Make A Graph

Dataset Title:	Near Real Time Surface Ocean Velocity
Institution:	Catalan Institute of Research for the Governance of the Sea (Dataset ID: HFradar_ICATMAR)
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 →

depth (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:
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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 1.7654652e+9, 1.7666604e+9;
    String axis "T";
    String calendar "standard";
    String ioos_category "Time";
    String long_name "time of measurement UTC";
    String standard_name "time";
    String time_origin "01-JAN-1970 00:00:00";
    String units "seconds since 1970-01-01T00:00:00Z";
  }
  depth {
    String _CoordinateAxisType "Height";
    String _CoordinateZisPositive "down";
    Float32 actual_range 0.0, 0.0;
    String axis "Z";
    String ioos_category "Location";
    String long_name "Depth";
    String positive "down";
    String standard_name "depth";
    String units "m";
    Float32 valid_range 0.0, 0.0;
  }
  latitude {
    String _CoordinateAxisType "Lat";
    Float32 actual_range 39.5851, 43.0681;
    String axis "Y";
    String grid_mapping "crs";
    String ioos_category "Location";
    String long_name "Latitude";
    String standard_name "latitude";
    String units "degrees_north";
    Float32 valid_range -90.0, 90.0;
  }
  longitude {
    String _CoordinateAxisType "Lon";
    Float32 actual_range 0.06352, 4.26898;
    String axis "X";
    String grid_mapping "crs";
    String ioos_category "Location";
    String long_name "Longitude";
    String standard_name "longitude";
    String units "degrees_east";
    Float32 valid_range -180.0, 180.0;
  }
  u {
    Float32 _FillValue 9.96921e+36;
    String ancillary_variables "qcflag, vart_qc, cspd_qc, ddns_qc, gdop_qc";
    Float64 colorBarMaximum 0.5;
    Float64 colorBarMinimum -0.5;
    String ioos_category "Currents";
    String long_name "Surface Eastward Sea Water Velocity";
    String standard_name "surface_eastward_sea_water_velocity";
    String units "m s-1";
    Float32 valid_range -10.0, 10.0;
  }
  v {
    Float32 _FillValue 9.96921e+36;
    String ancillary_variables "qcflag, vart_qc, cspd_qc, ddns_qc, gdop_qc";
    Float64 colorBarMaximum 0.5;
    Float64 colorBarMinimum -0.5;
    String ioos_category "Currents";
    String long_name "Surface Nortward Sea Water Velocity";
    String standard_name "surface_northward_sea_water_velocity";
    String units "m s-1";
    Float32 valid_range -10.0, 10.0;
  }
  stdu {
    Float32 _FillValue 9.96921e+36;
    String ancillary_variables "qcflag, vart_qc";
    Float64 colorBarMaximum 0.1;
    Float64 colorBarMinimum 0.0;
    String ioos_category "Statistics";
    String long_name "Standard Deviation Of Surface Eastward Sea Water Velocity";
    String units "m s-1";
    Float32 valid_range -10.0, 10.0;
  }
  stdv {
    Float32 _FillValue 9.96921e+36;
    String ancillary_variables "qcflag, vart_qc";
    Float64 colorBarMaximum 0.1;
    Float64 colorBarMinimum 0.0;
    String ioos_category "Statistics";
    String long_name "Standard Deviation Of Surface Northward Sea Water Velocity";
    String units "m s-1";
    Float32 valid_range -10.0, 10.0;
  }
  gdop {
    Float32 _FillValue 9.96921e+36;
    String ancillary_variables "qcflag, gdop_qc";
    Float64 colorBarMaximum 0.1;
    Float64 colorBarMinimum 0.0;
    String ioos_category "Statistics";
    String long_name "Geometrical Dilution Of Precision";
    String units "1";
    Float32 valid_range -20.0, 20.0;
  }
  cov {
    Float32 _FillValue 9.96921e+36;
    String ancillary_variables "qcflag";
    Float64 colorBarMaximum 50.0;
    Float64 colorBarMinimum 0.0;
    String ioos_category "Statistics";
