Radar On Top

Ten years ago, “high-tech” in marine electronics meant copying a series of loran TD numbers and plotting them on a paper chart. Today, units that can show your GPS latitude/longitude position on an electronic chart are common, and some units can also show echosounder and even radar information all on the same screen. The main advantage to showing multiple data sources on the same display is that you can easily cross-check information—for example, you can see a radar target on one half of the display, and on the other half you can check the electronic chart to see if that radar target is a buoy or a boat. Raytheon, for one, has made this cross-checking process easier by allowing you to place a marker on a radar target that corresponds with a similar marker created on an electronic chart. But this is an interim solution to the real goal of combining navigation information so a radar image can be placed directly on top of an electronic chart for instant target confirmations.

While companies like Furuno have been making electronic chart displays with radar overlays for years, those units are only found on ships. Why? Because it’s not easy—or inexpensive—to take radar images and place them precisely atop chart images. For one thing, the radar range and the chart range have to match perfectly, and for another a radar image becomes skewed as the vessel turns beneath a rotating antenna. As a result, the display has to process a tremendous amount of information, and until now it took a unit the size of an arcade video machine to get the job done. But thanks in part to the emerging role of the PC onboard, radar overlay technology is becoming available to the recreational boating community. Here’s a look at how several key players in this field plan to overcome the challenges of making radar overlay possible aboard recreational boats.

Furuno—Of all the companies I spoke with, only Furuno is meeting the challenge with a non PC-based product in its new FRS 1000. This innovative piece of marine electronics combines GPS input with an echosounder, electronic chart, and radar to provide a fishfinding, charting, and radar-overlay solution in a single unit. With a 10-inch color LCD display the FRS 1000 is designed for recreational boats, and Furuno USA’s marketing manager Roy Thompson says the unit should be on the market by the time you read this. “The problem in introducing a compact unit,” says Thompson, “is eliminating the many controls you have available on a shipboard-sized display. It gets difficult to put all of the controls you need into the smaller boxes.”

Available in 36-, 48- or 64-mile radar ranges, the FRS 1000 is the first integrated navigation display I’ve seen which needs no interfacing with other electronics. The unit can display Navionics or Furuno vector charts, and it appears to be a simple matter to toggle between radar, plotter, and sounder modes, or a combination of all three displays onscreen simultaneously. The unit comes with its own infrared remote controller, and options include a 48-rpm antenna for high-speed boats and ARPA capabilities for tracking multiple radar targets. “The next step,” says Thompson, “is a 12-inch monochrome display,” but with its FRS 1000 Furuno has broken through a significant barrier in marine-electronics technology.

Koden and Nobeltec—Si-Tex/Koden’s v.p. of marketing Dave Church echoed Thompson’s sentiments in the challenges of putting radar overlays in an affordable package. “Traditional marine electronics don’t have the capability to move the amount of data needed to superimpose a radar image on a chart,” says Church. “On boats, the unique challenge is that the sensor [radar antenna] and the computer are not close physically, and moving high-speed data over distance is hard to do.” Koden’s solution is to combine its radar technology with a personal computer and transfer data from the radar antenna to the display via a format called RS422. “The RS422 connection,” says Church, “moves serial data at high speed over fairly long distances, and it’s not susceptible to the RF noise that’s all over boats.”

As far as hardware is concerned, the Koden package consists of a radar transceiver housed in a 12-inch dome antenna that provides a 24-mile range. A cable coming from the antenna connects to a box below decks that “Converts the RS422 into something the PC can understand,” according to Church. The next piece of the puzzle is in the software, and that’s where Nobeltec comes in. Nobeltec’s v.p. of sales Jeff Hummel says, “This solution of combining Koden hardware with Nobeltec software is the cleanest and simplest way to eliminate complexity in the system.” You control all of the radar’s functions using your PC, and there are two versions of this package. For $2,595 you get the Koden transceiver with Nobeltec’s Visual Mariner software and radar overlay capabilities. But for $400 more, you get Nobeltec’s Visual Navigation Suite, plus the ability to enhance the radar targets for clarity. Chuch says with the upgrade package, “The color of the radar returns indicates target strength [much like a color echosounder], and the power of the PC opens up a world of opportunities,” to clean up and enhance the basic radar image. The Koden/Nobeltec package was undergoing final testing at press time and should be on the market Summer 2000.

Pinpoint Systems and Nautical Technologies—In another joint venture, Pinpoint Systems recently acquired Nautical Technologies, maker of “The Cap’n” software navigation system. In this PC-based solution, you install one of Pinpoint’s Titan Targetmaster processing boards in your PC so it can accept raw signals from your existing radar. Then on the software side, a $4,000 upgrade for The Cap’n electronic charting system gets you the Radar Watch program, which allows your PC to superimpose transparent radar images atop charts displayed by The Cap’n.

Nautical Technologies’ president Dennis Mills says there are a number of benefits with a PC-based system that are unavailable using traditional marine electronics. “With a PC, you can have a remote display as big as you want, and as many displays as you want around the vessel. This system will turn a monochrome radar into a color display, and even small radars can get North-Up capability on a PC display. It’s all done in the software.”

Mills says the future is bright for this technology and, “In the next five years you’ll see the software solution bringing ship-sized radar features to the consumer.” As an example, Mills says a rain squall on a traditional radar display may obscure vessels within the squall area since the radar only has six levels of quantization. But the PC has 256 levels of quantization, so it can actually reject weak returns from rain while displaying small-vessel targets within the squall. In this way the computer enhances the radar image to show vessels that may pose a risk of collision.

Given the fact that most PCs and computer displays are not designed for the marine environment, it may take some time for them to make their way aboard production boats as standard—or even optional--equipment. But make no mistake, that day is coming. And when it arrives, the ability to see radar images on top of electronic charts will only serve to increase safety-at-sea for us all.