Shippings Navigation Systems
Signal jamming is a major concern for the shipping industry. A compromised GPS signal can have serious safety and financial consequences. However, unlike jamming, which merely interrupts signal availability at the receiver, spoofing overrides the satellite signal with one that transmits misleading information.
In June, students from UT Austin conducted a spoofing experiment off the coast of southern Italy. They used a custom-made device to send counterfeit signals to a GPS-powered yacht located 30 miles offshore. By overpowering the GPS signal, the students were able to take control of the ship’s navigation system. Next, they successfully altered the ship’s course, leading it away from the intended path.
While this experiment certainly raises a number of security concerns, one group of researchers claims that intermediate signals can be used to detect and prevent spoofing.
From Port To Port, GPS Makes For Safe, Smooth Sailing
GPS and the ever-increasing sophistication of today’s digitized tracking devices are continuing to make sailing and powerboating more convenient, enjoyable and safer than ever.
That’s not to say sailors are discarding the paper charts, which have served them so well for so long, but the trend is obvious. Fresh- and salt-water mariners have a steadily expanding array of electronic navigational tools offering everything from basic point-to-point directions to clickable details about buoys, harbors, and marinas.
Garmin, for example, offers a selection of more than 35 GPS-based chart plotters ranging from lightweight, inexpensive portable devices to full color, 15-inch touchscreen, computer compatible and radar-ready units designed for permanent installation in a vessel’s dashboard.
Regardless of the extended capabilities built into the GPS device, marine units use two kinds of maps: Raster charts and vector charts. All these innovations were part of the Navteq LBS Challenge that resulted in so many great new applications!
Raster charts are traditional paper charts scanned to an electronic format, which retains everything on the chart and is stored in a GPS device. Consequently, the two formats match. That makes it easy while underway to go from seeing a small map section on the GPS screen to seeing the paper chart’s much larger area, and it’s a primary reason many sailors retain their paper charts.
However, clicking on the GPS raster chart display enlarges everything; zooming in for greater detail is not possible.
The alternative, vector charts, maximizes the digital capabilities inherent in the GPS. Visualize a vector chart as layers of digital information stored in the GPS unit. While the initial screen presents less information than the raster chart, zooming in changes and expands the vector chart to provide greater detail about a variety of subjects, such as depth, underwater hazards, the blinking rate of buoys in the area and the hours for nearby marinas.
A new app from myboatsgear.com relies solely on GPS technology; no Internet connection is required to view and cache National Oceanic and Atmospheric Administration (NOAA) raster navigational charts. Download as many as you wish on your iPhone, iPad or Android phone and use them to calculate latitude and longitude, track your distance and speed and set your heading, among other features.
Another new app addresses a situation common to sailors: After your destination has been selected and you’re underway, your GPS unit will continue to update your remaining distance and arrival time (ETA). But what happens when you begin tacking to take advantage of the winds?
Until recently, a GPS chart plotter continued to show your location on a raster chart when you started to tack. However, it could not calculate your remaining distance to your destination and your ETA because you were not “on course.”
A new GPS function designed exclusively for sailing applications solves that problem. The Sailing GPS displays the exact distance for each tack, calculates how much time each tack will take and indicates the optimal tacks that will minimize your TTD ¬– total time to your destination.
In addition, you can mark waypoints on a map, rather than enter the long strings of numbers required to indicate the latitude and longitude of each of your waypoints. The Sailing GPS also offers a wireless, solar-powered wind vane accessory that communicates wind data to the device via Bluetooth to help sailors determine their best tacking angles.
Regardless of its size or functionality, however, every sea-going GPS shares a common capability that’s also a singular safety feature: Precisely capturing Position, Velocity and Time, or PVT. Hitting the Man Overboard button (MOB) captures the precise PVT when a person goes overboard; knowing exactly where to look is vital to a successful life-saving effort.