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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 >> >> _______________________________________________ >> NOTE: All exchanges posted to Unidata maintained email lists are >> recorded in the Unidata inquiry tracking system and made publicly >> available through the web. Users who post to any of the lists we >> maintain are reminded to remove any personal information that they >> do not want to be made public. >> >> >> netcdf-java mailing list >> netcdf-java@xxxxxxxxxxxxxxxx >> For list information or to unsubscribe, visit: >> http://www.unidata.ucar.edu/mailing_lists/ > > -- *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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