Maretron vs. Airmar Ultrasonic Wind

[ChrisseH]

Originally Posted by dpddj

Great info - hoping you might be able to help me. I have been looking at the LCJ-CV7SF. I would like to go with the wireless for atop the masthead. Tired of the ospreys and their perching habits.

I still have the Raymarine ST60+ wind display (old NEMA 0183), in working condition. My chartplotter is a Raymarine e95 so I also have NEMA 2000 available.
Would you know if I'd be able to LJC masthead unit to work with the old ST60+ wind display? Or... would you have a recommendation for a repalcement display?

Thanks a ton.

If you aim for a reliable system you should not use wireless solutions. This and the lower night time update rate of the solar powered CV7 SF I assume are the reasons why LCJ Capteurs does not recommend this sensor for autopilots. So go with the model CV7-C if your ST60+ system can accept NMEA 0183 data. This is a 4 Hz sensor installed on a vertical carbon pole. The version CV7-E is also 4 Hz, but its aluminum pole is in my mind too short for a mast head installation. If you prefer a traditional forward pointing model go with the basic 2 Hz model CV7. And use the WindyPlug if you want to connect these sensors to a NMEA 2000 system.

LCJ Capteurs have a Raymarine ST option for connecting a CV7 directly to the ROTAVECTA input on a Raymarine ST60 Wind instrument, but I have no experience of this option.

When using LCJ Capteurs' wind sensors with other manufacturer's displays or plotters it is important to clarify how the wind angle offset and other settings will be adjusted. If you are lucky you can do at least the offset calibration in your display or plotter. If not, you can download a small Windows software from LCJ Capteurs' website by means of which you can change the wind angle offset and other sensor settings. This requires however a serial connection for connecting the sensor to the PC. I have used Digital Yachts USB NMEA Adapter cable for this purpose, but I think also LCJ Capteurs' own USB adapter should work.

[tanglewood]

I'm not sure if there is a connection, but Maretron told me that their WSO100 is of French origin. Makes me wonder if they come from LCJ Capteurs. If so, switching from the WSO to LCJ may just be jumping from one fire to another.

[barnakiel]

Originally Posted by tanglewood

I'm not sure if there is a connection, but Maretron told me that their WSO100 is of French origin. Makes me wonder if they come from LCJ Capteurs. If so, switching from the WSO to LCJ may just be jumping from one fire to another.

You can simply send emails to both companies and ask.

Imho, this theory is highly unlikely. Mareton sensors were on the market years before I even heard of LCJ.

Also, physically, the units look completely the opposite. It seems the LCJ has sensors in the top cap while Mareton seems to keep them in the base.

Ask at source, report back. My default theory is they have nothing in common but the technology employed.

Cheers,
b.

[VENTS]

Originally Posted by barnakiel

You can simply send emails to both companies and ask.

Imho, this theory is highly unlikely. Mareton sensors were on the market years before I even heard of LCJ.

Also, physically, the units look completely the opposite. It seems the LCJ has sensors in the top cap while Mareton seems to keep them in the base.

Ask at source, report back. My default theory is they have nothing in common but the technology employed.

Cheers,
b.

Apart from the principle of physical measurement of wind, Sonic anemometer LCJ Capteurs have nothing to do with Maretron. Even if we existed long before Maretron! In the year 2000 ...
By cons, AIRMAR, Watch the similarities between our CV3F and their wind sensors! CV3F - LCJ Capteurs

Since then we have made many innovations incorporated in our CV7 range.
How does it work? - LCJ Capteurs

[VENTS]

Originally Posted by ChrisseH

If you aim for a reliable system you should not use wireless solutions. This and the lower night time update rate of the solar powered CV7 SF I assume are the reasons why LCJ Capteurs does not recommend this sensor for autopilots. So go with the model CV7-C if your ST60+ system can accept NMEA 0183 data. This is a 4 Hz sensor installed on a vertical carbon pole. The version CV7-E is also 4 Hz, but its aluminum pole is in my mind too short for a mast head installation. If you prefer a traditional forward pointing model go with the basic 2 Hz model CV7. And use the WindyPlug if you want to connect these sensors to a NMEA 2000 system.

LCJ Capteurs have a Raymarine ST option for connecting a CV7 directly to the ROTAVECTA input on a Raymarine ST60 Wind instrument, but I have no experience of this option.

When using LCJ Capteurs' wind sensors with other manufacturer's displays or plotters it is important to clarify how the wind angle offset and other settings will be adjusted. If you are lucky you can do at least the offset calibration in your display or plotter. If not, you can download a small Windows software from LCJ Capteurs' website by means of which you can change the wind angle offset and other sensor settings. This requires however a serial connection for connecting the sensor to the PC. I have used Digital Yachts USB NMEA Adapter cable for this purpose, but I think also LCJ Capteurs' own USB adapter should work.

Information on the difference between the frequency of the wind measurements and the frequency of the data being made available to the user. It should not be confused!

The more measurement results we have, the more we can filter data and provide coherent and reliable wind values.

