**Using ArcExplorer Java Edition for Education (AEJEE) with MY NASA
DATA**

**Martin Schmidt**

**August 2007**

ArcExplorer Java Edition for Education software can be downloaded at

\<http://www.esri.com/software/arcexplorer/download-education.html\>.
The program comes with a tutorial (in the Help menu) to become familiar
with how the program works.

**[A. Simple use]{.underline}**

1.  For each image/map you would like to use as a map layer, use the
    server at MY NASA DATA to select the data you want and produce the
    output as a map (color plot). Right-click on the map and choose
    \"Save image as\...\", and save it (GIF image). Give each image
    saved a clear name to differentiate between multiple images, and be
    sure you know where the files are being saved.

![](media/image1.png){width="2.3340277777777776in"
height="2.2159722222222222in"}

2.  Start AEJEE and add each of the maps to a project using the Add Data
    icon which brings up the Content Chooser window.
    ![](media/image2.png){width="2.422222222222222in"
    height="1.9784722222222222in"}
    ![](media/image3.png){width="2.7125in"
    height="2.0208333333333335in"}

Since they are now layers, they can be turned on and off to compare maps
easily by unchecking and checking the box next to the layer name.
![](media/image4.png){width="3.0868055555555554in"
height="2.3430555555555554in"}
![](media/image5.png){width="3.0868055555555554in"
height="2.3430555555555554in"}

3\. You can also zoom to specific areas of the Earth without having to
download that area separately. Note, however, there are limits to the
resolution of the data, so if you zoom in to a local area, you may be
looking at places that the original data did not differentiate.

![](media/image6.png){width="3.0868055555555554in"
height="2.3430555555555554in"}
![](media/image7.png){width="3.0868055555555554in"
height="2.3430555555555554in"}

4\. Note that this method gives you a stack of images aligned with each
other, but not aligned in any way with geographic coordinates (that is,
not georeferenced), so they will not match GIS shapefiles brought into
AEJEE. Use the method below to create georeferenced images.

**[B. More complex use]{.underline}**

This method creates a good (though not perfect) georeferenced image of
data sets, so other geographic files can be added for comparison.

Introductory note: You may want to try this procedure a few times with
the maps drawing as the default from the Live Action Server (LAS), which
include continent outlines, to be sure the MY NASA DATA map matches the
GIS map of the world. But you can produce cleaner maps if you scroll
down the LAS page and for \"Land fill style\", choose \"None\", which
will give you maps with no continent borders. Though at first view these
maps without continent outlines may be hard to interpret, once they are
in the GIS, it can add borders that don\'t obscure as much of the data.

![](media/image8.png){width="2.7465277777777777in"
height="2.140972222222222in"}

1\. For each image/map you would like to use as a map layer, use the
server at MY NASA DATA to select the data you want and produce the
output as a longitude-latitude map. When you have the map in your
browser, right-click on the map and choose \"Save image as\...\", and
save it (GIF image). Give each image saved a clear name to differentiate
between multiple images, and be sure you know where the files are being
saved.

![](media/image9.png){width="2.5791666666666666in"
height="2.4541666666666666in"}

2\. Use a photo/image editor (for example Paint) to open the image saved
in step 1. Crop the image so the black border around the map is removed,
leaving just the map, but no pixels inside the border of the map are
lost, even if areas near the poles are not colored. In your photo
editor, it will be useful to zoom in on the image while cropping to be
sure this is done correctly. Often, the locations in pixels for the
corners are: Left = 77, Right = 636, Top = 89, Bottom = 427 (these are
for the Large images, which is the default). Then save the cropped image
with a different name to show it is the map only (no borders or other
marginal information); retain the original \".gif\" file extension. It
is useful to keep the original image in case you need to refer to the
legend or other caption information.

![](media/image10.png){width="2.752083333333333in"
height="2.1979166666666665in"}

3\. To place the image in the right place on a world map - called
georeferencing - AEJEE needs both a projection file (which tells it the
map projection, and has a \".prj\" extension), and a world file (which
tells it where this image goes on the map, and has a \".gfw\" extension
for gif images). For both of these, we\'ll use generic files that will
work for all of the MND maps, and rename them to match each image.

a\. For the projection file:

1\. Copy the file \"MND_projection.prj\" (easiest way is to right-click
on the file and choose Copy), then in the folder where you saved the
map-only image from step 2, paste this file (right-click in the folder
and choose Paste).

