Data Access Form

Dataset Title:	Ice Concentration, NOAA-20 VIIRS, Near Real-Time, Polar Stereographic (North), Daily
Institution:	NOAA NESDIS CoastWatch (Dataset ID: noaacwVIIRSn20iceconcNP06Daily)
Information:	Summary \| License \| Metadata \| Background \| Files \| Make a graph

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Dimensions	Size	Spacing
time (UTC)	78	3 days 22h 3m 0s (uneven)

altitude (m)	1	(just one value)

rows (m)	8640	-795.0 (even)

cols (m)	8640	795.0 (even)

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

IceConc (Ice Concentration, 1)

File type: (more info)

(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 1.6165213913285e+9, 1.6425920615195e+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";
  }
  rows {
    Float64 actual_range -3434002.5, 3434002.5;
    String axis "Y";
    String ioos_category "Location";
    String long_name "Northing of Pixel Centers";
    String standard_name "projection_y_coordinate";
    String units "m";
  }
  cols {
    Float64 actual_range -3434002.5, 3434002.5;
    String axis "X";
    String ioos_category "Location";
    String long_name "Easting of Pixel Centers";
    String standard_name "projection_x_coordinate";
    String units "m";
  }
  IceConc {
    Float32 _FillValue -9.99;
    Float64 colorBarMaximum 1.0;
    Float64 colorBarMinimum 0.0;
    String coordinates "longitude latitude";
    Int32 cw:fraction_digits 16;
    String grid_mapping "polar_stereographic_proj";
    String ioos_category "Ice Distribution";
    String long_name "Ice Concentration";
    Float32 missing_value -9.99;
    String units "1";
  }
  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/SOCD/CoastWatch";
    String creator_url "https://coastwatch.noaa.gov";
    String crs_wkt "PROJCS[\"WGS 84 / NSIDC Sea Ice Polar Stereographic North\",GEOGCS[\"WGS 84\",DATUM[\"WGS_1984\",SPHEROID[\"WGS 84\",6378137,298.257223563,AUTHORITY[\"EPSG\",\"7030\"]],AUTHORITY[\"EPSG\",\"6326\"]],PRIMEM[\"Greenwich\",0,AUTHORITY[\"EPSG\",\"8901\"]],UNIT[\"degree\",0.0174532925199433,AUTHORITY[\"EPSG\",\"9122\"]],AUTHORITY[\"EPSG\",\"4326\"]],PROJECTION[\"Polar_Stereographic\"],PARAMETER[\"latitude_of_origin\",70],PARAMETER[\"central_meridian\",-45],PARAMETER[\"scale_factor\",1],PARAMETER[\"false_easting\",0],PARAMETER[\"false_northing\",0],UNIT[\"metre\",1,AUTHORITY[\"EPSG\",\"9001\"]],AXIS[\"X\",EAST],AXIS[\"Y\",NORTH],AUTHORITY[\"EPSG\",\"3413\"]]";
    String cw:cwhdf_version "3.1";
    Float64 cw:et_affine 0.0, -795.0, 795.0, 0.0, -3434002.5, 3434002.5;
    Int32 cw:gctp_datum 12;
    Float64 cw:gctp_parm 0.0, 0.0, 0.0, 0.0, -4.5e+7, 7.0e+7, 0.0, 0.0, 0.0, 0.0, 0.0, 0.0, 0.0, 0.0, 0.0;
    Int32 cw:gctp_sys 6;
    Int32 cw:gctp_zone 0;
    String cw:orbit_type "ascending/descending";
