SKY and AIR on a boat

#1

Hello all.

I am/was a field tester for Weatherflow and have long thought that a marinized version of both SKY and AIr would be a natural fit on a boat.

There are a couple of issues, especially the SKY’s need to be oriented to the north, that would be dealt with though the maths is relatively simple knowing the boat’s bearing and SOG.

I am no programmer though I dabble. I do, however, own two masts on one boat and a SKY/AIR/hub system that I would like to modify for a sailboat.

Would anyone be interested in working with me to create an app that would allow the smart weather stations to function on a moving sailboat?

Cheers,
Mo

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#2

Mo,

I already have plans for this exact application. I am definitely interested.

PM me for details.
–Sam

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#3

if you have a GPS on the boat with serial output then you can use the data from that ( I already do that in a program I developed which works with WF, but would need to be changed to get the weather data from WF and not the GPS)

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#4

FYI – the WeatherFlow Wind & Weather meter app already allows for use of the WEATHERmeter on a moving sailboat and calculates apparent wind using GPS vectors. While the WEATHERmeter is not designed to affix permanently and record observations continuously…it works quite well for distinct observations on a boat. WeatherFlow has been working with a sailing syndicate in Australia to modify the WEATHERmeter and associated software for mast-top mounted use. Nothing has come out of the collaboration yet.

Although the SKY & AIR were not specifically designed for use on moving objects (boats, cars, storm chasing vehicles)…we’re quite curious to see what inventive solution you might come up with. Challenges include dynamic wind direction orientation, apparent wind vectors, vibrations on the haptic sensor, moving location assignment. Otherwise, the HUB and comms architecture is certainly flexible enough for remote operation — wireless between HUB and sensors, BLE to phone running app, phone sends data to cloud if desired, low power operation even with USB power brick, etc. Have at it!

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#5

It’s super simple. Start with a Raspberry Pi and an application such as WFArchiver.

Then you need the code to get the actual direction and speed of the craft. Simple calculations will give you an extremely close direction and speed.

You can record the data from the craft along with the timestamp so you can calculate any archival data at any time in the future.

It’s really very simple.

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#6

Beginning to work on just such a solution . . . a Raspberry Pi (with the GPS option) and WFArchiver should be able to talk to a Hub and its attached sensor devices and give (and log) all readings (with the likely exception of rain - which would probably be meaningless in that application). More looking at this from a storm-chaser point of view . . . because I don’t actually have a boat.

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#7

@WFmarketing is surely right about the challenges, but most seem to things that can be overcome. A couple jump out as problem areas. First, the haptic sensor is not likely to do much for rain measurement on a moving craft or vehicle (vibrations and non-vertical orientation seem difficult to overcome). Second, if AIR is used for barometric pressure measurment on a moving vehicle (particularly in hilly terrain), only station pressure would be a valid measurement and if sea level pressure was desired, then a local computing device would need to take station pressure and GPS elevation data and do the sea level adjustment on the fly. Many other issues/challenges are out there, but I think they can all be dealt with. Can’t wait to see how this discussion thread develops and what solutions are constructed.

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#8

Interesting. I will help you to modify the code if you want.

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#9

That could be overcome with data from the GPS. Modern phones already have this in place.

The obstacle is to find a really good GPS module for the Pi. I am looking for one for another project.

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#10

I have done a lot of work (in my head AND in practice) toward this goal. From my viewpoint, all the necessary hardware exists in our smartphones and a lot of the tablets produced today.

I had a quick discussion about this with Maurice already. Planning on having a working version of my smartphone app, modified to pull the BT data from the HUB and do the necessary windspeed & wind direction offsets in the next couple of weeks.

I agree with @WFmarketing about the WEATHERMeter. I’ve used mine for a quick sanity check of the winds on our boat… but it’s not ready for full-time use that way. Anything that we can do to take the existing SWS and use it for mobile Wx observations will be beneficial to everyone in the long run.

–Sam

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#11

I use sky and air on my 5th wheel RV. Right now, north is towards the front of the RV. Ideally, I could update location based on network GPS from one of my cellular hotspots. I’m less concerned about in motion logging but prefer not to have the invalid data eg, artificial wind speeds. I’ve been meaning to write a script to populate location information from afformentioned GPS data. Would be extremely simple. Without a compass it would be difficult with GPS data alone for me to determine final orientation after parking the RV. Since us RVers do not have the same level of navigation that marine vessels have its likely our solutions and overall requirements would differ. That said, interesting thread which I’ll continue to follow.

I haven’t dove into the data weather flow logs but suspect location is not stored historically. Therefore weather data would be relatively meaningless unless location and date time are captured along side weather information.

Btw, driving down the road at 70mph, the sky recorded average wind speads in the 30-40mph range. I suspect this was due to my antenna mast being lowered to near roof level. Has anyone tested accuracy of sky while in motion? Is wind chill a factor? Not a meteorologist but suspect some of the readings could be less accurate while in motion. Parked my rain sensor goes off now and then. I’m suspecting it’s vibration from an rv eg, walking around, shutting doors etc.

Enjoy folks!

Kirk

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#12

Like kirk said, orient the Sky so North is to the bow of the boat. This will give you relative winds. I assume this is what you would use on a sail boat? From there a GPS and a compass should give the rest of the data.

It would be interesting to output the data in NMEA 0183 format for use on other devices.

How far over can a sail boat roll? What kind of an error to winds will that cause, if any? Since the Sky and the sails are mounted on the mast, perhaps no issues?

#13

Getting output to NMEA xxxx would be super, of course. A sailboat routinely heels when under sail between 10 and 30 degrees. I have no idea what that would mean. A

#14

With the right forethought, and hardware, we can do some intelligent assumptions and correct for heeling…
–Sam

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#15

Hi @kirk We love your curiosity and experimentation! Our engineering team has done lots of SKY testing on moving vehicles. Pictured below is WeatherFlow engineer Phil Atkinson (Harvard trained engineer with 20+ years designing and installing weather measurement systems ) with an early test rig that was tested up to 90mph on the highways. We recorded tons of data and were surprised to find just how accurate the sonic sensors on the SKY performed. In fact, they performed better than the $1500 RM Young anemometer in comparison. One thing that stood out as interesting — when a semi-truck passed by, the SKY was able to sense the turbulence with far more accuracy than the traditional propeller anemometer (theoretically the propeller has momentum/inertia working against it). We suspect that your rooftop driving test showed an accurate display of the wind within the turbulent space where mounted – factor in the aerodynamics of your vehicle. Cool stuff.

Phil90mph_cartop_small

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#16

As an active sailor, had been looking into the idea of something like another WeatherFlow near/on the boat for seeing what is going on remotely. For a race boat, can’t see using this device for the actual boat instrumentation, but could see that as a possibility for others/makers. When looking what might be a good add for a powerboat for wind, was surprised that a similar product was suggested, but has one that has NMEA output. Would be a cool dual-purpose if the Tempest could support…

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#17

Doug,
Yeah… been working with the SWS trying to do something like you suggest. Hopefully, something will float to the top and work!
–Sam