanEagle naval drone, which is in service with littoral navies such as Singapore and Tunisia and commonly used for ISR, can remain on station for some 28 hours.[6] In stark contrast, the corresponding figure for the P-3 Orion MPA is 14 hours.[7] The sensor capabilities of some of the naval drones currently in service make them credible aerial maritime ISR platforms. Indeed, they are equipped with sophisticated technologies such as electro-optical and infrared sensors, as well as synthetic aperture radar (SAR) systems.

To be sure, the shipborne UAV is incomparable to the MPA vis-à-vis most performance attributes, and the two platforms definitely cannot be used interchangeably. The utility of the naval drone lies in the fact that it can complement the MPA by taking over some of the latter’s routine, less demanding surveillance duties. This would then free up the MPA to concentrate on other, more combat-intensive missions during a littoral campaign, such as attacking enemy ships. And for a littoral nation without MPAs, the shipborne UAV would be especially valuable as it can perform aerial ISR duties for a prolonged period.

The naval drone can contribute to information dominance in another way. In combat involving two littoral navies, the side with organic airpower tends to have better domain awareness over the other, ceteris paribus. However rudimentary it may be, the shipborne drone constitutes a form of organic sea-based airpower that extends the “eyes” of its mother platform. The curvature of the Earth limits the range of surface radars, but having an “eye in the sky” circumvents this and improves coverage significantly. Being able to “see” from altitude allows one to attain the naval equivalent of “high ground,” that key advantage so prized by land-based  forces. Indeed, the ScanEagle can operate at an altitude of almost 5,000 meters.[8] In the same vein, the Picador unmanned helicopter has a not inconsiderable service ceiling of over 3,600m.[9] In essence, the UAV allows its mother ship to detect threats that the latter would generally be unable to using its own sensors.

All in all, shipborne drones enable littoral fleets to have a clearer tactical picture, translating into improved survivability by virtue of the greater cognizance of emerging threats that they offer to surface platforms. Having greater battlespace awareness also means that the naval force in question would be in a superior position to dish out punishment on its adversary.

Increased Lethality

Sea-based UAVs would enable a littoral navy to target the opposing side more accurately as they can carry out target acquisition, hence increasing their side’s lethality. In this sense, the drone is reprising the role carried out by floatplanes deployed on battleships and cruisers in World War Two. During that conflict, these catapult-launched aircraft acted as spotters by directing fire for their mother ships during surface engagements. In more recent times, during Operation Desert Storm, Pioneer UAVs from the American battleship Wisconsin guided gunfire for their mother ship. Several current UAVs can fulfill this role. For instance, the Eagle Eye can be used as a guidance system for naval gunfire; ditto the Picador with its target-acquisition capabilities. There is also talk of drones carrying out over-the-horizon targeting so as to facilitate anti-ship missile strikes from the mother platforms.[10]

Though land-based UAVs are increasingly taking up strike missions, the same cannot be said for their sea-based counterparts as very few of the latter are even in service today in the first place due to their complexity and cost. The Fire Scout is one such armed naval UAV. This United States Navy rotorcraft can be armed with guided rockets and Hellfire air-to-surface missiles; however, with a unit cost of US$15-24 million[11], it is not a low-end platform. All in all, unarmed shipborne drones are likely to be the order of the day for littoral navies, at least in the near term, and such platforms can only carry out what they have been doing all this while, tasks like ISR and target acquisition.

Conclusion

In summary, the sea-based drone can, to some extent, complement the maritime patrol aircraft in the aerial ISR portfolio at sea by helping to maintain battlespace awareness for the littoral navy during a conflict. The naval UAV’s target-acquisition capability also means that it can improve its owner’s striking power to some extent. These statements, however, must be qualified as current shipborne drones can only operate in low-threat environments – in contested airspace, their survivability and viability would be severely jeopardized, as they are simply unable to evade enemy fighters and anti-aircraft fire. In the final analysis, it can perhaps be maintained that the rise of sea-based UAVs constitutes incremental progress for littoral navies, as the platform does not offer game-changing capabilities to these entities.

Going forward, ISR is likely to remain the main mission for sea-based drones in the near future. Though the armed variant seems to offer a breakthrough in this state of affairs, it must be stressed that it is neither a simple nor cheap undertaking. If and when defense industrial players provide lower-cost solutions to this issue in the future, however, the striking power of coastal fleets would increase considerably and with that, the nature of littoral and naval warfare in general would profoundly change. Until then, the sea UAV-littoral navy nexus will be characterized by evolution, not revolution.

