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Some tips on searching for data using Earthdata Search.

Searching: in general

While Earthdata Search's free text search field will attempt to understand free text queries. e.g. "land surface temperature over Uganda for the last 10 years" -- it sometimes doesn't return useful results.  If the free-text search includes the name of a location that Earthdata Search does not recognize, you may not get any results at all.

For best results,

  • If you know the specific collection name, shortname, id or project you are looking for, start your search using the free text field; 
  • otherwise, skip the free text field, and start your search by specifying keywords, projects, etc. using the checkboxes on the left.
  • Next, specify the location you are interested in using the spacial criteria button (the compass icon) located to the right of the free text field. 
  • Finally, specify the time you are interested in using the temporal criteria button (the clock icon) located to the right of the free text field.

So for example, to search for "land surface temperature over Uganda for the last 10 years"

  1. Check the following checkboxes on the left:
    Keywords | Land Surface | Land Temperature
    Keywords | Surface Radiative Properties | Land Surface Temperature
    Keywords | Surface Thermal Properties | Land Surface Temperature
  2. Enter temporal criteria:  click the clock button next to the free text field, and enter Start: 2008-01-01 00:00:00 and Stop: Today.
  3. Enter spacial criteria:  click the compass button next to the free text field, and draw a bounding rectangle around Uganda.

Getting data: in general

You can download a granule, multiple granules, a single collection, or multiple collections.

To download a granule, multiple granules, or a collection

Click a collection to view its granules.

In granule view, you'll see only the granules for the collection that fit your spacial and temporal constraints. 

You can further narrow the granules selected using the "Granule Search" text field, the "Filter granules" button (the funnel icon) on the right, and the date slider at the bottom of the screen.

To download all selected granules, click the "Download Data" button on the right hand side of the screen.

To download an individual granule, do one of the following:

  • To quickly download an individual granule without modification, click the "Download single granule data" button (the down arrow icon) beside the granule. 
  • To quickly customize just one granule (useful if the collection supports data customizations like subsetting), click the "Configure and download single granule data" button (the gear icon) beside the granule.

After clicking "Download Data" or "Configure and download single granule data," you will see one or more of the following options, depending on the order options supported by the data provider:

  1. Order Data | Direct Download
    Allows you to download data as-is now from your browser, either by accessing a list of download links, by downloading a file of data links for offline processing, or by downloading a script that can be used with curl or wget.   (Note: some helpful tips for using the download script can be found here.)
  2.  Order Data | Stage for Delivery
    Allows you to submit a request for a staged delivery.  
    You will receive an email with download instructions when the data is ready.
  3.  Order Data | Customize Product
    Allows you to select custom service options to be performed (e.g. subsetting, reprojection, etc.)
    You will receive an email with download instructions when the data is ready.

To download multiple collections

  1. Use the + button to add collections to your "project" (similar to a shopping cart), and then click the "My Project" button in the upper right hand side of the screen.
  2. For each collection in your project, and click the collection and select the granules you want to download.
  3. Go back to the project, and select the "Download Project Data" button on the right.

Searching: Filtering granules

In granule view, you can filter the granules selected using any combination of the following:

  • temporal criteria (clock button on the left) - enter / modify the date criteria
  • spacial criteria (compass button on the left) - enter / modify the location criteria
  • the date slider at the bottom
  • the "Granule Search" field – enter one or more granule names or patterns
  • the "Filter Granules" button (the funnel button on the right) - specify Day / Night, Cloud Cover and other collection-specific attributes

Searching for granules by filename

To search for a specific granule file, you will need to know the name or id of the collection name to which it belongs.

When you have that, search for the collection, and then filter the collection's granules using the filename. 

For example, to search for file N42W072.zip in in collection ASTGTM:

  1. Search for collection ASTGTM
  2. Click on the collection, and in granule view in the Granule Search field type *N42W072*

Searching by recurring date:  How to search for all Novembers from 2000 to 2018:

  1.  In the upper left corner of the screen, click the temporal icon (the clock).
  2. In the dialog, check "Recurring"
  3. In the dialog, click in "Start," then click "Nov," then click "1"
  4. In the dialog, click in "End," then click "Nov," then click "30"
  5. In the dialog, adjust "Year Range" to be 2000 - 2018  
  6. In the dialog, click "Apply Filter"

Subsetting services: Data reformatting, reprojection, subsetting

"Subsetting services" refers to data customization options offered by data providers for select products.  These may include data reformatting (e.g. to NetCDF,  GeoTIFF, KLM and other file formats), data reprojection, data subsetting, and other options. Collections for which subsetting services are available are indicated with the label "SUBSETTING" following the collection name.   

To see only products that support subsetting, check the "Features | Subsetting Services" checkbox on the left in collection view.

To specify subsetting services, when placing an order choose the "Customize Order" option.    