The refresh rate is the number of wind data at the sensor output. For example:
CV7-C = 4 per second
CV7 = 2 per second
CV7SF = 1 per second of day and 1 every 13 to 18 seconds at night

The wind measurement frequency is the number of wind measurements inside the sensor. For example:
CV7-C = 60 Hz continuously
CV7 = 30 Hz continuous
CV7SF = 4 measurements per second in 1 burst mode, in daylight / 8 measurements every 13 to 18 seconds at night.
In other words, the CV7SF does the measurements for a short time. During the rest of the period (1 second or ~15 seconds), we did not realize that it was past regarding the wind.
This seems dangerous for a sailing operation with an autopilot. This is why we do not recommend using the CV7SF with a sailboat.

We will have in September, a new wireless model with identical capacities of days and night ...

[poiu]

How do these sensors filter out the pitching motion of the boat? Is this always done in the autopilot or sensor display?

As the boat pitches down, wind will increase and move forwards in direction significantly as the mast swings forwards. The higher the mast, the greater the effect. The lower the wind the greater the effect of pitching such that it may completely swamp the wind sensor information.

Rolling also has an effect and needs filtering too.

[ChrisseH]

Thanks VENTS for pointing this out. So, when we talk about 2 or 4 Hz we talk about the rate the output of the sensor is updated, the signal of which has been internally filtered, or in case of mechanical wind sensors, integrated over a certain time period.

Although the data in many wind measurement applications (i.e. meteorology) is filtered quite a bit, it is, at least in sailboat racing, good if the wind sensor is very fast. Especially when compensating the wind data for the yacht’s motions, or when using the data for calculating Target Boat Speed or analyzing tacks, gybes etc. For cruising a fast wind measurement is less important.

[ChrisseH]

Originally Posted by poiu

How do these sensors filter out the pitching motion of the boat? Is this always done in the autopilot or sensor display?

As the boat pitches down, wind will increase and move forwards in direction significantly as the mast swings forwards. The higher the mast, the greater the effect. The lower the wind the greater the effect of pitching such that it may completely swamp the wind sensor information.

Rolling also has an effect and needs filtering too.

As far as I know there is no wind sensor on the boating market that has built in pitch and roll compensation. The sensors simply measure the overall airflow and its direction disregarding what has caused the flow. In many wind sensors the raw signals are filtered so much that at least the flow caused by the most rapid pitch and roll motions are "averaged out".
If you want true motion compensated wind information you need to compensate for this elsewhere in the system. Such advanced systems can typically also compensate for upwash and other effects and errors in the system. It is worth noticing that there is no point in compensating for pitch and roll motions in case the output of the wind sensor is filtered very much.

[tanglewood]

Originally Posted by ChrisseH

As far as I know there is no wind sensor on the boating market that has built in pitch and roll compensation. The sensors simply measure the overall airflow and its direction disregarding what has caused the flow. In many wind sensors the raw signals are filtered so much that at least the flow caused by the most rapid pitch and roll motions are "averaged out".
If you want true motion compensated wind information you need to compensate for this elsewhere in the system. Such advanced systems can typically also compensate for upwash and other effects and errors in the system. It is worth noticing that there is no point in compensating for pitch and roll motions in case the output of the wind sensor is filtered very much.

I believe the airmar device does precisely that.

[ChrisseH]

Originally Posted by tanglewood

I believe the airmar device does precisely that.

According to earlier posts in this thread Airmar is only using the motion sensors in their wind sensors for stabilizing the built-in heading measurement, not for pitch and roll compensation of the wind data. They initially had in mind to do this, but faced serious challenges.

[Jerry Woodward]

Back to the reliability issue. I was planning on getting a WSO 100 until I read this thread. Now I'm looking at mechanical sensors like the B&G 508. So what is worse, the potential moisture problem with Maretron, or the typical bird/corrosion problems with mechanical sensors? If you had no wind sensor, which one would you buy?

[lateral]

Originally Posted by Jerry Woodward

Back to the reliability issue. I was planning on getting a WSO 100 until I read this thread. Now I'm looking at mechanical sensors like the B&G 508. So what is worse, the potential moisture problem with Maretron, or the typical bird/corrosion problems with mechanical sensors? If you had no wind sensor, which one would you buy?

Search Navico simrad B&G 508 problem. I doubt you'll be rushing to buy.

http://www.cruisersforum.com/forums/...ry-189032.html

[Jerry Woodward]

Originally Posted by lateral

Search Navico simrad B&G 508 problem. I doubt you'll be rushing to buy.

http://www.cruisersforum.com/forums/...ry-189032.html

I did the search, didn't find anything particularly alarming. The link seems to show a unit that suffered physical damage and not necessarily a problem with the unit. What am I missing?

But that's really beside the point. What I'm really asking is, which is going to be more reliable: an ultrasonic or a traditional wind sensor?

[tanglewood]

Originally Posted by Jerry Woodward

I did the search, didn't find anything particularly alarming. The link seems to show a unit that suffered physical damage and not necessarily a problem with the unit. What am I missing?

But that's really beside the point. What I'm really asking is, which is going to be more reliable: an ultrasonic or a traditional wind sensor?

Just buy an Airmar 100WX or 110WX. The solid state weather instruments are great - just not the WSO100.

[a64pilot]

I bought a WSO six months or so ago, its on the mast now, but not connected.
My plan was to have it and the mechanical, but was talked out of it.
If nothing else if it breaks, it ought to be easy to change, three screws and one cable connector.
I hope the issues have been fixed.