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Drifter Newsletter #7

By on July 30, 2010 in Building the Drifter, Drifter Newsletter

July 2010

New Drifter Designs

We have been experimenting with alternative designs this summer in an effort to further reduce the cost and time needed to build surface drifters. Several new prototypes were built and tested in local Woods Hole waters including the:

  1. “Shawn Drifter” which has a 4 by 4 wooden mast and a flotation collar

  2. “Miles Drifter” which has a 4 by 4 PVC fence-post mast filled with 2-part foam

  3. “Eddie Drifter” which has a 2 by 4 wooden mast and a flotation collar

  4. “Vitalii Drifter” which is a mini-rachel drifter that uses a Garmin instead of a TrackPack

eddie drifter
Figure 1. The new “Eddie” drifter with a wooden 2-by-4 mast and collar flotation.

The first three are slight variations of the standard “Rachel Drifter”. The Eddie model (see photo below) holds the most promise in replacing the Rachel as our standard surface drifter. While the first Eddie prototype failed after a few days, the 2nd has been reporting regularly for 3 weeks. Not only is this drifter a bit more environmentally friendly, it is much easier to make and should cost hundreds less. More info on these alternative models is posted with photos on the “drifter deign and technology” link on the drifter website http://www.nefsc.noaa.gov/drifter

Gulf of Mexico Drifter Deployments

A couple dozen drifters were shipped to various labs on the gulf coast including University of South Florida in St Petersburg, Dauphin Island Sea Lab in Alabama, and NOAA’s Atlantic Oceanogrphic and Metereoology Lab in Miami. They were also sent down on both the R/V ENDEAVOR and the R/V DELAWARE to be deployed at various locations around the gulf. The tracks of these drifters can be viewed at http://www.nefsc.noaa.gov/drifter/drift_BP_Spill.html . They are contributing to a multi-lab effort to understand the transport of the oil around the entire gulf as can be best seen at the USF site http://ocgweb.marine.usf.edu/~liu/drifter_all.html .

Proposal Plans

We hope to submit a planning letter to NOAA’s Environmental Literacy Grant call for k-12 education projects in early September. Partnering with MATE, SMCC, GoMLF, and many New England-based marine educators, we hope to follow-up on what we have been doing for years: engaging students in drifter designing. building, and tracking. The idea would be to have marine science students at local college visit local high schools to teach educators, service providers, and students how to build drifters. The drifters will be deployed in offshore waters by fishermen.

Highlights of 2010 Drifter Deployments

More than 200 of the SMCC/GoMLF/NOAA drifters have been deployed this year, more than any year prior. While many of them were short deployments of just a few days or weeks in estuarine/coastal waters, some have traveled offshore waters for months. The raw statistics as posted at http://www.nefsc.noaa.gov/drifter/statsd.html show many of them that have each logged thousands of kilometers.

One of the most interesting tracks is that of unit # 105440672 which has been retained in the enormous tides of Bay of Fundy for nearly 3 months and is still traveling. While it has traveled a total distance of over 5000 kilometers, it is still only a few hundred kilometers from where it was originally deployed.

New Drifter Users

Since the last drifter newsletter, the following institutions have recently joined the cooperative effort to deploy drifters (or plan to do so in the coming year):

  • UMASS Dartmouth Ocean Mixing Lab

  • Sea Education Association

  • URI Narragansett Bay Project

  • Upper Cape Cod Regional High School

  • Woods Hole Science and Technology Education Partnership

  • NOAA’s Great Lakes Environmental Research Laboratory

Overlaying drifter tracks on sea-surface temperature images

MATLAB code has been developed to better visualize the relationship between SST structure and the path of drifters. The set of routines does that following:

  • browses remotely stored images at Rutgers University,

  • saves “good” images,

  • interpolates in time between good images,

  • interpolates in space over cloudy images,

  • generates animations of the drifter tracks on color-contoured imagery.

