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Ordering MODIS Snow and Ice Products Using the EOS Data Gateway

This tutorial provides simple instructions for searching and ordering MODIS snow and ice products from NSIDC using the EOS Data Gateway (EDG). It is not a comprehensive tutorial on EDG functionality. Help with using the EDG is available from every EDG page throughout the search and order process. Please contact NSIDC User Services for questions regarding your order and MODIS data products.

Note: The images in this tutorial generally show only particular sections or other smaller portions of the the full screens you will see during the search and order process. Only the portions relative to the step being described are shown. If a table (such as a data set list) is very wide or long, only certain rows and/or columns may be shown.


  1. Enter the EOS Data Gateway from the Main EDG Web page.
  1. Your browser should display the Earth Observing System Data Gateway Main Web page. Refer to Figure 1.
  1. From the Main EDG Web page, choose one of the following options:
  1. Click on Enter as guest.

  2. Click on Enter as a registered user, and enter your user name and password.

Note 1: Should you wish to register, click on the Become a registered user link and follow the registration prompts. Becoming a registered user can expedite the ordering process and provide other benefits.

Note 2: The current status of the data center is shown on this page under Data Center Status. If NSIDC is temporarily down or experiencing difficulties, a notice will be posted here. Check this status information frequently if you experience problems.

home page

Figure 1: Earth Observing System Data Gateway Main Web Page




Once you enter the EDG as either a guest or a registered user, the data search process begins. First, the Primary Data Search Web page is displayed. Refer to Figure 2. This page is divided into several sections. The first section is Choose Data Sets.

  1. Under the Cryosphere column heading, choose one of the following options:
  1. Click on the MODIS/Terra option button.

  2. Click on the MODIS/Aqua option button.

Note: This shows a list of available data sets in the Choose Data Sets scroll box.


select modis/terra

Figure 2: Primary Data Search Web Page




  1. Click on the desired MODIS data set in the Choose Data Sets scroll box.

Note 1: The V00x at the end of each data set name represents the version number, where x is a numerical number. Users are encouraged to work with the latest version available, which is the highest version number because it incorporates improvements to the older algorithms. For more information, see the MODIS Product Versions Web page.

Note 2: You may also select multiple data sets from the list in the scroll box. To select multiple data sets that are grouped together in the list (adjacent to each other), hold down the <Shift> key and click on one data set name with your mouse, then while still holding down the <Shift> key, click on another data set name; these two data sets and all the data sets between them in the list will be selected. To select multiple data sets from various locations in the list (for example, just the first and last data sets in the list), use the <Ctrl> key plus mouse click (PC or Unix) or <Command> key plus click (Mac) to select each individual desired data set.

select modis data sets




  1. Under the Choose Search Area section, choose a geographic search area for the data set. Refer to Figure 4.
  1. Under the Choose a Date/Time Range section, choose a data/time range. This sections is not required. Refer to Figure 4.
  1. Under the Choose Additional Options section, choose additional options. This sections is not required. Refer to Figure 4.
  1. Click on the Start Search button. Refer to Figure 4.

choose area and start search

Figure 4: Choose Search Area Section


The Search in Progress page should display while the matching data sets are found.

Note: If you receive a message that states, "This Data Center is not responding to your query" in the Search Completed page, the system may be temporarily down. Either try your search later or contact NSIDC User Services. If NSIDC is temporarily down or experiencing difficulties, a notice will be posted on the EOS Data Gateway main page, under Data Center Status. Check this status information frequently if you experience problems.


5.  The Data Set Listing page then displays the individual data sets found in the search. Select the desired data set(s) and click on the List data granules button near the top left of the page.

data set list results


6.  The Granule Listing page displays a table of the individual granules available. Respective data set names are listed for each granule, along with other information, such as geographic center points, time periods, etc. If browse images are available for a given data set, you can view the browse images by clicking the Available link under the "Image Quicklook" column. Select the preferred data granule(s), then click on the Add selections to cart button near the top left of the page.

granule list results

Note: The following data sets have browse images that accompany each data granule:


7.  As the shopping cart process begins, a Data Quality Summary page displays. Read the information, then click the Accept - Continue to Shopping Cart button at the bottom of the page to proceed.

data quality summary


8.  The shopping cart's Step 1: Choose Ordering Options page displays. Click the Choose Options link to the left of the desired data set name to begin options selection.

choose order options

A new Choose Ordering Options page displays. There are six ordering options, as shown below.

choose order options list

You may order the full data granule (using Option 1 or Option 2), but subsetting options are also available. You may retrieve the data from the FTP site (FtpPull) or you may have the data sent to your FTP site (FtpPush). Each of the ordering options indicates which data delivery method applies. Option 1 also provides additional delivery methods (media types). The subsetting options are only available for FTP delivery (FtpPull or FtpPush).

In this tutorial, we assume you will be ordering your data using Option 1, retrieving the data with FtpPull. In this scenario, you will be notified by e-mail when your data are staged. The e-mail message will also contain the FTP address and directory information you will need to transfer the data to your computer. (If you request data on other media, you will receive an e-mail message acknowledging your order, and NSIDC will ship the data to you on the medium you requested.)

