Accommodate platform information

[csjx]

ISO 19115 has a concept of a platform that is defined as:

vehicle or other support base that holds a sensor

and a sensor defined as:

device or piece of equipment which detects or records

In EML we have a similar concept in eml-methods of methods/methodStep/instrumentation:

the description of any instruments used in the data collection or quality control and quality assurance

We've received feedback about storing platform and sensor information in a way that is translatable to ISO 19115. This would mean accommodating a hierarchy of platform --> instrumentation information. Looking at the ISO 19115 spec, there isn't a platform field per se, but a DS_Platform is a subclass of the abstract DS_Aggregate type, and as an aggregation, the DS_Platform may have 0..n DS_Sensor descriptions. What's odd to me is that the subclass design of DS_Aggregate can technically make for some much less intuitive structures like a DS_Sensor with 0..n DS_Platform sections. Such is the nature of UML - looks good until you try it for real. Here's the model from the spec:

So, we'd need to discuss how this would work in a backward-compatible way for EML, if at all possible. A platform in ISO 19115 is baked into the aggregation structure, whereas EML uses a free form text field to describe this information.

[kmexter]

OK, so I only came accross this now, because we are needing to add platform to our metadata in EML. A platform is not really an instrument, but rather a place where instruments are attached to or launched from (a ship, a buoy, etc). I would really like there to be a field platform in methods, in addition to the currently available instrument. Platforms are much used in marine biology.

[mbjones]

If you are trying to tie your methods to particular instances of Platforms or Instruments, another approach to creating a new set of fields would be to use the dataset or entity annotation feature in EML 2.2 to link to specific instrument and platform vocabularies. Would there be an advantage of using a text field over structured annotations?

[kmexter]

Unfortunately, the destination of these data (EurOBIS, GBIF, ...) are still tied to EML 2.1.1 (and unless they recieve a push from publishers, I am told, they will not update to 2.2).
We are working on updating ourselves to 2.2, so it would be great if you could give me an example of what you mean for EML 2.2. But it does not answer my problem for 2.1 which we still need to keep providing.
Using structures annotaions is, indeed, better than using a text field (as long as it is clear to the human and the machine that we are talking about a platform).
(FYI I realise that 2.1 cannot be updated any more, so for that part of my work I am just trying to find the best place to add platform, as well as a few other "missing" fields)