The Simrad ST90 is a long range and low frequency fish finding sonar with a 360 degrees coverage. The ST90 is designed for medium and large sized fishing vessels.
If high performance is your number 1 criteria when choosing a sonar; such as long range, high resolution, narrow beams andhigh source levels, this is your natural choice. We made no compromises during the design of the ST90. Our goal was simply to make the ultimate high performance fish finding sonar. With the Simrad ST90, we use lower frequencies than the SX90 and SU90 sonars.
In order to achieve this, a completely new transducer has been designed. Each element is larger than the SX90 and SU90 elements, but the number of elements is the same as the SU90. This allows for the same narrow beam, and ultimately alonger range. The ST90 has been designed to search with very long ranges in all weather and sea conditions. Whether it is heavy weather, hard bottom, open waters, weak targets - all echoes are handled by the sonar due to the fully stabilized and very narrow beams combined with the cutting edge signal processing.
The centre operational frequency is 19 kHz, but you can select any operational frequency from 14 to 24 kHz in steps of 1 kHz. The cylindrical multi-element transducer allows the omnidirectional sonar beams to be tilted electronically from -10 to +84 degrees. This allows you to automatically track schools of fish, and to observe the whole water volume around the vessel.
The narrow beam opening angle (6.5° @ 17 kHz) and the high source level makes the ST90 a very powerful and high resolution low frequency sonar. The narrow beams provided by the ST90 give you several advantages.
- They increase the range and resolution, and offer a vertical view with additional details and a clearer picture.
- They make the ST90 even more ideal when you need to search for fish close to the sea bottom, or close to the surface, at long ranges.
- They provide a far better vertical view with less "bottom climbing" that what is seen on sonars with a wider beam.
- The narrow beams also decrease the noise level.
It is common for sonars to require many pings to build the various views in the echo presentation. These sonars may for example need one ping to build the 360 degrees omni view, and then several additional pings to fetchthe echoes for the vertical views. On the ST90, all the sonar views in the presentation are built using the echoes from one single ping. This dramatically improves the update rate and provides better real-time information.
By providing a number of standard interface lines, it is easy to comunicate with peripheral devices and sensors. Typical inputs are geographical information from a positioning system, vessel speed and current heading. By default, the sonar uses a built-in motion sensor. For improved operational accuracy, an external motion reference unit (MRU) can be connected.
The echo presentations are optimized for multiple displays. Provided that you have connected additional displays to your Processor Unit, you can use the Docking Views function to take any sonar view and place it on a separate display. When you move a view to another display, it will automatically be scaled for the best possible result.
It is common for sonars to require many "pings" to build the various views in the echo presentations. We build the presentation using the echoes from one single ping. This dramatically improves the update rate and provides better real-time information.
You can record real-time sonar situations. This allows you to replay complete sequences. The playback contains the exact same echo information, and can be used for mission history, training or troubleshooting purposes.
Compared to our previous sonars, the tracking function has been improved. It can now use echo information from both the horizontal and vertical transmissions.
Great emphasis has been placed on an intuitive user interface and the best possible sonar presentations on a high resolutioncolour display.
The sonar is equipped with our celebrated signal processing software. This includes Hyperbolic FM (HFM) transmissions. This pulse type is also known as "chirp". It ensures a clutter free picture with very high resolution in range. The signal processing and beamforming is performed in a fast digital signal processing system using the full dynamic range of the signals.