Geoscience Reference
In-Depth Information
image2_reg = imwarp(image2,tform,'OutputView', ...
imref2d(size(image1)));
We can compare the result with the original images using
subplot(1,3,1), imshow(image1)
subplot(1,3,2), imshow(image2)
subplot(1,3,3), imshowpair(image1,image2_reg,'blend')
print -djpeg70 -r600 sugutavalley_aligned.jpg
As we can see, the second image is now nicely aligned with the i rst image
(Fig. 8.4). h e two images can now be used to map changes in the area (e.g.,
in the size of the lake) between 20th February and 31st August 2003. h is
script can also be used to automatically align other images, in particular
those captured by dif erent sensors.
8.6 Processing and Exporting EO-1 Hyperion Images
h e Earth Observing-1 Mission (EO-1) satellite is part of the New Millennium
Program of the US National Aeronautics and Space Administration (NASA)
and the US Geological Survey (USGS), which began with the launch of this
satellite on 21st November 2000. EO-1 has two sensors: the Advanced Land
Image (ALI) has nine multispectral bands with a 30 m spatial resolution and
a panchromatic band with a 10-m resolution, and the hyperspectral sensor
(Hyperion) has 220 bands between 430 and 2,400 nm (Mandl et al. 2002,
Line 2012). General information about the EO-1 program can be obtained
from the webpage
http://eo1.gsfc.nasa.gov
Hyperion data (together with data from of other NASA satellites) are freely
available from the webpage
http://earthexplorer.usgs.gov
On this webpage we i rst select the desired map section in the
Search
Criteria
, either by entering the coordinates of the four corners of the map or
by zooming into the area of interest and selecting
Use Map
. As an example
we enter the coordinates 2°8'37.58"N 36°33'47.06"E of the Suguta Valley in
the Northern Kenya Rit . We then choose
Hyperion
from the
EO-1
collection
as the
Data Set
and click
Results
. Clicking
Results
produces a list of records,
together with a toolbar for previewing and downloading data. Clicking the
Show Browse Overlay
button allows us to examine the images for cloud cover.
We i nd the cloud-free image