Click on the Option 1 button in the options list.

choose option 1


Note: For information on using other ordering options, click on one of the links below. This will display additional information in a new browser window. If you choose one of these ordering options, follow its instructions and then return to Step 11 of this tutorial to complete the ordering process.

For Information and Instructions About Go To
Row and column subsetting (Option 5 example) Subsetting by Row and Column
Latitude and longitude subsetting (Option 6 example) Subsetting by Latitude and Longitude
Using FtpPush (Option 2 example) Ordering with FtpPush Option


9.  A new Choose Ordering Options page displays. This lists data granules for each available media type. Select Native Granule - FtpPull from the list. Then click the OK! Accept my choice & return to the shopping cart! button at the bottom of the page.

select native granule


10.  The shopping cart's Step 1: Choose Ordering Options main page displays again, updated to indicate the selected option for this data set. If you placed multiple products (not simply multiple versions of the same product) in your shopping cart, you must select ordering options for each (click the Choose Options link to the left of the desired data set name to begin options selection, as described in Step 8). Once you have selected ordering options for all data sets in the shopping cart, this page will display with a Go to Step 2: Order Form button. Click on the Go to Step 2: Order Form button.

go to order form


11.   The shopping cart process moves on to the final step, which is the order form completion. The Step 2: Order Form page displays. Fill out your user contact information, being sure to enter information in all fields marked "required".

Note: If you are a registered user of the EOS Data Gateway, the fields will automatically populate with your contact information.

order form

You must select both a Type and Category from the drop-down lists in the "Your Affiliation" section. After you fill in the order form, click on the Submit Order Now! button, which is about mid-way down the Step 2: Order Form page.

submit order

The Order in Progress page should display while your order is processed.


12.  An Order Submitted page displays. Make sure you see the status message, "Successful query; query results returned" (see highlighted section below). You have successfully completed an order for MODIS data.

successful order

13.  When your order is processed, you will receive a confirmation e-mail that contains an order summary. When your data are staged (using the FtpPull option), you will receive a second e-mail, with the subject, "ECS Notification." This notification contains instructions and information for retrieving your data using FTP. The notification e-mail will contain information similar to the following example (the FTP host name and FTP directory are shown in red below):

Subject: ECS Notification
    From: CM SHARED (CM Code Delivery)   <cmshared@n0ins02u.ecs.nasa.gov>
Thank you for using the Earth Observing System Distribution System.
For more information on your request contact User Services at the NSIDC DAAC.
Instructions on retrieving your data--
1) Type "ftp " to connect to the FTPHOST specified below.
2) Type "anonymous" to log in as the user anonymous.
3) Type in your email address as the password.
4) Type "cd " to change to the FTPDIR directory specified below.
5) Type "ls" to see the list of files.
6) Type "binary" to set the transfer mode to binary.
7) Type "get " to copy a file to your host, or
8) Type "mget *" to copy all of the files to your host.
9) Type "quit" to log off.
The data will remain available via FTP for 72 hours, after which they will be automatically purged.
Please contact NSIDC User Services if you need assistance.

NSIDC User Services
449 UCB
University of Colorado
Boulder, CO 80309-0449
e-mail: nsidc@nsidc.org
phone: 303-492-6199
fax: 303-492-2468
++++++++++

ORDERID: 0800357404
REQUESTID: 0800249433
USERSTRING:
FINISHED: 07/22/2005 11:06:47

MEDIATYPE: FtpPull
FTPHOST: n0acg01u.ecs.nasa.gov
FTPDIR: 0800249433uCxNw
FTPEXPR: 07/25/05 11:06:26
MEDIA 1 of 1
MEDIAID:

 GRANULE:UR:10:DsShESDTUR:UR:15:DsShSciServerUR:13:[NSC:DSSDSRV]:22:SC:MOD10C1.004:7631090
 ESDT: MOD10C1.004

   FILENAME: MOD10C1.A2004365.004.2005002053801.hdf
   FILESIZE: 103791894

   FILENAME: MOD10C1.A2004365.004.2005002053801.hdf.met
   FILESIZE: 64349


14.  To retrieve your data, access the command prompt on your local system (in this example, the system is a PC), then connect to the FTP host site by typing "ftp FTPHOST", replacing FTPHOST with the FTP host name from your ECS Notification e-mail (shown in red above). Follow the steps in the ECS Notification e-mail, as shown in the image below (the commands and responses that you type are highlighted). This downloads the selected file(s) to the current directory on your local system. If you use the "mget" command to download all the files to your system, you will be prompted to enter "y" for each file to confirm download. If you are retrieving a large number of files, you may want to enter the "prompt" command before entering "mget"; this downloads all the files without prompting for individual confirmation.

FTP retrieve files


Note: If you use an FtpPush option, you will receive an ECS Notification e-mail when the data have been staged on your FTP host. This notification will state the location of the data using the FTP host name and directory that you provide in your FtpPush order options.


Page last updated: 08/14/07