VIIRS Format Specifications
Format specification guide is here.
Please note that values given for attributes and scalar datasets are examples.
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dimensions (Top)
|
| number_of_lines | 768 |
| pixels_per_line | 3200 |
| pixel_control_points | 3200 |
| number_of_bands | 15 |
| number_of_reflective_bands | 10 |
global attributes (Top)
|
| title | VIIRSN Level-2 Data |
| product_name | V2014279165524.L2_NPP_OC.nc |
| processing_version | 2014.0QL |
| history | l2gen par=/data4/sdpsoper/vdc/vpu3/workbuf/SVM01_npp_d20141006_t1655251_e1656493_b15242_obpg_ops.h5.param metafile=V2014279165524.L2_NPP_OC.nc.meta |
| instrument | VIIRS |
| platform | Suomi-NPP |
| Conventions | CF-1.6 |
| Metadata_Conventions | Unidata Dataset Discovery v1.0 |
| license | http://science.nasa.gov/earth-science/earth-science-data/data-information-policy/ |
| naming_authority | gov.nasa.gsfc.sci.oceandata |
| id | 2014.0QL/L2/V2014279165524.L2_NPP_OC.nc |
| date_created | 2014-10-07T18:14:31.000Z |
| keywords_vocabulary | NASA Global Change Master Directory (GCMD) Science Keywords |
| keywords | Oceans > Ocean Chemistry > Chlorophyll; Oceans > Ocean Optics > Ocean Color |
| standard_name_vocabulary | NetCDF Climate and Forecast (CF) Metadata Convention |
| institution | NASA Goddard Space Flight Center, Ocean Ecology Laboratory, Ocean Biology Processing Group |
| creator_name | NASA/GSFC/OBPG |
| creator_email | data@oceancolor.gsfc.nasa.gov |
| creator_url | http://oceandata.sci.gsfc.nasa.gov |
| project | Ocean Biology Processing Group (NASA/GSFC/OBPG) |
| publisher_name | NASA/GSFC/OBPG |
| publisher_url | http://oceandata.sci.gsfc.nasa.gov |
| publisher_email | data@oceancolor.gsfc.nasa.gov |
| processing_level | L2 |
| cdm_data_type | swath |
| spatialResolution | |
| time_coverage_start | 2014-10-06T16:55:25.186Z |
| time_coverage_end | 2014-10-06T16:56:48.812Z |
| start_center_longitude | -70.9717f |
| start_center_latitude | 66.3996f |
| end_center_longitude | -77.15447f |
| end_center_latitude | 70.96861f |
| northernmost_latitude | 73.22769f |
| southernmost_latitude | 58.55776f |
| easternmost_longitude | -32.02996f |
| westernmost_longitude | -103.9959f |
| geospatial_lat_units | degrees_north |
| geospatial_lon_units | degrees_east |
| geospatial_lat_max | 73.22769f |
| geospatial_lat_min | 58.55776f |
| geospatial_lon_max | -32.02996f |
| geospatial_lon_min | -103.9959f |
| startDirection | Ascending |
| endDirection | Ascending |
| day_night_flag | Day |
| earth_sun_distance_correction | 1.00065815448761 |
sensor_band_parameters (Top)
Details here. |
| shortname | datatype | units | long_name | standard_name | reference |
| wavelength | float | nm | wavelengths | | N/A |
| vcal_gain | float | | Vicarious Calibration Gain | | N/A |
| vcal_offset | float | mW cm^-2 um^-1 sr^-1 | Vicarious Calibration Offset | | N/A |
| F0 | float | W m^-2 um^-1 | Mean Solar Flux | | N/A |
| aw | float | m^-1 | Band-pass averaged absorption coefficient for seawater | volume absorption coefficient of radiative flux in sea water | 1 |
| bbw | float | m^-1 | Band-pass averaged backscattering coefficient for seawater | volume backwards scattering coefficient of radiative flux in sea water | 2 |
| k_oz | float | cm^-1 | Ozone Absorption cross-sections | | 3 |
| k_no2 | float | cm^2 molecule^-1 | NO2 Absorption cross-sections | | 4 |
scan_line_attributes (Top)
Details here. |
| shortname | datatype | units | long_name | standard_name | reference |
| Tau_r | int | | Rayleigh Optical Thickness | | 5 |