Thanks to Emily Motz, a summer student from SUNY Maritime School who has spent her summer in Woods Hole with the “Partnerships in Education Program”, the code has produced these animation at, for example:

http://www.nefsc.noaa.gov/epd/ocean/MainPage/anim/sst_may2010/sst.html

The next phase of this project will overlay circulation model vectors. We are also developing a Phython application for drifter processing and visualization which will not require a MATLAB license.

ComTechMobiles satellite fee

As noted previously, there are two ways to pay for satellite fee:

  1. one time bill through the Gulf of Maine Lobster Foundation
  2. monthly bills from ComTechMobile

Drifter users are asked to be aware of which option they are under and, in the case of option #2, be ready to respond.

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Drifter Newsletter #6 April 2010

By on April 28, 2010 in Building the Drifter, Drifter Newsletter

Drifter building and support team

We are happy to have a growing drifter support team to help users with various aspects of the operations. While all members of this team participate in nearly all phases of the process, the specific tasks are as follows:

Southern Maine Community College Marine Science:

  • Tom Long – supervisor
  • Kara LaLomia – lead drifter builder

Gulf of Maine Lobster Foundation (GoMLF):

  • Erin Pelletier – purchasing and billing

NOAA:

  • Jim Manning – lead design and tech supporter
  • Joe Letourneau – programmer
  • Shawn Wolff – assistant tech support
  • Tanya Stoyanova – web developer
  • Grant Emde – field tech
  • Dave Novak – outreach

Marine Advanced Technology Education:

  • Deirdre Sullivan – connection to national COSEE-like initiatives

Since we are all involved with the drifter operations on a part time basis (typically one day per week each), we do not derive our living from the sale of drifters. This is a not-for-profit organization devoted to maximizing the amount of drifters that go in the water and the students who are exposed to the science and engineering aspects of drifter use. If you correspond with Jim, Erin, or Tom via email about any drifter-related issue, please copy all three: james.manning@noaa.gov, erin@gomlf.org, and tlong@smccme.edu so that all three parties are in-the-loop.

New website still under development

While the new drifter homepage is still under development , you can visit it at: http://gisweb.wh.whoi.edu/cgi-bin/ioos/drift/driftTable.cgi . We ask for feedback from you, the participants in this collective effort. We do NOT want to publicize this site until we have heard your feedback and suggestions. Please do not distribute this address to others or link to it from any other website. It may be months before this becomes our primary drifter website. During this transition, we will still consider: http://www.nefsc.noaa.gov/drifter/ as the main page.

Dealing with your satellite bills

There are two options now available to pay for satellite fees:

  1. pay GoMLF upfront for your expected satellite fees and then get billed by GoMLF if you exceed that amount.
  2. get monthly bills directly from the satellite service provider ComTech Mobile.

In this second case, if you are a new user and haven’t got billed from them yet, you need to fill out the ComTech “business agreement” form. To get one of these forms essentially filled out, email Erin (erin@gomlf.gov). Again, please copy tlong@smccme.edu and james.manning@noaa.gov on any emails concerning drifters. MATE participants do NOT have to worry about satellite fees since they are still covered by the NSF grant.

Two Deployment Forms

You need to visit the drifter website both before you deploy and after. Here’s why: If you want to label your drifter deployment with the distinct “deployment ID”, you will need to know what that is. For this you visit the “Plan deployment” site. If you want us to process your deployment and make real-time plots, you need to tell us the exact time and place of the deployment. For this you visit the “Report deployment”. Let me know if you have any troubles with these sites. As with most of our sites, they are “under development”.

New Drifter Users:

  • Center for Student Coastal Research (Cohasett MA)
  • Redwoods Community College (Fort Bragg, California)
  • Falmouth High School (Falmouth MA)
  • Zephyr Education Foundation (Falmouth MA)
  • Atlantic Salmon Federation (St Andrews, New Brunswick)
  • On building drifters from “kits”

Those that have been through it know that building a drifter from a “kit” is not easy. It requires shopping for a lot of hardware that is not supplied and several hours per drifter of labor. To make things easier we have the following suggestions:

  1. new users should either buy at least one complete drifter (as a model to go by) or attend one of our “drifter building workshops” that we have from time to time.
  2. Jigs have been constructed that help with the drilling and cutting
  3. certain tools make things easier like professional drill presses, table saws, and heat guns
  4. ask for our latest “Rachel Construction Document” before you start building

On sealing the transmitter

We recently purchased a machine to vacuum-pack the transmitters in clear plastic bags. This eliminates the need for the white vinyl bags we have used in the last few years and provides a way to insert a readable label. We still wrap the edges of the unit with black tape both before and after the vacuum packing. Users should supply us with the cell phone number that beach combers and mariners should call when they find a unit. We will seal the transmitter so that this number is visible.

