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Question V
Write shortly about the following Image
processing techniques?
1- Merging data sets
2-
Supervised classification
Answer:
1-
Merging data sets
It is a fusion
between colored low spatial resolution data (eg. Colored Landsat image of 30
resolution), and black and white higher resolution data (eg. Pan. SPOT image of
10 resolution) to produce colored higher resolution image.
2-
Supervised
classification
The supervised classification is carried
out in order to make the classifier work
with thematic (instead of spectral) classes;
we must feed some knowledge about
the relationship between classes and
feature vectors into the computer.
This type of classification is divided
into two main phases: a training phase,
where the user "trains" the computer
by telling for a limited number of pixels to
what classes they belong in this particular
image, the second phase is the
"decision making phase", where
the computer assigns a class label to all (other)
image pixels, by looking for each pixel to
which of the trained classes this pixel is most similar.
Question I
Define the following:
1- Hyperspectral sensor
2- Image enhancement
3- Nondirectional Filters
Answer:
1-
Hyperspectral
sensor:
Hyperspectral
instruments collect tens to hundreds of measurements
“continuous” spectrum (depends on detector
bandwidth)
2-
Image enhancement
Alters the visual
impact that the image has on the interpreter in a fashion that improves the
information content.
3-
Nondirectional
Filters (Laplaciant Filters)
They have no directional bias in
enhancing linear features; almost all directions are enhanced
Question II
1- What are the advantages of principal components transformation?
2- What are the methods of image registration?
Answer:
1-
The advantages of
principal components transformation
- Most of the variance in a
multispectral data set is compressed into the first
two PC images
- Noise is generally relegated to the
less-correlated PC images
- Spectral differences between materials may be
more apparent in PC
images than in individual bands
2-
The methods of image
registration:
1-
تسجيل المرئية الفضائية بواسطة خريطة طوبغرافيةImage to
map registeration
2- تسجيل المرئية
الفضائية بواسطة مرئية فضائية أخرى مسجلة Image to image
rectification
3- بواسطة جهاز
تحديد الاحداثيات الجغرافية GPS
Question IV
1- Write the main characteristics (spectral resolution and spatial
resolution) of SPOT-5 satellite?
2- The following Table shows the main characteristics of Quickbird
satellite, complete the Table?
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.......................................................
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Orbit Name
|
|
) km....... X........)
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Scene
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Pansharpened
Band
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Panchromatic Band
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Bands- 1, 2, 3, 4
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Spectral
Resolution
|
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m........
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m.......
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m..........
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Spatial Resolution
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Answer:
1-
The main
characteristics of SPOT-5 satellite:
SPOT-5 (France)
Launch - 2002
Swath- 60 x 60 km
Altitude - 822 km
Spectral Bands : 6
- B1 (green) 10 m
- B2 (red) 10 m
- B3 (near IR) 10
m
- B4 (SWIR) 20 m
- (Panchromatic) 5 m
- (Panchromatic) 2.5
m
2-
The main characteristics of
Quickbird satellite:
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..Near
polar- Sun Synchronous....
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Orbit Name
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|
) km.16.5..
X..16.5..)
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Scene
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|
Pansharpened
Band
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Panchromatic Band
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Bands- 1, 2, 3, 4
|
Spectral
Resolution
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0.60 or 0.70 m
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m...0.61
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m....2.4..
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Spatial Resolution
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