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wmo-im / wmdr

WIGOS Metadata Standard: UML model and schemas
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Cardinality of GeopositioningMethodType #32

Open fierz opened 4 years ago

fierz commented 4 years ago

Nowadays one is often faced with instruments using more than one GNSS-system to determine the coordinates of a point. Unfortunately, this is not reflected in Table 11-01 (see attached).

I propose to add a general method that could be called GNSS (general)

Screenshot 2020-04-21 at 15 20CEST Screenshot 2020-04-21 at 15 21CEST

joergklausen commented 4 years ago

Instead of "GNSS (general)", I propose to add "GNSS (multiple)". That way, individual GNSS can still be specified, and the new entry satisfies the requirement in the case where actually several GNSS systems are used.

fierz commented 4 years ago

Great, thanks! Adding "GNSS (multiple)" is indeed more appropriate and serves the purpose perfectly.

KarlBureau commented 4 years ago

I support GNSS (multiple)

KarlBureau commented 4 years ago

WMDS_Validation_Report_162_GeopositioningMethod_v0.2.docx Updated version of Validation report with proposal that multiple (>=1) GeoPositioning Methods be allowed. @joergklausen @toakley76 @fierz

joergklausen commented 4 years ago

I concur with the recommendation in the validation report. Please be aware that this is a CR for the WMDR schema as well as requiring a CR for OSCAR/Surface. I will move the issue over to the WMDR repo. image

toakley76 commented 4 years ago

The proposal to allow more that one method to be selected is acceptable to me, Perhaps GNSS should also be one of the options?

fierz commented 4 years ago

Agree the possibility to select one ore more GNS-System may help. Nevertheless, one is faced with situations where this info is not available (I am checking with a colleague whether I could have retrieved that info from the measurements I did). Thus an option with multiple GNS-Systems looks better to me than having to choose 'unknown' or 'inapplicable'.

toakley76 commented 4 years ago

Lets go with both options. Being able to select more than one system and the option of GNSS (multiple). Sometimes providing the user with an 'easy' option means that they don't check their system information in more detail to see if they have the requested metadata. It is always a balance of getting something, the full details or getting nothing.

fierz commented 4 years ago

I could check with my colleague that the instrument I used works with GPS and GLONASS satellites only. More recent instruments will allow to use even more systems, possibly storing the satellites used). In summary, having the two options will be very valuable and I support it. PS would GNSS (multiple sources) be even a better entry?

joergklausen commented 3 years ago

@fierz @toakley76 @KarlBureau Revisiting this issue after a long dormant period, I solicit feedback if the requirement is

  1. include an entry "GNSS (multiple sources)" in the code list
  2. allow more than one entry under geopositioningMethod. Option 1 is straight-forward and cheap, option 2 is an easy change in the model, but a much more costly change in any implementation (because the cardinality changes). My recommendation is to go for option 1, unless there are strong arguments for option 2.
fierz commented 3 years ago

Option 2 would have been nice indeed but I am not longer convinced of the added value given the possible implications. I thus would definitely go for option 1.