This article reviews current and future developments in the field of naval sonar, with specific focus on sonar markets, drawing on proprietary data from naval market experts AMI International. It begins by looking at the current state of sonar fit in the world’s naval forces, presenting information on the four main types of naval sonar: hull-mounted, towed array, variable depth, and flank array.
Next, the article examines prospects for the naval sonar market in the coming two decades, using AMI’s detailed forecast of future markets for ship and submarine-mounted sonars. Finally, it reviews recent technological, operational and acquisition developments in naval sonar that suggest how this key naval capability will further evolve in its second century of service.
Introduction
It has been just over 100 years since the sonar became practical as a remote sensing device for naval operations. Sonar remains a primary means to detect and localise underwater objects of tactical interest—most prominently submarines. The state of the sonar art has accelerated in the last two decades with technological advances in two main areas—information technology for signal processing, and materials science affecting most components of sonar systems. Taken together, these technology drivers have increased the effectiveness and reduced the size, weight, power and cost of sonar systems.
These technological advances in sonar systems come at time when the options for platforms to deploy sonars are expanding. Notably, unmanned maritime systems (surface and underwater vessels) are emerging as more effective and longer range platforms with sufficient space and power to mount some sonar sets. Equipped with better sonars, USVs and UUVs promise to further complicate the already challenging business of operating submarines at sea undetected.
Current Market Scope – Ships in Service
The AMI Existing Ships Data Base (ESDB) identifies almost 4000 sonars now in service in all navies around the world. The four different sonar types installed on ships or submarines now in service are hull, towed, varable depth, and flank (submarine).
Breaking down the percentages for all sonar shows that the hull type is most numerous, representing almost 60 per cent of all types of sonars (2348 of 3990 sets) on ships and submarines now in service (all ages). Towed array types are next most common, making up over 20 per cent (819 of 3990 sets).
A look at the current fit for the most modern ships and submarines, those commissioned since 2000, shows 1,462 sonars in service, or 36 per cent of total world naval inventory. This suggests that,with over 2/3s of current sonar on ships and submarines over 20 years old, modernisation will only grow in importance when looking at market activity for sonar systems.
Another observation is that towed sonars are more numerous than hull sonars on more modern ships as a percentage (44 per cent compared to 35 per cent). This highights the development of towed arrays as especially suited for detecting modern submarines at extended ranges. As noted above, the growth in towed array systems has been aided by reductions in their size and weight, and improvements in signal processing.
The chart above provides a regional assessment of the existing sonar market on ships commissioned since 2000. The Asia Pacific region has the largest share of the current hull and towed array segments, reflecting the more general increase in naval spending on new ships in the area over the past two decades. About 50 per cent of all hull and towed sonars globally are equipping Asia-Pacific navies.
NATO navies (excluding the US) and the US Navy remain heavily invested in sonar capability, with the two areas accounting for between 30-40 per cent of hull and towed sonar worldwide. The other regions of the world make up the difference, with Russia and the MENA region leading the rest of the table. The paucity of sonar equipment in navies of the Caribbean/Latin America and Sub-Saharan Africa regions is explained both by the more limited numbers of submarine targets found in those regions, and constraints on overall naval ship-building budgets.
Future Market Scope
AMI’s World Naval Projections Report (WNPR) forecasts new naval ship and submarine contruction worldwide through 2041. This two-decade forecast segments the sonar market into the same three types of systems: hull, variable depth and towed array. Hull-mounted sonar on both surface ships and submarines are the most numerous in the forecast, with over 1100 systems of that type projected to be acquired.
This represents just over half of the future market for the 20 years period, with variable depth and towed array sonars combined making up the other 45 per cent of the market. Since more than one sonar can be fitted to a ship or submarine, the 1100 sonars in the table above represent installation on a fewer number of ships.
Ship construction contracts, and their system fits, are concentrated in the nearest 5 years period out to 2026. This pattern helps explain why future sonar acquisitions in the data are “front-loaded,” with about 35 per cent of forecasted sonar acquisitions found in the 2021-2026 period. The chart below examines estimated future sonar buys for this period, and compares the percentages and trends for each of the three types to numbers for the 20-year period.
The near term market forecast for sonars is representative of the longer term projections. Breakdowns by market subsegment in that five year period shows patterns similar to the 20-year forecast: just over 50 per cent of the near-term market is for hull-mounted sonars, just under 30 per cent for towed arrays, and close to 20 per cent for variable depth sonar.
Supplier Positions
Germany’s Atlas Elektronik and French-Dutch Thales are the leading manufacturers of sonar on the European side of the market, representing 18 per cent and 25 per cent (respectively) of the market represented by 576 sonar sets equipping navies outside Russia, China and other non-addressable markets such as Iran and North Korea. Norway’s Kongsberg (including ex-Simrad) British companies BAE and Ultra also make up a notable part of this market segment.
On the US side, Lockheed Martin and Raytheon Technologies have the strongest position in the US market. Both European and US companies also compete effectively in the sonar export market.
Recent Developments
As noted above, the joining of sonar and unmanned maritime platforms offers budget-constrained navies some promising alternatives in fielding more effective anti-submarine warfare systems. As noted in a recent US Naval Institute article, NATO’s Centre for Maritime Research and Experimentation continues to organise exercises and tests of this approach.
Exercises such as the DYNAMIC MANTA event continue to offer a venue for novel combinations of new sonar and unmanned host platform capabilities. While the unmanned platform is not likely to replace manned multi-mission surface combatants or submarines as the leading choice for new sonar deployments, they promise to contribute to the ASW mission (and anti-mine or other barrier defense applications of sonar).
Deployment of sonar in fixed acoustic arrays linked to the shore is another proven operational configuration being tested for new sonars. The US Navy’s Office of Naval Research is seeking solutions for the Affordable Mobile Anti-Submarine Warfare Surveillance System (AMASS). The goal of the programme is to field “persistent, deep water, active ASW [anti-submarine warfare] system that can detect new emerging threat submarines at extended ranges.”
The Naval Research Lab is also exploring low-frequency broadband (LFBB), an active sonar using advanced synthetic aperture processing drawing on advances in artificial intelligence (AI). The ability to extract even more tactically and operationally significant information from low frequency returns using advanced information technologies will prove critical for detection and classification of submarine targets.
Existing sonars are also seeing investments to upgrade their performance. Pennsylvania State University’s Applied Research Laboratory is working with the U.S. Navy’s Surface Warfare Centers in Crane, Indiana and Newport, R.I. in areas that include sonar development. Tests include the work on the TR-343 transducer, a core component of the AN/SQQ-89(V) undersea warfare combat platform now equipping US Navy DDG-51 destroyers. This work is taking place under a 10-year US$2.1Bn contract awarded in 2018.
