Loran Measurement Mission

Coast Guard Auxiliary Provides Vital Support for Homeland Security Scientific Mission

by Bill Smith - FSO/CM-67

While many of us work hard to keep our charting skills sharp, we have all come to rely more heavily on GPS. As GPS systems become increasingly precise in pinpointing our location, our reliance on that technology tends to grow. But there are imperfections in GPS technology that are not addressed by this improved precision. Actually, these imperfections may be magnified as our dependence and confidence in GPS grow. In other words, we run the risk of putting blind faith in something that might steer us wrong someday.

We all know that our GPS can one day fail: bad batteries, lightning or a damaged cable. So we carry paper charts and practice navigating with them. But what happens if the GPS appears to still be working, but it’s wrong? How could that happen? GPS signals can be jammed – either intentionally or unintentionally. Certain conditions can cause erroneous or fake signals to be received by a GPS receiver. Under these conditions, your GPS can think you are in a spot that you are not. If you are running a chartplotter, it will place your ship in the wrong spot on the chart.

USCG Capt. Richard J. Hartnett (Ph.D., P.E.), Head of the Department of Engineering at the Coast Guard Academy, points out that despite these risks “many vessels today rely on sole-means GPS/DGPS for restricted visibility harbor entrance/approach.” Instead, he believes that “it would make a lot of sense for a receiver to use ‘all means available’ (i.e. all signals available) in the Harbor Entrance and Approach environment; possibly to detect and correct any GPS anomalies.”

What other means (signals) are available? Another source of positioning signal widely deployed is Loran-C. Capt. Hartnett believes that an enhanced version of these signals can be used along with GPS signals to create an integrated navigation system more resistant to these anomalies.

To determine the feasibility of this approach, the Coast Guard Academy, the USCG Loran Support Unit and Alion Science & Technology have teamed up to more deeply analyze the behavior of Loran signals and their potential use in this regard. Since Loran signals themselves are also affected by the environment through which they pass (through, around and bounced off of buildings for example) a critical phase of their project was to determine how enhanced Loran-C signals would behave at precisely selected locations in NY Harbor. Capt. Hartnett described this phase of the project best:

“This effort, which directly supports the Departments of Homeland Security and Transportation, amounts essentially to doing an electronic navigation survey of NY Harbor. The survey will consist of gathering GPS, DGPS, WAAS, and Loran-C information, in an effort to determine whether DIFFERENTIAL eLoran … can be used as part of an integrated fix solution to meet required Harbor Entrance and Approach accuracies.”

Alion Science & Technology were to supply test equipment and perform the actual measurements. Taking these measurements would be no small effort. The teams from Alion Science and the Coast Guard needed measurements taken from a vessel throughout NY Harbor. Some of the measurements would require a slow bell along a pre-defined track running a total of 35 nautical miles. More challenging would be 50 fixed point measurements throughout the harbor. To meet the accuracy requirements of these measurements, the vessel providing the platform would need to hold station within a 15’ diameter circle for fifteen minutes. The plan called for 3-4 days of these fixed measurements.

In order to accomplish this mission, they needed a capable crew and vessel that they could rely on over a 5 day period. The vessel had to be large enough to accommodate the test equipment and comfortable enough to spend 5 eight hour days on. Most importantly, she had to have the maneuverability and a crew capable of the helmsmanship needed to accurately hold station in the rough waters of NY Harbor for 15 minutes at a time. They turned to the Coast Guard officials in Sector New York who in turn reached out to the auxiliary facility Patrolman Walburger (a.k.a. Launch 5).

Patrolman Walburger (http://launch5.com) is a 52 ft. steel hulled, twin screw vessel that began her life in 1966 as an NYPD patrol launch. Restored by Greg Porteus (FSO/OP-67) and put back in service in 2002, she now serves as Auxilary 523356 for Flotilla 6-7 in the Auxiliary’s First Southern District.

Faced with the opportunity to serve a worthy cause – and sharpen skills at the same time – Greg agreed to take on the mission and began recruiting crew. Bill Smith (FSO/CM-67) began communicating with SectNY and the team at Alion Science to confirm requirements, timeframes etc. Since this mission covered 5 weekdays, recruiting employed volunteers to crew would be a challenge. Greg’s commitment of all five days and Bill’s commitment of two didn’t quite get them all the crew they needed. The call went out to members willing to sacrifice vacation days. Flotilla 6-7 members Rich Detz, Paige Flori (FSO/PA-67), Ted Foster, Janet Morra, Jim Picciano, Pete Van Markwyk (SO/SR-06) and Lynn Valenti all stepped up to take tours of duty as deckhands and pilots. Jon Romero (SO/OP-06) got right on the job of securing orders for all 6 days (including travel time).

