ULISSES

The Ultra Light SonicS Enhanced System, ULISSES, is a lightweight acoustic system developed by Leonardo. ULISSES is designed for use in anti-submarine warfare (ASW) and maritime patrol missions onboard aircraft including fixed or rotary wing, uncrewed aerial vehicles (UAVs) or naval platforms. Leonardo bills ULISSES as the only such system capable of integration on small remotely controlled aerial platforms such as the Leonardo AWHERO.

When in operation, ULISSES collects multistatic acoustic information from sensors such as sonobuoys and sonars, processing the data on an operator console installed on an aerial or naval platform while providing real-time audio and video signals through the Leonardo Wide Band Data Link (WBDL) at rates up to 45 Mb per second. It can process data from a wide range of sonobuoys, with a capacity of up to 64 sonobuoys.

A target library allows ULISSES to reduce operator workload through simultaneous automatic detection and tracking of multiple targets and passive signature classification. The system can also be made fully remote, integrating ULISSES data with information on a ship or land-based command center.

The ULISSES system is comprised of an acoustic sonobuoy processor (UAP) with an embedded data recorder, a common function transmitter (CFT) and a digital very high-frequency (VHF) receiver. The system’s VHF receiver can be configured with a sonobuoy localization system (SLS) or without. Leonardo designates the VHF fitted with SLS capabilities as SDSR, and that without as SWAP. The ULISSES processor card can also be integrated with Leonardo’s Telemachus transmitter/receiver.

The acoustic processor unit (UAP) performs both the system’s active/passive and audio processing, tracking algorithms as well as localization and classification of targets. The UAP features embedded data recording, video processing, and audio capabilities for two operators, ensuring efficient data management and analysis. Multiple mission computer interfaces, active and passive energy maps and a geographical map improve operator situational awareness. The UAP features autoalert processing and a command generator for active sonobuoys. Furthermore, the UAP enables selectable parameter management (CFS and CSG) for sonobuoy operations, allowing operators to customize settings for various operational scenarios and environments.

The system’s common function transmitter (CFT) is a dedicated component for ultra-high frequency (UHF) downlink to sonobuoys. The component is capable of measuring incident and reflect power at output and filtering output. A linear power amplifier operates with a gain of 50 dB. CFT software is programmable by ethernet.

The VHF receiver features a 99-radio frequency (RF) coverage capability and a 32-acoustic channel output using Gigabit ethernet. The receiver provides a single VHF antenna input, ethernet digital output, an integrated test signal generator, GPS sonobuoy support and a sonobuoy downlike in conjunction with the ULISSES CFT. When fitted with SLS capability (SDSR) the receiver can provide robust optimal digital telemetry reception, anti-RFI and anti-shading measures, continuous signal strength updating and channelization to any of the 99 RF frequencies. The SDSR is designed to process sonobuoys within the standard range of 136 to 174 MHz. The system has self-cooling properties and requires a voltage of 115 VAC, and 400 Hz of single-phase AC power for operation. Options are available for sonobuoy homing and an on-top position indicator (OTPI).

The system is capable of sound velocity profile and environmental noise measurement. It is provisioned with two sets of video interfaces supporting both DVI (Digital Visual Interface) and VGA (Video Graphics Array) connections. Additionally, ULISSES features two independent stereo audio interfaces.

ULISSES is compatible with sonobuoys including LOFAR, WIDEBAND LOFAR, DIFAR, VLAD, BATHY, HIDAR, ALFEA, CAMBS, LFA, ANM, DICASS.

In service.

The ULISSES acoustic system was developed by Leonardo based on the company’s experience with the OTS-90 sonar installed on the Netherlands’ NH90 helicopters. Leonardo announced the development of the ULISSES system as a partnership with Ultra Electronics and L3 Technologies at the July 2018 Farnborough Airshow. Ultra would provide the miniaturized sonobuoys and multistatic technology, while L3 would contribute the dipping sonar given its experience with the HELRAS DS-100 and FireFly systems. The three companies would work to develop an acoustic sensor suite built around the ULISSES.

On Nov. 14, 2019, Leonardo reported that the ULISSES had been successfully used in a live trial off the coast of Italy. ULISSES was used to detect a number of simulated undersea targets including Ultra Electronics sonobuoys deployed from a ship. Leonardo’s press release stated that development would be completed by the end of December, with production beginning in 2020.

The company announced the ULISSES was successfully developed and ready to enter production on April 10, 2020.

The Italian Navy’s fleet of SH90 helicopters was upgraded with the ULISSES system in 2020, with the installation concluding in August.

In late 2020, a demonstration took place involving the installation of a single-processor ULISSES on a ship in La Spezia along with an L3 FireFly dipping sonar, Leonardo announced on Jan. 12, 2021. During this trial an Italian navy SH90 helicopter launched three sonobuoys, a bathythermal sensor and two DIFAR passive detectors into the water. During the test the sonobuoy’s processor card was integrated into the underwater sonar processor, reducing the system’s weight by approximately 15.0 lb (7.0 kg). Once the sonobuoy range and sonar had been set, transmission of the impulses generated by the different frequencies detected by the sensors began. The acoustic information was then collected and processed by the operator console on-board the ship, before being sent to shore in real-time with audio and video signals over the WBDL system (Wide Band Data Link).

European Defense Review reported on Oct. 1, 2021, that Leonardo had privately revealed the ULISSES had a launch customer. A deal was reportedly made at in September 2021 at the Seafuture naval show at the La Spezia naval base. The client’s details and contract information were not disclosed.

Leonardo announced on May 25, 2023, that the company had inked a contract for the two ATR 72 maritime patrol aircraft at the LIMA 2023 international defense exhibition with the Malaysian Ministry of Defense. The aircraft would be equipped with the ULISSES acoustic system.

Leonardo S.p.A, Rome, Italy

 Italy
   Navy
      helicopter           (SH90)

 Malaysia
   Navy
      patrol               (ATR 72)

 WEIGHTS
   Acoustic Processor      16.5 lb (7.5 kg)
   Common Function Transmitter
                           10.0 lb (4.5 kg)
   Receiver w/o SLS (SWAP)
                           15.0 lb (6.8 kg)
   Receiver w SLS (SDSR)   57.3 lb (26 kg)

 DIMENSIONS
   Length
      acoustic processor    0.71 in (17.9 cm)
      common function transmitter
                            9.72 in (24.7 cm)  
      receiver w/o SLS (SWAP)
                            5.85 in (14.9 cm)
      receiver w SLS (SDSR)
                           11.54 in (29.3 cm)
   Width
      acoustic processor    6.65 in (16.9 cm)
      common function transmitter
                            5.12 in (13.0 cm)
      receiver w/o SLS (SWAP)
                            4.88 in (12.4 cm)
      receiver w SLS (SDSR)
                           17.72 in (45.0 cm)
   Height
      acoustic processor   12.07 in (30.7 cm)
      common function transmitter
                             5.0 in (12.7 cm)
      receiver w/o SLS (SWAP)
                           12.75 in (32.4 cm)
      receiver w SLS (SDSR)
                           10.59 in (26.9 cm)

 SENSORS/ELECTRONICS
   Voltage                 115 VAC, 400 Hz