    Int32 cw:pass_date 19011, 19011, 19011, 19011, 19011, 19011, 19011, 19011, 19011, 19011, 19011, 19011, 19011, 19011, 19011, 19011, 19011, 19011, 19011, 19011, 19011, 19011, 19011, 19011, 19011, 19011, 19011, 19011, 19011, 19011, 19011, 19011, 19011, 19011, 19011, 19011, 19011, 19011, 19011, 19011, 19011, 19011, 19011, 19011, 19011, 19011, 19011, 19011, 19011, 19011, 19011, 19011, 19011, 19011, 19011, 19011, 19011, 19011, 19011, 19011, 19011, 19011, 19011, 19011, 19011, 19011, 19011, 19011, 19011, 19011, 19011, 19011, 19011, 19011, 19011, 19011, 19011, 19011, 19011, 19011, 19011, 19011, 19011, 19011, 19011, 19011, 19011, 19011, 19011, 19011, 19011, 19011, 19011, 19011, 19011, 19011, 19011, 19011, 19011, 19011, 19011, 19011, 19011, 19011, 19011, 19011, 19011, 19011, 19011, 19011, 19011, 19011, 19011, 19011, 19011, 19011, 19011, 19011, 19011, 19011, 19011, 19011, 19011, 19011, 19011, 19011, 19011, 19011, 19011, 19011, 19011, 19011, 19011, 19011, 19011, 19011, 19011, 19011, 19011, 19011, 19011, 19011, 19011, 19011, 19011, 19011, 19011, 19011, 19011, 19011, 19011, 19011, 19011, 19011, 19011, 19011, 19011, 19011, 19011, 19011, 19011, 19011, 19011, 19011, 19011, 19011, 19011, 19011, 19011, 19011, 19011, 19011, 19011, 19011, 19011, 19011, 19011, 19011, 19011, 19011, 19011, 19011, 19011, 19011, 19011, 19011, 19011, 19011, 19011, 19011, 19011, 19011, 19011, 19011, 19011, 19011, 19011, 19011, 19011, 19011, 19011, 19011, 19011, 19011, 19011, 19011, 19011, 19011, 19011, 19011, 19011, 19011, 19011, 19011, 19011, 19011, 19011, 19011, 19011, 19011, 19011, 19011, 19011, 19011, 19011, 19011, 19011, 19011, 19011, 19011, 19011, 19011, 19011, 19011, 19011, 19011, 19011, 19011, 19011, 19011, 19011, 19011, 19011, 19011, 19011, 19011, 19011, 19011, 19011, 19011, 19011, 19011, 19011, 19011, 19011, 19011;
    String cw:pass_type "day/night";
    Float64 cw:polygon_latitude 47.19707393813945, 55.58931044425786, 59.044940950383335, 55.58931044425786, 47.19707393813945, 55.58931044425786, 59.044940950383335, 55.58931044425786, 47.19707393813945, 55.58931044425786, 59.044940950383335, 55.58931044425786, 47.19707393813945, 55.58931044425786, 59.044940950383335, 55.58931044425786, 47.19707393813945;
    Float64 cw:polygon_longitude -180.0, 161.565051177078, 135.0, 108.43494882292201, 90.0, 71.56505117707799, 45.0, 18.434948822922006, 0.0, -18.43494882292201, -45.0, -71.56505117707799, -90.0, -108.43494882292201, -135.0, -161.565051177078, -180.0;
    String cw:projection "Polar Stereographic";
    String cw:satellite "NOAA-20";
    String cw:sensor "VIIRS";
    String cw:software_name "JRR-IceConcentration";
    String cw:software_version "v2r3";
    Float64 cw:start_time 1291.766, 1375.736, 1461.492, 1547.249, 1633.005, 1718.761, 1802.731, 1888.487, 1974.243, 2059.998, 2143.969, 2229.725, 2315.481, 2401.237, 2485.207, 2570.963, 2656.719, 2742.476, 2828.232, 7435.842, 7521.598, 7607.354, 7693.11, 7777.08, 7862.836, 7948.592, 8034.349, 8118.318, 8204.074, 8289.831, 8375.587, 8461.343, 8545.313, 8631.069, 8716.825, 8802.581, 8886.551, 13495.947, 13581.704, 13667.46, 13751.429, 13837.186, 13922.942, 14008.698, 14094.454, 14178.424, 14264.18, 14349.936, 14435.692, 14519.662, 14605.418, 14691.175, 14776.931, 14862.687, 14946.657, 19556.053, 19641.809, 19727.566, 19811.535, 19897.291, 19983.048, 20068.804, 20152.774, 20238.53, 20324.286, 20410.042, 20495.798, 20579.768, 20665.524, 20751.28, 20837.037, 20921.006, 21006.763, 21092.519, 25701.915, 25785.885, 25871.641, 25957.397, 26043.154, 26128.91, 26212.879, 26298.636, 26384.392, 26470.148, 26554.118, 26639.874, 26725.63, 26811.386, 26895.356, 26981.112, 27066.868, 27152.625, 31762.021, 31845.991, 