Michael,

actually support for those products was already there at 95% since they use the HDF5EOS GRID formalism which we support since 3.7. But that particular type of products has an oddity. They have an empty GROUP=Dimension within the GROUP=GridStructure in the HDF5EOS metadata, which our parser didn't like as we use the information in this group to map dimension names to dimension index and size. Fixed/worked around in https://github.com/OSGeo/gdal/pull/9807 . Hard to tell if those products are in fault given that the HDF5EOS specification at https://www.earthdata.nasa.gov/s3fs-public/imported/ESDS-RFC-008-v1.1.pdf , appendix A, is extremely minimum regarding the HDF5EOS metadata itself (for once, I complain for a spec to be too minimal !), and the example they give for grids doesn't make sense to me (the declared dimension names and sizes have nothing to do with the ones use in the grid)

I now get:

$ gdalinfo HDF5:"AMSR_U2_L3_SeaIce12km_B04_20120702.he5"://HDFEOS/GRIDS/SpPolarGrid12km/Data_Fields/SI_12km_SH_18H_ASC
Driver: HDF5Image/HDF5 Dataset
Files: AMSR_U2_L3_SeaIce12km_B04_20120702.he5
Size is 632, 664
Coordinate System is:
PROJCRS["unnamed",
    BASEGEOGCRS["Unknown datum based upon the custom spheroid",
        DATUM["Not specified (based on custom spheroid)",
            ELLIPSOID["Custom spheroid",6378273,0,
                LENGTHUNIT["metre",1,
                    ID["EPSG",9001]]]],
        PRIMEM["Greenwich",0,
            ANGLEUNIT["degree",0.0174532925199433,
                ID["EPSG",9122]]]],
    CONVERSION["Polar Stereographic (variant B)",
        METHOD["Polar Stereographic (variant B)",
            ID["EPSG",9829]],
        PARAMETER["Latitude of standard parallel",-70,
            ANGLEUNIT["degree",0.0174532925199433],
            ID["EPSG",8832]],
        PARAMETER["Longitude of origin",0,
            ANGLEUNIT["degree",0.0174532925199433],
            ID["EPSG",8833]],
        PARAMETER["False easting",0,
            LENGTHUNIT["metre",1],
            ID["EPSG",8806]],
        PARAMETER["False northing",0,
            LENGTHUNIT["metre",1],
            ID["EPSG",8807]]],
    CS[Cartesian,2],
        AXIS["(E)",north,
            MERIDIAN[90,
                ANGLEUNIT["degree",0.0174532925199433,
                    ID["EPSG",9122]]],
            ORDER[1],
            LENGTHUNIT["Meter",1]],
        AXIS["(N)",north,
            MERIDIAN[0,
                ANGLEUNIT["degree",0.0174532925199433,
                    ID["EPSG",9122]]],
            ORDER[2],
            LENGTHUNIT["Meter",1]]]
Data axis to CRS axis mapping: 1,2
Origin = (-3950000.000000000000000,4350000.000000000000000)
Pixel Size = (12500.000000000000000,-12500.000000000000000)
Metadata:
  Conventions=CF-1.6
  HDFEOS_INFORMATION_HDFEOSVersion=HDFEOS_5.1.15
  history=This version of the Sea Ice processing code contains updates provided by the science team on September 16, 2019. For details on these updates, see the release notes provided in the DAP.
  institution=NASA's AMSR Science Investigator-led Processing System (SIPS)
  references=Please cite these data as: Markus, T., J. C. Comiso, and W. N. Meier. 2018. AMSR-E/AMSR2 Unified L3 Daily 12.5 km Brightness Temperatures, Sea Ice Concentration, Motion & Snow Depth Polar Grids, Version 1. [Indicate subset used]. Boulder, Colorado USA. NASA National Snow and Ice Data Center Distributed Active Archive Center. doi: https://doi.org/10.5067/RA1MIJOYPK3P.
  source=satellite observation
  title=AMSR-E/AMSR2 Unified L3 Daily 12.5 km Brightness Temperatures, Sea Ice Concentration, Motion & Snow Depth Polar Grids
Corner Coordinates:
Upper Left  (-3950000.000, 4350000.000) ( 42d14'27.21"W, 39d11'27.54"S)
Lower Left  (-3950000.000,-3950000.000) (135d 0' 0.00"W, 41d23'59.41"S)
Upper Right ( 3950000.000, 4350000.000) ( 42d14'27.21"E, 39d11'27.54"S)
Lower Right ( 3950000.000,-3950000.000) (135d 0' 0.00"E, 41d23'59.41"S)
Center      (       0.000,  200000.000) (  0d 0' 0.01"E, 88d 8'51.76"S)
Band 1 Block=632x1 Type=Int32, ColorInterp=Undefined
  NoData Value=0
  Metadata:
    add_offset=0
    coordinates=lon lat
    long_name=18.7 GHz horizontal daily average ascending Tbs
    packing_convention=netCDF
    packing_convention_description=unpacked = scale_factor x packed + add_offset
    scale_factor=0.1
    standard_name=brightness_temperature
    units=degree_kelvin
    _FillValue=0