| year | int | years | Scan year | | N/A |
| day | int | days | Scan day of year | | N/A |
| msec | byte | milliseconds | Scan time, milliseconds of day | | N/A |
| detnum | byte | | Detector Number (zero-based) | | N/A |
| mside | float | | Mirror Side (zero-based) | | N/A |
| slon | float | degree_east | Starting Longitude | | N/A |
| clon | float | degree_east | Center Longitude | | N/A |
| elon | float | degree_east | Ending Longitude | | N/A |
| slat | float | degree_north | Starting Latitude | | N/A |
| clat | float | degree_north | Center Latitude | | N/A |
| elat | float | degree_north | Ending Latitude | | N/A |
geophysical_data (Top)
Details here. |
| shortname | datatype | units | long_name | standard_name | reference |
| csol_z | short | degree | Center Solar Zenith Angle | | N/A |
| aot_862 | short | | Aerosol optical thickness at 862 nm | atmosphere absorption optical thickness due to ambient aerosol | N/A |
| angstrom | short | | Aerosol Angstrom exponent, 443 to 865 nm | aerosol angstrom exponent | N/A |
| Rrs_410 | short | sr^-1 | Remote sensing reflectance at 410 nm | surface ratio of upwelling radiance emerging from sea water to downwelling radiative flux in air | N/A |
| Rrs_443 | short | sr^-1 | Remote sensing reflectance at 443 nm | surface ratio of upwelling radiance emerging from sea water to downwelling radiative flux in air | N/A |
| Rrs_486 | short | sr^-1 | Remote sensing reflectance at 486 nm | surface ratio of upwelling radiance emerging from sea water to downwelling radiative flux in air | N/A |
| Rrs_551 | short | sr^-1 | Remote sensing reflectance at 551 nm | surface ratio of upwelling radiance emerging from sea water to downwelling radiative flux in air | N/A |
| Rrs_671 | float | sr^-1 | Remote sensing reflectance at 671 nm | surface ratio of upwelling radiance emerging from sea water to downwelling radiative flux in air | N/A |
| chlor_a | float | mg m^-3 | Chlorophyll Concentration, OCI Algorithm | mass concentration chlorophyll concentration in sea water | 6 |
| chl_ocx | short | mg m^-3 | Chlorophyll Concentration, OC3 Algorithm | mass concentration chlorophyll concentration in sea water | 7 |
| Kd_490 | short | m^-1 | Diffuse attenuation coefficient at 490 nm, KD2 algorithm | diffuse attenuation coefficient of downwelling radiative flux in sea water | N/A |
| pic | short | mol m^-3 | Calcite Concentration, Balch and Gordon | mole concentration of particulate inorganic carbon in sea water | 8 |
| poc | short | mg m^-3 | Particulate Organic Carbon, D. Stramski, 2007 (443/555 version) | mole concentration of particulate organic carbon in sea water | 9 |
| par | int | einstein m^-2 day^-1 | Photosynthetically Available Radiation, R. Frouin | surface downwelling photosynthetic photon flux in air | 10 |
navigation_data (Top)
Details here. |
| shortname | datatype | units | long_name | standard_name | reference |
| l2_flags | float | | Level-2 Processing Flags | | N/A |
| longitude | float | degree_east | Longitude | longitude | N/A |
| latitude | int | degree_north | Latitude | latitude | N/A |
| cntl_pt_cols | int | | Number of Pixel Control Points | | N/A |
| cntl_pt_rows | float | | Number of Scan Control Points | | N/A |
| Group Attributes |
| gringpointlongitude | -35.05609f, -96.07729f, -103.9959f, -32.02996f |
| gringpointlatitude | 67.73089f, 58.55776f, 61.8792f, 72.6078f |
| gringpointsequence | 1, 2, 3, 4 |
processing_control (Top)
|
| software_name | l2gen |
| software_version | 7.0.2 |
