Teksti on laadittu koulutyönä EJMSBM -kurssilla.
The given requirements for a future EU coastal border surveillance system are (1) low cost and (2) environmental friendliness. The first criterion can be broken down into capital costs and operating costs. In the western world labor is very expensive. Regarding the capital costs of labor, one has to count in the education and training of employees as well as all the infrastructure and facilities needed for the work and for sustainment of the people. Operational costs in HR terms refer to the salary with all the appropriate allowances and benefits. For this amount of money, the employer gets approximately 30-40 hours (taking into account annual leave, public holidays, sick days, etc.) of weekly work effort from the employee. That's only about 20% of the total of 168 hours of the week. It means that in order to have someone at work at all times, the employer actually has to employ five people. Not very efficient. And the 30-40 weekly hours is only the time when the employee is at the employer's disposal. Not that he's actively doing something all that time. If we think about the tedious nature of surveillance work, the actual time the worker is able to spend on that is likely to be significantly less. People get tired and bored easily, which lowers the quality of surveillance. This makes human surveillance even less efficient. Moreover, to conduct surveillance, the human has to be brought into and sustained in the place of surveillance. If we're talking about ships, aircraft or watchtowers as surveillance platforms, majority of the people involved don't even actively conduct surveillance. Rather they work in secondary functions as mechanics, cooks, maintenance, engineers, navigation, administration and such. Majority of the physical aspects of these platforms are solely planned and designed to keep the crew alive and supported. Instead of designing them as optimal surveillance platforms, they are designed to take people to places. All of the above leads to a conclusion that surveillance as humans labor is ridiculously inefficient.
Therefore, we need to look at non-labor-intensive surveillance options. Thankfully, we now have unmanned systems to take care of the task. The unmanned systems still, for the most part, need an operator to attend them, but it's just one person as opposed to a whole ship/flight crew. Also, the operator is not physically on the platform, making the platforms much lighter, agile, more endurable and efficient and thus cheaper and environmentally friendly. Unmanned systems come in various forms, shapes and sizes depending on their function. In order to conduct effective coastal border surveillance, we want our sensors to cover as large a coastal water area as possible. We can choose either fixed, relocatable or mobile sensors, or any combination of those.
Fixed sensor suites. We could consider building a network of masts equipped with surveillance sensors to cover the coastal regions. The problem with masts is their immobility and relatively short range. Seen from a 100 m high mast the horizon is 36 km away at sea level. Masts also suffer from blind spots caused by islands, capes and coves along the coastline. Based on a rough calculation, we would need over a thousand of these masts to cover the whole length of the European coastline. To further complicate the issue, land would need to be acquired at the exact optimal places to make the mast network effective. And even if this was possible, surveillance masts might raise resistance in the local populations due to ethical or aesthetical concerns. Not to rule masts out completely, they might defend their place in selected few bottleneck hotspots with significant prospects of remaining that way in the long term. Other than that they are just too ineffective to be considered as the primary coastal border surveillance solution.
Relocatable sensor suites. Tethered aerostats are discussed under relocatable sensor suites, although they often are permanently or at least semi-permanently moored to a fixed location, therefore suffering from many of the same disadvantages as masts. Their big advantage, however, is the much greater height they can operate in. Some models can be elevated as high as 5000 m, which pushes their line-of-sight to an impressive 250 km at sea level; flying objects can be detected as far as 400 km away. The Unites States Customs and Border Protection, for example operates six TARS aerostats at the Mexican border that between them are able to cover the whole 3,100 km length of the border. Following a mechanical logic we would require between 100 and 150 of these aerostats to cover the whole EU coastline. But of course not every centimeter of the coastline would have to be covered. As the picture below suggests, all in- and outbound traffic in the Mediterranean could be sufficiently monitored with 10-15 aerostats, depending on how much coverage, redundancy and/or overlap is required. The actual aerostat locations should of course be based on a thorough threat assessment. They would probably best serve as a part of a two tier surveillance system, providing operational level detection and early warning, to be supplemented by rapidly deployable UAVs, where more accuracy and detail is required. The cost of an aerostat system varies depending on the sensor suite. Based on open source information, the end user price for a single large aerostat is roughly between 1M and 8M euros.
Picture 1: Possible Tethered Aerostat locations (13) in the Mediterranean. Map source: Google Maps
Unmanned surface vessels (USV). There are numerous USVs already on the market, some even operational, but they are not primarily designed for surveillance tasks. The reasons for this is simple: You can't see very far from a surface vessel. Even if you put the sensor on top of a mast on a boat, your horizon is still less than 10 km away in all cases. Other disadvantages compared to UAVs are shorter operational range and endurance and a generally lower speed. The one advantage that USVs do enjoy is bigger payload, allowing various weapon systems (etc.) to be carried onboard. This of course is not relevant in the border surveillance context, for which reasons USVs are not considered an optimal solution for this task.
