Some things about radar that used to be considered common knowledge are no longer valid — and some, of course, never were.
Common knowledge says radar scanners mounted in compact radomes are great for short- to mid-range performance but that you need an open-array antenna for longer ranges and better detail; the problem for most recreational boaters has been choosing one or the other.
At least it used to be a problem.
Simrad reports that its new HALO Radar, the culmination of 10 years of work, combines the advantages of its broadband radar and traditional pulse radar systems to show targets as close as 6 meters away while offering exceptional long-range performance out to 72 nautical miles.
Simrad calls it the first high-performance, solid-state, open-array radar system with pulse compression technology designed for recreational and light marine markets.
Until the advent of broadband radar, it was difficult to see targets close to your boat, even with smaller systems, because the “bang effect” from transmitted signals near the antenna blanked out close-in returns.
You see something somewhat similar on your sonar screen when the band of surface clutter is so thick it hides targets less than 6 to 10 feet deep.
The short-range blind spot was worse with pulse radar. Thanks to broadband radar’s technology, the blind spot has diminished to about 20 feet. You can almost reach out with a boat hook or landing net handle and touch the closest targets you see on your screen.
How far a radar unit can see is largely dependent upon how high you can mount its scanner on your boat. I wouldn’t expect to see a system with a 72-mile maximum range actually show you echoes from that distance while mounted on a 20-foot center console boat.
Radar signals travel in almost a straight line, making its operation pretty much line of sight. A 6-foot-tall skipper standing on the deck can see about 7 miles across open water before the curvature of the earth limits his visible horizon.
Most fishing boats without towers don’t offer a mounting elevation high enough to see 72 miles. Still, the higher you mount the scanning antenna the farther the radar can see so, as they say, your mileage will vary.
HALO radars have a beam sharpening feature designed to enhance target separation control and give you better resolution both close-in and far away. It boosts the resolution of HALO models with 3-foot open-array antennas to that typical for a 4-foot array, the HALO 4-foot array to the resolution of a 6-foot array and its 6-foot array to the resolution of an 8-foot array.
This is one of those things you have to see on a screen to really appreciate, and it is more impressive than it might sound to someone who has not used radar very much.
A dual range mode lets HALO units function as two radars in one: They can scan two distance ranges simultaneously in separate screen windows with independent controls and 10-target MARPA tracking in each window, and it does it all with no compromise in detection at either range.
In case you aren’t familiar with MARPA, it stands for mini-automatic radar plotting aid. It’s a radar feature that helps track moving targets in the hope of avoiding collisions with them.
You manually select targets that concern you, and MARPA automatically tracks them, showing their range, bearing, speed, direction of travel, estimated closest point of approach and closest time of approach. It rates them as safe or dangerous, and can activate a proximity alarm when they get uncomfortably close.
Five special operating modes are available on HALO radars.
Custom (for manual tuning), harbor, offshore, weather and bird-finder modes tune HALO’s advanced signal processing to optimize your view of targets in both good and bad weather.
This processing includes digital sidelobe reduction and directional sea clutter rejection to enhance the detection and discrimination of smaller targets.
A sector-blanking function also helps by eliminating unwanted reflections for less clutter on the screen. Simrad says HALO can spot even small flocks of birds from miles away and track their position to right off the bow as you close in for the hot fishing they promise.
Traditional pulse radar relied on a high-powered magnetron or vacuum tube to transmit pulses, and that meant powering the unit up and waiting through a two- or three-minute warm-up period. HALO’s Instant On feature requires no warm up from standby and just 16 to 25 seconds from a power-off state.
Radar scanners used to be installed well clear of where the skipper and passengers rode and fished. We joked about avoiding the scanner’s “rays” to keep from becoming sterile, but the humor was only half-hearted.
But radiation is no longer a problem here, as HALO’s solid-state technology means compliance with the latest low-emission and radiation standards. Simrad says all HALO radar models are radiation-safe to people within the swing circle of their arrays, and safe to use in anchorages and marinas.
HALO units not only return all family planning back to you, but they also place a lighter load on your boat’s electrical system. Transmission power consumption is only 6.5 watts versus 10 to 15 watts for traditional pulse radar.
Add in the rotating motor’s draw and HALO requires 40 watts average in no wind and 150 watts at maximum wind velocity. The scanner can turn at up to 48 rpm.
Looking at the whole picture, its low power consumption, support for 12- or 24-volt electrical systems, and availability in 3-, 4- and 6-foot open arrays makes it practical for boats of all sizes — including smaller craft where open-array radar might never have been seriously considered as an option.
The new HALO radars are compatible with Simrad’s NSS evo2 and NSO evo2 multifunction display systems. They connect via Ethernet using a bulkhead-mounted interface box mounted below deck.
The units even look good sitting on their curved pedestals and accented with built-in soft-glow, blue LED lighting with variable brightness.
Simrad says they are also reliable and quiet, thanks to a rugged helical gear train and a brushless motor.
Three 25-watt, pulse compression models are available: the HALO-3 with 3-foot array (MSRP $4,500), the HALO-4 with 4-foot array ($5,000), and the HALO-6 with 6-foot array ($5,500).
Visit www.simrad-yachting.com/en-us/products/radars/halo-radar for more information.