Data Access Form

Dataset Title:	Kd490, NOAA S-NPP VIIRS, Near Real-Time, 750m Sector VZ, Daily
Institution:	NOAA NESDIS CoastWatch (Dataset ID: noaacwNPPVIIRSkd490SectorVZDaily)
Information:	Summary \| License \| FGDC \| ISO 19115 \| Metadata \| Background \| Files \| Make a graph

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Dimensions	Size	Spacing
time (UTC)	78	1 day 4h 51m 14s (uneven)

altitude (m)	1	(just one value)

latitude (degrees_north)	6000	-0.0075 (even)

longitude (degrees_east)	8010	0.0075 (even)

Grid Variables (which always also download all of the dimension variables)

kd_490 (Diffuse Attenuation Coefficient at 490 nm, m^-1)

swath_latitude (Latitude, degrees_north)

swath_longitude (Longitude, degrees_east)

graphics (graphics overlay planes)

File type: (more information)

(Documentation / Bypass this form)

(Please be patient. It may take a while to get the data.)

The Dataset Attribute Structure (.das) for this Dataset

Attributes {
  time {
    String _CoordinateAxisType "Time";
    Float64 actual_range 1.7227470234955e+9, 1.730745299537e+9;
    String axis "T";
    String bounds "time_bounds";
    String calendar "gregorian";
    String ioos_category "Time";
    String long_name "Time";
    String standard_name "time";
    String time_origin "01-JAN-1970 00:00:00";
    String units "seconds since 1970-01-01T00:00:00Z";
  }
  altitude {
    String _CoordinateAxisType "Height";
    String _CoordinateZisPositive "up";
    Float64 actual_range 0.0, 0.0;
    String axis "Z";
    String ioos_category "Location";
    String long_name "Altitude";
    String positive "up";
    String standard_name "altitude";
    String units "m";
  }
  latitude {
    String _CoordinateAxisType "Lat";
    Float64 actual_range 44.77875, 89.77125000000001;
    String axis "Y";
    String ioos_category "Location";
    String long_name "Latitude";
    String source_name "rows";
    String standard_name "latitude";
    String units "degrees_north";
  }
  longitude {
    String _CoordinateAxisType "Lon";
    Float64 actual_range -120.03375, -59.96625;
    String axis "X";
    String ioos_category "Location";
    String long_name "Longitude";
    String source_name "cols";
    String standard_name "longitude";
    String units "degrees_east";
  }
  kd_490 {
    Float64 _FillValue -32.768001556396484;
    Float32 colorBarMaximum 10.0;
    Float32 colorBarMinimum 0.01;
    String colorBarScale "Log";
    String coverage_content_type "physical_measurement";
    String grid_mapping "coord_ref";
    String ioos_category "Ocean Color";
    String long_name "Diffuse Attenuation Coefficient at 490 nm";
    Float64 missing_value -32.768001556396484;
    String units "m^-1";
    Float64 valid_max 32.00000151991844;
    Float64 valid_min 0.01600000075995922;
  }
  swath_latitude {
    Float32 _FillValue NaN;
    Float64 colorBarMaximum 90.0;
    Float64 colorBarMinimum -90.0;
    String grid_mapping "coord_ref";
    String ioos_category "Location";
    String long_name "Latitude";
    Float32 missing_value NaN;
    String units "degrees_north";
  }
  swath_longitude {
    Float32 _FillValue NaN;
    Float64 colorBarMaximum 180.0;
    Float64 colorBarMinimum -180.0;
    String grid_mapping "coord_ref";
    String ioos_category "Location";
    String long_name "Longitude";
    Float32 missing_value NaN;
    String units "degrees_east";
  }
  graphics {
    Int16 _FillValue 0;
    Float64 colorBarMaximum 20.0;
    Float64 colorBarMinimum 0.0;
    String grid_mapping "coord_ref";
    String ioos_category "Other";
    String long_name "graphics overlay planes";
    Int16 missing_value 0;
  }
  NC_GLOBAL {
    String cdm_data_type "Grid";
    String Conventions "CF-1.6, COARDS, ACDD-1.3";
    String creator_email "coastwatch.info@noaa.gov";
    String creator_name "NOAA/NESDIS/STAR";
    String creator_type "institution";
    String creator_url "https://coastwatch.noaa.gov/";
    String date_created "2024-11-05T07:34:29Z";
    Float64 Easternmost_Easting -59.96625;
    String geospatial_bounds "POLYGON((-120.03375 89.77125,-105.016875 89.77125,-90.0 89.77125,-74.983125 89.77125,-59.96625 89.77125,-59.96625 78.523125,-59.96625 67.275,-59.96625 56.026875,-59.96625 44.77875,-74.983125 44.77875,-90.0 44.77875,-105.016875 44.77875,-120.03375 44.77875,-120.03375 56.026875,-120.03375 67.275,-120.03375 78.523125,-120.03375 89.77125))";
    Float64 geospatial_lat_max 89.77125000000001;
    Float64 geospatial_lat_min 44.77875;
    Float64 geospatial_lat_resolution 0.0075000000000000015;
    String geospatial_lat_units "degrees_north";
    Float64 geospatial_lon_max -59.96625;
    Float64 geospatial_lon_min -120.03375;
    Float64 geospatial_lon_resolution 0.0075;
    String geospatial_lon_units "degrees_east";
    Float64 geospatial_vertical_max 0.0;
    Float64 geospatial_vertical_min 0.0;
    String geospatial_vertical_positive "up";
    String geospatial_vertical_units "m";
    String history 
"[MSL12 1.30][cwutils 3.6.0.111 20200520_165650]
2024-11-09T00:14:46Z (local files)
2024-11-09T00:14:46Z https://coastwatch.noaa.gov/erddap/griddap/noaacwNPPVIIRSkd490SectorVZDaily.das";
    String id "noaacwNPPVIIRSkd490SectorVZDaily";
    String infoUrl "https://coastwatch.noaa.gov/cw/satellite-data-products/ocean-color/near-real-time/viirs-single-sensor.html";
    String institution "NOAA NESDIS CoastWatch";
    String instrument "VIIRS";
    String keywords "algorithm, altitude, available, chemistry, coefficients, color, color/ocean, cols, concentration, daily, data, day, diffuse attenuation, earth, Earth Science > Oceans > Ocean Chemistry > Diffuse Attenuation, Earth Science > Oceans > Ocean Optics > Ocean Color/Ocean Turbidity/Water-Leaving Radiance/Extinction Coefficients, extinction, graphics, imager, imager/radiometer, imaging, infrared, kd490, latitude, leaving, longitude, mass, merge, national, npp, oc3, ocean, ocean color, oceans, optical, optical properties, optics, orbiting, overlay, par, partnership, photosynthetically, planes, polar, polar-orbiting, properties, radiance, radiance/extinction, radiation, radiometer, rows, s-npp, science, sea, seawater, star, suite, swath_latitude, swath_longitude, time, turbidity, turbidity/water-leaving, viirs, visible, water";
    String keywords_vocabulary "GCMD Science Keywords";
    String license 
"The data may be used and redistributed for free but is not intended
for legal use, since it may contain inaccuracies. Neither the data
Contributor, ERD, NOAA, nor the United States Government, nor any
of their employees or contractors, makes any warranty, express or
implied, including warranties of merchantability and fitness for a
particular purpose, or assumes any legal liability for the accuracy,
completeness, or usefulness, of this information.";
    String naming_authority "gov.noaa.coastwatch";
    Float64 Northernmost_Northing 89.77125000000001;
    String OBSERVED_PROPERTY "kd_490";
    String platform "S-NPP";
    String processing_level "L2";
    String project "Ocean Color Science Team (NOAA/NESDIS/STAR/OCST)";
    String publisher_email "coastwatch.info@noaa.gov; ncei.info@noaa.gov";
    String publisher_name "NOAA CoastWatch; National Centers for Environmental Information (NCEI)";
    String publisher_type "group";
    String publisher_url "https://coastwatch.noaa.gov; https://www.ncei.noaa.gov/";
    String source "S-NPP_VIIRS_kd490";
    String sourceUrl "(local files)";
    Float64 Southernmost_Northing 44.77875;
    String standard_name_vocabulary "CF Standard Name Table v29";
    String summary "Ocean color standard products include normalized water-leaving radiances, chlorophyll-a concentration, diffusive attenuation coefficient at 490 nm and diffusive attenuation coefficient of the photosynthetically available radiation (PAR).";
    String time_coverage_end "2024-11-04T18:34:59Z";
    String time_coverage_start "2024-08-04T04:50:23Z";
    String title "Kd490, NOAA S-NPP VIIRS, Near Real-Time, 750m Sector VZ, Daily";
    Float64 Westernmost_Easting -120.03375;
  }
}

