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Simrad FM90 System description

The Simrad FM90 is a third-wire Multibeam Trawl Sonar. It allows for accurate and efficient monitoring of the net opening, the catch situation, and the fishing conditions.

The FM90 has a fast refresh rate that allows you to view the sonar images in real time. The FM90 enables use of your existing PI/PX catch monitoring sensors. It operates equally well in the water column and close to the bottom.

The FM90 Multibeam Trawl Sonar offers many advantages over conventional mechanically-scanning trawl sonars in most applications. However, it is not a complete replacement in some applications. We recommend the FM90 mainly for surface, pelagic, and semi-pelagic trawling on soft bottom. For bottom trawling and trawling on hard bottom we recommend the FS70 Trawl Sonar.


The FM90 Sonar communicates with the vessel by means of a third-wire system using very high bit-rate digital subscriber line (VDSL2) communication, transmitting real-time images of the net opening at rapid refresh rates. In addition, an echo sounder looking up ("up sounder") monitors fish escaping over the net, while another echo sounder shows the foot-rope, the sea bottom, and the fish entering the net.

By means of the submerged Trawl Unit, the FM90 communicates with a number of Simrad PI/PX 40 kHz catch monitoring sensors by means of hydroacoustic links. Up to six measurements can be made simultaneously. Standard pitch, roll, depth, and temperature sensors are also built in to the Trawl Unit.

The FM90 is a solid-state sonar system. This design eliminates moving parts, and increases reliability and availability during fishing operations. The FM90 is backed by the product warranty and global service network offered by Simrad.

The FM90 is a unique sonar, both in design and functionality. When the FM90 sonar pings, it sends out sound energy in a 240-degree sector. This energy is reflected from the net, from fish, and from other targets in the water column. The reflected energy is received by the transducer, processed, and shown on the display. Because the FM90 pings across a wide area in one ping, the refresh rate to generate a picture of the net opening is almost instantaneous. This gives you real-time images, allowing you to adjust to very fast movements of fish schools.

The FM90 uses an updated version of Kongsberg Mesotech's tried and tested M3 Sonar® multibeam processing software, successfully deployed world-wide for many years. The software uses innovative processing algorithms to automatically optimize the image quality specifically for fishing applications. It includes FM transmissions (also known as "Chirp") to ensure a clutter-free picture with a very high resolution in range.

The FM90 Processor Unit is controlled by the Microsoft® Windows® operating system. This allows for a flexible choice of presentation modes, and for a large range of user applications.