Make A Graph

Dataset Title:	Kd490 (Gap-filled DINEOF), NOAA S-NPP NOAA-20 VIIRS and Copernicus S-3A OLCI, Science Quality, Global 9km, 2018-recent, Daily
Institution:	NOAA NESDIS STAR (Dataset ID: nesdisNPPN20S3AkdSCIDINEOFDaily)
Information:	Summary \| License \| FGDC \| ISO 19115 \| Metadata \| Background \| Data Access Form \| Files

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Graph Type:
X Axis:
Y Axis:
Color:

Dimensions

Start

Stop

time (UTC)

specify just 1 value →

altitude (m)

specify just 1 value →

latitude (degrees_north)

longitude (degrees_east)

Graph Settings
Color Bar:	Continuity:	Scale:
Minimum:	Maximum:	N Sections:
Draw land mask:
Y Axis Minimum:	Maximum:

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

Optional:
Then set the File Type: (File Type information)
and

or view the URL:
(Documentation / Bypass this form

)

Click on the map to specify a new center point.

Zoom:

[The graph you specified. Please be patient.]

Things You Can Do With Your Graphs

Well, you can do anything you want with your graphs, of course. But some things you might not have considered are:

Web page authors can embed a graph of the latest data in a web page using HTML <img> tags.
Anyone can use ERDDAPs Slide Sorter to build a personal web page that displays graphs with the latest data (or other images or HTML content), each in its own, draggable slide.