Using griddap to Request Data and Graphs from Gridded Datasets

griddap lets you request a data subset, graph, or map from a gridded dataset (for example, sea surface temperature data from a satellite), via a specially formed URL. griddap uses the OPeNDAP (external link)

Data Access Protocol (DAP) (external link)

and its projection constraints (external link)

The URL specifies what you want: the dataset, a description of the graph or the subset of the data, and the file type for the response.

(easy) You can get data by using the dataset's Data Access Form. It makes the URL for you.
(easy) You can make a graph or map by using the dataset's Make A Graph form. It makes the URL for you.
(not hard) You can bypass the forms and get the data or make a graph or map by generating the URL by hand or with a computer program or script.

griddap request URLs must be in the form
https://coastwatch.pfeg.noaa.gov/erddap/griddap/datasetID.fileType{?query}
For example,
https://coastwatch.pfeg.noaa.gov/erddap/griddap/jplMURSST41.htmlTable?analysed_sst[(2002-06-01T09:00:00Z)][(-89.99):1000:(89.99)][(-179.99):1000:(180.0)]
Thus, the query is often a data variable name (e.g., analysed_sst), followed by [(start):stride:(stop)] (or a shorter variation of that) for each of the variable's dimensions (for example, [time][latitude][longitude]).

For details, see the griddap Documentation.