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Re: MODIS HDF-EOS Data in the NetCDF-Java CDM and THREDDS



Hi David:

I had a look at this again. I changed HdfEosModisConvention to use a 1D instead of a scalar time coordinate.

However, joinExisting isnt working because the dataset needs to be "enhanced" (with HdfEosModisConvention) first, before the time coordinate is available. Currently joinExisting aggregation doesnt do that.

I can probably hack that in. Really I want to get the GRID feature collection working, but thats going to be a few months. Aggregation is old and crufty.

Anyway, Ill let you know if i can get "enhanced" working.

John



On 3/20/2013 7:50 AM, Blodgett, David wrote:
Morning John,

I pulled down the latest thredds war and have been testing a few things
out. Did you get temporal aggregation working on the structured data at
all? Any hints on how to structure the ncml for that?

Looks like the spatial stuff is working. Fantastic.

Thanks!

- Dave



On Mon, Mar 4, 2013 at 9:07 AM, Blodgett, David <address@hidden
<mailto:address@hidden>> wrote:

    OK, we'll keep an eye out for the release, thanks so much John!

    No worries on the aggregation, the tiles are big enough that I think
    we can deal without aggregation.


    On Mon, Mar 4, 2013 at 8:43 AM, John Caron <address@hidden
    <mailto:address@hidden>> wrote:

        On 3/1/2013 12:03 PM, Blodgett, David wrote:
        John,

        Really happy you added this stuff in, what's your plan for
        releasing it?

        going to try to release 4.3.16 in next week or two.



        You think there's any chance that tiled aggregation will work?

        im reluctant to recommend using whats there currently. But doing
        it right is a challenge and wont be done soon.




        - Dave


        On Tue, Feb 26, 2013 at 8:30 AM, address@hidden
        <mailto:address@hidden> <address@hidden
        <mailto:address@hidden>> wrote:

            Yes the tiling scheme is consistent for all the MODIS tiles.

            Thanks,

            Jason Werpy
            Enterprise Architect
            Information Dynamics
            USGS/EROS
            Sioux Falls, SD 57198
            phone: 605-594-2723 <tel:605-594-2723>
            cell: 605-690-3576 <tel:605-690-3576>
            fax: 605-594-2530 <tel:605-594-2530>
            address@hidden <mailto:address@hidden>

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            On Feb 26, 2013, at 8:26 AM, "Blodgett, David"
            <address@hidden <mailto:address@hidden>> wrote:

            In this case, the data is 16 day from about 2000 to
            present. So, on the order of 275 time steps. There are
            daily products and annual products though, in wich case,
            we are looking 12 to 4000+ time steps.

            Jason, is the tile scheme you sent over used for all the
            different resolutions? Looking at a few of them it looks
            like that is the case.

            - Dave



            On Tue, Feb 26, 2013 at 7:48 AM, John Caron
            <address@hidden <mailto:address@hidden>>
            wrote:

                Heres an image of this file.

                questions about aggregations: how many time steps
                will be in each aggregation ? how many different
                aggregations (tiles?) will you serve?



                On 2/24/2013 6:55 PM, David Blodgett wrote:

                    Sweet, thanks John. There was data in the tile,
                    but was hard to find... BORING, I know. Sorry
                    about that.

                    Here's a tile over the great lakes to give you a
                    coast to compare locations to.

                    
http://e4ftl01.cr.usgs.gov/MOLT/MOD13Q1.005/2000.03.05/BROWSE.MOD13A1.A2000065.h11v04.005.2008238024700.1.jpg
                    
http://e4ftl01.cr.usgs.gov/MOLT/MOD13Q1.005/2000.03.05/MOD13Q1.A2000065.h11v04.005.2008238031620.hdf
                    
http://e4ftl01.cr.usgs.gov/MOLT/MOD13Q1.005/2000.03.05/MOD13Q1.A2000065.h11v04.005.2008238031620.hdf.xml

                    - Dave

                    On Feb 24, 2013, at 6:33 PM, John Caron wrote:

                        Hi:

                        Im hacking away at this, but the datafiles i
                        downloaded _seem_ to have nothing but missing
                        values. Or im doing something wrong. Can you
                        send me a file that you know has real data in
                        it. thanks

                        John

                        On 2/24/2013 9:22 AM, David Blodgett wrote:

                            Hi John,

                            Actually, I was assuming that the
                            sinusoidal projection was in there, doh!
                            That was based on gdal_translate creating
                            a geotiff with this projection info:

                            PROJCS["unnamed",
                                 GEOGCS["Unknown datum based upon the
                            custom spheroid",
                             DATUM["Not_specified_based_on_custom_spheroid",
                                         SPHEROID["Custom
                            spheroid",6371007.181,0]],
                                     PRIMEM["Greenwich",0],
                                     UNIT["degree",0.0174532925199433]],
                                 PROJECTION["Sinusoidal"],
                                 PARAMETER["longitude_of_center",0],
                                 PARAMETER["false_easting",0],
                             PARAMETER["false_northing",0],
                                 UNIT["metre",1,
                             AUTHORITY["EPSG","9001"]]]

                            There's a georeferencing section here
                            (http://www.gdal.org/frmt_hdf4.html) that
                            has a bit more info about gdal's
                            implementation. Might be something
                            helpful there? Looks like the ODL text
                            you point to is where its coming from.

                            4 and 5 are questions for Jason and maybe
                            Jordan. Guys?

                            - Dave





                            On Feb 23, 2013, at 1:22 PM, John Caron
                            wrote:


                                On 2/22/2013 2:07 PM, David Blodgett
                                wrote:

                                    Welcome back John. Hope you had a
                                    good trip!

                                thanks!

                                    I actually just spent a bunch of
                                    time with this the other day and have
                                    been meaning to summarize what
                                    I'm finding.

                                    The first issue we are running
                                    into is your #1 below. In this
                                    case there
                                    is an external xml file that
                                    contains a lot of metadata, including
                                    information about the projection
                                    (sinusoidal), which is currently
                                    unsupported by NetCDF-Java?

                                1) where do you get this xml file?

                                2) im looking at

                                MOD13Q1.A2000065.h00v08.005.2008238080422.hdf
                                
MOD13Q1.A2000065.h00v08.005.2008238080422.hdf.xml

                                in your union subdirectory. The xml
                                file does not seem to have projection
                                info in it.

                                3) the internal ODL text
                                (StructMetadata) has

                                ...
                                
UpperLeftPointMtrs=(-20015109.354000,1111950.519667)
                                LowerRightMtrs=(-18903158.834333,-0.000000)
                                Projection=GCTP_SNSOID
                                
ProjParams=(6371007.181000,0,0,0,0,0,0,0,0,0,0,0,0)
                                                SphereCode=-1

                                ...

                                which may be enough to calculate the
                                lat/lon values. Since this is the
                                best choice, lets investigate it
                                before we go down any other paths.

                                4) Can anyone track down the code in
                                the hyrax handler that does this? Or
                                does the hyrax handler actually link
                                in the hds-eos libraries ??

                                5) how confident are you that all the
                                files that you want to aggregate have
                                the same lat/lon geolocation ?


                                John