    String long_name "Covariance Of Surface Sea Water Velocity";
    String units "m2 s-2";
    Float32 valid_range -20.0, 20.0;
  }
  qcflag {
    Byte _FillValue -127;
    String _Unsigned "false";
    Float64 colorBarMaximum 10.0;
    Float64 colorBarMinimum 0.0;
    String flag_meanings "no_qc_performed good_data probably_good_data potentially_correctable_bad_data bad_data value_changed value_below_detection nominal_value interpolated_value missing_value";
    Byte flag_values 0, 1, 2, 3, 4, 5, 6, 7, 8, 9;
    String ioos_category "Quality";
    String long_name "Overall quality flag";
    String standard_name "aggregate_quality_flag";
    String units "1";
    Byte valid_range 0, 9;
  }
  vart_qc {
    Byte _FillValue -127;
    String _Unsigned "false";
    Float64 colorBarMaximum 10.0;
    Float64 colorBarMinimum 0.0;
    String flag_meanings "no_qc_performed good_data probably_good_data potentially_correctable_bad_data bad_data value_changed value_below_detection nominal_value interpolated_value missing_value";
    Byte flag_values 0, 1, 2, 3, 4, 5, 6, 7, 8, 9;
    String ioos_category "Statistics";
    String long_name "Variance threshold quality flag";
    String units "1";
    Byte valid_range 0, 9;
  }
  gdop_qc {
    Byte _FillValue -127;
    String _Unsigned "false";
    Float64 colorBarMaximum 10.0;
    Float64 colorBarMinimum 0.0;
    String flag_meanings "no_qc_performed good_data probably_good_data potentially_correctable_bad_data bad_data value_changed value_below_detection nominal_value interpolated_value missing_value";
    Byte flag_values 0, 1, 2, 3, 4, 5, 6, 7, 8, 9;
    String ioos_category "Quality";
    String long_name "GDOP threshold quality flag";
    String units "1";
    Byte valid_range 0, 9;
  }
  ddns_qc {
    Byte _FillValue -127;
    String _Unsigned "false";
    Float64 colorBarMaximum 10.0;
    Float64 colorBarMinimum 0.0;
    String flag_meanings "no_qc_performed good_data probably_good_data potentially_correctable_bad_data bad_data value_changed value_below_detection nominal_value interpolated_value missing_value";
    Byte flag_values 0, 1, 2, 3, 4, 5, 6, 7, 8, 9;
    String ioos_category "Quality";
    String long_name "Data density threshold quality flag";
    String units "1";
    Byte valid_range 0, 9;
  }
  cspd_qc {
    Byte _FillValue -127;
    String _Unsigned "false";
    Float64 colorBarMaximum 10.0;
    Float64 colorBarMinimum 0.0;
    String flag_meanings "no_qc_performed good_data probably_good_data potentially_correctable_bad_data bad_data value_changed value_below_detection nominal_value interpolated_value missing_value";
    Byte flag_values 0, 1, 2, 3, 4, 5, 6, 7, 8, 9;
    String ioos_category "Quality";
    String long_name "Velocity threshold quality flag";
    String units "1";
    Byte valid_range 0, 9;
  }
  NC_GLOBAL {
    String acknowledgement "ICATMAR HF Radar Network has been established with the support of the European Maritime and Fisheries Fund, the European Maritime, Fisheries and Aquaculture Fund and the fund provided by the Government of Catalonia. The network has been designed, implemented and managed through the efforts of the Direcció General de Política Marítima i Pesca Sostenible (Government of Catalonia) and the Insitut de Ciències del Mar (CSIC), Barcelona.";
    String area "Mediterranean Sea";
    String cdm_data_type "Grid";
    String citation "These data were collected and made freely available by ICATMAR and the programs that contribute to it. Data was collected by the Government of Catalonia and processed by ICATMAR with the support of the European Maritime, Fisheries and Aquaculture Fund (EMFAF) and the Climatic Funds Program of the Government of Catalonia.";
    String Conventions "CF-1.10, COARDS, ACDD-1.3";
