Hi Sean,
Thank you for your prompt and comprehensive response. This information will
help us a lot. We look forward to collaborating.
I appreciate the offer of a teleconference, all the more so given your
team's time constraints. I will follow up with my availability and contact
information in a private message.
Thanks again,
On Tue, Jul 24, 2018 at 9:48 AM Sean Arms <sarms@xxxxxxxx> wrote:
> Greetings Carl!
>
> Appolgies for the delay in response. I was out of the office all last week
> with extremely limited internet connection.
>
> First off, most certainly any effort towards adding Simple Geometry
> support to netCDF-Java and the TDS would be welcome! We had planned on
> doing this ourselves in the near future (actually, the September timeline
> is what we had envisioned), but the developer most suited to do that work
> is no longer at Unidata as of last month. Our development team is
> quite...pressed...at the moment, and so outside efforts are even more so
> welcome!
>
> In general, the first step would be to represent a simple geometry in the
> Common Data Model.
>
> https://www.unidata.ucar.edu/software/thredds/current/netcdf-java/CDM/
>
> The machinery for doing that would start off at the IOSP layer. Given that
> this is an addition to CF and presumably stored in a netCDF file, then
> supporting the data access layer of the CDM would be very simple as it's
> already done. The next step would be to add coordinate system layer
> support. Again, given that this is going to be part of CF, the coordinate
> system layer should be pretty straight forward, if not working as is. The
> tricky part would be supporting things at the Scientific Feature Type
> layer. It might be the case that the GRID feature type would take you a
> long way, but it's very likely that a new, Simple Geometry Feature Type
> would need to be created.
>
> Once the new specification is supported in the CDM, the next step would be
> to talk about how you envision interacting with simple geometries via the
> TDS. I can think of many cool things to support, for example looking at
> the intersection of a simple geometry and a GRID and performing an
> extraction of some sort, but they might not be all that useful. There are
> also more basic things, like subsetting data by requesting specific
> geometries by index or id. These things would likely involve extending the
> netCDF Subset Service API to allow for such queries.
>
> For the past few years, we have been working to get the next major release
> of netCDF-Java and the TDS out the door, and are getting very close. That
> said, it would be best to target any work on the 5.0 branch of the THREDDS
> repository, as opposed to the 4.6 branch (i.e. master).
>
> Supporting the Simple Geometries addition to CF would almost certainly
> involve adding dependencies. Some of the dependencies may already rely on
> artifacts from netCDF-Java, but might be pinned to older versions. In
> addition to adding a circular dependency, the change in major version could
> pose a stumbling block to using them in the 5.0 branch. Neither of those
> are show stoppers, but are issues to be aware of. Also, many of the users
> of netCDF-Java rely on the netCDFAll jar file, which has grown quite a bit
> over the years. When adding new dependencies one would need to keep the
> size of the netCDFAll jar file in mind. One way to work with this would be
> to do the work in a simple geometry module. Projects that want to use, say,
> the simple geometry IOSP would need to include that artifact in their maven
> pom or download it in addition to netCDFAll.jar, although the "all" at this
> point would be misleading...
>
> I hope this gives you an idea of the work involved in support Simple
> Geometries. I'd be happy to have a teleconference at some point if you
> think that would be helpful. Once again, thank you for reaching out!
>
> Cheers,
>
> Sean
>
>
>
>
> On Tue, Jul 17, 2018 at 7:59 AM Carl Schroedl <cschroedl@xxxxxxxx> wrote:
>
>> Hi NetCDF Java Folks!
>>
>> Thanks for you hard work on this important open source project. I am Carl
>> Schroedl, a software developer for the US Geological Survey. We will be
>> working on a surface water model archiving platform this summer. Our
>> surface water model archives will be leveraging a new CF Convention on
>> Simple Geometries to represent things like rivers and watersheds. If you
>> would like to dig into the details on the new CF Convention, check out the
>> specification pull request
>> <https://github.com/cf-convention/cf-conventions/pull/115>, the attached
>> poster, or the Simple Geometry portion of this lecture
>> <http://wiki.esipfed.org/index.php/Interoperability_and_Technology/Tech_Dive_Webinar_Series#10_May_2018:_.22NetCDF-CF_Advances_-_Simple_Geometries.2C_Swaths.2C_and_Groups.22:_Dave_Blodgett_.28USGS.29.2C_Tim_Whiteaker_.28UT_Austin.29.2C_Aleksander_Jelanek_.28HDF_Group.29_and_Daniel_Lee_.28EUMETSAT.29>
>> .
>>
>> We would like to contribute support for this new convention to open
>> source tools, possibly including THREDDS, and the CDM. I know from
>> experience that projects are not always in a great position to accept
>> contributions (large in-flight refactor branches, closely-related
>> concurrent work, etc.). Do you foresee any problems with an influx of these
>> types of contributions to between now and September? Do you have any advice
>> on how our team could best contribute support for this convention to
>> THREDDS, the CDM, or related projects?
>>
>> Thanks again for your work on these important open source efforts.
>>
>> Wishing you all the best,
>>
>> --
>>
>> *Carl Schroedl *| Computer Scientist | USGS | Water Mission Area |
>> Integrated Modeling and Prediction Division | Modeling Support and
>> Coordination Branch | 8505 Research Way | Middleton, WI 53562 | 608-821-3836
>> | https://www.usgs.gov/science/mission-areas/water
>>
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>
>
--
*Carl Schroedl *| Computer Scientist | USGS | Water Mission Area |
Integrated Modeling and Prediction Division | Modeling Support and
Coordination Branch | 8505 Research Way | Middleton, WI 53562 |
608-821-3836 | https://www.usgs.gov/science/mission-areas/water
