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RE: The Multiple types of coverage requirement

From: <Simon.Cox@csiro.au>
Date: Fri, 5 Jun 2015 15:50:14 +0000
To: <frans.knibbe@geodan.nl>, <public-sdw-wg@w3.org>
CC: <allaves@fi.upm.es>, <p.baumann@jacobs-university.de>, <Kerry.Taylor@csiro.au>
Message-ID: <2A7346E8D9F62D4CA8D78387173A054A6020F02D@exmbx04-cdc.nexus.csiro.au>
ISSUE-19



Frans asks:

Does this mean some kind of standard classification of coverage types is
required, so the coverage type can be indicated in the metadata for example?



Or does this mean that there should be standard encodings for different
coverage types?

'Yes' to the first.



'Maybe' to the second, but I would draw attention to the 's' on the end of 'encodings'. We know that there is and will continue to be diversity in coverage encodings for several very valid reasons. GMLCOV, netCDF, GeoTIFF, JPEG-2000 are widely used. There are current activities in OGC (WaterML2, TimeseriesML) to harmonize the interleaved geometry-value pair representation of coverages (building on earlier work going back to 2006). Each of these approaches addresses a known need and is used by viable communities, meeting requirements that are not going to go away. We should have a goal of recognising the diverse uses, minimising the number of solutions as much as possible, but there is no way the count of solutions will be reduced to one.


Simon Cox | Research Scientist
CSIRO Land and Water
PO Box 56, Highett Vic 3190, Australia
Tel +61 3 9252 6342<tel:%2B61%203%209252%206342> | Mob +61 403 302 672<tel:%2B61%20403%20302%20672>
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________________________________
From: Frans Knibbe [frans.knibbe@geodan.nl]
Sent: Saturday, 6 June 2015 1:28 AM
To: SDW WG Public List
Cc: Alejandro Llaves; Peter Baumann; Taylor, Kerry (Digital, Acton); Cox, Simon (L&W, Highett)
Subject: Re: The Multiple types of coverage requirement

Hello all,

I have the feeling my original question still needs answering: What exactly do we think is required?

I have created an issue for this in the tracker: ISSUE-19<https://www.w3.org/2015/spatial/track/issues/19>.

Regards,
Frans



2015-06-04 23:30 GMT+02:00 <Simon.Cox@csiro.au<mailto:Simon.Cox@csiro.au>>:

There is an existing branch of the OGC /def/ space for 'coverage-type' - see http://www.opengis.net/def/coverageType/

Currently the types listed there all relate to some special requirements from some OGC Earth Observation standards - http://www.opengis.net/def/coverageType/OGC-EO/ but this is a potential place to put a suitable list.



BTW - real soon now we will change the platform used to manage and publish the OGC definitions. This will enable management of branches of the tree to be delegated. This could support other requirements emerging from SDWWG.


Simon Cox | Research Scientist
CSIRO Land and Water
PO Box 56, Highett Vic 3190, Australia
Tel +61 3 9252 6342<tel:%2B61%203%209252%206342> | Mob +61 403 302 672<tel:%2B61%20403%20302%20672>
simon.cox@csiro.au<https://vic.owa.csiro.au/owa/redir.aspx?C=Y8HMKTuUBkmbM97NjtDx5lGOnwxj1c9IdyRdGXbcQ8yykNtSsGHlgXUbOJN1bdSmnc9NFxd8E0M.&URL=mailto%3asimon.cox%40csiro.au> | http://people.csiro.au/C/S/Simon-Cox

________________________________
From: Alejandro Llaves [allaves@fi.upm.es<mailto:allaves@fi.upm.es>]
Sent: Wednesday, 3 June 2015 11:57 PM
To: Peter Baumann
Cc: Taylor, Kerry (Digital, Acton); Frans Knibbe; SDW WG Public List
Subject: Re: The Multiple types of coverage requirement

For instance, the description of the coverage type and a link to a superclass entity, such as "coverage types by grid complexity"?

Alejandro

On 1 June 2015 at 16:20, Peter Baumann <p.baumann@jacobs-university.de<mailto:p.baumann@jacobs-university.de>> wrote:
Alejandro-

nope, no URIs defined as of yet. What information could be provided at the target of the URI?

-Peter



On 06/01/15 15:16, Alejandro Llaves wrote:
Thanks, Peter! Are there URIs for these identifiers? If not, I think this may be work for the group's Coverage in Linked Data deliverable. For now, I can add them as examples for the Multiple types of coverage<http://w3c.github.io/sdw/UseCases/SDWUseCasesAndRequirements.html#MultipleTypesOfCoverage> requirement.

Cheers,
Alejandro

On 1 June 2015 at 14:49, Peter Baumann <p.baumann@jacobs-university.de<mailto:p.baumann@jacobs-university.de>> wrote:
Here is a classification by grid complexity, hope it helps somehow:

- just array, mapping is 1:1
    -> GridCoverage (GML 3.2.1)
- linear mapping from n-D array to n-D grid, g = a*x+b for a,b in R^n
    -> RectifiedGridCoverage
- linear mapping with g = A*x+b for A in R^n*n
    -> ReferenceableGridCoverage, byVector
- linear mapping from n-D array (x_n) to m-D grid (g_m), m>n: g_m = A * x_n + b for A in R^n*m
    ->ReferenceableGridCoverage, byArray
- nonaffine transformations, ex: Sensor geometries

(anybody disagreeing?)