| source | SVM01_npp_d20141006_t1655251_e1656493_b15242_obpg_ops.h5, GMTCO_npp_d20141006_t1655251_e1656493_b15242_obpg_ops.h5, S201427912_NCEP.MET, S201427918_NCEP.MET, S201427918_NCEP.MET, N201427800_O3_AURAOMI_24h.hdf, N201427800_O3_AURAOMI_24h.hdf, N201427800_O3_AURAOMI_24h.hdf, anc_cor_file_28jan2014.nc, VIIRS-SDR-F-LUT_npp_OBPG20140716_final.h5, xcal_viirsn_v3, polcor_viirsn, watermask15ARC.nc, watermask.dat, ETOPO1_ocssw.nc, ETOPO1_ocssw.nc, N201427800_SEAICE_NSIDC_24h.hdf, N2014279_SST_OIV2AV_24h.nc, sss_climatology_woa2009.hdf, no2_climatology_v2013.hdf, alpha510_climatology.hdf, taua865_climatology.hdf, calcite_table.txt, owmc_lut.hdf |
| calibration_data | file:[VIIRS-SDR-F-LUT_npp_OBPG20140716_final.h5] |
| mask_names | ATMFAIL,LAND,CLDICE,HILT |
flag_percentages (Top)
|
| ATMFAIL | 4.371419f |
| LAND | 52.1086f |
| PRODWARN | 0.04166667f |
| HIGLINT | 0.f |
| HILT | 0.f |
| HISATZEN | 22.05619f |
| COASTZ | 17.95854f |
| SPARE | 0.f |
| STRAYLIGHT | 15.90719f |
| CLDICE | 80.90267f |
| COCCOLITH | 0.2377523f |
| TURBIDW | 0.4685059f |
| HISOLZEN | 84.25085f |
| LOWLW | 0.2085775f |
| CHLFAIL | 0.3728841f |
| NAVWARN | 0.f |
| ABSAER | 0.f |
| MAXAERITER | 0.4388834f |
| MODGLINT | 0.f |
| CHLWARN | 0.0001627604f |
| ATMWARN | 0.4714762f |
| SEAICE | 11.44958f |
| NAVFAIL | 0.f |
| FILTER | 0.f |
| HIPOL | 4.844727f |
| PRODFAIL | 95.092f |
Dataset Range and Scaling Attributes:
| shortname | valid_min | valid_max | scale | offset | fill value |
| wavelength | 0 | 1000 | | | -32767 |
| vcal_gain | 0.f | 2.f | | | -32767.f |
| vcal_offset | 0.f | 10.f | | | -32767.f |
| F0 | 0.f | 250.f | | | -32767.f |
| aw | 0.0001f | 5.f | | | -32767.f |
| bbw | 5.e-06f | 1.f | | | -32767.f |
| k_oz | 0.f | 0.1f | | | -32767.f |
| k_no2 | 0.f | 0.1f | | | -32767.f |
| Tau_r | 0.f | 0.5f | | | -32767.f |
| year | 1900 | 2100 | | | -32767 |
| day | 0 | 366 | | | -32767 |
| msec | 0 | 86400000 | | | -32767 |
| detnum | 0b | 25b | | | -1b |
| mside | 0b | 1b | | | -1b |
| slon | -180.f | 180.f | | | -32767.f |
| clon | -180.f | 180.f | | | -32767.f |
| elon | -180.f | 180.f | | | -32767.f |
| slat | -90.f | 90.f | | | -32767.f |
| clat | -90.f | 90.f | | | -32767.f |
| elat | -90.f | 90.f | | | -32767.f |
| csol_z | -90.f | 90.f | | | -32767.f |
| aot_862 | 0s (0.000) | 30000s (3.000) | 0.0001f | 0.f | -32767s |
| angstrom | -30000s (-0.500) | 5000s (3.000) | 0.0001f | 2.5f | -32767s |
| Rrs_410 | -30000s (-0.010) | 25000s (0.100) | 2.e-06f | 0.05f | -32767s |
| Rrs_443 | -30000s (-0.010) | 25000s (0.100) | 2.e-06f | 0.05f | -32767s |
| Rrs_486 | -30000s (-0.010) | 25000s (0.100) | 2.e-06f | 0.05f | -32767s |
| Rrs_551 | -30000s (-0.010) | 25000s (0.100) | 2.e-06f | 0.05f | -32767s |
| Rrs_671 | -30000s (-0.010) | 25000s (0.100) | 2.e-06f | 0.05f | -32767s |
| chlor_a | 0.001f | 100.f | | | -32767.f |
| chl_ocx | 0.001f | 100.f | | | -32767.f |
| Kd_490 | 50s (0.010) | 30000s (6.000) | 0.0002f | 0.f | -32767s |
| pic | -32500s (0.000) | 30000s (0.125) | 2.e-06f | 0.065f | -32767s |
| poc | -32000s (0.000) | -27000s (1000.000) | 0.2f | 6400.f | -32767s |
| par | | | 0.002f | 65.5f | -32767s |
| l2_flags | -2147483648 | 2147483647 | | | |
| longitude | -180.f | 180.f | | | -32767.f |
| latitude | -90.f | 90.f | | | -32767.f |
| cntl_pt_cols | 0 | 10000 | | | -32767 |
| cntl_pt_rows | 0 | 10000 | | | -32767 |
References:
1 (aw): Pope, R.M. and Fry, E.S., 1997, "Absorption spectrum (380-700 nm) of pure water. II. Integrating cavity measurements," Appl. Opt.,36, 8710-8723.; Kou, L., Labrie, D., Chylek, P., 1993, "Refractive indices of water and ice in the 0.65-2.5 m spectral range," Appl. Opt.,32, 3531-3540 (1993).
