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User guide for accessing VIIRS data from the

Comprehensive Large Array-Data Stewardship System (CLASS).

1.  Start at http://www.nsof.class.noaa.gov/saa/products/welcome

2.  Login to your account (create one first, if necessary).

3.  From the CLASS home page, the Search - VIIRS tool can be accessed two ways;

  1. From the pull down menu that prompts, “Please select a product to search,” select, “NPP Visible/Infrared Imager/Radiometer Suite (VIIRS)” and click ‘GO.’
  2. From the blue menu bar on the left of the web page, select Around CLASS -> Search for Data. In the next page, expand “Suomi National Polar-orbiting Partnership (NPP)” and then select “NPP Visible/Infrared Imager/Radiometer Suite (VIIRS).”

4.  The Search – VIIRS tool has three components.

  1. Spatial. To specify the desired spatial extent, use a mouse to change the bounding box border or enter in lat/long coordinates.
  2. Temporal. Bound the temporal range using the date and time fields. The default time range is set to the current day or the most recent 8 days, depending on the product.
  3. Advanced Search. The options that can be accessed by expanding the Advanced Search section serve to limit the results that the search will return. Under Datatype, there is a checkbox for each VIIRS data product. (Is it worth expounding upon the sub-categories?) Under the Node category, the user can specify whether to return Ascending Nodes, Descending Nodes, or Either. (What is the significance?) For VIIRS data, the only Satellite option is NPP.

5.  The search can be conducted two ways;

  1. Clicking on the Search button will load the Search Results – VIIRS page. To download the data, execute the following steps;
  2. Click the checkbox(s) for the desired dataset(s) under the Shopping Cart heading. There are two mechanisms to help ascertain which datasets to download. Clicking the Generate Map button results in a pop up window that displays all of the swaths (if there are multiple results pages, it only shows the swaths for the current page). Note that the color coding in the table matches the color coding of the swaths in the map. Clicking on a numbered button under the View Details heading links to a page of that dataset’s metadata.
  3. Click the Update button to place the items into the shopping cart (the message indicating how many items are in your shopping cart will automatically update). Note that a limit of 100 datasets can be downloaded using this method.
  4. Click the Goto Cart button
  5. Click on the Quick Search & Order button to receive all results without first reviewing the metadata.

6.  In the Shopping Cart page that will appear next, click on the Place Order button. Notes:

  1. Include Digital Signature option. http://www.nsof.class.noaa.gov/saa/products/savekeys
  2. If a user is logged into his/her account, the email address associated with that account should already be entered into the “You will be notified at:” field.
  3. If a user is not logged in, the Place Order button will instead say Register. (From what scenarios I ran) A user can either login or register at this point and the state of the Shopping Cart will be preserved.
  4. Under Advanced Options.
  5. The VIIRS Results button returns the user to the Search Results – VIIRS where he/she can modify the granule selection.
  6. The VIIRS Search Page button returns the user to the Search – VIIRS page where he/she can modify the search parameters.