Center for Student Coastal Research Project


It took two days for high school students from Cohasset MA (and surrounding towns) to build 15 drifters. These units will be used by the Massachusetts Division of Marine Fisheries to investigate the pathways of lobster larvae in the vicinity of the new LNG terminal in Mass Bay. In exchange for the students efforts, the Cohasset Center for Student Coastal Research will get 6 drifters of their own to deploy in order to investigate the tidal flushing of their local harbor. See photos below and full story at: http://www.wickedlocal.com/cohasset/features/x1060307512/Cohasset-High-students-study-harbor-tidal-flow


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Drifter Newsletter #5

By on February 22, 2010 in Building the Drifter, Drifter Newsletter, Tracking the Drifter

Drifter Newsletter #6
February 2010

Drifter Website Update
We have made some progress in designing a new website to plot all the drifter tracks and to serve the data but we have not yet released it. It will take the place of the rather cluttered site: http://www.nefsc.noaa.gov/drifter/ before the 2010 drifter season gets underway in a few months. Tanya Stoyanova, a computer science student from Bulgaria, is working on it one day per week.

Figure 1. Example of comparing an observed drifter track (blue) with simulated forecast tracks (other colors). In this case, we are using the UMASS-Dartmouth’s FVCOM model output on the “GOM2 grid” provided on the web. We are developing a routine to track particles through their 3-d velocity fields.

Figure 1. Example of comparing an observed drifter track (blue) with simulated forecast tracks (other colors). In this case, we are using the UMASS-Dartmouth’s FVCOM model output on the “GOM2 grid” provided on the web. We are developing a routine to track particles through their 3-d velocity fields.

Collaboration with Coast Guard
Working with SMCC and UMASS-D, we provided the USCG with one of our drifters which they deployed off of Cape Elizabeth Maine in mid-January 2010 (see Fig 1). This was part of the USCG Search and Rescue Training Operations where they practice some of their routines following drifting objects over the coarse of several days. Since we have similar interests for scientific reason (such as following patches of toxic algae), we are trying to combine our efforts in this endeavor. Animation of these forecasts vs observed tracks are linked from the drifter website but may be found directly is at, for example: http://www.nefsc.noaa.gov/drifter/fvcom_sarops.html. If you are interested in implementing this sort of forecast operation in your waters, let us know. All you need is to find a URL for some webserved “CF-compliant” circulation output in your local waters and a MATLAB programmer.

COSEE podcast
Ari Daniel Shapiro’s interview with us including a trip to Casco Bay to deploy drifters was released last week and posted on the COSEE NOW website where it will be heard by many educators and their students around the country. It can be found at http://coseenow.net/podcast/2010/02/drifter/.

New Drifter Deployers
We are happy to add Long Beach Community College from California, Clatsop Community College from Washington State, and the Atlantic Salmon Federation from New Brunswick, Canada to the list of drifter users. LBCC students are actively designing new rigs to radio track bucket drifters in Los Angeles river runoff events. CCC students are following their surface drifters (rachels) rapidly moving north and east of their deployment location off Astoria. ASF will be deploying several drifters in the St Lawrence River in May to track the potential transport of young smolts.

New Transmitters on the Market
We are watching the development of various transmitters such as the new “Spot2” come on the market. There are a variety of options available “off-the-shelf” for doing our sort of tracking but we are sticking to the TrackPack II in 2010. Given its increased battery power this year and improve circuitry, we are hoping it will serve our needs. We will see.

Figure 2. Approximate location, institution, #, purpose, principal investigator, and month of SMCC/eMOLT drifter deployments planned for 2010 on the northeast continental shelf.

