DSC Testing
February 1, 1999 was a special day in the history of Maritime Communications. On that day, a whole new style of communicating between and among ships, boats, and coast stations around the world officially came into being. This new method, called the Global Maritime Distress and Safety System or GMDSS, has replaced the old "sparks" or radio operator on many ships. Many Auxiliary members, whether or not they are "comms qualified" think that such matters are the concern of the "big boys", the tankers and merchant ships, the passenger liners and cruise ships. They usually believe that because most of our activity is centered around recreational boaters and vessels, these are not of concern to us. But, that's not really true.
Because of these changes, we (Division 3 of 11sr and the DSO-CM) undertook a project to evaluate one of the new technologies and see how we could use them effectively in AUX operations and also see whether we could make a contribution to TEAM COAST GUARD in this new arena. One of the parts of GMDSS will have a big impact on the way we all communicate when we're on or around the water. And that is something called "Digital Selective Calling" or DSC for short. You've seen the ads from radio manufacturers for these new "DSC" radios. But just what is DSC?
The big difference between a DSC radio and a regular radio is that the DSC radio contains a unique number (called a Maritime Mobile Service Identity or MMSI) that identifies the vessel the radio is associated with. The impact of that simple fact is tremendous. For example, with a DSC radio, if you send certain kinds of messages like distress messages, the radio will automatically transmit that identifying number and whoever receives the message knows what vessel sent the message, WITHOUT YOUR HAVING TO IDENTIFY YOURSELF by voice. Further, DSC radios are designed so that you can hook your GPS to the radio and automatically tell a listener not only who you are, but where you are. But it goes even further than that, if you and I are on different vessels, each with a DSC radio, and if I know your unique identifying number, then I can send a message from my radio to your radio and your radio will respond by sounding an audible alert and automatically switching to some working channel that I pick.
But wait, there's more! Remember a GPS can be hooked to your (or my) radio. Suppose we're both out on patrol and suppose I want to rendezvous with you. With DSC I can again select your MMSI from a pre-programmed list, press another two or three buttons, and a transmission is automatically made which your radio hears. Your radio then queries the GPS it's connected to, and transmits back to me your current latitude and longitude. All without your having to do any thing at all! So while DSC is advertised as an automated distress system, it is actually much much more. In fact on the Coast Guard's website under their description of GMDSS and DSC, the following quote appears:
"GMDSS telecommunications equipment should not be reserved for emergency use only. The International Maritime Organization . encourages mariners to use that equipment for routine as well as safety communications."OK, enough of the theory . what did we do here in 11 South and what were the results? We asked the question, "How can we use this technology to help us in our regular patrol activities and how can this help support the Coast Guard?" We asked ourselves, "Suppose we had a way to gather position information on a regular basis WITHOUT disturbing the vessel's crew? Then all we'd have to do is call the vessel each half hour, read them a position for confirmation and ask for an "ops report". Or another scenario was, suppose we had three vessels on patrol, and we received a report of pollution at a particular location. We wish to dispatch one of the vessels to investigate. It would be very convenient if we had an exact, CURRENT position of the vessel, so that we could give them not only a destination, but a course and distance as well. These and other scenarios were put together into a "test plan" and we developed a project to carry it out. Through the cooperation of two radio manufacturers, the willingness of three vessel owners to offer their vessels as test beds, and the commander and crew of Station Los Angeles, we were able to conduct a real life, on the water test of this new technology. Here's what we did .
In January of 2001, a project was proposed to the Bridge and Board of Division 3 of the 11th South which would investigate and test the use of some new radio and data technologies to allow us to automate position data gathering. Gordon West (Flotilla 11S2-7) and I began some planning and initiated discussions with radio manufacturers to ensure that commercially available (and reasonable cost) VHF radios were available to meet our needs. At the same time, a "test plan" was created that defined what we hoped to accomplish and also defined what would be considered as a "successful" experiment. In mid-March, I sent out a loooong email to all the potential participants, outlining the test plan, specifying some questions like "Who should be the audience for the test/demonstration?", and requesting input from the recipients. Two manufacturers were of immense assistance in that not only did they willingly offer much information about their products, but they also unselfishly provided loaner equipment to us, with no strings attached except that they would be informed of the results of the test. Had it not been for the cooperation of Standard Communications division of Yaesu Vertex Standard, and ICOM America, our project would not have been practical, not even perhaps possible. We are very grateful. The third leg of our plan was to enlist the aid and attention of the Commander and crew of Station Los Angeles in San Pedro. First of all, we wished to use the physical facilities and antennas of Station LA to conduct our test, and also we hoped that demonstrating the use of DSC in AUX operations might help them to an understanding of how DSC could be of value to Station LA people and vessels. The Senior Chief and his crew were unfailingly helpful. As with the radio manufacturers, our project would not have been successful without their aid. We borrowed three DSC capable VHF radios from the manufacturers and they were installed by AUX personnel on three different AUX vessels. The vessels were: Bill,FISH!, Coxswain/Owner Bill Barrett; Moonlight Express, Coxswain/Owner Hal Burkett, and Sea Kaye III, Coxswain Gary Norgaard, Owner Rick Wilson. In some cases, we also provided GPS units for the test and in others existing GPS's already on the vessels were interfaced to the new radios. Before the installation, Gordon West and myself conducted land-based tests of the radio's DSC capabilities (we both have FCC Coast Station Licenses) to verify operation and to define actual operating procedures for the test. Additionally, a DSC radio was temporarily installed on Moonlight Express and used during a routine ATON patrol in early April, and one additional test was performed using Sea Kaye III.