31931.747, 32017.503, 32103.26, 32187.229, 32272.985, 32358.742, 32444.498, 32528.467, 32614.224, 32699.98, 32785.735, 32871.492, 32955.462, 33041.218, 33126.974, 33212.731, 37820.341, 37906.097, 37991.853, 38077.609, 38161.579, 38247.335, 38333.091, 38418.848, 38504.604, 38588.573, 38674.33, 38760.086, 38845.842, 38929.812, 39015.568, 39101.324, 39187.08, 39271.05, 39356.806, 43966.203, 44051.959, 44137.715, 44221.685, 44307.441, 44393.197, 44478.954, 44562.923, 44648.679, 44734.436, 44820.192, 44904.161, 44989.918, 45075.674, 45161.43, 45247.186, 45331.156, 45416.912, 50026.309, 50112.065, 50196.035, 50281.791, 50367.547, 50453.303, 50537.273, 50623.029, 50708.786, 50794.542, 50880.298, 50964.268, 51050.024, 51135.78, 51221.536, 51305.506, 51391.262, 51477.018, 56086.415, 56170.385, 56256.141, 56341.897, 56427.654, 56513.41, 56597.379, 56683.136, 56768.892, 56854.648, 56938.618, 57024.374, 57110.13, 57195.886, 57281.643, 57365.612, 57451.368, 57537.125, 57622.881, 62230.491, 62316.247, 62402.003, 62487.759, 62571.729, 62657.485, 62743.241, 62828.998, 62914.754, 62998.723, 63084.48, 63170.236, 63255.992, 63339.962, 63425.718, 63511.474, 63597.23, 63681.2, 68290.596, 68376.353, 68462.109, 68547.865, 68631.835, 68717.591, 68803.347, 68889.103, 68973.073, 69058.829, 69144.585, 69230.341, 69314.311, 69400.067, 69485.824, 69571.58, 69657.336, 69741.306, 74436.458, 74522.214, 74606.184, 74691.94, 74777.696, 74863.453, 74947.422, 75033.179, 75118.935, 75204.691, 75290.447, 75374.417, 75460.173, 75545.929, 75631.685, 75715.655, 75801.411, 75887.168, 80496.564, 80580.534, 80666.29, 80752.046, 80837.802, 80923.558, 81007.528, 81093.284, 81179.04, 81264.797, 81348.766, 81434.523, 81520.279, 81606.035, 81690.005, 81775.761, 81861.517, 81947.273;
    Int32 cw:swath_sync_lines 16, 16, 16, 16, 16, 16, 16, 16, 16, 16, 16, 16, 16, 16, 16, 16, 16, 16, 16, 16, 16, 16, 16, 16, 16, 16, 16, 16, 16, 16, 16, 16, 16, 16, 16, 16, 16, 16, 16, 16, 16, 16, 16, 16, 16, 16, 16, 16, 16, 16, 16, 16, 16, 16, 16, 16, 16, 16, 16, 16, 16, 16, 16, 16, 16, 16, 16, 16, 16, 16, 16, 16, 16, 16, 16, 16, 16, 16, 16, 16, 16, 16, 16, 16, 16, 16, 16, 16, 16, 16, 16, 16, 16, 16, 16, 16, 16, 16, 16, 16, 16, 16, 16, 16, 16, 16, 16, 16, 16, 16, 16, 16, 16, 16, 16, 16, 16, 16, 16, 16, 16, 16, 16, 16, 16, 16, 16, 16, 16, 16, 16, 16, 16, 16, 16, 16, 16, 16, 16, 16, 16, 16, 16, 16, 16, 16, 16, 16, 16, 16, 16, 16, 16, 16, 16, 16, 16, 16, 16, 16, 16, 16, 16, 16, 16, 16, 16, 16, 16, 16, 16, 16, 16, 16, 16, 16, 16, 16, 16, 16, 16, 16, 16, 16, 16, 16, 16, 16, 16, 16, 16, 16, 16, 16, 16, 16, 16, 16, 16, 16, 16, 16, 16, 16, 16, 16, 16, 16, 16, 16, 16, 16, 16, 16, 16, 16, 16, 16, 16, 16, 16, 16, 16, 16, 16, 16, 16, 16, 16, 16, 16, 16, 16, 16, 16, 16, 16, 16, 16, 16, 16, 16, 16, 16, 16, 16, 16, 16, 16, 16, 16, 16, 16, 16, 16, 16;