Figure 2. Approximate location, institution, #, purpose, principal investigator, and month of SMCC/eMOLT drifter deployments planned for 2010 on the northeast continental shelf.

Drifter plans for 2010
More than 100 drifter deployments will be made this year (Fig 2) to document flow patterns around the Gulf of Maine. Most of the deployments this year will be made in Massachusetts Bay. The state has funded a project, for example, to investigate the potential effects of the LNG facility on the lobster population. We will deploy dozens of drifters in the coastal waters north and south of Boston Harbor. Some of the drifters for this project will be put together by the Center for Student Coastal Research in Cohassett, MA. In exchange for their efforts, they will get several drifters of their own to deploy in their local harbor to examine the exchange mechanisms with the bay.

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Long Beach City College – LA River Drifter

By on January 22, 2010 in Building the Drifter, Long Beach Community College

We are in the final stages of putting together our river drifter.  It’s our plan to use this drifter to show the path that trash takes from the urban areas of Los Angeles County out to the ocean.   The drifter is a hybrid utilizing both the Amateur Radio APRS (http://www.aprs.org ) tracker and Jim Manning’s NOAA satellite tracker.   I’ve pasted a description email below.

From: Scott Fraser [mailto:sfraser@lbcc.edu]
Sent: Friday, January 22, 2010 9:20 AM
To: Jim Manning
Cc: Deidre Sullivan
Subject: RE: on battery power

Hi Jim,
I brought the unit in out of the window on Wednesday night and put it into inventory then configure.  Hopefully I shut it down properly.
I did a bit of research looking for handheld gps units to put in with it and after reading specs, realized that if we run it until the battery dies, that we will likely loose all the saved tracks.  We started talking about putting in a battery pack instead of ballast to power the gps until the unit was recovered.

At that point, I brought out my ham radio/gps trackers that use the ham APRS service.  We did some testing yesterday and have a unit about set up and ready to go.  It will transmit to the ham network once every 60 seconds and will last about 4 days on the battery we have.  The satellite tracker can then be dialed down to give less frequent reports and if it makes it out of the harbor, we’ll let it go for a week or so.

The recovery plan is if close by, to go out and get it; if it makes it to the open ocean, hope that it is recovered and contact made with us.

The ham electronics module (APRS) will be sealed inside two 1/4″ thick acrylic domes today and then foamed into the bottom (top) of a bright orange Home Depot bucket.   The APRS needs a 2m quarter wave antenna, so I got two 18″ bright orange safety flags with wood poles.  We used the pole to run the antenna up under the flag.   The antenna ground plane is a wire along the top rim and a second wire dropping down into the water.   The antenna works great and we are able to hear lots of network stations and able to get into the network also.

Here’s an example of the APRS raw data we put onto the network yesterday

http://www.findu.com/cgi-bin/raw.cgi?call=KN6f-1

On the APRS tracker we were having problems getting it to transmit, so I disabled the “Send only Valid Positions” mode for testing and the last transmission before we shut down shows this unit way up in Canada.  I’ll turn that mode back on today to keep that from happening when live.  We found out that we had a flaky GPS unit and the replacement is working fine.

This link will provide a map of the unit’s current location

http://www.findu.com/cgi-bin/find.cgi?call=KN6F-1

The problem with this service is that once the unit is beyond line of sight communication, it goes dark and we loose it.  That’s where the satellite unit would pick up and take over, so this gets us the best of both worlds.  High rate live reports while in the urban areas running down the river and then low rate tracking once it settles out in the ocean.

We’ll keep you posted
Scott

Scott Fraser
Dept. Chair
Electrical Dept.
Long Beach City College
4901 E. Carson Street
Long Beach, CA 90808
562-938-4505 office

Update: 1/22/10 9:30pm

It was a frustrating day of testing with some success in testing and lots of problems.  It turns out that our 11 year old GPS unit does not function well in cloud cover and rain.  It took some time but we finally correlated the lock periods with times when the sun was out.  At one point there was an awesome double full rainbow on the horizon, but our day was not so awesome.