The test and demonstration was performed on 11 April with the attendance of the involved AUX personnel and was watched by the Commander of Station LA, our district Operations and Training Officer, Mark Matuschek, and our Division Captain. Standard Communications provided a VHF/DSC radio for use at Station LA as well as a chart plotter interfaced to the radio.
Here's a quote from the report on the test and demonstration which gives an idea of the format of the exercise:
"Installation and final tests were completed at approximately 0945. The vessels were dispatched as follows: Bill,FISH! Was directed to proceed out through Angel's Gate, offshore about 1 mile from the breakwater and then turn to parallel the breakwater to the East. Moonlight Express was directed to proceed parallel to the shoreline within the breakwater, heading East. Sea Kaye III was dispatched out through Angel's Gate and then to take up a heading of 225 magnetic."The result of this dispersal of the vessels meant that within about an hour, there were some 8 to 9 nautical miles between the vessels themselves, and between individual vessels and Station LA. Beginning immediately after the vessels departed Station, we in the Station LA Comms facilities began interrogating the vessel's DSC radios approximately every 3 to 5 minutes. The result of the interrogation was that the radio on each vessel automatically returned to us the vessel's current latitude and longitude. These positions were plotted (semi-automatically) on the screen of the chart plotters loaned to us. Each vessel's positions were identified by vessel on the plotter screen, and more detail of the position could be retrieved simply by moving a cursor to the position and pressing a button. This periodic interrogation was maintained for a period of about 1 hour and clearly demonstrated the effectiveness of the DSC tool as a tracking device.
Having completed the basic test, we then moved on to something a bit more complicated. Via voice comms, the test director instructed the coxswain of Sea Kaye III to have his DSC radio interrogate the radio on Bill,FISH! and retrieve that vessel's current latitude and longitude without any further voice communications. This was accomplished, vessel to vessel and within less than one minute from the time the test director made the request, Sea Kaye III had a current latitude and longitude of the vessel which was the target of a simulated rendezvous., WITH NO ACTION ON THE PART OF THE TARGET VESSEL'S CREW.
The final part of the test and demonstration was to attempt to determine whether this form of data transmission was less effective, equally effective, or more effective at gathering position information from vessels in areas which are notorious for their difficulty in maintaining voice comms with Station LA. Therefore we sent Moonlight Express to "hide" behind the mass of the Queen Mary (the ocean liner) which is docked in San Pedro Bay as a tourist attraction and floating hotel. Even though voice comms were not possible with Moonlight Express, her DSC radio received our request for lat/lon and we at Station LA received perfect copy of her position.
So all aspects of the test were completed to our satisfaction, including "whetting the appetite" of Station personnel for such a tool! All in all a very successful day. Now came the question of what we would do with the information we had. Discussions with our DSO-CM led to the conclusion that we should move forward with an implementation of VHF DSC as a safety tool for Southern California waters. We are preparing to install a permanent monitoring station at an excellent receiving site that the District already staffs. That should be up and running by some time in August. The next step will be establishment of additional receiving sites both north and south of the first location providing coverage over more than 100 miles of coast. Equally important, we are working on standard operating procedures and training materials for AUX members who will be the watchstanders at these locations. This is of critical importance since at least for one or two years, the sites will give us capabilities which are not available at the CG comms facilities in our area.
Finally, we are beginning to work on a public education campaign to alert the boating public to the fact that DSC monitoring is becoming available. What DSC can do for them and how they can take advantage of it is important information. DSC will be a major safety enhancement, but only if they understand how to use it, and we understand how to integrate it into the maritime communications world.
| WRITTEN BY: | BILL SCHOLZ | ADSO/Comm | W1HIJCW@aol.com |
| R. Vanleir | DSO/comm. 11S | dvleir@aol.com | |
| W. Schneider | DVC-OT | s157125@aol.com | |
| Joesph Rzucidlo | BC-OTM | jr46@erols.com | |
| Daniel Amoroso | BC-OTT | nm3s@prodigy.net |
Copies of the detailed report on the experiment are available from Bill Scholz, 11S-3SO-CM via email at W1HIJCW@aol.com.