Software Defined Sonar

World Leaders in Software Defined Sonar®

Many sonar systems are obsolete and cannot support the changes needed to adapt to new threats. Solutions to obsolescence typically involve replacing rather than modifying the existing systems, which is an expensive option. To lower this risk and expense, Marport C-Tech has designed and developed Software Defined Sonar - a multimode sonar technology that uses reconfigurable embedded signal processors to provide the features needed for next generation underwater surveillance and communications.

Being a genuine broadband, multimode system, Software Defined Sonar is not restricted to operation on a single frequency or proprietary transducers. As such, it can serve a wide variety of legacy sonar applications and can support rapid development and deployment of novel sonar solutions.

Unlike fixed function hardware designs, the software-centric architecture can be dynamically reconfigured for multimode sonar functions. Significant amounts of acoustic signal processing, including adaptive beam-forming, are done in software rather than dedicated hardware.

The system increases underwater tactical capability, improves functionality, enhances signal processing and substantially reduces costs - all while replacing racks of legacy sonar equipment.

Software Centric Architecture

The electronics package incorporates transceiver modules called “sonar blades”. The base module has 16 transmit (TX) and 16 receive (RX) channels and can be expanded to hundreds of TX/RX channels. The base module measures 12L x 12W x 16H cm, with each additional sonar blade measuring 12L x 12W x 5H cm. Multiple sonar blades can be operated synchronously to support a significantly higher number of channels.

The broadband transceiver can be dynamically tuned from 1 kHz to 1.25 MHz. The modular design significantly reduces the size, weight, power and cost of electronics on both legacy and future sonar platforms. The electronics utilize the latest FPGA and DSP technologies and are designed with commercial-off-the-shelf (COTS) components. The transceiver enables frequency-diverse waveform generation integrated to an open architecture signal processor with embedded wideband analog-to-digital converters for real-time data acquisition and processing.

It also interfaces to commercial navigation systems and sensors for vessel motion and attitude compensation. All sonar data can be linked to geospatial information or combat control systems, including undersea battlespace networks, such as Cooperative Engagement Capability.

The transceiver features a programmable FPGA for broadband signal processing and filtering in the digital domain. The FPGA core implements high-speed digital up and down conversion, data formatting and time stamping, and high-speed transport between the FPGA and host processor.

Marport uses the latest generation FPGA from the XILINX® VIRTEX 5 family. The FPGA incorporates embedded high performance DSP blocks that are ideal for filtering, FFT, correlation, modulation, etc. The FPGA delivers filtered and prepared data to the embedded PC for mathematical processing. It can also emulate a 32 bit microprocessor, which enables it to run practically any type of firmware. The architecture incorporates a commercial-off-the-shelf embedded PC with a Linux real time operating system to process and store sonar data.

The PC communicates with the FPGA on a Marport developed transport protocol and provides data I/O via TCP/IP networking. The interface provides high speed data flow between analog inputs, processing elements, and analog outputs. The standard provides for multiple interfaces to share the same cable, allowing synchronous data transfer between high channel count (multiple board) data acquisition systems and processing elements.

The PC incorporates Giga-Ethernet and USB for interfacing to other 3rd party sensors. The design also includes a spare embedded PC for external applications such as a Mission Control Unit for actively controlled underwater vehicles.

Software Defined Sonar System Architecture