Please note that subsetting services are not offered for all products, and not all subsetting-capable products support every option. 

Entering grid coordinates: coordinate system options

CALIPSO
Dimensions - Orbit/Path
Enter orbit and path coordinates separated by spaces, e.g. "2,3 5,7 8,8"
Note - Orbit and Path values are not continuous and cannot be used in a range.
More info:
https://www-calipso.larc.nasa.gov/resources/calipso_users_guide/faq.php

MISR
Dimensions - Path/Block
Enter path and block coordinates separated by spaces, e.g. "2,3 5,7 8,8"
Note - Path values are not continuous and cannot be used in a range.
More info:
https://eosweb.larc.nasa.gov/
https://eosweb.larc.nasa.gov/sites/default/files/project/misr/guide/MISR_Science_Data_Product_Guide.pdf

MODIS EASE
Dimensions - Horizontal/Vertical
Enter h and v coordinates separated by spaces, e.g. "2,3 5,7 8,8"
More info:
"For MODIS Sea Ice EASE-Grid products. Tiles are 951 pixels x 951 pixels and 10 degrees by 10 degrees, with half of the tiles (313) located in the north polar grid and half in the south polar grid. In addition:

    • The north polar grid tile coordinate system starts at (0,0) (horizontal tile number, vertical tile number) in the upper left corner and proceeds right (horizontal) and downward (vertical). The tile in the bottom left corner is (18,18).
    • The south polar grid tile coordinate system starts at (0,20) and the tile in the bottom left corner is (18,38).
    • The polar grids are based on the Lambert Azimuthal Equal Area map projection centered on each pole. The grids are compatible with the NSIDC EASE-Grid."

https://nsidc.org/data/modis/ease-grid-tile-locations-sea-ice
http://nsidc.org/data/ease

MODIS Sinusoidal
Dimensions - Horizontal/Vertical
Enter h and v coordinates separated by spaces, e.g. "2,3 5,7 8,8"
More info:
"MODIS Land products use the Sinusoidal grid tiling system. Tiles are 10 degrees by 10 degrees at the equator. The tile coordinate system starts at (0,0) (horizontal tile number, vertical tile number) in the upper left corner and proceeds right (horizontal) and downward (vertical). The tile in the bottom right corner is (35,17)."
http://spatialreference.org/ref/sr-org/modis-sinusoidal/
https://modis-land.gsfc.nasa.gov/MODLAND_grid.html
https://lpdaac.usgs.gov/dataset_discovery/modis

WELD ALASKA Tile
Dimensions - Horizontal/Vertical
Enter h and v coordinates separated by spaces, e.g. "2,3 5,7 8,8"
More info:
A U.S. Landsat ARD 30m tile system based on the Web-Enabled Landsat Data (WELD) project, with coordinates anchored in ALASKA.


Upper Left Tile (ul corner)
Lower Right Tile (lr corner)

(h)(v)ulX (m)ulY (m)(h)(v)lrX (m)lrY (m)
Alaska00-851715247432516131698285374325

https://landsat.usgs.gov/what-us-ard-tile-grid
https://landsat.usgs.gov/ard#Tile%20Grid

WELD CONUS Tile
Dimensions - Horizontal/Vertical
Enter h and v coordinates separated by spaces, e.g. "2,3 5,7 8,8"
More info:
A U.S. Landsat ARD 30m tile system based on the Web-Enabled Landsat Data (WELD) project, with coordinates anchored in CONUS (the continental U.S.)


Upper Left Tile (ul corner)
Lower Right Tile (lr corner)

(h)(v)ulX (m)ulY (m)(h)(v)lrX (m)lrY (m)
CONUS00-256558533148053221238441514805

https://landsat.usgs.gov/what-us-ard-tile-grid
https://landsat.usgs.gov/ard#Tile%20Grid

WRS-1 (Landsat 1-3)
Dimensions - Path/Row
Enter path and row coordinates separated by spaces, e.g. "2,3 5,7 8,8"
More info:
"The Worldwide Reference System (WRS) is a global notation used in cataloging Landsat data. Landsat 8 and Landsat 7 follow the WRS-2, as did Landsat 5 and Landsat 4. Landsat 1, Landsat 2, and Landsat 3 followed WRS-1.""
https://landsat.usgs.gov/what-worldwide-reference-system-wrs

WRS-2 (Landsat 4+)
Dimensions - Path/Row
Enter path and row coordinates separated by spaces, e.g. "2,3 5,7 8,8"
More info:
"The Worldwide Reference System (WRS) is a global notation used in cataloging Landsat data. Landsat 8 and Landsat 7 follow the WRS-2, as did Landsat 5 and Landsat 4. Landsat 1, Landsat 2, and Landsat 3 followed WRS-1.""
https://landsat.usgs.gov/what-worldwide-reference-system-wrs

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