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Spotter FAQ

Team Sofar

What does Spotter measure?

Spotter measures 3D surface motions at 2.5Hz. Our onboard analysis translates that to wave motions (0.03Hz -1Hz) and position tracking of Spotter. Surface velocities are estimated from differential positions and low-pass Doppler velocities. Our on-board wave analysis computes a complete cross-spectral matrix from the displacement data from which we estimate variance spectra and directional moments. Spotter calculates the local wind from the equilibrium range of the wave spectrum. What this means is that Spotter estimates wind speed and direction from the intensity and direction of the higher-frequency wave field (‘sea’) which represent a measure of sea surface roughness and is forced by the local wind field. This is a highly effective proxy measurement for open water (effective unobstructed fetch >5 miles), but should not be relied on in confined waters or behind obstacles (e.g. headlands).

In addition to the standard bulk parameters, Spotter can now provide the same parameters over  ‘sea’ and ‘swell’ wave partitions

To compress the data for satellite transmission we generally reduce spectral wave data to bulk parameters such as significant wave height, peak and period, peak and mean direction, and peak and mean directional spreading. In Waves mode, these bulk statistics, wind velocity and a position update are computed every 30 minutes and transmitted every hour (two updates) to your data dashboard. If you need more than bulk statistics, you can chose to transmit full spectra and directional moments, and set a custom update rate to throttle you data transfer needs. Displacement time series and more detailed statistics are all stored on the Spotter's on-board SD card. In Track mode the system will send position updates every 15 minutes (so you can track the instrument), but wave data is not transmitted and stored on the SD card only. This mode is used to retrieve or track a free-drifting Spotter. 

We are continuously working to develop additional capabilities for Spotter, including on-the-fly customizable data transmission packages, and additional sensor capabilities. And we want to hear your ideas!

Spotter Bulk Wave Parameters

How do I setup my global data service?

Spotter comes fully setup to transmit data to our online Dashboard and to get you going we include one year of real-time data transmission, free of charge. So all you do is logon to your account and register your new Spotter using the activation codes in the box. Once registered, you’re ready to deploy. Turn Spotter on and wave data, status updates, and Spotter position will flow to the online Dashboard. It’s that simple.

How much global data service is included with Spotter?

Spotter comes with a free, one-year global data package (365 days). This free data period starts when you activate your Spotter for the first time, or 3 months after the Spotter is shipped to you, whichever comes first, whichever comes first. The period of use is based on the standard transmission rate in Waves mode, but you will have full access to two-way communication and Track mode, and any new features we would make available during the period your real-time subscription is active. If you only use Waves mode, you will have a full 12 months of use covered. In Track mode you transmit four times more data, so if you use that a lot the total use time may be reduced accordingly. Rest assured, you will never have any surprise fees. We keep track of your data use, and will give you a warning when you are about one month out of running out of real-time connectivity. At that point you can decide whether you want to extend the real-time connectivity.

What happens when my remote data package runs out?

Your remote data package starts on the day you register your Spotter device, or three months after we ship your Spotter to you (whichever comes first), and it expires 365 days later, or earlier depending on your data usage. We will give you a heads up when you’re about 1 month out from running out of data service. Once expired you have the option to renew or choose to use Spotter without real-time data service.

Does Spotter have to be moored, or can it be free floating?

Spotter was born from experimentation with free-drifting wave buoys, so yes, you can either free-float your Spotter or put in on a mooring, whatever fits your application best! Spotter can be moored in place for wave measurements, or be used as a wave-enabled Lagrangian drifter to measure both waves and track surface currents. The Spotter on-board analysis is designed with free drifting in mind, and will continue to measure waves accurately even in fast flowing currents. With the Track made option on the Dashboard, you can track your Spotter anytime, anywhere.

Does Spotter come with Mooring?

We don't include a mooring in our standard package. But if you need help, we'll provide that. We offer detailed instructions on how to develop a low-cost and light-weight mooring for your Spotter so you can build your own. And if you need more help, we can put one together and ship it to you. Just contact us at support@sofarocean.com if you have more questions about that.

Why does Spotter come with a wall charger?

It’s a nice gesture. Spotter can do without. However, Spotter is basically a rechargeable system, and normally the sun takes care of that. The nice thing about this is that you absolutely don’t have to worry about batteries. Just put it out in the ocean, and Spotter will start working when the sun comes up (and keep working through the night of course). However, if Spotter’s battery is drained, it may take 15-20 minutes of sunlight for the system to get back on. So if you are doing a night deployment and want to make sure the system is on right away, you can simply charge the battery with the wall charger. Or top it off, just in case.

How long will Spotter continue in the dark?

Spotter will run through the night of course. So during normal deployments, even at higher latitudes and overcast conditions, Spotter can run continuously. If you put it in absolute darkness it will run out of power in about 10.5 days if started from a full battery. Spotter is fully solar powered, so even if you drain the battery completely, put it in the sun (or outside during the day), and it will start running again, usually within 15 minutes. If the system for some reason runs out of power, it simply goes to sleep. Once it’s in the light again, it comes back and will pick up where it left off. No big deal.

Do I have to service Spotter?

You don’t! Spotter is designed to operate continuously with no need for maintenance or servicing. Only thing it may need after prolonged deployment is a quick cleaning to remove marine fouling and growth, which in severe cases may affect motion response.

How do I deploy Spotter?

Spotter is designed to be easily deployed by a single person. For more information on pre-deployment procedure, you can check out the video below.

Does Spotter need calibration before use?

No calibration needed. Spotter is ready-to-go, right out of the box.

What should I do if my Spotter hull has been compromised?

If you suspect damage (or water inside), do not use or charge your Spotter and disconnect your solar panels. Extra care is needed to store and transport potentially damaged lithium batteries. Place Spotter safely in a cool, dry place away from combustible materials and contact us at support@sofarocean.com

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