I’ve ordered a Parallax GPS board that has the sensitivity needed and we’ll swap that our with our “ancient” receiver.

I also had some problems with our second satellite unit not responding to the configuration program.   After numerous trys with and without a passkey I figured that the battery might be dead.  Rather than sending it back to Jim for a replacement, I surgically opened up the case and started checking it out.  The battery voltage was OK at 4.63volts.  So I unplugged the battery and let the unit sit for a minute unpowered.  After plugging the battery back in, I tried connecting to it without a passkey.  It woke up on the second try – YEA!

I set the passkey and was able to take it in and out of operational mode.  Looks like this one is back from the dead.

In doing this I found out that the battery pack is a non-rechargable three AA lithium pack from Energizer.  It has a capacity of about 3000mA hours.  This started me thinking.  I found a solar cell phone charger on Ebay for about $12 (including shipping) that has a 2600mA hour battery pack.  The output voltage is the same as the satellite unit pack.  I’m thinking that on our drifter, I could put the solar cell on the top and connect it to the unit.  It could power the unit for quite a while.

I’ve uploaded some photos of the unit’s insides.

Saturday 1/23/09

It was a bright and sunny day today, no rain!   Dropped by school to see if the GPS unit would establish lock.  It finally did after 10 minutes.  Nothing like 12+ year old technology.  I found a 1997 date code on one of the devices.   Took the drifter for a stroll around campus and was able to record a number of locations over APRS, but it was still spotty.  As soon as the clouds started rolling in, it had a hard time maintaining lock.   So…. with all that in mind.

I ordered the Parallax GPS data logger kit.  We will now have three ways of recording locations.

1. Using the Data logger, a position will be written to a USB flash drive every 3 seconds

2. Using the Ham Radio APRS system, a position will be sent out over the air and onto the internet every 60 seconds

3. Using the satellite transceiver, a position will be sent out once per hour.

We’ll have the satellite transceiver connected to the solar charged battery pack.   Now check my math here.

Jim tells me that the batteries are good for about 1000 transmissions.  Sending one per hour, gives about 41 days per battery pack.  But it may try as many as three times to make a connection so worst case is that the pack would last for about 14 days.

So our worst case is that we use 1/14 of the battery pack per day and best case 1/40.   It looks like a charge time of 0.6 to 1.7 hours per day will be needed to maintain the battery pack.  The solar cell on the pack will charge the entire pack in 15 hours of sunlight.   This is the entire pack.   All I’m asking is a 1/14 pack charge over the day.

That’s it for now. With these changes, we won’t make it in time for this rain storm, but there will be more down the road.

Scott

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Drifter Newsletter #3

By on November 10, 2009 in Building the Drifter, Drifter Newsletter

November 2009

Satellite Account Setup

Our satellite service-provider has recently instituted a new policy.  Those of you  who get billed directly (or plan to get billed directly in the future) now need to fill out a one-time “business agreement form”. If you haven’t already done so and you plan to deploy drifters in 2010, please let me know. I will email a copy of this form partially filled out for you to fax or email to ComTech Inc.

Note: Those of you funded by the MATE project do not have to worry about this until your “message count” exceeds a few thousand. You can see your message count on the 8th column of the sensservice.com spreadsheet.

New Drifter Designs

Two new designs were tested in November 2009:

  • “Kathleen” Bucket

Dan McDonald and his crew from UMASS Dartmouth successfully deployed 26 bucket drifters off the mouth of the Merrimack River (Newburyport, MA) on Nov 7th after a large runoff event. All units, many of them fitted with additional sensors (temp, salinity, GPS, high-powered strobes), worked well and were successfully recovered after being quickly expelled into the open ocean. See figures below with stacked buckets and their tracks on the ocean.

SMCC-built bucket drifters stacked in the lab. The buckets float upside-down with only an inch or two above the waterline.

