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10 st / June 2015 www.sea-technology.com for in-water targets, as well as in-water stabilization for both in-water targets and the seafoor. The auto-squelch may be overridden by the operator, if desired. The SonaSoft 3.0 software is easy to visualize, with each generation building upon the last. A 3D display is one of the standard views for operators. There is also the option to display a 2D slice at any bearing to be viewed at the bottom of the display, in a manner similar to an echosounder. How- ever, instead of showing a historical view, this shows the depth in front of the vessel, before one approaches the area. Another visualization technique that is employed is for the seafoor, which may be set for either color mapped to depth or color mapped to signal strength, depending on need. In regards to increasing the situational awareness, FarSounder has incorporated a chart overlay. Early on, the company incor- porated raster charts, then vector charts, followed by vector with IWT (in-water target) overlay, and now includes a full overlay, with both IWT and the seafoor below ahead of the vessel out to eight wa- ter depths. Jeppesen C-MAP Professional+ Database The charts used in FarSounder's plat- form come from the Jeppesen (Denver, Colorado) Professional+ database. Jeppe- sen Professional+ is a global vector chart database that seafarers have benefted from for years in ECDIS and ECS systems. The chart sources are based on offcial charts (both paper and digital). This ensures high chart quality, while also mak- ing sure the appearance of the viewed chart is similar to the ECDIS on board. This increases both safety and simplicity for the mariner. It also ensures that the data facilitate the full functionality of an ECDIS, and is an excellent training choice for navigators before switching from paper to ENC. Though many users are running a full ECDIS side by side with the FarSounder sonar, having basic chart plotting ca- pabilities built into the FarSounder software adds a lot to S ituational awareness is key for safe navigation. As more and more vessels operate in challenging environments, the risk of allusions with uncharted or wrongly placed ob- stacles and collisions with transient obstacles (such as ice and submerged shipping containers) increases signifcantly. Groundings on large underwater structures, such as rocks, reefs, sandbanks and shoals, are, unfortunately, signifcant risks for the mariner. Requirements in an FLS There are several important metrics to consider when designing a forward-looking sonar (FLS) system. The frst is 3D capability. The sonar should be capable of generating a 3D image and determining range, bearing and depth with a single ping. The next metric to consider is the cov- erage zone. To be an effective navigation tool, an FLS system must have a wide feld of view, be capable of detecting obstacles at navigationally signifcant ranges and also provide depth information. Next, in order to make quick decisions, the sonar must have a fast update rate. This means that the entire coverage zone should be updated with a single ping. Me- chanically scanned sonars, which build an image from multiple pings, take too long to be useful as a real-time navigation solution. Last, and most important, the image the sonar displays should be easy to un- derstand. In order to be an easy-to-understand and effective tool, particularly in real-time applications, the FarSounder (Warwick, Rhode Island) team focuses on three mantras when making design choices: simple controls, easy visual- ization and good situational awareness. FarSounder's State of the Art FarSounder's latest generation of sonar processing is no exception to this design process. As far as focusing on sim- ple controls, this latest processing includes an auto-squelch Software Advances in Forward-Looking Sonar Better Navigation, Situational Awareness via 3D FLS By Cheryl M. Zimmerman • Matthew J. Zimmerman • Paul Elgar A sonar being installed into an ice-hardened bul- bous bow.