    Float64 cw:temporal_extent 82.0, 84.0, 84.0, 84.0, 84.0, 82.0, 84.0, 84.0, 84.0, 82.0, 84.0, 84.0, 84.0, 82.0, 84.0, 84.0, 84.0, 84.0, 82.0, 84.0, 84.0, 84.0, 82.0, 84.0, 84.0, 84.0, 82.0, 84.0, 84.0, 84.0, 84.0, 82.0, 84.0, 84.0, 84.0, 82.0, 84.0, 84.0, 84.0, 82.0, 84.0, 84.0, 84.0, 84.0, 82.0, 84.0, 84.0, 84.0, 82.0, 84.0, 84.0, 84.0, 84.0, 82.0, 84.0, 84.0, 84.0, 82.0, 84.0, 84.0, 84.0, 82.0, 84.0, 84.0, 84.0, 84.0, 82.0, 84.0, 84.0, 84.0, 82.0, 84.0, 84.0, 84.0, 82.0, 84.0, 84.0, 84.0, 84.0, 82.0, 84.0, 84.0, 84.0, 82.0, 84.0, 84.0, 84.0, 82.0, 84.0, 84.0, 84.0, 84.0, 82.0, 84.0, 84.0, 84.0, 82.0, 84.0, 84.0, 84.0, 82.0, 84.0, 84.0, 84.0, 84.0, 82.0, 84.0, 84.0, 84.0, 82.0, 84.0, 84.0, 84.0, 82.0, 84.0, 84.0, 84.0, 84.0, 82.0, 84.0, 84.0, 84.0, 82.0, 84.0, 84.0, 84.0, 82.0, 84.0, 84.0, 84.0, 84.0, 82.0, 84.0, 84.0, 84.0, 82.0, 84.0, 84.0, 84.0, 82.0, 84.0, 84.0, 84.0, 84.0, 82.0, 84.0, 84.0, 84.0, 82.0, 84.0, 84.0, 84.0, 82.0, 84.0, 84.0, 84.0, 84.0, 82.0, 84.0, 84.0, 84.0, 82.0, 84.0, 84.0, 84.0, 82.0, 84.0, 84.0, 84.0, 84.0, 82.0, 84.0, 84.0, 84.0, 82.0, 84.0, 84.0, 84.0, 84.0, 82.0, 84.0, 84.0, 84.0, 82.0, 84.0, 84.0, 84.0, 82.0, 84.0, 84.0, 84.0, 84.0, 82.0, 84.0, 84.0, 84.0, 82.0, 84.0, 84.0, 84.0, 82.0, 84.0, 84.0, 84.0, 84.0, 82.0, 84.0, 84.0, 84.0, 82.0, 84.0, 84.0, 84.0, 82.0, 84.0, 84.0, 84.0, 84.0, 82.0, 84.0, 84.0, 82.0, 84.0, 84.0, 84.0, 82.0, 84.0, 84.0, 84.0, 84.0, 82.0, 84.0, 84.0, 84.0, 82.0, 84.0, 84.0, 84.0, 82.0, 84.0, 84.0, 84.0, 84.0, 82.0, 84.0, 84.0, 84.0, 82.0, 84.0, 84.0, 84.0, 82.0, 84.0, 84.0, 84.0, 84.0;
    String cw:viirs_band_naming_convention "IDPS";
    String cw_satellite "NOAA-20";
    String date_created "2022-01-20T05:02:49Z";
    String defaultGraphQuery 
"IceConc%5B(time_coverage_end)%5D%5B(0.0)%5D%5B(3255922.5):(-3255922.5)%5D%5B(-3255922.5):(3255922.5)%5D%26.draw=surface%26.vars=cols
%7Crows%7CIceThickness%26.colorBar=CMOCEAN_ice%7C%7CLog%7C%7C%7C%26.bgColor=0xffccccff";
    Float64 geospatial_vertical_max 0.0;
    Float64 geospatial_vertical_min 0.0;
    String geospatial_vertical_positive "up";
    String geospatial_vertical_units "m";
    String history 
"JRR Ice Concentration v2r0
2022-01-23T08:31:33Z (local files)
2022-01-23T08:31:33Z https://coastwatch.noaa.gov/erddap/griddap/noaacwVIIRSn20iceconcNP06Daily.das";
    String identifier_product_doi_authority "https://dx.doi.org";
    String infoUrl "https://coastwatch.noaa.gov";
    String institution "NOAA NESDIS CoastWatch";
    String instrument "VIIRS";
    String keywords "Earth Science > Cryosphere > Sea Ice > Sea Ice Concentration, Earth Science > Oceans > Sea Ice > Sea Ice Concentration";
    String keywords_vocabulary "GCMD Science Keywords";
    String license 
"https://science.nasa.gov/earth-science/earth-science-data/data-information-policy/ 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";
    String OBSERVED_PROPERTY "IceConc";
    String platform "NOAA-20";
    String proj4text "+proj=stere +lat_0=90 +lat_ts=70 +lon_0=-45 +k=1 +x_0=0 +y_0=0 +datum=WGS84 +units=m +no_defs";
    String source "NOAA-20_VIIRS_IceConc";
    String sourceUrl "(local files)";
    String srid "EPSG:3413";
    String standard_name_vocabulary "CF Standard Name Table v29";
    String summary "Enterprise Ice Concentration/ Ice Mask/ Ice Surface Temperature Products";
    String testOutOfDate "now-2days";
    String time_coverage_end "2022-01-19T11:34:21Z";
    String time_coverage_start "2021-03-23T17:43:11Z";
    String title "Ice Concentration, NOAA-20 VIIRS, Near Real-Time, Polar Stereographic (North), Daily";
  }
}

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.