HD Radar: Is it Sensitive Enough to Pick Up Small Objects ?

[Exiles]

I am looking for peoples feedback on HD radar. I am planning to buy a system and was wondering if anyone knows if it is sensitive enough to pick up icebergs and if so to what size.

Also I would appreciate feedback on proven models.

If you want further information check out my expedition blog at www.belzebub2.com.

Thanks for your advice!

[AKSailor]

For two years, I have had a Raymarine 2Kw radome connected to C80. I live and sail in Alaska. Distance, above-water-height, and above-water-shape all contribute to reflections of radio waves. We regularly "see" bergy bits about a meter on a side that protrude above water about half meter. Rounded bergs don't reflect as well. Bigger bergs reflect very well. I know that you are aware that 90% of the berg is below water, so even a berg smaller than 1 m^2 can do severe damage. We also depend on a forward-looking sonar. Personally, I think that it's as important as the radar. I have to do a bit of fiberglass work each spring to repair the dings and dents in our bow from pushing through brash ice.

[Exiles]

Wow, thank you for the great information! Can you suggest any forward looking sonar systems?

Thanks!

[AKSailor]

We have an Interphase Probe, a model almost ten years old now. Interphase: Manufacturer of Forward Looking Sonars, Navigational Chart Plotters, WAAS/GPS and Fish Finders I don't think that's being made now, but newer units certainly are, including a "black box" that will send info to most chart plotters.

Our Probe scans (no moving parts so has been completely trouble-free) from the level of the transducer, parallel to the water surface, to directly below the boat: a 90° view. The beam can also be steered: quite useful in ice since the water behind a sunken terminal moraine is usually quite deep. We can "see" about 1200 ft in front of the boat, and 800 feet down. Glacial water usually has a lot of ground-up mountain in it so has a lot of particulate: getting to 800 ft will not happen. The thermoclines (layers of dramatically different water temps) also bounce sonar off and can drastically limit the usefulness of any sonar. Be careful out there!

[I bought the Interphase when a friend told me his story. His newly installed Probe sounded an alarm for a danger ahead, although he could not see anything. He slowed anyway, and swerved. The Probe had "seen" a submerged cargo container that had dropped from a container ship! It was just awash so virtually invisible. Since it was a very large steel box, we're sure that it saved his boat. I bought one that season and it has changed our sailing. Up here, things are not as well charted as in the rest of the US: stone pillars (reaching up to near-surface from very deep water) are not charted at all or are charted out of place. There's an island in Prince William Sound that's 1/4 mile out of place on the chart. In addition, the land is still rebounding from the glaciers so charted depths are wrong by quite a bit. Some areas are not charted at all since they are recently out from under glaciers! Up here, water is usually 1000 ft deep, but it changes quickly.]

[AKSailor]

By the way, great site! We're currently headed south, but plan to return to AK via the NW Passage. Be safe. Have fun.

SV Wings.index

[Exiles]

Thank you for the great information!

Enjoy your travels. Maybe see you in the NWP

[CarlF]

I've never used one, but you might want to consider one of the new broadband radars. Small radome, low power consumption and extremely good close range-in target discrimination. I think their weak point is long range but that may not matter to you.

Broadband Radar™ | SIMRAD BR24 | Marine Radar

Carl

[JJB]

Originally Posted by Exiles

I am looking for peoples feedback on HD radar. I am planning to buy a system and was wondering if anyone knows if it is sensitive enough to pick up icebergs and if so to what size.

Also I would appreciate feedback on proven models.

If you want further information check out my expedition blog at www.belzebub2.com.

Thanks for your advice!

Till we got dismasted last weekend, I had a brand new Furuno UHD open array 6kw, I never really got to use it at sea, but my bit of experience with it, was it just makes contacts easier to isolate, especially in heavy rain.
I've never sailed far enough south to run into ice bergs, so have no two clues on that one, but maybe drop Raymarine, Furuno and Simrad an Email and see if they have any info on ice bergs.

[roverhi]

Are broadband and HD radar the same or different technology??

[JJB]

Originally Posted by roverhi

Are broadband and HD radar the same or different technology??

They are different, my understanding, HD uses pulse technology, where as Broadband uses a constant beam. I think.

[Maggie-K]

Read the Panbo review on HD Radar
Panbo: The Marine Electronics Weblog: HD radar, especially Furuno's

[Exiles]

Thanks all!

[amytom]

We have the older Raymarine RD218 2kw dome. On the ICW at night or in fog we can easily pick out the channel markers then spot them with the spotlight.

In bluewater the wave action affects the radar and it automatically adjusts to reduce the "sea clutter". You can probably find the older models cheap as other sailors upgrade.

[goboatingnow]

I dont think that the broadband radar sees water very well, hence it cant detect rain squalls and would probably not be great against bergs, only by uneducated view though.

Dave

[Paul Elliott]

Originally Posted by goboatingnow

I dont think that the broadband radar sees water very well, hence it cant detect rain squalls and would probably not be great against bergs, only by uneducated view though.Dave

The problem that broadband has (had? -- they were working on it) with rain was one of sensitivity to small diffuse targets, not water per se. In my different uneducated view the broadband radar should see bergs at least as well as regular (pulse) radar.

I've got a Furuno HD radar and it should see bergs as well as any. I've never personally sailed where the water gets hard, though.