|
||||||
|
|
||||||
MODIS Data at NSIDCHome | Data Summaries | Versions | Image Gallery | Order Data | News | V004 CMG Browse | Research | FAQs | Terra vs. Aqua |
 |
Once you select the Choose Options link (in Step 8 of the tutorial), you are given several ordering options, including the option to subset the data by row and column.
With row/column subsetting, you can specify the precise spatial region of any input data array to be subsetted. In contrast, subsetting by latitude and longitude is only precise for cylindrical (latitude/longitude) grids because they are rectangular. For data in other projections, such as EASE-Grid or Sinusoidal, results of row/column subsetting are much better because the subsets are defined by exact grid cells. In these cases, output arrays closely match the requested region with minimal extraneous data.
Click the Option 5 button in the options list to order row/column subsets via FtpPull, as shown in this example.
A new Choose Ordering Options page, containing several sections, displays. In the "Ordering Option 5" section, select Native Granule - FtpPull from the items list. 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.
In the "Grid" section, enter row and column numbers for the upper-left (UL), lower-left (LL), lower-right (LR), and upper-right (UR) corners of your desired subset.
Or, you can drag your mouse to define a bounding box in the accompanying Java-based map, which displays in a separate pop-up window. Defining a box on the map populates the row and column fields in the "Grid" section with the corresponding values (this also populates latitude/longitude).
Near the bottom of the page is the "Parameter" section. Select your preferred subsettable field(s), if any, from the list (the default is to subset with all parameters).
Finally, click on the OK! Accept my choice & return to the shopping cart! button at the bottom of the page.
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 of the tutorial). 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. Return to the EDG tutorial main page (Step 11) for further instructions on completing your order.
If you closed the EDG tutorial main page browser window, reopen the main tutorial in this window.
