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From "Mattmann, Chris A (398J)" <chris.a.mattm...@jpl.nasa.gov>
Subject Re: Research project on integrating geoservices with Apache Airavata
Date Sat, 06 Apr 2013 05:00:14 GMT
Hi Amila,

I think that WPS can potentially be something that Airavata and/or OODT
help to layer on top of SIS as a core library.

Thanks!

Cheers,
Chris

++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
Chris Mattmann, Ph.D.
Senior Computer Scientist
NASA Jet Propulsion Laboratory Pasadena, CA 91109 USA
Office: 171-266B, Mailstop: 171-246
Email: chris.a.mattmann@nasa.gov
WWW:  http://sunset.usc.edu/~mattmann/
++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
Adjunct Assistant Professor, Computer Science Department
University of Southern California, Los Angeles, CA 90089 USA
++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++






-----Original Message-----
From: AMILA RANATUNGA <newair007@gmail.com>
Reply-To: "dev@oodt.apache.org" <dev@oodt.apache.org>
Date: Friday, April 5, 2013 9:25 PM
To: Martin Desruisseaux <martin.desruisseaux@geomatys.fr>
Cc: "dev@sis.apache.org" <dev@sis.apache.org>, "dev@airavata.apache.org"
<dev@airavata.apache.org>, Harsha Kumara <harsz89@gmail.com>, Shahani
Markus Weerawarana <shahani.w@gmail.com>, Nipuni Perera
<nipuni880917@gmail.com>, "dev@oodt.apache.org" <dev@oodt.apache.org>
Subject: Re: Research project on integrating geoservices with Apache
Airavata

