Katie Sard: A Brief History, and the “Simple” Science of Sonar, August 9, 2013

NOAA Teacher at Sea
Katie Sard
Aboard NOAA Ship Rainier
July 29-August 15, 2013

Mission:  Hydrographic Survey
Geographical Area of the Cruise:  Shumagin Islands, AK
Date:  August 5-8, 2013

Weather Data from the Bridge:
GPS location:  54°49.402’N, 159°33.182’W
Sky condition: Overcast (OVC)
Visibility: 5 nm
Wind: 210 true, 15 kts
Water temperature: 8.3°C
Air temperature: 11.0°C

Science and Technology Log

While I was speaking with ENS Rosemary Abbitt, a Junior Officer on board, she used an analogy to describe the amount of information that she takes in every day while on the job.  She said that it is like trying to get a drink from a fire hose.  I thought that this was fitting as each day as a Teacher at Sea I am constantly trying to take in and process the huge amount of new information I am learning.  I have jumped in to the heart of hydrographic surveys, but in this post I would like to take a step back and look at a brief history of how the use of sonar has evolved.

Before coming on the Rainier, I knew that the use of sonar on ships had something to do with sound waves traveling in the water in order to map the ocean floor.  After gathering information from the crew, and a bit of my own research, I found out that sonar actually stands for Sound Navigation and Ranging.  I also found out that sound waves travel better in water as compared to radar or light waves, so that is why they are used for this type of work.

The NOAA Ship Rainier is equipped with a Kongsberg EM710 Multibeam Sonar System which falls in the category of active sonar.  The system emits acoustic signals into the water, and when the sound bounces off of an object it returns an echo to the sonar transducer.  By determining the time between emission and reception, the range and the orientation of the object can be determined.  The range of an object is equal to the sound speed times the travel time divided by two.

It is extremely important that the hydrographers using this technology have accurate measurements for sound speed.  The Rainier is equipped with a Moving Vessel Profiler (MVP) which generates sound speed profiles.  These profiles include information such as temperature, salinity, depth, and most importantly, sound speed.  These measurements are applied to real-time sonar data in order to make sure that these variables are controlled for.

Sonar was first used during World War I as a way of detecting submarines.  The US Coast and Geodetic Survey were the first to use sonar to map deep water areas in the 1920s.  As I discussed in a previous post, lead line surveys were the primary way to gather bathymetric data up until that point.  It astounds me to see all of the technology on board, but it also leaves me wondering where we’ll be in another 10 to 20 years.  I suppose only time will tell what new technologies will allow for the continued exploration of our Ocean!

Personal Log

The beauty of Alaska has truly come to life for me in the last few days.  Last night, the CO was kind enough to take a group of people to a nearby beach on Chernabura Island.  From time to time he will do this, and the crew calls these events “Beach Parties”.  It took me several minutes to gain my land legs as my body has acclimated to life on a ship.  I walked the beach, but I soon turned to hike up one of the peaks that I had been seeing from a distance for so many days.

The hike up to the top was HARD!  The ground beneath my feet was not solid earth, but rather soft, boggy terrain that required a great deal of energy to hike through.

When I made it to the top I could not believe my eyes.  The beauty of this untouched land was overwhelming, and I realized how very lucky I am to be on this wonderful adventure.

Just another Day at the Office…

Christie Reiser, Hydrographic Assistant Survey Technician

I began getting to know Christie while I was out on my first launch with her last week.  Before this time, I had heard her mentioning that she is currently doing an internship with NOAA.  This immediately caught my attention as I am always interested in how students are able to involve themselves with real-world organizations such as NOAA.  As I began interviewing her I found out that she is working on her bachelor’s degree through the University of Colorado with hopes of someday becoming a physical scientist.  She began her internship with NOAA last field season, and she is now a permanent employee while also completing her internship.  Before her current school work she obtained an associates degree in business marketing and worked for an oil company as an executive assistant.  During that time, her boss asked if she wanted to learn Geographic Information Systems (GIS) for her work, and so she was signed up for a crash course which allowed her to begin using the software to make maps.  Unfortunately, she was laid off but during this time she was able to move to Europe because she has dual nationality in Germany. While overseas, she spent a year working as an apprentice in a saddlery in Austria.  When she came back to the states, she decided to go back to school at the University of Colorado.  She enjoyed her previous GIS experience, so she began her work in the geography department which led her to the internship with NOAA.

Christie told me that has truly enjoyed her time in Alaska.  She loves seeing the marine life and getting to know the people she works with so well.  Her favorite part of the work is the night processing where she is able to work directly with the data in order to see the sea floor come to life.  When asked what advice she would give a young person trying to break into this field, she said that she would recommend waiting to go to college until you are ready.  Wait to find something that makes you happy and that you have a passion for.

When not on the ship, Christie enjoys leather working, saddle making, and book binding.

Your Questions Answered!

One question that I’ve had from several people has to do with the morale of the crew.  These people are out to sea for 18 days at a time, and so people wanted to know if it gets depressing out here.  Also, it was asked if there is  good comradery and banter among the crew?

In response, I can say this; life at sea is not for the shy or the meek.  While there are many amazing advantages to this type of work it definitely takes a certain type of person.  As far as the morale of the crew, from my perspective it seems like field season up here means time to get business done.  Everyone has important tasks to be completed, and most of the time people are busy with work.  Operations run 24 hours, and the point of being here is to gather the data. However, it’s not all work and no play.  Morale on the ship is important, and I’ve heard many people speak of the crew as a second or extended family.  I don’t know any other job where you work, live, and share space 24 hours a day with the same people.  I’ve noticed that people on the ship really look forward to meals.  It is one of the small pleasures of life at sea and it is a time to gather with everyone and take a break.  The universal struggle on board is the time away from home. Nobody wants to be away from their loved ones, but the crew on the Rainier work as hard as possible to make life at sea enjoyable.

My Aunt Kathy wanted to know if I have seen any whales.  The ship has had to navigate around pods of whales, but it seems to be whenever I am busy with something else.  Yesterday the crew called me to the bridge as they had been seeing a lot of whale activity.  Of course, as soon as I got my camera out, there wasn’t a whale in sight.  However, last night I was walking on Chernabura Island during the beach party, and I saw a pod of whales out in the distance.  I saw four of five spouts, but they were too far to get a picture.

Did You Know…

Here are a few ship specific terms that I have learned during my time aboard the Rainier:

To come about – to turn the ship around

Aft – the back of the ship

Helm – ship’s steering equipment, found on the bridge

Pitch – the forward and backward rise and fall of the ship as it moves

Leeward – the side of an island or a ship that is sheltered from the wind

Also, when making a call to another vessel, it is important to say the call sign of the vessel you are calling for first followed by your own call sign.  When I was out on RA-6 doing survey launches, I had to call the Rainier to give hourly updates.  In a previous blog I told you that the call sign for the Rainier is WTEF, but they typically shorten it when out on surveys to just ET.  In this case when I was calling for the ship I would say, “Echo Foxtrot this is RA-6.”  The OOD would respond with, “RA-6 this is Echo Foxtrot go ahead.”  This type of universal communication system is one of the ways that the team aboard the Rainier maintains safety while at sea.