    String creator_name "Catalan Institute of Research for the Governance of the Sea";
    String date_created "2025-12-25T14:02:06Z";
    String date_modified "2025-12-25T14:02:06Z";
    String distribution_statement "These data follow Copernicus standards; they are public and free of charge. User assumes all risk for use of data. User must display citation in any publication or product using data. User must contact ICATMAR prior to any commercial use of data.";
    String doi "https://doi.org/10.20350/digitalCSIC/16139";
    Float64 Easternmost_Easting 4.26898;
    Float64 geospatial_lat_max 43.0681;
    Float64 geospatial_lat_min 39.5851;
    Float64 geospatial_lat_resolution 0.02700000000000003;
    String geospatial_lat_units "degrees_north";
    Float64 geospatial_lon_max 4.26898;
    Float64 geospatial_lon_min 0.06352;
    Float64 geospatial_lon_resolution 0.03534;
    String geospatial_lon_units "degrees_east";
    String history 
"2025-12-25T14:02:06Z data collected.2025-12-25T14:02:06Z NetCDF file created
2025-12-25T14:09:21Z (local files)
2025-12-25T14:09:21Z http://erddap.icatmar.cat/griddap/HFradar_ICATMAR.das";
    String id "HFR_ICATMAR_Total_2025-12-25T14:02:06Z";
    String infoUrl "???";
    String institution "Catalan Institute of Research for the Governance of the Sea";
    String institution_edmo_code "5801";
    String keywords "aggregate, aggregate_quality_flag, catalan, circulation, cov, covariance, cspd_qc, currents, data, ddns_qc, density, depth, deviation, dilution, earth, Earth Science > Oceans > Ocean Circulation > Ocean Currents, eastward, flag, gdop, gdop_qc, geometrical, governance, institute, near, near real time, northward, nortward, nrt, ocean, oceans, overall, precision, qcflag, quality, real, research, science, sea, seawater, standard, statistics, stdu, stdv, surface, surface_eastward_sea_water_velocity, surface_northward_sea_water_velocity, threshold, time, u, v, variance, vart_qc, velocity, water";
    String keywords_vocabulary "GCMD Science Keywords";
    String L2_source_files "RDLm_CREU_2025_12_25_0900_l2b.ruv; RDLm_BEGU_2025_12_25_0900_l2b.ruv; RDLm_AREN_2025_12_25_0900_l2b.ruv; RDLm_GNST_2025_12_25_0900_l2b.ruv; RDLm_TOSS_2025_12_25_0900_l2b.ruv; RDLm_SCAL_2025_12_25_0900_l2b.ruv";
    String license "HF radar sea surface current velocity dataset by ICATMAR is licensed under a Creative Commons Attribution 4.0 International License. You should have received a copy of the license along with this work. If not, see https://creativecommons.org/licenses/by/4.0/.";
    Float64 Northernmost_Northing 43.0681;
    String processing_level "3B";
    String publisher_email "info@icatmar.cat";
    String publisher_name "ICATMAR";
    String publisher_type "institution";
    String publisher_url "https://icatmar.cat";
    String references "Quirós-Collazos, L.; Bueno-Herrero, C.; Martínez, J.; Llorach-Tó, G.; González-Haro, C.; Ribera-Altamir, J.; Ballabrera, J.; García-Ladona, E.; Isern-Fontanet, J.: Level 3 velocity products from ICATMAR High-Frequency Radar network. 2024, ICATMAR Technical Report, number 3, pp:27. https://doi.org/10.20350/digitalCSIC/17191";
    String source "Surface ocean velocity field from HF-radar";
    String sourceUrl "(local files)";
    Float64 Southernmost_Northing 39.5851;
    String standard_name_vocabulary "CF Standard Name Table v70";
    String summary "Near Real Time Surface Ocean Velocity";
    String testOutOfDate "now-4days";
    String time_coverage_end "2025-12-25T11:00:00Z";
    String time_coverage_resolution "PT1H";
    String time_coverage_start "2025-12-11T15:00:00Z";
    String title "Near Real Time Surface Ocean Velocity";
    Float64 Westernmost_Easting 0.06352;
  }
}

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.