The FM90 is a third line multibeam trawl sonar. It can accurately and efficiently monitor net mouth distance, catch status and fishing environment.

FM90 updates quickly and can view sonar images in real time. FM90 can also be used with existing PI/PX fishing monitoring sensors. It works equally well in a column of water and near the bottom of the sea.

In most applications, FM90 multi-beam trawl sonar has many advantages that traditional mechanical scanning sonar does not have. However, it can not completely replace the traditional sonar in some applications. We recommend that FM90 should be used primarily for surface, middle and middle-like trawling on soft soles. For bottom trawling and hard bottom trawling, we recommend using FS70 trawling sonar.

The FM90 sonar USES a third cable to communicate with the ship, using very high bit rate digital wire (VDSL2) communication, which transmits the network port image in real time at a fast update rate. In addition, an upward-facing echolometer (" echolometer ") monitors the fish as they escape from the net, while another echolometer shows the fish as they enter the net, the ocean floor and the fish.

Using submerged trawling units, the FM90 communicates with a large number of Simrad PI/PX 40 KHZ fishing monitoring sensors using a hydroacoustic chain. Up to 6 measurements can be obtained simultaneously. Standard pitch, roll, depth and temperature sensors are also built into the trawl unit.

FM90 is a solid state system. The design removes moving parts and enhances the stability and practicality of the system during fishing operations. The maintenance of the FM90 is supported by Simrad's worldwide network of services.

In terms of design and functionality, the FM90 is a very special sonar. When FM90 sonar fires a ping, the sound energy is transmitted outward in a 240-degree sector. Sound energy returns from nets, shoals of fish, and other objects in the water column. The returned energy is received by the transducer, processed and displayed on the display. Since a ping of the FM90 traverses a wide area, the update rate of the resulting network port image is almost instantaneous. Real-time images can be obtained, and the fish can be quickly adjusted as they move very fast.

FM90 USES Mesotech's updated M3 sonar multibeam processing software, which has been successfully deployed around the world for many years. This software applies innovative processing algorithms to automatically optimize image quality, especially for fishing applications. The FM90 also includes an FM emission (also known as "chirp") that ensures high-definition images at range.

The FM90 processor is installed with Microsoft's Windows operating system. Display mode selection is very flexible and has a large number of user applications.