INSPIRE Thematic Clusters

FoI for ProfileObservation: Point or Curve?

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Quick question: the way ProfileObservation has been defined, the FoI is currently constrained to SF_SamplingCurve. I had thought that a Profile is always vertical (there's also a non-formalized constraint that "Profile is grid with one vertical axis"), so would have expected a SF_SamplingPoint. At the same time I've been picking up ideas on non-vertical profile (i.e. providing data on non-vertical bore-holes).

My current conclusion is that it's basically a question of which constraint to I break? (or do I just assume a vertical profile with an infinitely short Curve?)

Thoughts?

:?

Kathi

Replies

    • Public

    By Ilkka RINNE

    Hi Kathi,

    I think it makes sense to have a curve geometry for the FoI of a ProfileObservation, a point alone does not describe where did the observation "happen" sufficiently: one may want to search for ProfileObservations intersecting a particular volume of the sea (say 100 - 250 m below surface), and if the FoI only describes a point at the surface, this becomes difficult.

    The idea that the FoI geometry is continuous (the line/curve of the intended observation profile) and the domain of the result grid is a discrete (the sampling along the intended observation curve) has been helpful for me.

    • Public

    By Katharina SCHLEIDT

    Hi Ilkka,

    do you by any chance have such an example available? I tend to struggle with 3d CRS!

    Also - due to the other constraints on ProfileObservation (domain axis must be vertical), the only additional information provided by the curve is the depth, which is also covered by the GridLimits/IndexAxis

    And, my current profile isn't even based on depths but on pressure (is that vertical? ;) ). Attached.

    The more I look at the specialized observations, the more I feel we must urgently revisit and rethink some of the constraints (apart from the fact that there are serious errors!)

    :)

    Kathi

    O&M ProfileObservation Pressure Depth with GeneralGridCoverage from CIS1.1

    • Public

    By Keiran MILLARD

    Hi Kathi,

    Having a curve geometry is correct for a profile; I can't think of any truly vertical profile in the real world.  Don't confuse vertical axis with the state of being vertical.  The vertical axis can be depth or elevation (in m) or an equivalent such as pressure;  these are the two most commonly used for profiles.  Pressure is also used in the atmospheric community for profiles above the earth as well as in the oceanographic community for profiles in the ocean.

    From a representation perspective, a profle is really like a time series, except time is replaced with depth/pressure (typically) and the axes are switched.  You can have multiple phenonema observed along the profile; temperature, salinity, current speed, current direction are common.

    Keiran

    • Public

    By Katharina SCHLEIDT

    Hi Keiran,

    thanks for the info! Question - you differentiate between vertical axis and the state of being vertical. I believe that I understand the vertical axis bit (different heights or pressure readings coupled with phenomena values at one (mostly) static location represented by a coordinate pair); what do you mean with the "state of being vertical" (my mind is throwing up trash like "being an upright citizen" ;) ). As the profiles are expected to have a static geolocation, provision of a curve seems a bit absurd (becomes a sequence of line segments), the depth boundaries are provided in the result. Ilkka's example of wanting to search for observations within a specific volume of space via the FoI does make sense; think what I really want is an example of 3D encoding of the profile FoI!

    A further bit on the Profiles that bothers me is the time; the models assume one point in time, in reality this is unlikely - are the times just lumped, or are there cases where the time also gains relevance?

    Also - thanks for throwing the bit on multiple phenonema into the fray! Question here: in the atmospheric community they're basically good with providing most phenomena seperately (just because you wish to access temp and salinity together doesn't mean everybody does!); just a few integrally linked ones are to be provided as pairs (standard example is wind speed&direction, would assume the same for current). Any insights as to how the marine community views this?

    :)

    Kathi

Environmental Monitoring and Observations Cluster

Environmental Monitoring and Observations Cluster

Environmental Monitoring Facilities, Observations and Measurements