The Dataset Attribute Structure (.das) for this Dataset

Attributes {
  time {
    String _CoordinateAxisType "Time";
    Float64 actual_range 1.5181776e+9, 1.7435088e+9;
    String axis "T";
    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";
    Float32 actual_range -89.95834, 89.95834;
    String axis "Y";
    String ioos_category "Location";
    String long_name "Latitude";
    String source_name "lat";
    String standard_name "latitude";
    String units "degrees_north";
    Float32 valid_max 90.0;
    Float32 valid_min -90.0;
  }
  longitude {
    String _CoordinateAxisType "Lon";
    Float32 actual_range -179.9583, 179.9584;
    String axis "X";
    String ioos_category "Location";
    String long_name "Longitude";
    String source_name "lon";
    String standard_name "longitude";
    String units "degrees_east";
    Float32 valid_max 180.0;
    Float32 valid_min -180.0;
  }
  kd_490 {
    Float32 _FillValue -6.5534;
    Float64 colorBarMaximum 10.0;
    Float64 colorBarMinimum 0.01;
    String display_scale "log";
    String ioos_category "Optical Properties";
    String long_name "Diffuse attenuation coefficient at 490 nm, kd2 algorithm";
    String references "Wang, M., S. Son, and L. W. Harding, Jr. (2009), Retrieval of diffuse attenuation coefficient in the Chesapeake Bay and turbid ocean regions for satellite ocean color applications, J. Geoph ys. Res. Oceans, 114, C10011";
    String standard_name "diffuse_attenuation_coefficient_of_downwelling_radiative_flux_in_sea_water";
    String units "m^-1";
    Float32 valid_max 6.0;
    Float32 valid_min 0.01;
  }
  NC_GLOBAL {
    String _lastModified "2025-04-11T20:30:06.000Z";
    String cdm_data_type "Grid";
    String Conventions "CF-1.6 ACDD-1.3, COARDS";
    String creator_email "coastwatch.info@noaa.gov";
    String creator_name "NOAA CoastWatch";
    String creator_type "institution";
    String creator_url "https://coastwatch.noaa.gov";
    String date_created "2025-04-11T20:30:06.000Z";
    Float64 Easternmost_Easting 179.9584;
    Float64 geospatial_lat_max 89.95834;
    Float64 geospatial_lat_min -89.95834;
    String geospatial_lat_units "degrees_north";
    Float64 geospatial_lon_max 179.9584;
    Float64 geospatial_lon_min -179.9583;
    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 grid_mapping_epsg_code "EPSG:4326";
    Float32 grid_mapping_inverse_flattening 298.2572;
    Float32 grid_mapping_longitude_of_prime_meridian 0.0;
    String grid_mapping_name "latitude_longitude";
    String grid_mapping_proj4_params "+proj=longlat +ellps=WGS84 +datum=WGS84 +no_defs";
    Float32 grid_mapping_semi_major_axis 6378137.0;
    String history 
"/data/data652/coastwatch/oc/L3/scripts/bin/l3mapgen par=/data/data652/coastwatch/oc/L3/scripts/bin/../config/l3mapgen_par_dineof_kd_490 ifile=/data/data652/coastwatch/oc/L3/scripts/bin/../temp/Config_dineof3_kd490/V2025091_kd_L3.nc ofile=/data/data369/viirs/L3_dineof/091/B2025091_A1_WW00_kd_490.nc   Fri Apr 11 20:30:19 2025
: /data/data652/coastwatch/oc/L3/scripts/bin/l3cnvtr -b -s Suomi-NPP,NOAA-20,Sentinel-3A /data/data369/viirs/L3_dineof/091/B2025091_A1_WW00_kd_490.nc /data/aftp/socd1/mecb/coastwatch/viirs/science/L3/global/kd/dineof3/2025/B2025091_A1_WW00_kd490.nc
2025-04-19T17:21:45Z (local files)
2025-04-19T17:21:45Z https://polarwatch.noaa.gov/griddap/nesdisNPPN20S3AkdSCIDINEOFDaily.das";
    String id "L3//data/dmz/pub0070/DINEOF/EOF-viirs-olci/reconstructed_mix_nsw/V2025091_kd_L3.nc";
    String identifier_product_doi "https://doi.org/10.1016/j.jag.2022.102714";
    String identifier_product_doi_authority "https://dx.doi.org";
    String infoUrl "https://coastwatch.noaa.gov";
    String institution "NOAA NESDIS STAR";
    String instrument "VIIRS,OLCI";
    String keywords "algorithm, altitude, attenuation, coefficient, data, diffuse, diffuse_attenuation_coefficient_of_downwelling_radiative_flux_in_sea_water, dineof, downwelling, environmental, filled, flux, gap, information, kd2, kd_490, L4, national, nesdis, noaa, optical, optical properties, properties, radiative, satellite, sea, seawater, service, star, time, water";
    String keywords_vocabulary "NASA Global Change Master Directory (GCMD) Science Keywords";
    String l2_flag_names "ATMFAIL,LAND,HIGLINT,HILT,HISATZEN,CLOUD,HISOLZEN,LOWLW,CHLFAIL,NAVWARN,CLDSHDSTL,MAXAERITER,CHLWARN,ALGICE,SEAICE,NAVFAIL,FILTER";
    String license "CC0-1.0. 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, CoastWatch, NOAA, nor the US Government, nor any of their employees or contractors, make 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 map_projection "geographic";
    String measure "Mean";
    String Metadata_Conventions "Unidata Dataset Discovery v1.0";
    String naming_authority "gov.noaa.coastwatch";
    Float64 Northernmost_Northing 89.95834;
    String platform "Suomi-NPP, NOAA-20, Sentinel-3A";
    String processing_level "L3 Mapped";
    String product_name "B2025091_A1_WW00_kd490.nc";
    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 Satellite 
"Suomi-NPP
 NOAA-20, Sentinel-3A";
    String Sensor "VIIRS,OLCI";
    String sourceUrl "(local files)";
    Float64 Southernmost_Northing -89.95834;
    String spatialResolution "9.28 km";
    String standard_name_vocabulary "NetCDF Climate and Forecast (CF) Metadata Convention";
    String summary "Visible and Infrared Imager/Radiometer Suite/Suomi-NPP and NOAA-20 (VIIRS) and Sentinel-3A OLCI DINEOF gap filled L4 data. NOAA National Environmental Satellite, Data, and Information Service (NESDIS) STAR data. Sentinel-3A courtesy of Copernicus Program";
    String temporal_range "daily";
    String testOutOfDate "now-23days";
    String time_coverage_end "2025-04-01T12:00:00Z";
    String time_coverage_start "2018-02-09T12:00:00Z";
    String title "Kd490 (Gap-filled DINEOF), NOAA S-NPP NOAA-20 VIIRS and Copernicus S-3A OLCI, Science Quality, Global 9km, 2018-recent, Daily";
    Float64 Westernmost_Easting -179.9583;
  }
}

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.