A quick introduction to the EOS Data Gateway (EDG)
1: Begin Search and Order Session
To begin your search and order session, log on to EOS
Data Gateway (if you have not done so already).
The log-on screen appears as figure 1 below.
New users may click the 'Enter as guest' link. Registered users can
click the 'Enter as a registered user' link and login.
This will take you to the 'Primary Data Search' screen.
Should you wish to register, click the 'Become a registered user' link
and follow the registration prompts.
Figure 1 : EDG Entry and Logon Screen
2: Primary Data Search
Choose Search Keywords
After logging-on the Primary Data Search screen appears. The upper half of
this screen appears below in figure 2.
Highlight 'DATA_CENTER_ID' in the scroll window and click the
'SELECT ->' button.
This will take you to the 'Valids Selection: Data Center' screen.
The upper part of the Data Center screen appears in figure 3 below.
Locate the scroll window 'Data Center list 1'.
Highlight one or more Data Centers from 'Data Center list 1' -
for example 'ISA-MEIDA' - and click the 'OK!' button at the bottom of the screen.
This returns you to the 'Primary Data Search' screen.
Figure 2 : EDG Primary Data Search Screen
Figure 3 : EDG Data Center Selection Screen
3: Back at Primary Data Search
Choose Search Keywords
Click the 'Data Set' button and you will be taken to the 'Valids
Selection: Data Set' screen, which is similar to the previous
Data Center Selection screen.
A list of data sets available in the Data Center you selected are displayed
in the 'Data Set list 1' scroll window.
Highlight the data set or sets you wish to search - for example, for
ISA-MEIDA, the 'AVHRR Israel subset' data set.
Click the 'OK!' button at the bottom.
This returns you to the 'Primary Data Search' screen.
4: Back at Primary Data Search
Choose Search Keywords
Click the 'Parameter' button and you will be taken to the 'Valids
Selection: Parameter' screen, which is similar to the previous Data Center Selection
and Data Set Selection screens.
A list of parameters in the Data Set you selected are displayed in the
'Parameter list 1' scroll window.
Highlight the parameter you wish to search - for example,
for the AVHRR Israel data set, 'Infrared Imagery'.
Click the 'OK!' button at the bottom of the screen.
This will return you to the 'Primary Data Search' screen.
5: Back at Primary Data Search
Choose Search Keywords
Note that above the 'Parameter or Data Set or Sensor' buttons
now appears a listing of the Parameter, Data Set,and Data Center chosen, as
seen in figure 4 below.
Figure 4 : EDG Primary Data Search Screen with Choices
6: Primary Data Search
Choose Search Area
You may now enter your area and time of interest.
For a first search it is recommended to leave the defaults as they
are.
'Type in Lat/Lon Range' will be the default method to define your search
area. If you know the Latitude and Longitude, enter the coordinates.
To define the geographic area on a map, click the radio button next
to your map of choice and select the region by clicking on the map.
You may now enter your Time Range. You may use either a Standard Date
Range or Julian Date Range. Be sure to enter the date and time by following
the provided format.
To search seasonally, select the radio button next to 'Annually Repeating'.
7: (optional): Primary Data Search
Choose Additional Options (not required)
If you prefer to customize your search options, make the appropriate
selections in the 'Choose Additional Options' section. To see other options,
click the radio button next to 'All Options'. Pay special attention to
the red text as it contains valuable information on criteria that may cause
a search to fail.
8: Primary Data Search
Start Search!
You are now ready to execute your search. Click the 'Start
Search!' button at the bottom of the Primary Data Search screen to begin.
The screen seen below in figure 5 will appears.
The default duration is for a 45 minute search, usually the search requires
less than a minute, please be patient.
If you chose one Data Set, then when the search is finished you will
be transferred automatically to the 'Results:Granule:Listing' screen.
This screen is shown below in figure 6.
If you ran a search on more than one data set and the EDG found granules
for each data set, the results are shown in the 'Results:Data Set' screen,
with the number of granules found for each set.
To view the list of granules, click on the 'Select' box of one or more
data sets and then on 'List data granules'.
This will transfer you to the 'Results:Granule:Listing' screen.
Figure 5 : EDG Searching for Data
Figure 6 : Granule Listing Screen
9: Results: Granule: Listing
When your results are returned, you will see a table of granules.
A granule is the smallest aggregation of data, which is independently managed.
For example, a granule for Landsat data would be one particular path and
row for one particular acquisition date.
A granule for the AVHRR Israel
subset data is an HDF file with the 5 channel radiometer data, the geolocation
of each pixel, and the solar and satellite zenith angles. For the AVHRR
Israel there is also an image attached for quick viewing.
To view a 'Browse Product' image of the granule, click the 'View Image'
button. Be sure to view each granule you intend to order, if it is available.
The browse will give a good representation of data anomalies or cloud cover
in the granule. For detailed information on a particular granule, click
on 'Granule attributes'.
To order the data, click the box in the 'Select' column of the desired
granule. Next, click the 'Add to cart' button. For Shopping Cart options
see below.
You will be sent an FTP address to download the data from.
10 : Data Manipulation with DIAL
From the 'Data Granule Attributes' page click on the 'Actual
data Access Data with DIAL' link.
In DIAL you can select a data array (for example CT5 for AVHRR data),
and after the picture is displayed change the pallette (for example to
Rainbow256).
11: Shopping Cart
Step 1: Choose Ordering Options
Click the 'Order options' button and choose your output media.
For Landsat 7 Level 1 data, you will need to select your processing parameters.
You will have the option to apply the output media and processing
parameters to all granules or to just one granule. Click the 'Ok! Accept
my choice & return to the shopping cart' button to proceed.
You will want to repeat this for each remaining granule if you are ordering
data from more than one data set, or if you did not apply the ordering
options to all granules.
When finished with your processing parameters, click the 'Go to Step
2: Order Form' button.
Step 2: Order Form
Enter your appropriate address in the contact, shipping and
billing address fields. You are required to enter text in the red fields.
If you are a registered user, this page will be completed for you. When
finished, choose your affiliation and click the 'Go to Step 3: Review Order
Summary' button.
Step 3: Order Summary
Review the order summary. If all of the information is correct,
click the 'Go to Step 4: Submit Order!' button.
Step 4: Order Submitted
Your order has now been submitted. You will receive systematic
email(s) confirming the receipt of your order. The DAAC email will summarize
your order, cost, and provide information on modes
of payment. Payment must be received before order processing can begin.
This document is an excerpt of the
full document at the USGS NASA Distributed Active Archive Center
Please read this general Disclaimer
URL: http://edcdaac.usgs.gov/tutorial/index.html
Maintainer: edc@eos.nasa.gov
Last Update: Tuesday, December 05, 2000.