FarSounder's Technology Blog
From time to time, FarSounder's development team likes to toot their own horn and tell the world about some of the cool things they are working on. We can't share all our secrets and development plans, but we can share some of the excitement that our engineers experience every day working for FarSounder.
When evaluating a diver detection sonar system, one of the most basic metrics to consider is threat detection range. To be effective, the system must provide underwater surveillance with good coverage out to a tactically significant range. Many diver detection systems advertise their maximum detection ranges. However, most of these ranges are under optimal acoustic propagation conditions. In reality, the local underwater environment can greatly affect the maximum performance of all types of sonar systems. To evaluate if a particular underwater intrusion system meets your needs, it is not enough to only understand what your minimum detection range requirements are. You must also determine if the system is capable of detecting an intruder at that range in real-world conditions. In this blog posting, we will explore how to determine such detection range requirements.
When the temperatures start to drop well below freezing, most of the boat traffic on the Narragansett Bay disappears. Even if we would prefer to stay indoors by a fire or head for warmer waters, the FarSounder engineering team continues on water testing new sonar innovations. Recently, a few of the team boat tested FarSounder's latest 3D forward looking sonar equipment: our new bulkhead mount Power Module and our new flat faced Transducer Module option for the FarSounder-1000 and SPS systems. Though setting up the equipment in the morning was quite frigid, we had beautiful calm waters, interacted with a pod of porpoises and spent a little time watching harbor seals bask on the rocks. We thought we'd share a little bit of a "typical" work day on the water.
FarSounder's engineers spend a lot of their time working with customers to understand their navigation sonar needs. We strive to design our 3D FLS products with a good balance of performance metrics. However, our systems are more than just hardware. The software display is an important component, too, and as the saying goes, "a picture is worth a thousand words". That's why we've invested heavily in our operator interface, making a system that is easy to operate and easy to understand. Let's take a closer look at some of these features.
As with many technical products, understanding the differences between navigation sonar products sold by different vendors can be confusing. Much of the technical product literature can be confusing with different companies assigning different meanings to similar terms. At trade shows, we are often asked "What's the difference between Company X's product and yours?" or "Which is a better? FarSounder's sonars or Company B's sonars?". We don't like to presume we know every detail about every sonar on the market. Rather, we believe that once a customer understands which metrics they should be considering they can easily choose the best "look ahead sonar" for them. For our customers' class of ships, we're confident that they will choose a FarSounder. In this blog posting, we'll take a look at what we feel are the most important metrics you should use to compare forward looking sonars: Coverage Zone and Update Rate.
When looking at our software's 3D Sonar display it is sometimes difficult to correlate what we see on the screen to what we see (or don't see) out the bridge window. However, many users are used to correlating what they see on a radar display, especially if they have a radar overlay on top of electronic nautical charts. In our continuing efforts to improve user experience, we've recently added chart overlay of in-water sonar targets to our software. This enables users to more quickly and easily make the jump from what they see on the sonar's display to where potential navigation obstacles are located.
Due to natural variations in fluid characteristics (such as water temperature, salinity and density) and the presence of small in-water reflectors (such as moving currents, marine life, and bubbles), the underwater environment is acoustically dynamic and often unpredictable. That’s why we at FarSounder have committed ourselves to building incrementally smarter tools to help keep our customers on the edge of technology and as far from harm’s way as possible. As a result, we’re happy to give a sneak peek of our most intelligent underwater collision avoidance system yet, capable of stabilizing in-water targets detected by the sonar and providing you with the most accurate representation of the water in front of your vessel to date. Our new stabilization feature relies on tracking in-water targets detected across multiple transmit/receive cycles (i.e. “pings”). By grouping these detections and monitoring their movements over time, we can use that information to both filter out unreliable targets, and fill in gaps where we are confident targets should be seen.
As more and more yachts choose expedition style itineraries, the risk of collision with poorly charted obstacles or wrongly placed obstacles (due to GPS malfunctions) increases significantly. Groundings with large underwater structures such as rocks, reefs, sandbanks and shoals are unfortunately significant risks for the adventurer. Having a navigation sonar installed which is capable of detecting such hazards at long range is important in these scenarios. More importantly, the detection range of the installed sonar should be suitable for the vessel. In this blog posting, we discuss how to calculate a suitable detection range for your ship's obstacle avoidance sonar.
Not all forward looking sonars are created equal. Most only produce a view of a single 2 dimensional slice. Some use scanning technology to build an image from multiple pings. Few employ 3D technology. FarSounder sonars are the only look-ahead sonars which produce a true 3-dimensional image at navigationally significant ranges. They do this with a single ping enabling a fast update rate. Clearly, range is an important metric. However, one number alone cannot fully describe a sonar's range capabilities. A navigation sonar should specify its range not only in terms of maximum detection range for a given in-water target size, but also maximum range at which it can map the bottom. This blog posting explains what drives this limit and how these same concepts can explain other “unexpected” echo reflections.
Throughout the centuries that man has taken to the seas, ship (and crew/passenger) safety has been a critical concern. In both known and unknown waters, groundings and collisions have cost the lives of countless souls. These accidents have significant economic impacts with loss of ships and cargo as well as environmental impacts due to oils spills and destruction of marine habitats. Over these centuries, incremental improvements to navigation have improved safety at sea. In particular, the 20th century saw huge leaps forward in safety technologies and regulations, saving lives, cargo, and ships. In today's world, one would not even think of operating large vessels without the use of radar, depth sounders, ECDIS, and/or electronics charts with GPS. But still these technologies are missing an important piece of information. They can't tell the ship operator what is under the water in front of the ship right now. FarSounder navigation systems provide this missing piece of the puzzle. They detect sand shoals, rocky shores, ice, coral, and whales - things that passenger ships (or any ship) should never touch.
When considering one of our forward facing navigation or diver detection sonars, customers are often curious about the sonar's impact on the performance of their vessel. Most people are familiar with the general concepts of streamlining with reference to their car. Such effects when operating in air are described by the vehicle's aerodynamics. Similar effects as they relate to ships and boats traveling through water are called hydrodynamics. In this blog posting, we'll be discussing the general concepts that should be considered with evaluating the hydrodynamic impact of a particular installation.