Ben Ho Wan Beng is a Senior Analyst with the Military Studies Programme at the S. Rajaratnam School of International Studies in Singapore; he received his master’s degree in strategic studies from the same institute. The ideas expressed above are his alone. He would also like to express his heartfelt gratitude to colleague Chang Jun Yan for his insightful comments on a draft of this article.

This article featured as a part of CIMSEC’s September 2015 topic week, The Future of Naval Aviation. You can access the topic week’s articles here. 

Endnotes

[1] For instance, the Scan Eagle drone has a unit cost of $100,000. See www.nytimes.com/2013/01/25/us/simple-scaneagle-drones-a-boost-for-us-military.html?_r=0.

[2] Geoffrey Till, Seapower: A Guide for the Twenty-first Century (London: Routledge, 2013), 268.

[3] Marcus Hand, “Malacca Straits transits hit all-time high in 2013, pass 2008 peak,” Seatrade Maritime News, February 10, 2014, accessed September 4, 2015, www.seatrade-maritime.com/news/asia/malacca-straits-transits-hit-all-time-high-in-2013-pass-2008-peak.html.

[4] Milan Vego, “On Littoral Warfare,” Naval War College Review 68, No. 2 (Spring 2015): 41.

[5] Some of the more common MPAs include the P-3 Orion, which is in service with nations like New Zealand and Thailand which has a unit cost of US$36 million, according to the U.S. Navy. See www.navy.mil/navydata/fact_display.asp?cid=1100&tid=1400&ct=1.

[6] “ScanEagle, United States of America,” naval-technology.com, accessed September 5, 2015, www.naval-technology.com/projects/scaneagle-uav.

[7] “P-3C Orion Maritime Patrol Aircraft, Canada,” naval-technology.com, accessed September 5, 2015, www.naval-technology.com/projects/p3-orion.

[8] “ScanEagle, United States of America.”

[9] “Picador, Israel,” naval-technology.com, accessed September 5, 2015, www.naval-technology.com/projects/picador-vtol-uav.

[10] Martin Van Creveld, The Age of Airpower (New York: Public Affairs, 2012), 274.

[11] United States Government Accountability Office, Defense Acquisitions: Assessment of Selected Weapons Program, March 2015, 117.

Drones, Future Tech

Unmanned Underwater Vehicles: A Conversation with Chris Rawley

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To start our UUV Week, we’re talking with Chris Rawley, owner of the website Naval Drones: Unmanned Naval Systems and author of Unconventional Warfare 2.0. Chris is a surface warfare officer in the US Navy Reserve.

Penguins: They Love UUVs. NSF-funded SeaBED shown.
Penguins: they love UUVs. NSF-funded SeaBED shown.

SD: Thanks for talking with us today, Chris. Let’s get right to it with some initial broad strokes. There’s clearly a great deal of potential out there for UUV platforms, but in a very general sense, what mission areas of those set out by the US Navy’s UUV Master Plan show the most promise in terms of cost effectiveness and practicality?

CR: Thanks Sally. Before I start, I have to provide the disclaimer that I am speaking here in my personal capacity and my comments and opinions do not reflect U.S. Navy or DoD policy. Also, I am by no means an expert in this field, though I have picked up some knowledge the past few of years writing for “Naval Drones,” which was initially established as a marketing tool for a UUV concept I developed. After some fits and starts, my company is currently working on this UUV design with a prototyping firm.

From my perspective, mine countermeasures is the mission area ripest for disruption by unmanned undersea vehicles. As CIMSEC’s readers know, mine clearance involves a painstaking, methodical process of hunting to rule out false positives detected by various sensors or using sweeping gear to activate the mines. Dedicated mine countermeasures ships, though still in service, will eventually be replaced multi-mission platforms embarking UUVs. Most readers know about the Littoral Combat Ship’s dedicated mine countermeasures payload, but pretty much any naval combatant or auxiliary with a margin of payload capacity such as the JHSV can launch UUVs or carry boats or unmanned surface vessels (USVs) that can launch UUVs directly into a mine field at a safe stand-off distance from the mother ship . Multiple UUVs operating together will eventually become faster at mine hunting than dedicated surface ships with sweeping gear or mine-detection sonars. ROVs and UUVs such as the SeaFox can also localize, identify, and neutralize the mines. Though I think the UUV Master plan specifically mentions nine mission areas, besides MCM, at some point UUVs will play a part in pretty much any kind of naval operation one could imagine.