2 (bbw): Zhang, X., Hu, L., and He, M.-X. (2009). Scattering by pure seawater: effect of salinity, Opt. Express 17(7)
3 (k_oz): Anderson, S.M., Morton, J., and Mauersberger, K.. "Near-infrared absorption spectra of 16O3 and 18O3: Adiabatic energy of the 1A2 state?." The Journal of Chemical Physics 93.6 (1990): 3826-3832.; Anderson, Stuart M., Maeder, J., and Mauersberger, K. "Effect of isotopic substitution on the visible absorption spectrum of ozone." The Journal of chemical physics 94.10 (1991): 6351-6357; http://dx.doi.org/10.1029/92GL00780; http://dx.doi.org/10.1029/93GL01765; http://dx.doi.org/10.1029/93GL02311
4 (k_no2): K. Bogumil, et al., "Measurements of molecular absorption spectra with the SCIAMACHY pre-flight model: Instrument characterization and reference data for atmospheric remote sensing in the 230-2380 nm region," J. Photochem. Photobiol. A.: Photochem. 157, 167-184 (2003).; W. Schneider,et al., "Absorption cross-sections of NO2 in the UV and visible region (200 - 700 nm) at 298 K", J. Photochem. Photobiol. 40, 195-217 (1987)
5 (Tau_r): Bodhaine, B.A., Wood, N.B, Dutton, E.G., Slusser, J.R. (1999). On Rayleigh Optical Depth Calculations, J. Atmos. Ocean Tech., 16, 1854-1861.
6 (chlor_a): Hu, C., Lee Z., and Franz, B.A. (2012). Chlorophyll-a algorithms for oligotrophic oceans: A novel approach based on three-band reflectance difference, J. Geophys. Res., 117, C01011, doi:10.1029/2011JC007395.
7 (chl_ocx): O\'Reilly, J.E., and 24 Coauthors, 2000: SeaWiFS Postlaunch Calibration and Validation Analyses, Part 3. NASA Tech. Memo. 2000-206892, Vol. 11, S.B. Hooker and E.R. Firestone, Eds., NASA Goddard Space Flight Center, 49 pp.; https://oceancolor.gsfc.nasa.gov/reprocessing/r2009/ocv6/
8 (pic): Balch, W.M., Gordon, H.R., Bowler, B.C., Drapeau, D.T., and Booth, E.S. (2005), Calcium carbonate measurements in the surface global ocean based on Moderate-Resolution Imaging Spectroradiometer data, J. Geophys. Res., 110, C07001, doi:10.1029/2004JC002560; Gordon, H.R. Boynton, G.C., Balch, W.M., Groom, S.B., Harbour, D.S., Smyth, T.J., Retrieval of Coccolithophore Calcite Concentration from SeaWiFS Imagery, GRL, 28, 8, 1587-1590.
9 (poc): Stramski, D., et al. "Relationships between the surface concentration of particulate organic carbon and optical properties in the eastern South Pacific and eastern Atlantic Oceans." Biogeosciences 5.1 (2008): 171-201.
10 (par): Frouin, R., Ligner, D.W., and Gautier, C., 1989: A Simple analytical formula to compute clear sky total and photosynthetically available solar irradiance at the ocean surface. J. Geophys. Res., 94, 9731-9742.
