NN3D & the Q factor, road trip!

... written for Panbo by Ben Ellison and posted on May 14, 2008

Furuno_test_boat_May_2008

Yeeeeha…today I’m driving down to Cape Cod so that on Thursday I can ride on Furuno’s test boat equipped with the geekalicious NN3D network of gear shown above, and bigger here. Hosting the demo will be Brice Pryszo, founder of MaxSea, and his son Iker, who now works at Furuno USA headquarters. I’ll be Spot sharing, taking pictures, pushing buttons, and asking questions. And I’m open to suggestions about just what to ask and look for.

And that’s not all. On Friday I’ll be joining the knowlegable Airmar marketing dept.—Jennifer Matsis and Mark Reedenauer—in Portsmouth, NH, for a ride on their test boat. Which is bristling with transducers—one each: P79, P66, B164, M260, B260, & SS264W—and screens from all the usual suspects to view their goodness on. In an NMEA seminar last fall, Jennifer taught us all a little about “Q”, a measure of sonar sensitivity (Q = fr/delta f, where fr is the resonance frequency and delta f is the bandwidth at the –3 dB point, if you must know), and I’m expecting to see what good Q looks like in action. Among other things, like the PB200 Weather Station, and maybe some fishing. Again, your suggestions about what to look for are welcome. By the way, Airmar’s “technical presentation”—graphic examples of Q, install tips, and more; 10MB worth—can be downloaded from their marine brochure page.

Posted by Ben E on May 14, 2008 9:46 AM

Comments

Ben,

I'm very interested in what the cost for non-US charts will be for NN3. Info says that Carib will be available this summer. Cost of charts could influence another look at NN2 and C-Map.

You have an outstanding Web site. Thanks for doing such a great job for all of us out here in the ether.

Roger

Posted by: Roger at May 14, 2008 7:22 PM | Reply

This is probably a dumb question, but here goes. What sort of vulnerability is there in these hubs? Can this take out a lot of the system? If so are they just transfer stations with little likelihood of failure or do they have electronics in them which I know can and do fail.

One argument against MFDs is that when they go down, you can loose at lot - plotter, radar, AIS,fish finder, weather data and so forth. Can hubs put you in the same place?

Posted by: DefJef at May 14, 2008 8:07 PM | Reply

Ben,

I was told by Furuno that they had no definite plans yet to bring out chart updates. Can you grill them on that, US + non US?

@DefJef:

An Ethernet hub or switch does contain electronics, and I have seen them pack up in our data center here at work. On the other hand, carrying a $50 (non-Furuno) spare is not a big problem, whereas I don't think somebody would carry spare MFDs! You'd lose the 'remote on/off' capability but at least you'd still have AIS/Radar etc.

Having 2 MFD's wired in (or as in the picture - an MFD and a BB computer) will provide the same fallback capability and gives dual station capability at most times.

Posted by: Kees at May 15, 2008 4:41 AM | Reply

Ask them when to design a good solution, where a laptop is the center of the system, and all other equipment can be connected via firewire. :-)

Posted by: Rolf at May 15, 2008 9:45 AM | Reply

DefJef: If you mean the Ethernet hubs, you're absolutely right, it's a single point of failure. However, you don't have to have a Furuno hub. If you used a generic hub, you'd lose the power up sync, but you'd still have a functioning network. Ethernet hubs are very inexpensive and generally very pretty reliable. I've never heard of an ethernet hub failing.

Posted by: Russ at May 15, 2008 3:37 PM | Reply

Ben,

Big Airmar Question.

I would think the Airmar sensor laden PB200G ultrasonic mast mount weather station would be perfect for use in a sailboat applications if they would focus on that. I would like to hear why they are not targeting sailboats when you speak to them Friday.

I would think that not much effort would be required to have their "dynamic motion correction" software be able to correct apparent and true wind for my boat being suddenly jerked forward by a spinnaker filling, or decelerating when it collapses. Currently when I set my autopilot to follow a course that is a 110 to 130 degrees off the wind, it gets confused by my wind instrument providing the wrong information each time the spinnaker collapses and fills ... as happens often in following seas. If "dynamic motion correction" could calculate quickly ... it would enable both the apparent and true wind to be correctly determined, this would be the number one reason for a cruising boat such as mine to buy their product. With accelerometers built into the instrument, I can see it being able to correct for this ... if the software allowed (e.g. didn't average out) such sudden acceleration / deceleration and allowed that to be valid input at low boat speeds typical of sailboats.

I had asked airmar this, but their technical support wrote back "We do not have any data to support whether we will be able to provide corrected data this quickly. Based on the calculations we need to make, it will take approximately 4 seconds to come up with the new data. I'm not sure this is adequate for what you require." also they wrote "we are technically not marketing the product for sailboat applications."