SMCC-built bucket drifters stacked in the lab. The buckets float upside-down with only an inch or two above the waterline.
UMASS Dartmouth Nov 2009 River Plume Study

UMASS Dartmouth Nov 2009 River Plume Study
  • “Ruben” Radio-tracked

I spent an afternoon on Buzzards Bay with Ruben Davis of Datissystems Inc of Catamet, MA a few weeks ago. Ruben, a retired electronic engineer, has devised a radio-tracked GPS drifter that can be monitored from a laptop on board or at a base station ashore. He demonstrated the successful operation of his prototype and plans to work on expanding the range capabilities of these units this winter. So, those of you interested in near-shore applications that are free of satellite costs, let me know.

Viewing Tracks in GoogleEarth

Some of you had trouble accessing and viewing the kml files. They are linked from the www.nefsc.noaa.gov/drifter site under the “drogue depth” column of the 2nd table. Please note that the best way to do this is to click on the link and then “viewèpage source” on the upper toolbar of your browser. This is the file you input to GoogleEarth. If your track does not have a kml file linked, or you have trouble viewing it, call  my cell at 508-566-4080 or email james.manning@noaa.gov .

Buoy sticks and toggle supplies

Some of you have had trouble obtaining more drifter parts that are NOT sold in most hardware/marinas. The buoy sticks and toggles (ie flotation component attached to the end of the fiberglass spars), for example, are sold specifically in Maine for the lobster and herring fishermen, respectively.  For help in obtaining these parts, you may contact erin@gomlf.org.

Proposals in the works

We have two proposals in the works that include drifter deployments. One is a small part of the Northeast Regional Associations of Coastal Ocean Observing Systems (NERACOOS) request to the 2010 NOAA IOOS. While we do not have much hope that it will be funded, we have nevertheless suggested routine deployments by fishermen at selected sites around the Gulf of Maine throughout the HAB season (Apr-Sep). Another proposal, in the early stages of development, is a follow-up to the eMOLT project in 2004 where, similar to the NERACOOS objective, lobstermen deploy student-made instrumentation around the Northeast region to obtain data for the purposes of validating numerical simulations. If any of you are interested in similar proposals in your region, let me know. I’ll send you a copy. If you have other ideas for drifter proposals, let’s hear them!

Drifter-related books

For an entertaining read about things that float in the ocean look up “Flotsametrics and the floating world”.  For more technical discussions on the science of things floating in the ocean see “Lagrangian Analysis and Prediction of Coastal and Ocean Dynamics”.

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Drifter Newsletter #2

By on October 19, 2009 in Building the Drifter, Drifter Newsletter

October 2009

Urethane Foam

There has been some discussion about what  “2-part marine urethane foam” to use when filling the PVC pipe. While SMCC suggests “Poly-U-Foam” (available on line for about $40/quart), there are probably other types in smaller qquantities that will do the job.  US Composites sells a “4-lb kit” for about $20 (catalog # “FOAM-0204”).  In fact, as Jason Hyatt (Mass Maritime) suggest, we MAY be able to get by with a can of “Great Stuff” from your local hardware but we do not know yet how well this will hold up in seawater.  Note that we did not use any foam at all for the first few years we deployed drifters. We only added this extra buoyancy within the pipe in hopes that the transmitter stays afloat  despite the inevitable loss of the other flotation.

MATE Drifter Blog

Thanks to our colleagues at MATE, you can follow a blog of drifter experiences at: http://coseenow.net/mate/ .  To make an entry in the blog, click on the “Register” link , “Log in”, and blog away. Note that they already have a set of “categories” to choose from including, for example, “curriculum development”, “collaborating with scientists”, etc. Under the “resources” page, there is a link back to the various SMCC/GoMLF/NOAA effort. I plan to enter this newsletter in their “Tracking the Drifter” blog.

Drifter Photos

We have compiled a gallery of drifter photos (linked from the bottom of the “drifter construction and technology” document at http://www.nefsc.noaa.gov/drifter/ ) and may harvest some more from the blog. Please send your contributions to james.manning@noaa.gov (or upload them to the blog) and supply the photographer’s name so that we can give the proper credit.

