Govt. Agencies & Military

Utilize Side Scan Sonar


 

Wilmington Office of Emergency Management first responders
with JW Fishers SSS-100K/600K side scan sonar.
Inset - European military officers with their Fishers side scan.   
 

  Many fire and police departments consider side scan sonar an essential piece of equipment for their pe teams.  Side scan is the ideal tool for search and survey operations because it produces detailed images of the underwater environment regardless of water clarity. In addition, the sonar is able to search large areas quickly, scanning several hundred feet of ocean, lake, or river bottom with each pass of the boat. The acoustic beam reflects off any objects lying there and the data is sent topside where vivid color images are displayed and stored on a laptop computer. Side scan can easily locate a variety of targets including sunken boats, submerged vehicles, and drowning victims. 
  The sonar saves hours of search time and dramatically increases the safety factor. Towing a side scan over an area produces a detailed map of the underwater terrain so pers know exactly what’s down there before entering the water. Even in zero visibility the images can be almost photographic quality. Some sonars also allow vertical structures to be scanned by rotating the angle of the transducers on the towfish. This means a team can survey the face of a dam, seawall, pier, bridge support, or ship’s hull to look for damage or any “unnatural” device like an explosive that may have been attached to the structure. A significant number of state emergency management agencies and sheriffs departments have received homeland security grants to acquire this equipment to aid in the protection of ports and crucial infrastructure. 
 One of the agencies employing side scan sonar is Wilmington Delaware’s Office of Emergency Management. Director George Giles says the agency coordinates the efforts of all city departments to ensure a fast response in the event of an emergency. The agency’s first responders include members of both fire and police departments. The team works hard to keep communications networks, transportation systems, infrastructure facilities, and vital public goods and services flowing. They were put to the test in 2012 when Superstorm Sandy battered the US east coast causing more than $68 billion in damage and claiming the lives of 268 people. Having JW Fishers SSS-100K/600K side scan allowed the team to search for missing persons, survey canals and waterways choked with debris, and inspect support structures of the many bridges crossing over waterways.
 Another agency using sonar for infrastructure inspection is the North Carolina Department of Transportation which has vast responsibilities, including maintenance of the state’s 12,712 bridges. NCDOT purchased Fishers SSS-600K with adjustable transducers, which makes it possible for the sonar to scan vertical structures. With this capability the DOT can inspect the supports of any bridge that crosses over water, or survey an area prior to the construction of a new bridge.  Owning the sonar allows the department’s engineers to perform inspections at a moments notice, instead of waiting for a contractor. Other key features of their system are a Splashproof computer, handy to have when operating the sonar from a small open boat, and mapping software which shows the track of the boat moving over the search area and the swath being scanned.     
  Military units around the globe, including the US Naval Explosive Ordinance Disposal Technology pision, are finding a variety of applications for side scan. The pision traces its origins back to WWII when there was an urgent need for countering advanced weapons systems of other nations. Current global events and evolving threats have reemphasized the importance of their mission for homeland defense and our on going military efforts. EOD technicians are deployed worldwide and tasked with neutralizing unexploded ordnance of any kind. Countering these threats requires they have quick reliable access to a broad range of tools and information. NAVEODTECHp determines which equipment and procedures are most effective for ordnance location and disposal. One instrument identified as extremely useful is side scan sonar, and the pision purchased several of JW Fishers SSS-600K sonar systems for this work. The 600K can scan a swath up to 150 meters with each pass of the boat and provides the high resolution necessary to identify small objects on the bottom, or in the water column. A number of European military units have also purchased Fishers side scans for similar operations.
 A  few of the many other teams using Fishers side scan sonars are Dong Huan Firefighting Company in China, Yell County Office of Emergency Management in Arkansas, Placer County Sheriffs Dept in California, the Brazilian Navy,  the Rockland County Sheriffs Office in NY, Union Fire Company in Pennsylvania, Livingston Parish Office of Homeland Security in Louisiana, Argentina’s Perfectura Naval - similar to US Coast Guard, Wheeling Police Dept in West Virginia, Miami-Dade Police Recovery Unit and Franklin County Sheriffs Dept in Florida.
 For more information on JW Fishers complete line of underwater search equipment go to MailScanner has detected a possible fraud attempt from "jwfishers.us1.list-manage1.com" claiming to be www.jwfishers.com.

JW Fishers Side Scan Sonars

  JW Fishers sonars offer a number of advantages over other low cost side scan systems. Some of these are; a larger towfish for greatly increased stability of the transducers, sophisticated software, the ability to have two sets of transducers in one towfish, and the capability to operate with cable lengths up to 1,000 feet. feet.
   The quality of the images produced by any side scan system is directly related to the stability of the platform that moves the transducers through the water. Many low cost side scans have a small towfish. The drawback of a small fish is that it can easily be tossed about by underwater currents or affected by movement of the boat due to wave action which can be transmitted down the cable. This leads to poor quality images from the unstable movement of the fish. Fishers four foot long towfish provides an extremely stable platform for the transducers. The fish moves through the water like an arrow through air, which produces high resolution images.
  The quality of the software, which is the "brains" of a sonar system, is another feature that differentiates Fishers side scan from other low cost systems. Fishers SONAR VIEW software has a vast array of features that gives the operator tremendous versatility in displaying and manipulating the sonar data coming up from the towfish. In addition, optional mapping software allows the operator to see the track of the boat as it travels over the search area and the size of the area being scanned, ensuring no part of the search area is missed. During playback the track can be overlaid onto a nautical chart showing the exact location of the search operation.
  Many low cost side scan systems are available in only one frequency, or have different towfish for different frequencies. To change frequencies requires "reeling in" one towfish and then deploying another, an arduous and time consuming operation.
  JW Fishers offers three frequencies; 100K, 600K, and 1200K. Side scans are available in either single or dual frequency, with the customer selecting which frequency or frequencies they require. In Fishers dual frequency side scan there are two sets of transducers in one towfish. This allows the operator to quickly and easily switch between frequencies at any time during operation. Lower frequencies have longer range, but lower resolution, Higher frequencies have a shorter range, but higher resolution. 
  The typical ratio of cable length to tow depth is 4 to 1. This means to tow the side scan fish at a depth of 100 feet requires 400 feet of cable. Some low cost systems have a limited length of cable they can operate with. Fishers sonars can work with cable lengths up to 1,000 feet. This means they can be towed at a depth of 250 feet. When coupled with the optional DDW-1 deep pe wing, Fishers side scans can be towed at depths up to 500 feet, which is beyond the depth capability of many of the small systems.