Make A Graph

Dataset Title:	Bathymetry from OSOM grid - Narragansett Bay
Institution:	Rhode Island Data Discovery Center (Dataset ID: bathymetry_35a3_914d_8129)
Information:	Summary \| License \| Metadata \| Background \| Data Access Form

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Graph Type:
X Axis:
Y Axis:
Color:

Dimensions

Start

Stop

eta_rho (count)

xi_rho (count)

Graph Settings
Color Bar:	Continuity:	Scale:
Minimum:	Maximum:	N Sections:
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

)

[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 {
  eta_rho {
    Int32 actual_range 0, 1099;
    String long_name "X-location of RHO-points";
    String units "count";
  }
  xi_rho {
    Int16 actual_range 0, 999;
    String long_name "Y-location of RHO-points";
    String units "count";
  }
  longitude {
    String long_name "longitude of RHO-points";
    String standard_name "longitude";
    String units "degrees_east";
  }
  latitude {
    String long_name "latitude of RHO-points";
    String standard_name "latitude";
    String units "degrees_north";
  }
  model_bathymetry {
    Float64 colorBarMaximum 80.0;
    Float64 colorBarMinimum 0.0;
    String colorBarPalette "KT_dense";
    String long_name "Model bathymetry at RHO-points";
    String standard_name "sea_floor_depth";
    String units "meters";
  }
  landmask {
    Int32 colorBarMaximum 1;
    Int32 colorBarMinimum 0;
    String colorBarPalette "BlackWhite";
    String flag_meanings "land water";
    String flag_name "land, water";
    String flag_values "0.0, 1.0";
    String long_name "mask on RHO-points";
  }
  NC_GLOBAL {
    String cdm_data_type "Grid";
    String Conventions "COARDS, CF-1.10, ACDD-1.3";
    String defaultGraphQuery "model_bathymetry[0:last][0:last][last]&.draw=surface&xi_rho=xi_rho&eta_rho=eta_rho&model_bathymetry=model_bathymetry&";
    String history 
"Wed Jul 16 09:37:48 2025: ncpdq -a -lat_rho osom_grid4_mindep_smlp_mod10.nc osom_grid4_mindep_smlp_mod10.nc
Wed Jul 16 09:37:33 2025: ncpdq -a -lon_rho osom_grid4_mindep_smlp_mod10.nc osom_grid4_mindep_smlp_mod10.nc
GRID file using Matlab script: c_grid, Tuesday - May 3, 2016 - 11:31:28.2636 AM
2025-10-08T18:08:36Z (local files)
2025-10-08T18:08:36Z http://qa-erddap.riddc.brown.edu/griddap/bathymetry_35a3_914d_8129.das";
    String infoUrl "https://data-explorer.riddc.brown.edu/dataset/osom/summary";
    String institution "Rhode Island Data Discovery Center";
    String keywords "bath, bathymetry, data, depth, earth, Earth Science > Oceans > Bathymetry/Seafloor Topography > Bathymetry, eta, eta_rho, floor, hraw, local, ocean, oceans, points, rho, rho-points, science, sea, sea_floor_depth, seafloor, source, topography, working, xi, xi_rho";
    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 NCO "netCDF Operators version 5.1.5 (Homepage = http://nco.sf.net, Code = https://github.com/nco/nco)";
    String sourceUrl "(local files)";
    String standard_name_vocabulary "CF Standard Name Table v70";
    String summary "Data from a local source. Latitude and longitude included as data variables than can be mapped to the OSOM grid.";
    String title "Bathymetry from OSOM grid - Narragansett Bay";
    String type "GRID file";
  }
}

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.