2\. Rename the projection file so it has [exactly]{.underline} the same
name as the image saved in step two, except retain the .prj file
extension.

b\. For the world file:

1\. Copy the file \"MND_world.gfw\", then in the folder where you saved
the map-only image from step 2, paste this file.

2\. Rename the world file so it has [exactly]{.underline} the same name
as the image saved in step two, except retain the .gfw file extension.

c\. When finished with this step, you should have 3 files all with the
same name (projection & world files will be very small in file size),
but with different extensions; all 3 files need to be in the same
folder. You can repeat this process with other MND images, and all sets
of 3 files that result can go in the same folder (that is, a separate
folder for each set of 3 files is not needed).

4\. Open AEJEE, and add a world country borders map (such as country.shp
or country06.shp, which comes with AEJEE) to the project to establish
that it uses decimal degrees; you will probably want this layer to have
no fill, so it is country outlines only. To do this, right click the
Country layer, select Properties, and in the Style drop down, select
'Transparent fill'.

![](media/image11.png){width="2.247916666666667in"
height="1.7972222222222223in"}
![](media/image12.png){width="2.247916666666667in"
height="1.8041666666666667in"}

Then add the image created in step B2 above; the program will
automatically read the projection and world files (they won\'t be
visible in the file listings) and use them to place the image in
reasonable alignment with the vector country borders. You can then add
other layers to this map as usual, to compare with the MY NASA DATA map.

![](media/image13.png){width="2.4965277777777777in"
height="2.0027777777777778in"}
![](media/image14.png){width="2.5055555555555555in"
height="1.988888888888889in"}

5\. Some cautions:

a\. This procedure does a good job of matching the MND data to continent
and country borders, but not a perfect job. So don\'t draw firm
conclusions based on pixels that fall close to a border, as they might
be geographically off a bit.

b\. And more generally, note that the MND datasets have a certain
resolution (such as 2.5-degree or 1-degree squares). In AEJEE you can
zoom in on parts of the Earth and exceed this resolution, so it might
seem the data is more detailed that it really is. In general, you should
use MND data to look at conditions in a broad area such as regions of
continents or areas of oceans, not local areas.

6\. If desired, you can also use a photo editor to \"cut out\" the
colored legend that usually appears to the right of the maps from the
LAS, and give this file a new name with the .gif extension. If you
prepare .prj and .gfw files as in step 3 above for this legend image
(even though it is not a map), it should appear on the left side of your
map. Though this legend covers some of the map, it can easily be turned
on or off, and may put the legend in a more accessible place than if you
had to look back at the original complete .gif file from the LAS.

![](media/image15.png){width="1.29375in" height="1.9180555555555556in"}
![](media/image16.png){width="3.45625in" height="2.770138888888889in"}

7\. Note this procedure (cropping out the map and adding world and
projection files) will also work with other GIS programs for education,
such as MyWorld GIS, except the images will need to be converted to
JPEGs, since MyWorld does not read GIFs. World files for JPEG images end
in .jgw - just rename the MND world file so it has your file name and
the .jgw ending (projection files remain .prj).

Examples of other files that could be used with MND data once it is
georeferenced in AEJEE or ArcView:

1\. World bioecoregions map from World Wildlife Foundation:
\<http://www.worldwildlife.org/science/data/terreco.cfm\>.

![](media/image17.png){width="2.5805555555555557in"
height="2.053472222222222in"}
![](media/image18.png){width="2.6708333333333334in"
height="2.0076388888888888in"}

Click on a location and get ecoregion information.

![](media/image19.png){width="4.118055555555555in" height="2.35625in"}

2\. Various environmental subjects from UN Environmental Program:
\<http://geodata.grid.unep.ch/\>.

3\. MODIS satellite images for various areas are at:
\<http://rapidfire.sci.gsfc.nasa.gov/\>. The \"Near-real-time Subsets\"
can be downloaded with a world file that will place the image in a GIS
map. If you need a projection file, rename the MND projection file so it
matches your downloaded image.

4\. Search for data at \<http://www.geographynetwork.com/\>.

5\. At ArcLessons:
\<http://gis2.esri.com/industries/education/arclessons/arclessons.cfm\>,
you can download the lesson called \"Geotools for Mapping and Spatial
Analysis\". This has an extensive list of websites for Internet mapping,
software, data, and many other sources.