Tracks of the Month

There are always particular tracks that stands out from the rest. This month, the Cape Fear Community College drifters have provided some interesting tracks.  Their first drifter that was deployed just a few weeks ago has traveled over 2000 kilometers in the Gulf Stream but, even more amazing,   their 2nd drifter traveled over  hundred kilometers in one direction, turned around and came directly back nearly to where it started. CFCC is now working on building more drifters and some of the students are designing a wooden (ie biodegradable) drifter!

New Drifter Designs

Two new-style drifters will be deployed within the next few weeks. One is the “Kathleen” bucket drifter  which will track the very-near surface waters of the Merrimack River Plume for Dr. Dan McDonald of UMASS Dartmouth. Many of these units have powerful strobes, Garmin receivers, temperature and salinity sensors installed along with the TrackPacks.  There will be a total of 27 units deployed at the river mouth during an outgoing tide after a large runoff event. Stay tuned.

The other new style drifter, developed recently by Ruben Davis of  DatisSystems of N. Falmouth, MA, eliminates the need for satellite transmissions by implementing a radio-based system for near-shore high resolution applications. Stay tuned for the result of these prototypes.

TrackStick GPS receiver

Jason Goldstein and Win Watson (UNH) have come across the TrackStick.  Google this and you will see a compact device that may be a nice alternative to the Garmin units (for internal storage of fixes) and apparently provides more battery life.

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Drifter Newsletter #1

By on September 20, 2009 in Building the Drifter, Drifter Newsletter

Sept 2009

Newsletter plan
This is the first of what I imagine to be a nearmonthly “newsletter” on drifter issues. Now that there are a few dozen labs using the SMCC/eMOLT drifters, we should probably try to compile our notes. If you have anything you would like to share with others (photos, funny stories, bad experiences, etc), please send it along to james.manning@noaa.gov. Keep in mind that most of the information regarding the drifters is now linked from the realtime website http://www.nefsc.noaa.gov/drifter but these periodic newsletters will provide your information on “what’s new”. If you want to be removed from the mailing list or you want some of your colleagues to be added, let me know.  This first issue is going out to all users that have deployed, or plan to deploy, this fall.

Check transmissions for a day or two before deployment
Given that the transmitter technology is constantly evolving and not all of these units work flawlessly, it is a good idea to set your transmitter outside the day before you deploy it under a clear sky view to make sure you are getting good fixes.

Set transmitters outdoors after shutting them off to verify they are indeed off.
Those of you who were at the workshop in August should put your transmitters outdoors to make sure they were properly turned off. There was at least one case where the transmitter was left on which probably resulted in a 2030% battery loss. A transmitter makes 3 attempts to get a fix with each sampling period so, if it is hidden from the satellite, the battery will run down 3times faster.

Watch for fiberglass rods wearing due to buoy stick chaffing
We recovered several fiberglass rods this summer which, after having been at sea for a multiple weeks, were worn down at the point of contact with the plastic buoy stick. This might have been due to the holes in the buoy sticks being two small so that they didn’t swing easily with wave movement.

Refrain from enabling the “advanced configuration” motion sensor
After experimenting with the this function on a couple units attached to my bicycle, I found that it didn’t work as it was suppose to. So, we may need to wait for another generation of transmitters before implementing this setting. We have however made use of the advanced configuration in order to get
“48 samples per day”.

Hoseclamps vs cable tie transmitter mounts
In our quest to minimize the cost of drifters, we recently started using heavy cable ties to secure the transmitters (where we used stainless hose clamps in the past). Last month, there was at least one documented case of the cable tie breaking. While this may have been due to the unit crashing on the rocks, it is worth noting nevertheless. If you experience any faults like this, PLEASE let us know.

Marine Advanced Technology Education (MATE) deployments
We are very excited to have expanded the use of these drifters around the country thanks to a NSF funded workshop in August where nine schools each went home with two drifters. As noted on the realtime site, UMaine Machias and Cape Fear CC, for example, have already made deployments.

Documenting your deployments
One of the links under the realtime website allows you to document your deployment. Based on the information you enter it is suppose to give you the “deployment ID”. If you want to know this deployment ID BEFORE you deploy, see the “deployment ID convention” link that is under the “construction and technology” notes. Please keep in mind that these websites are constantly under development in our attempts to automate things as much as possible.

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