>Hi,
>
>Thank you for the long reply. As you suggest "GeoTk" is the core part
>which
>suits to scientists. And "Constellation-SDI" is intended to
>provide web-services using maximum use of those tools. Constellation-SDI
>consisted of WPS, WMS, WFS as server modules. So will that integration
>make
>Apache SIS be considered as those services enabled?
>
>And why you said " Having SIS to implement WMS, WMTS, WCS and WFS is a
>must"?
>What about WPS. Will that make SIS out of the scope. Because we feel that
>since Airavata using Science gateway concept, really essential to
>implement
>WPS too.
>
>Thank You !
>
>
>
>
>
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>
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>
>
>
>On Fri, Apr 5, 2013 at 7:04 PM, Martin Desruisseaux <
>martin.desruisseaux@geomatys.fr> wrote:
>
>> Hello Amila
>>
>> Le 05/04/13 12:57, AMILA RANATUNGA a écrit :
>>
>>  the slide 21 describes remaining code to move as WMS, WCS, WCTS, WPS
>>and
>>> more. Is that mean Apache SIS does not support them?
>>>
>>
>> Yes. SIS is still in an early stage and does not support WMS, WCS and
>> similar services yet.
>>
>>
>>
>>  And GeoTk code was moved to SIS and claims that reference
>>implementation
>>> of
>>> GEOAPI.
>>>
>>
>> Geotk code is in process of being moved to SIS. But only metadata port
>>is
>> close to completion. The next module to port will be referencing
>>(hopefully
>> completed before FOSS4G in September).
>>
>>
>>  geotoolkit.org (...snip...) Mapfaces (...snip...) constellation-sdi
>>> (...snip...) puzzle-gis (...snip...)
>>>
>>>
>>> Will integrating those into sis make one step ahead to "SIS
>>>well-suited to
>>> some communities (*scientists, but also non-scientists* wanting to
>>>explore
>>>
>>> data in more dimensions than the usual x,y)."?
>>>
>>
>> Maybe I should said that those projects will not be automatically added
>>to
>> SIS. They will be offered, but by the time we reach them, the
>>technologies
>> may have evolved to a point where peoples may want to explore other
>> approaches. For example MapFaces is built on top of JSF. But maybe some
>> peoples will want to explore the Play framework instead. An other
>>example
>> is Swing-based technologies, which are going to be phased out in favour
>>of
>> JavaFX. However we may still use the existing code as a starting point
>>and
>> try to port them to the new technologies. We will revisit this issue
>>when
>> we will be there.
>>
>> The core part aiming to make SIS "well suited to scientists" is Geotk.
>> First by its focus on ISO 19115 metadata for describing the data. Those
>> metadata include a package for describing data quality, an aspect
>>usually
>> neglected by mass-market projects but important for scientists. The
>>GeoTk
>> (future SIS) referencing module takes its information directly from the
>> EPSG database, which provides us information about transformation
>>accuracy
>> and CRS (Coordinate Reference System) area of validity. Many popular
>> projects use simplified version of EPSG database without those
>>information,
>> since not anyone see them as useful. GeoTk paid high attention to
>> correctness through our current effort of expanding 'geoapi-conformance'
>> test suite with the GIGS tests (provided by the EPSG authors). GeoTk
>>also
>> have support for n-dimensional CRS. Those CRS may be more than
>>(x,y,z,t),
>> for example meteorologists use 2 time axes and oceanographers often use
>> pressure instead of z. On the coverages (rasters) side, GeoTk provides a
>> way to describe the meaning of pixel values (by contrast with some
>>projects
>> handling rasters basically as RGB images), which allow for example to
>> compute "gradient of sea surface temperature" without confusing a
>> temperature value with a pixel covered by a cloud (without such
>>knowledge,
>> calculations like "gradient" produce strong artefacts). Large dataset
>>can
>> be organized in a database schema designed for making easier the
>> statistical analysis over time series.
>>
>> Constellation-SDI simply uses the "building blocks" provided by
>>SIS/GeoTk
>> for providing web services. Our approach for aiming such web services as
>> "well suited to scientists" is to make sure that we use properly the
>>tools
>> provided by SIS. Similar reasoning apply to Puzzle-GIS. Providing those
>>web
>> services and desktop application directly in SIS would allow SIS to run
>> "out of the box", but community may decide that this is not a goal.
>>
>>
>>
>>  We also referred the white paper[2].There are OGC compliance products
>>and
>>> OGC implementing products[3]. What is the main difference? For an
>>>example
>>> zoo project is considered as OGC implementing. But the site says " It
>>> provides an OGC WPS compliant developer-friendly framework to create
>>>and
>>> chain WPS Web services".
>>>
>>
>> I suspect that "OGC compliant products" and "OGC implementing products"
>> can be understood as synonymous. However Frédéric Houbie would known
>>better.
>>
>>
>>
>>  As Jun mentioned Osgeo live dvd has many products [4]. If they are
>>> compliance with OGC. implementing OGC standards with Airavata will make
>>> such products inter-operable with Airavta. But those have implemented
>>> specific OGC standards (As Martin said " I think that OGC standards
>>>are so
>>> large that no single software in the world implement all of them"). So
>>>for
>>> such a project what will be the major consideration should be. Or how
>>>far
>>> an integration SIS with Airavata will solve this problem?
>>>
>>
>> The Web Map Services (WMS) is probably the most widely implemented OGC
>> standard. Having SIS to implement WMS, WMTS, WCS and WFS is a must.
>>Those 4
>> standards will probably allow inter-operability with the vast majority
>>of
>> OGC-compliant products.
>>
>> Next, there is other standards not as-widely known but nevertheless of
>> interest for us. For example Web Processing Services (WPS) for launching
>> calculations on distant machines. SensorML for expressing sensor data
>>(e.g.
>> monitoring environmental parameters). There is an ungoing
>>"uncertainties"
>> working group at OGC which may be seen as a specialized work for
>> geoscientists. There is also other groups like "hydrology", "aviation"
>>and
>> "law enforcement" for policemen. "Law enforcement" is an example of OGC
>> work which will probably not by my personal priority. This illustrates
>>the
>> idea that a single project may not implement every OGC standards.
>>
>> Next, there is what OGC calls "best practice" for specific domains. For
>> example the OGC Met-Ocean working group has emitted recommendations
>>about
>> the way to use WMS with meteorological and oceanographical time series.
>> This is because meteorologist have specialized needs for example in the
>>way
>> to handle time, not considered of common interest enough for being part
>>of
>> the base WMS standard. Those recommendations are a kind of gray area,
>>not
>> official standards but nevertheless something we should comply to if we
>> want to increase the chances to be inter-operable with Meteo-France or
>>the
>> UK MetOffice.
>>
>>     Martin
>>
>>


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