Even

Le 29/04/2024 à 21:10, Michael Sumner via gdal-dev a écrit :
This HDF5 (requires earthdata credentials your "Authorization: Bearer <token>" in GDAL_HTTP_HEADERS, or equiv) presents without geolocation arrays.

gdalinfo "/vsicurl/https://n5eil01u.ecs.nsidc.org/AMSA/AU_SI12.001/2012.07.02/AMSR_U2_L3_SeaIce12km_B04_20120702.he5"; -sd 26
Driver: HDF5Image/HDF5 Dataset
Files: /vsicurl/https://n5eil01u.ecs.nsidc.org/AMSA/AU_SI12.001/2012.07.02/AMSR_U2_L3_SeaIce12km_B04_20120702.he5
Size is 608, 896
Metadata:
  Conventions=CF-1.6
  HDFEOS_INFORMATION_HDFEOSVersion=HDFEOS_5.1.15
  history=This version of the Sea Ice processing code contains updates provided by the science team on September 16, 2019. For details on these updates, see the release notes provided in the DAP.   institution=NASA's AMSR Science Investigator-led Processing System (SIPS)   references=Please cite these data as: Markus, T., J. C. Comiso, and W. N. Meier. 2018. AMSR-E/AMSR2 Unified L3 Daily 12.5 km Brightness Temperatures, Sea Ice Concentration, Motion & Snow Depth Polar Grids, Version 1. [Indicate subset used]. Boulder, Colorado USA. NASA National Snow and Ice Data Center Distributed Active Archive Center. doi: https://doi.org/10.5067/RA1MIJOYPK3P.
  source=satellite observation
  title=AMSR-E/AMSR2 Unified L3 Daily 12.5 km Brightness Temperatures, Sea Ice Concentration, Motion & Snow Depth Polar Grids
Corner Coordinates:
Upper Left  (    0.0,    0.0)
Lower Left  (    0.0,  896.0)
Upper Right (  608.0,    0.0)
Lower Right (  608.0,  896.0)
Center      (  304.0,  448.0)
Band 1 Block=608x1 Type=Int32, ColorInterp=Undefined
  Metadata:
    comment=data value meaning: 0 -- Open Water, 110 -- missing/not calculated, 120 -- Land
    coordinates=lon lat
    long_name=Sea ice concentration daily average
    units=percent



gdalinfo --version
GDAL 3.9.0dev-cb4d30f56d, released 2024/04/15

The geolocation arrays are sds 33 and 32 respectively:

HDF5:"/vsicurl/https://n5eil01u.ecs.nsidc.org/AMSA/AU_SI12.001/2012.07.02/AMSR_U2_L3_SeaIce12km_B04_20120702.he5"://HDFEOS/GRIDS/NpPolarGrid12km/lon

HDF5:"/vsicurl/https://n5eil01u.ecs.nsidc.org/AMSA/AU_SI12.001/2012.07.02/AMSR_U2_L3_SeaIce12km_B04_20120702.he5"://HDFEOS/GRIDS/NpPolarGrid12km/lat

And things work when lining those up in VRT with warp. Can the HDF5 driver be made to auto-detect these geolocation arrays?

I see that the NETCDF driver actually does:

gdalinfo "NetCDF:/vsicurl/https://n5eil01u.ecs.nsidc.org/AMSA/AU_SI12.001/2012.07.02/AMSR_U2_L3_SeaIce12km_B04_20120702.he5"; -sd 26

I'm asking as an email rather than pursuing the fix because, these data are actually a regular grid on the north and south poles, and so geolocation by arrays is sub-optimal  the specification is listed in

https://nsidc.org/sites/default/files/au_si12-v001-userguide_1.pdf

and the two parameter sets are

Np-north: -te -3850000,  -5350000, 3750000, 5850000 -t_srs EPSG:3411
Sp-south: -te -3950000,  -3950000, 3950000, 4350000 -t_srs EPSG:3412

Is this generally something we should pursue within GDAL? It seems like an endless task to detect-on-open exactly this situation and assign the easy fix, but this is a pretty fundamental data stream and it's very common so the longlat/arrays might be numerically detectable with other heuristics hinting that it's polar (??) and there are plenty of other sources that present equivalents in the right way e.g. this one:

"/vsicurl/https://noaadata.apps.nsidc.org/NOAA/G02135/north/daily/geotiff/2012/07_Jul/N_20120702_concentration_v3.0.tif";

The right approach is probably to inform the providers and get the right metadata baked in ... but there's pros and cons to either. I'm not sure there's even enough information in these files to clearly detect the situation, it would be a bit like the NSIDCbin driver with its very strict requirements.

Cheers, Mike


--

Michael Sumner
Software and Database Engineer
Australian Antarctic Division
Hobart, Australia
e-mail: mdsum...@gmail.com

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