One could classify along dimension axes (horizontal, vertical, time, ...) but the above one I believe is most helpful for the purpose on hand, and it also very much determines implementation complexity and dataset sizes (in particular: byArray approx. doubles data set size).

-Peter




On 05/31/15 09:35, Kerry.Taylor@csiro.au<mailto:Kerry.Taylor@csiro.au> wrote:
I am quite ok with the UCR expressed as it is, but I note that our use cases do not actually require very many of these multiple types and I suggest that we should look more closely at * which* of the multiple types we really need as we go progress. I would like to suggest that we make a note of this in the UCR, attached to this requirement, to prevent  the "multiple" being interpreted as"all that have ever been thought of" .

note- i am prepared to back down on the request for the note, as  I think argued almost contradictorily in the case of "multiple" applied to "multilingual" in last week's meeting. Although in that language case I saw no harm other than realism in attacking every conceivable language, but in the coverage case I think there is a risk of harm in confusion if we take  on too many, which is worse.

Kerry



On 29 May 2015, at 11:47 pm, "Peter Baumann" <p.baumann@jacobs-university.de<mailto:p.baumann@jacobs-university.de>> wrote:

Frans-

here a slate (not comprehensive, but likely covering all considered by W3C currently):
- gridded coverages:
    - by dimension: 1-D through 4-D (climate people also consider 5-D)
    - by grid type:
        - regular grid (equidistant spacing ("resolution"), such as ortho imagery)
        - irregular grids (grid lines have individual spacing per axis, such as timeseries often have)
        - warped grids (grid points sit anywhere in space, but still topologically isomorphic to a grid)
        - sensor grids (geo position of grid points determined by sensor model, usually some involved non-linear algorithm)
- non-gridded coverages:
    - point clouds
    - (rest likely not of interest here)

cheers,
Peter


On 05/29/15 14:36, Frans Knibbe wrote:
Hello Alejandro,

I am looking at the Multiple types of coverage<http://w3c.github.io/sdw/UseCases/SDWUseCasesAndRequirements.html#MultipleTypesOfCoverage> requirement now: "It should be possible to represent many different types of coverage."

Does this mean some kind of standard classification of coverage types is required, so the coverage type can be indicated in the metadata for example?

Or does this mean that there should be standard encodings for different coverage types?

Greetings,
Frans

--
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--
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--
Dr. Peter Baumann
 - Professor of Computer Science, Jacobs University Bremen
   www.faculty.jacobs-university.de/pbaumann<http://www.faculty.jacobs-university.de/pbaumann>
   mail: p.baumann@jacobs-university.de<mailto:p.baumann@jacobs-university.de>
   tel: +49-421-200-3178<tel:%2B49-421-200-3178>, fax: +49-421-200-493178<tel:%2B49-421-200-493178>
 - Executive Director, rasdaman GmbH Bremen (HRB 26793)
   www.rasdaman.com<http://www.rasdaman.com>, mail: baumann@rasdaman.com<mailto:baumann@rasdaman.com>
   tel: 0800-rasdaman, fax: 0800-rasdafax, mobile: +49-173-5837882<tel:%2B49-173-5837882>
"Si forte in alienas manus oberraverit hec peregrina epistola incertis ventis dimissa, sed Deo commendata, precamur ut ei reddatur cui soli destinata, nec preripiat quisquam non sibi parata." (mail disclaimer, AD 1083)






--
Alejandro Llaves

Ontology Engineering Group (OEG)

Artificial Intelligence Department

Universidad Politécnica de Madrid

Avda. Montepríncipe s/n

Boadilla del Monte, 28660 Madrid, Spain


http://www.oeg-upm.net/index.php/phd/325-allaves


allaves@fi.upm.es<mailto:allaves@fi.upm.es>


--
Dr. Peter Baumann
 - Professor of Computer Science, Jacobs University Bremen
   www.faculty.jacobs-university.de/pbaumann<http://www.faculty.jacobs-university.de/pbaumann>
   mail: p.baumann@jacobs-university.de<mailto:p.baumann@jacobs-university.de>
   tel: +49-421-200-3178<tel:%2B49-421-200-3178>, fax: +49-421-200-493178<tel:%2B49-421-200-493178>
 - Executive Director, rasdaman GmbH Bremen (HRB 26793)
   www.rasdaman.com<http://www.rasdaman.com>, mail: baumann@rasdaman.com<mailto:baumann@rasdaman.com>
   tel: 0800-rasdaman, fax: 0800-rasdafax, mobile: +49-173-5837882<tel:%2B49-173-5837882>
"Si forte in alienas manus oberraverit hec peregrina epistola incertis ventis dimissa, sed Deo commendata, precamur ut ei reddatur cui soli destinata, nec preripiat quisquam non sibi parata." (mail disclaimer, AD 1083)






--
Alejandro Llaves

Ontology Engineering Group (OEG)

Artificial Intelligence Department

Universidad Politécnica de Madrid

Avda. Montepríncipe s/n

Boadilla del Monte, 28660 Madrid, Spain


http://www.oeg-upm.net/index.php/phd/325-allaves


allaves@fi.upm.es<mailto:allaves@fi.upm.es>



--
Frans Knibbe
Geodan
President Kennedylaan 1
1079 MB Amsterdam (NL)

T +31 (0)20 - 5711 347
E frans.knibbe@geodan.nl<mailto:frans.knibbe@geodan.nl>
www.geodan.nl<http://www.geodan.nl>
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Received on Friday, 5 June 2015 15:51:16 UTC

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