... certainly 4 seconds won't be fast enough, but I would think if they would target the sailboat market and/or consider this in their software requirements, this use of their product for cruising and racing sailboats would be greatly valued by me and others.

Best Regards,
Dan

Posted by: Dan (b393capt) at May 15, 2008 3:42 PM | Reply

NN3D question ... can you use off the shelf ethernet cable, and if not, is the ethernet cable a reasonable price ?

The ethernet cable from Raymarine is very pricy ($50 for 1.5 meters, $220 for 20 meters, for example), and the RJ45 connectors in the equipment is slightly different preventing normal cables from being used.

Posted by: Dan (b393capt) at May 15, 2008 4:05 PM | Reply

Reply to Dan:

I am not sure that the wind "shifts" you see are so much due to the accelerations from the spinnaker, or from the flow off the top of the spinnaker. Unless you have a 10+ foot wand (or I suppose a fractional kite) the flow off the top of the spin affects the wind instruments significantly.

Posted by: ibsailn at May 16, 2008 10:01 AM | Reply

ibsailn

The top of my kite is not in plane with the wind instrument. Especially having a sock on the top of my asymetric spinnaker (causing the top of my kite to be five feet below the height of my mast) and 6-8 foot forward .. I don't believe the wind deflections (at 130 degrees apparent) are as significant as the other forces that cause my current wind instrument to be fooled.

I believe the main effect comes from the mast top flopping around as a follow sea catches me from behind pitching/yawing the entire boat, or the sudden movement from the kite filling ... which transmits its energy along three lines, the top of the mast having the least amount of mass and most amount of sudden movement.

Posted by: Dan (b393capt) at May 16, 2008 11:26 PM | Reply

Sorry, many of my answers need more work, but here's what I'm pretty sure of now:

Roger, Non U.S. MM3 cartography (the NN3D/MSTZ raster and vector format) will cost $400, but I'm not sure how big those regions are. At least at first, some will only include Map Media rasters, some only Navionics vector data, and only a few will have high res photography. The Bahamas is expected this summer, based on Navionics latest data, and will have "the best" photo maps available.

Kees, The U.S. online chart updating service has been developed and is being tested now, expected to go live this summer. None U.S. updating can not be done online because of H.O. copyright issues, but there will be a card based system, with a fee. Not sure when.

Dan, you can use standard Ethernet cables on any of the MFD gear, but if you want the connection on the MFD waterfproof you'll need a special cable, price unknown.

As for the PB200, I remain confused. Yesterday Airmar told me that it's not intended for masthead mount, but later handed me a preliminary brochure that lists sailboats as an application. It's also not quite ready for shipping, and the N2K version of the software won't be done for some months. The specs suggest great potential though.

Posted by: Ben at May 17, 2008 10:54 AM | Reply

I, too, have been talking to AIRMAR about sailboat uses. One interesting idea that came up is to use their pb200 atop the mast and another matching instrument (without wind) at the mast base. A custom program could even measure your top of the mast movement relative to the hull - good experiment in and of itself - and before that is run you have a good compass with rate accelerometer running hull position relative to ground and matching correction of wind for pitch, roll, and whip of masthead giving accurate wind angle relative to hull, water, or ground.

What will the data mean to us? I don't know. I am hoping that the wind correction alone will make the pilot run better when steering to wind, but no one seems to know if it will.

Posted by: artist/scientist at May 17, 2008 12:46 PM | Reply

Dan, Can you be a little more specific and let us know what autopilot you currently have, how big is your boat, etc?

Thanks in advance

-Aaron

Posted by: Aaron Lynch at May 17, 2008 4:07 PM | Reply

Aaron, yes ... I have a 39 foot Beneteau sailboat with a Raymarine S2G autopilot, and incidently an airmar cs4500 ultrasonic speed sensor (great product !). The full electronics suite on my sailboat is here on the panbo site ... follow the links [Features] / Marine Electronics Systems / Better / Dan's Sailboat.

I am both a cruising sailor, racking up many day sails, a dozen 2-day trips, and a single 16-day cruising trip every season; and I race my boat 8-10 times a year as well under the PHRF handicap system. My sail inventory includes two different types of spinnakers, a standard cruising asymetric plus a Doyle UPS / Code-0 style sail.

What are your thoughts Aaron ?

Posted by: Dan (b393capt) at May 17, 2008 11:50 PM | Reply

G'day, Can you please assess the SC-30 as an alternative to a gyro compass. I am looking into replacing a gyro due to the service required with a SC-30.

Cheers,

Stu

Posted by: Stuart Kennedy at May 19, 2008 11:50 PM | Reply

Stu, I plan an SC-30 entry soon, but in the meantime I can tell you that we test it a lot off Cape Cod, and I thought it an amazingly fast and accurate sensor.

Posted by: Ben at May 20, 2008 6:48 AM | Reply

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