With the roster all set and orders requested, Bill focused on firming up additional logistics. He contacted Alion Science and obtained an advance list of all coordinates and tracks to be covered and cross-referenced them against all NY Harbor security zones. After making proper notifications with Sector NY and securing appropriate authorization for all locations, they were pre-programmed them into Launch 5’s navigation system – a step that would prove to be a time-saver once the mission got underway.

Day One – Monday May 15, 2006

Coxswain: Bill Smith; Crew: Greg Porteus, Janet Morra

Launch 5 left Ossining at 0800 for the trip to MOTBY to meet up with Christian Oates from Alion Science who was on his way from Connecticut with all the test equipment. Most of the day was spent loading and installing equipment and performing some calibration rides through the harbor. Since MOTBY was to be the base of operations for the week, permission had been obtained to leave the Launch there overnight all week. Bill, Greg and Janet were ferried to Manhattan by two USCG 25 foot patrol boats and caught a train home.

Day Two – Tuesday May 16, 2006

Coxswain: Greg Porteus; Crew: Rich Detz, Paige Flori, Pete Van Markwyk

Mission of the day was to slowly traverse a pre-programmed track around the entire shoreline of NY Harbor as well as some tracks down the middle (see chart below). After the crew arrived at MOTBY by car, they were joined again by Christian and Lt Dave Lown from the USCG Loran Support Unit. They got underway and Paige piloted Launch 5 out of MOTBY and into the harbor. Pete Van Markwyk then took the helm and circumnavigated NY Harbor following the pre-programmed 35 nm path. It was a full day for the crew who, again, left Launch 5 at MOTBY and drove home after the patrol was secured.

"Slow Bell" measurement path around NY Harbor's Upper Bay

Day Three – Wednesday May 17, 2006

Coxswain: Bill Smith; Crew: Rich Detz, Greg Porteus, Janet Morra

The goal for day three was to attack as many of the fixed measurement points as possible in an 8 hour patrol. After getting underway out of MOTBY with Bill at the helm, Greg spotted a suspicious boat being offloaded from a freighter and taking flight. After conferring with SectNY on landline, we stayed behind the boat past the Verrazano Bridge until a USCG boarding team could be deployed in a couple of 25 ft. patrol boats. That detour cost us a bit of valuable time so we got right back to the task at hand and headed for our first fixed measurement point – a buoy just outside the MOTBY fairway. Of course, it is not permitted to tied up to a buoy so Bill had to hold the launch several feet off the buoy using the engines alone. The first attempt was a little nip and tuck. But two of the Alion Science team members on board (Christian Oates and Dr. Greg Johnson - CDR USCGR) had some experience with this type of maneuver. With some advice from them and a bit of practice, Bill settled into a groove and was able to keep the launch within 3 ft. of the buoy for the fifteen minutes. This was better than the 15’ requirements laid out by the test plan. Over the next two days of similar measurements, both Greg and Jim Picciano proved equally proficient at holding accurate position. All agreed that it was great training. Dr. Johnson also got some wheeltime in on a couple of buoys.

Day Four – Thursday May 18, 2006

Coxswain: Greg Porteus; Crew: Rich Detz, Ted Foster, Lynn Valenti

Another grueling day of holding station and tying up at various locations making fixed measurements. While day three had been very productive, not all planned measurements were taken due to the loss of time early in the day. So day four was a little bit about playing catch-up. The crew maintained focus and pushed on to as many points as they could. With Greg at the helm, all goals were met. Since a number of measurements required tying up at some piers, Rich, Ted and Lynn got a good workout handling the lines and fenders.

Day Five – Friday May 19, 2006

Coxswain: Jim Picciano; Crew: Janet Morra, Greg Porteus

Day five called for the completion of the fixed measurement points. With Jim Picciano providing the able helmsmanship, all points were successfully measured. In fact, despite having to fight his way through a couple of squalls in the Harbor, Jim was able to accomplish a few additional points that had been added to the list. At the end of the day, the skies cleared and all the electronics were broken down and offloaded from the Launch.

For the duration of the mission, Launch 5 traveled a total of approximately 200 nm and logged a total of 51 hours on each of her main engines and generator. 252 man hours were devoted each mission day for travel prep and mission time. Pre mission coordination and launch prep accounted for about 24 man hours.

Overall, this mission can be declared a success on several fronts. Aspects of planning and logistics, crew response, technical planning and helmsman training were all rated high in our mission debrief. All the underway time provided great opportunity to cross-train all crewmembers in various activities. Even those that weren’t able to attend pitched in such as Cliff Forrest (SO/AN-06) and Mike Murphy who provided on-call engineering support. But the final word on the success of the mission goes to Capt. Hartnett when he wrote to say:

“Our team had a VERY successful trip, thanks to your efforts and those of your NY team -- Lots of great data that will help us tell the story on what can and cannot be accomplished in NY -- Sincerest thanks for your efforts to make this happen!”

[ Photos of this mission can be viewed at: http://launch5.com/PhotoGallery/Missions/Loran/index.htm ]

Click on the photo above to see a bunch of photos taken during the day.