While we continue to wait for the silver bullet of long-endurance propulsion systems, the three areas of UUV development with the most potential I see are payload miniaturization, payload modularity, and swarming algorithms.

USN sailors load a SeaFox MCM UUV (U.S. Navy photo by Lt. Colby Drake/Released)
USN sailors load a SeaFox MCM UUV (U.S. Navy photo by Lt. Colby Drake/Released)

SD: Let’s talk specifically about UUVs in an ASW capacity. A lot of readers (okay, especially me) are interested in what UUVs can bring to anti-submarine warfare (ASW). In all likelihood, such a platform would need to detect low-frequency signals, demanding a large array and a vehicle to support it. Will there have to be a trade off between the reasonable size of a notional platform (to support such an array) and such a platform’s detection capabilities? Are leave-behind arrays delivered as part of a UUV payload a more desirable option?

CR: Autonomous underwater vehicles such as gliders are already helping to characterize the water column, which as you know is one of the most important foundations of ASW. As far as sub-hunting goes, a large UUV towing a passive array might be one way to do it, though I’m not sure that is feasible for a variety of reasons. Or as you’ve alluded to, a larger UUV could basically become a means to more precisely deploy sonobuoys or emplace arrays on the bottom. What about smaller, more numerous UUVs each carrying a single hydrophone and operating at different depths? Or UUVs able to surface and act as non-acoustic data relays between bottom arrays and ASW aircraft? I think there is certainly room for some R&D and experimentation in this area.

SD: The idea of an UUV with the capacity to surface and communicate as a non-acoustic data relay with an MPRA asset is particularly promising and offers a solution to some of the major complexities of airborne prosecutions. Further, the idea of employing UUVs to deploy hydrophones or arrays at specific depths is a novel turn on a well-established technique. But perhaps getting those assets on-station at the appropriate times would present a difficulty; after all, one of MPRA/airborne ASW’s major advantages is speed and flexibility relative to the target. On to another ASW question: in an increasingly crowded underwater environment, do you think that submarine-launched UUVs will offer more or less stealth to launching platforms? Do you see any applicability for UUVs as a decoy, or would maintaining acoustic superiority for existing and future subs prove a more worthwhile, cost-effective pursuit?

CR: Unlike a sub-fired missile, I’m not sure a UUV will make a launching submarine any less stealthy. To my knowledge, most of the UUVs that have been tested have been “swim out,” so they wouldn’t add much extra acoustic signature to the launch platform. Some sort of acoustic or magnetic decoy UUV does seem like a viable and useful payload for a submarine.

SD: U.S. Submarine-launched UUVs may have somewhat of a compatibility crisis in the coming decades. SSGNs are uniquely suited for UUV operations, but as modified-Ohio class platforms reach the end of their service life in the coming decades, how do you think UUV platforms will fit into the Virginia Payload Module program?

A Naval Sea Systems Command illustration depicting the VPM concept.
A Naval Sea Systems Command illustration depicting the VPM concept.

CR: Though launching and recovering a UUV from a submarine certainly adds an element of “stealthiness” for the UUVs themselves, it also comes with several complications. There are trade-offs in a submarine’s limited tube space – be it torpedo tubes or the VPM – between UUVs and other payloads such as torpedoes and missiles. Moreover, as you note, more submersible vehicles will result in an increasingly crowded operating environment. A manned submarine operating in conjunction with a large number of friendly (and potentially, enemy) UUVs makes waterspace deconfliction challenging and puts a capital ship at risk for a collision, especially as the size and speed of UUVs grows.

But here’s the thing: a UUV is inherently stealthy. Why do we need to launch it from another low signature platform (a submarine) when it can be launched more cheaply and across wider areas (such as shallow water littorals) by more numerous surface vessels or even air platforms?   Where there is no other way to get a shorter ranged UUV into the water column, a submarine may be the answer. To answer your question, we should save limited submarine payload capacity for offensive weapons and insert the majority of UUVs into the battlespace using more affordable means.

SD: Interesting points. I hadn’t considered the idea of mutual interference, and it certainly makes sense to deploy UUV assets from surface or air assets, where space would not be as much of a premium. This is another broad question, but what role do you see for UUVs in developing a cogent strategy to counter A2AD?

