Knowledge Base

How do I search, order, and customize SMAP data using Earthdata Search?

In this step-by-step tutorial, we will demonstrate how to search, order, and customize NASA Soil Moisture Active Passive, or SMAP data using the NASA Earthdata Search application. NASA Earthdata search provides an interactive map-based search environment where you can filter your results based on spatial and temporal constraints and perform numerous services on your data order, including re-formatting and spatial and parameter subsetting.

Step 1: First, go to the NASA Earthdata Search main page and start your search by entering SMAP into the main search bar.

https://search.earthdata.nasa.gov

Tip: You will notice that the collection list has been automatically updated to show matching collections for SMAP

STEP 2: Refine your search by applying a temporal filter for 11 - 15 August 2019.

Tip: Notice that the collection list has changed yet again, and the filter is now displayed under the search bar.

Step 2a - Select 'Temporal' drop down.

Step 2b - Select August 11, 2018 in the 'Start' box.

Step 2c - Select August 15, 2018 in the 'End' box.

Step 2d - Click on 'Apply Filter.'

Step 3: Choose spatial filter. 

Note: In this demo, we are interested in soil moisture over the state of Colorado.

Tips: There are several spatial filter options. Filter by drawing a polygon or rectangle over your geographic region of interest, select a point, or upload a polygon in KML or Shapefile format as your spatial constraint. You may also type the latitude/longitude coordinates for a point or polygon or grid coordinates for several different grids.

Step 3a - Select 'Rectangle' which results in a drawing tool to draw box on map.

Step 3b - Manually enter coordinate for the SW corner (37, -109) and NE corner (41, -102) into the rectangle bounding box.

Step 3c - Click 'Enter' and note that the blue outline is now present over the selected bounding box, over Colorado.

Step 4: Select data set (collection) in the search results to view granule extents for an individual collection.

Note: We are interested in the SMAP L2 Radiometer Half-Orbit 36km EASE-Grid Soil Moisture V006 (SPL2SMP)

Step 5: Click on 'Add to project' button on the right side of the page, above the green 'Download All' button.

Note: Repeat steps 4 and 5 for additional data sets.


Data Selection Tips:

  • You can see each of the granule outlines that correspond to the search criteria displayed on the map in green.
  • Hover over granule footprints on the main screen to see those outlines or click on them.
  • View the temporal coverage of these data with the time scale at the bottom.
  • Sort filtered granules by data. 
  • Immediately download a granule to your computer by selecting the download button.
  • Remove the granule from the list by clicking on the 'x'.

Step 6: Once you're done selecting your data sets of interest, click on the gray 'My Project' button at the top right.

After clicking on the 'My Project' button, you will be directed to the Earthdata Login authentication page. Enter your Earthdata Login username and password, or register for a new account if needed by going to https://urs.earthdata.nasa.gov.

After authentication, you will land on the Project page, providing information on the data granules requested, data access methods available, and a map displaying the selected data.

Step 7: Customize each SMAP granule.

Tips: Several options to customize SMAP granule. Reformatting from original HDF5 is available.

Step 7a - Click on 'Edit Options' to customize the data

Step 7b - Click on GeoTIFF in the 'Reformat' Output (Optional)' Box

Step 7c - Spatially subset granules so that only data within the Colorado bounding box are received by checking the 'Enter bounding box' option. The Spatial filter that was previously entered is automatically added as the coordinates.

Step 7d - Subset the bands or parameters of interest.

Step 8: Click on the green 'DOWNLOAD DATA' button to submit your order.

Step 9: Retrieve your Order

Tips for retrieving your order:

  • Watch the progress of your order on the final page.
  • when processing is complete, two URLs are presented to you in the 'Download Link' option.
  • Click on the top URL and you can see all of your output granules displayed. You can download individual granules with this link.
  • Click on the bottom URL to download the whole order as one single zip file.

Need Help or Have Questions?

  • If you have any questions on Earthdata Search or any feedback, you can always click on this 'Feedback' button on the top right of the page.
  • If you're interested in learning more about Earthdata Search, you can go back to the home and you can start an introductory tour.
  • Finally, if you have any questions about ordering SMAP data or performing services on SMAP data, you can email the National Snow and Ice Data Center User Services Office at nsidc@nsidc.org.

Last Updated Aug 2019