Unmanned Systems Maritime Search and Rescue

On October 1, 2015, the U.S. Flagged El Faro went missing as it traveled from Puerto Rico to Jacksonville, Florida.  Onboard was its crew of 33, who were all presumed dead.  At the time of its trip Hurricane Joaquin, a category 4 storm, threatened its route back to Jacksonville.  During the trip the ship went missing, when its main propulsion failed stranding the crew in the path of the storm.

The U.S. Navy used an unmanned underwater vehicle (UUV) called CURV 21 which was able to locate and identify the sunken El Faro, (Almasy, 2015).  The CURV 21 is a 6,400 poubd UUV capable of reaching depths of 20,000 feet.  It uses a “.680 fiber-optic umbilical cable and a shared handling system that can switch at sea between side-scan sonar and ROV operations” (CURV 21 - REMOTELY OPERATED VEHICLE, 2015).  Among its exteroceptive sensors is found a side-scan sonar, CTFM sonar, high resolution still camera, and black and white and color video cameras (CURV 21 - REMOTELY OPERATED VEHICLE, 2015).  Its proprioceptive sensors include an electronic gyrocompass, attitude and heading reference unit, 1200 kHz Doppler velocity log, and 200 kHz altimeter.

The CURV 21 could benefit from the loss of the umbilical, however this umbilical is required due to the amount of data that must pass to and from the remotely located operators.  Currently underwater wireless systems would not allow the CURV 21 to operate at depth of 20,000ft.

With the declining prices of small unmanned aerial systems (sUAS), these systems are finding their ways in to search and rescue as well.  “In the vast wilderness of the Everglades, the SAR operations are often conducted in remote areas accessible by boat or aircraft,” (Safety, 2016).  In a search and rescue environment time is of the essence and sUAS give support teams the ability to quickly launch air assets to begin the SAR process.  The relatively flat area of the everglades would help to keep operators with in visual line of sight (VLOS); remaining VLOS is a current restriction imposed by the Federal Aviation Administration (FAA) of sUAS usage.   Unmanned Surface Vehicles (USV) could also be used to access areas covered by trees or inaccessible by boat.  Additionally, the use of USVs can keep searchers in one central area without the possibility of losing a rescue member or exposing rescuers to dangerous wildlife such as snakes, alligators, and mosquitoes.  While this is not the same environment where the El Faro sank, the benefits of a multi-sensor search and keeping all of the searchers in one area could be beneficial.

Sensor suits of sUAS and UUVs can be similar, but are often used differently.  For example, a camera on a sUAS or on a larger UAS often serve as a long range and short range visual cues.  However on a UUV, light does not penetrate the water as well and built-in lights only have a limited range, thus the cameras are used in close up viewing.  RADAR and SONAR work in similar ways as an exteroceptive sensor, however this is the primary way an UUV is able to see underwater, and would most likely be a tertiary way for the UAS to see.

Platforms in the air, surface (ground and water), and underwater can work together to make search and rescue efforts executed in a timely fashion and centralizing all information.  While collaboration will be key in unmanned operations, this also holds true in the realm of people and sUAS products.  For example an all-volunteer group called Search With Areal Rc Multirotor (SWARM), who has, “over 1,100 SAR Drone Pilots dedicated to searching for missing persons. Our primary mission is to offer and provide multi-rotor (drone) and fixed wing aerial search platforms for ongoing Search and Rescue operations at no cost to the SAR organization or to the family,” (Search With Aerial RC Multirotors (SWARM), 2016).  Through continued advances in sensor technology, all missions of unmanned systems will continue to benefit.

References

CURV 21. (2016 Jun 7). Office of the Director of Ocean Engineering Supervisor of Salvage and Diving. Retrieved from http://www.supsalv.org/00c2_curv21Rov.asp?destPage=00c2

CURV 21 - REMOTELY OPERATED VEHICLE. (2015 Nov 13). US Navy. Retrieved from http://www.navy.mil/navydata/fact_display.asp?cid=4300&tid=50&ct=4

Safety. (16 Feb 2016). Everglades National Park, Florida. National Park Service.  Retrieved from http://www.nps.gov/ever/getinvolved/supportyourpark/safety.htm  

Search With Aerial RC Multirotors (SWARM). (16 Feb 2016). SAR Drones. Retrieved from http://sardrones.org/

Almasy, S. (2015 Nov 2). Sub with camera to dive on sea wreck believed to be missing ship El Faro. CNN. Retrieved from http://www.cnn.com/2015/11/01/us/el-faro-search/