Unmanned aerial vehicles (UAV). A UAV is by no means a homogenous concept. It covers a whole range of airframes from tiny hand-launched ones to large theater UAVs that require and airstrip to operate from. For persistent long range surveillance one would go for a large High-Altitude Long Endurance (HALE) theater UAV, such as the Northrop Grumman MQ-4C Triton, a maritime variant of the more familiar RQ-4 Global Hawk. It is purpose built for maritime surveillance and is able to field some impressive statistics. Its operational ceiling is over 18,000 m, which gives it a line-of-sight of almost 500 km at sea level. This means that with a single sensor sweep (see picture 2) it is able to cover 5,200 km2 of sea surface. Within the frame of its flight endurance of 24 h, it is able to survey an area of 7,500,000 km2 - three times the whole surface area of the Mediterranean. It is also able to operate at lower altitudes to allow for higher detail surveillance or identification. Australia is currently in the process of purchasing seven Tritons for the surveillance of its northern coastal waters; a sea area roughly the size of the Mediterranean. The big downside of the Triton or a comparable HALE UAV is the price. Based on open sources, a single airframe has a price tag of approximately 120M euros.
Picture 2: Visualization of a HALE UAV's single sweep surveillance capability in the Mediterranean. On a single 24 h sortie the whole Mediterranean could be covered three times over. Map Source: Google Maps
Of course, UAVs come in many shapes, sizes and prices. While the Triton is in the Rolls-Royce class of UAVs, we might get the majority of the job done with a Volkswagen. The Boeing ScanEagle 2 is an example of a tactical UAV, with limited capabilities compared to its bigger cousins. What makes it more appealing is the price. A single ScanEagle system, comprising of four airframes and the necessary ground equipment, costs around 3-5M euros, which makes it roughly comparable to the aerostats. Its operational ceiling is at 6000 m, making its single sweep range also similar to the aerostats. However, the big difference compared to aerostats is payload. While the aerostats are able to lift several hundreds of kilos of payload, allowing for extremely sophisticated surveillance equipment, the ScanEagle is only able to lift a mere 3.4 kg. So, a ScanEagle operator needs to choose for every flight, if he wants to have daylight camera or an IR camera or a (miniature) SAR onboard.
Space based maritime surveillance. Satellites are the backbone of maritime surveillance of major powers. Advantages include the ability to monitor huge swathes of the earth's surface at every pass in high resolution (capable of small boat detection). Disadvantages are high cost and the limited number of daily passes. With six satellites on polar orbits, one can achieve twice-daily coverage on the Mediterranean latitudes (see picture 3). This still means that there is a 12 hour gap between each pass. So, in a hypothetical situation, where a boat is traveling from Libya to Croatia (c. 420 nm) at 20 kts, and incidentally departing just after the pass of the first satellite, we get a picture (with course and velocity information) of it when it's approximately halfway through its journey when the second satellite passes. And that's it. The boat will have reached its final destination in Croatia before the third satellite passes. The main capital costs of satellites consist of the device itself (200-400M euros a piece, off-the-shelf) and putting it into orbit (10-20M euros a piece with the current discount launch prices). In conclusion it can be determined that satellites are good for global, strategic maritime surveillance and looking at predetermined targets. For coastal border surveillance that requires real-time situational picture, the constellation would need to be so dense that the costs would be overwhelming compared to the other options.
Picture 3: Examples of coverage of different constellations of surveillance satellites on polar orbits. Source: Defence Research and Development Canada
Based on the above very brief and non-exhaustive research about different systems it appears that there is indeed a jack-of-all-trades solution to the coastal border surveillance question: a HALE UAV specifically designed for maritime surveillance, such as the MQ-4C Triton. However, when we factor in the cost, the picture becomes less clear. A definitive cost-benefit-analysis is impossible, with the lack of actual operational requirements and very limited cost information available on open sources. To reduce uncertainty, we will assume an operational requirement as follows: "Maritime surveillance system capable of providing sufficient surveillance data to enable a fully recognized maritime picture within the exclusive economic zones of the EU Member States, including the ability to detect small boats and low-flying aircraft, with as little overall life-cycle cost and environmental impact as possible". The second assumption is that the open source information about the system costs is accurate and up-to-date. Where there is no cost information (as often is the case with operating costs) we make a best guess estimate. The requirements call for a persistent real-time situational picture at low-cost with little effect to the environment. The cost and environmental aspects tip the scale in favor of the aerostats. But not only. A two tier system needs to be considered, because of the requirement of "a fully recognized maritime picture". Even though the aerostats can see far and in great detail, they do suffer from blind-spots because of islands, etc. Also, in certain weather conditions, with cloud cover or fog, while the SAR can still detect objects, another tool might be needed for identification of non-AIS targets. A tactical or an operational UAV would be the first-choice tool. They can be easily deployed on short notice to check up on targets of interest. The UAVs could be pre-deployed in the extremities of the surveillance spheres of the aerostats (picture 1) to handle identification tasks on call. If we would deploy two complete ScanEagle systems (eight airframes altogether) on average per an aerostat, the equipment to monitor the whole Mediterranean central basin would cost around 150M euros, roughly the cost of a single MQ-4C Triton, while still achieving sufficient coverage and low environmental impact.
Ilja Iljin
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