2nd Apr, 2009

L4 buoy hiatus

A few developments this week.

You may have noticed about 10 days ago the data stream from the buoy suddenly dried up. Our initial thought was that the radio-modems were playing up and Chris and Al went out in the RIB to solve the problem armed with a replacement unit. It was duely replaced but it turns out from the error messages that a power glitch cause the onboard PC to hang, a situation that we have now rectified and shouldn’t happen again (for that particular reason!). A great deal of these problems can only be sorted out post launch because even with the most rigorous testing we cannot know everything. Some changes to the scheduling have also been effected: the data acquisition is only for 30 seconds every hour and the data is only downloaded from the buoy every three hours as well to preserve the power and cut down on the likelihood of power problems.

The latest data should be appearing at:


In addition I have manged to process some of the limited E1 deployment from last year.  Some of the data is from Mayflower Marina (giving very high nitrate loadings as expected).  This can be found at:


Graphical representation of the data together with a web site is the next step … if anyone wants to do this whilst I am a way then please feel free.

The AIS also gave out at one point (probably a power issue too). The AIS can be tracked, thanks to Peter Walker via the development site:


Clicking on the in-situ “latest buoy position” shows the buoy to be in place – and you can even look at the different ships as they sail around the channel (right clicking on the dots gives the ship’s name). This system will text us when the buoy moves out of position … which hopefully it will never do!

I’m off to sea now – so my last blog until June. Hopefully by then we will be in a position to deploy the E1 buoy.


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