Recoveries criteria

[Alberto-GS]

Hi guys,

I think we have to choose unique criteria to collect Argo floats. That is, what will be the parameter that gives us information to collect an Argo float? So far, I have been considering 300 work cycles as the limit to recover an Argo buoy.

I have the feeling that little by little the average life of the profilers increases every year, and therefore they are able to work longer at sea. Do we choose a limited number of work cycles to decide whether to recover a float or not? Perhaps a limit of voltage? @Martin-ifr suggested that a profiler is already profitable (cost per cycle) a few cycles before its final work cycle. I think @RomainCancouet shared that information at some point in a meeting, can you confirm @RomainCancouet? However, as Martin said, picking up one profiler and launching another on the same site is a win-win.

Once we decide this, we will have more options to work properly.

[Martin-ifr]

Hi Alberto,

As far as I know, the profiler by itself has the same mechanical/electronic/software parts since the original design of it. However, over the years, some improvements on each of these parts could have happen. For
example, in order to solve at sea issues or just to optimize the sleep mode. Moreover, thanks to best practices from the manufacturing until the deployment, all of this results to a better average life of the profiler every years.

So I think that we should consider 2 criterias :

• The theorical life expectancy coupled with the float parameters (being aware they could be updated thanks to Iridium);
• The float "state". I mean, if the float is known to have a problem such has a failed sensor, an unexepected energy consumption, etc.

On the first criteria, we should compute how many cycles the float is expected to do, taken into account his parameters (at least the ones with the greatest energy impact). Then knowing the price of the float, compute at which moment it is affordable to recover. At this point, the float should be considered "ready to be picked up". We already did draft exercises of these at Ifremer.
The second criteria is more like "ok this float is not working as expected". In that case, it should be "ready to be picked up" as soon has possible.

Important fact, each float family (Provor, Arvor, Deep Arvor, Provor-BGC, etc.) has is own life expectancy.

[Alberto-GS]

Hi Alberto,

As far as I know, the profiler by itself has the same mechanical/electronic/software parts since the original design of it. However, over the years, some improvements on each of these parts could have happen. For
example, in order to solve at sea issues or just to optimize the sleep mode. Moreover, thanks to best practices from the manufacturing until the deployment, all of this results to a better average life of the profiler every years.

So I think that we should consider 2 criterias :

* The theorical life expectancy coupled with the float parameters  (being aware they could be updated thanks to Iridium);

* The float "state". I mean, if the float is known to have a problem such has a failed sensor, an unexepected energy consumption, etc.

On the first criteria, we should compute how many cycles the float is expected to do, taken into account his parameters (at least the ones with the greatest energy impact). Then knowing the price of the float, compute at which moment it is affordable to recover. At this point, the float should be considered "ready to be picked up". We already did draft exercises of these at Ifremer.
The second criteria is more like "ok this float is not working as expected". In that case, it should be "ready to be picked up" as soon has possible.

Important fact, each float family (Provor, Arvor, Deep Arvor, Provor-BGC, etc.) has is own life expectancy.

Hi Martin,

It sounds great to me! Do you mind to include all this information in the draft document?:) If that's the case, please feel free to write every detail and expand on this as much as you like. Even mentioning those Ifremer draft exercises documents that you commented. I just created a section fot this called '3.1. WHEN IS A PROFILER CONSIDERED RECOVERABLE?' This may seem like a trivial question, but I don't think it is. So to avoid confusion among readers, it is better to write a definition as clear as possible.

If we want to cover as many criteria as possible, we should consider those you proposed (2), greylisted floats and #3 (comment) suggested by @RomainCancouet if I understood him well. Maybe there is a way to consider all of these criteria and develop a "tag system", which tags a float as "ready to be picked up" as you suggested.

[Martin-ifr]

Hi @Alberto-GS ,

Ok I'm gonna write something about it this week.