CR: UUVs could potentially serve as fire control sensors, decoys, and deception tools during a counter-A2AD campaign. I’ll leave it at that.

SD: Fair enough. One of the most frequently cited criticisms of developing UUV platforms is the inherent difficulty of communication and navigation in an underwater environment, as well as limitations on data links and processing. What is your answer to these criticisms?

CR: The easiest solution is the surface the UUV every now and then to transmit its data and get its bearings. But advances in underwater data modems (both acoustic and non-acoustic), along with autonomy will mitigate some of these challenges

SD: If operating covertly in a denied area, surfacing might be detrimental to the UUVs mission, but no more so than other subsurface assets that might be required to surface to receive or transmit data. But, admittedly, this is a pretty narrow scope to view a very broad potential mission set, and such a concern would not apply to all those potential applications. Let’s talk autonomous vehicles. AUVs operating at a distance will undoubtedly carry the potential for loss or interception. Is there an acceptable level of platform loss or risk operators of UUVs will have to accept?

CR: Sure. I think we will need a variety of UUV types. Some, like Large Displacement Unmanned Underwater Vehicle (LDUUV), will be large, expensive, and multipurpose. Others will be designed to be single-purpose, affordable, and expendable, while some others will be somewhere in the middle.

SD: Specifically though, do you think that there might be inherent risks to doing business via UUVs that do not exist for manned counterparts? Not necessarily that these risks outweigh the benefits, but, if there are any, they’re worth discussing.

CR: Signal interception is a problem faced with pretty much any platform these days. Even manned aircraft are going to be hard pressed to operate without emissions given how networked everything is.  Many UUV atmospheric signals will be on commercial channels, so hard to differentiate from civilian traffic. As to the technology being recovered by an enemy, that is certainly possible too, and a much higher risk for unmanned vehicles. We’ve learned lessons from UAVs that are applicable in this area.

SD: Great point; the risk for signal interception would likely not be any greater for unmanned platforms, and could be mitigated in similar ways. Let’s scale down a bit. On your blog, you recently discussed possible applications of small-scale UUVs, such as those fielded by the University of Graz’s Collective Cognitive Robots project. What applications do you envision for small-scale UUVs like these operationally?

CR: Search and recovery, especially in inshore waters or the littorals, comes to mind. But also acoustic decoys, and maybe even small, mobile sonobuoys for ASW. I’d love to get some reader feedback on this one actually.

SD: I really look forward to reading what others have to say on this issue as well. I think the MPRA ASW applications are especially promising. Last but certainly not least, let’s discuss the LDUUV program. What is your take on pier-launched or even surface-ship based systems with longer endurance and on-station capabilities?

The U.S. Navy's LDUUV
The U.S. Navy’s LDUUV

CR: For some applications, a pier-launched UUV might be viable. But a Navy’s strength is based on its mobility. So yes, as we seem to agree, surface ships are a pretty viable launch platform for large UUVs. The Naval Special Warfare Command’s Swimmer Delivery Vehicle is an analogy. Of course, they are most stealthy when operated from a submarine, but can also be launched from ships and smaller combatant craft. And depending on the operational range of the LDUUV, surface ships would be fine for many mission profiles. And if you are looking for stealth, the stealthiest platform is the one that hides in plain sight, so not every launch platform has to be a naval vessel.

SD: This has been tremendously interesting discussion! Thank you, Chris, for your time; congratulations on your progress with your own UUV design. We look forward to following its development! Thanks as well to the CIMSEC readers who have followed along. Let’s continue this discussion in the comments section.

Sally DeBoer is an Associate Editor for CIMSEC.

Visit Chris Rawley’s blog at: blog.navaldrones.com

 

 

 

Podcast

Sea Control 54 – Innovation, Littorals, and Unmanned at NPS

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seacontrol-birthdayWe cover the Warfare Innovation Workshop at the Navy Postgraduate School – hosted by Navy Warfare Development Command (NWDC) and NPS’s Consortium for Robotics and Unmanned Systems Education and Research (CRUSER).  For today’s episode, we are joined by two guests – CAPT Jeff Kline (USN Retired), Chair of Warfre Innovation for the (NWDC) and Lyla Englehorn, the Director of Concept Generation for Consortium for Robotics and Unmanned Systems Education and Research (CRUSER).

DOWNLOAD: Sea Control 54 – Innovation, Littorals, and Unmanned at NPS

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