Agriculture Reference
In-Depth Information
TABLE 4.1
Spectral Characteristics for WorldView-2, QuickBird, GeoEye-1, and
IKONOS
Spectral Band (
μ
m)
Band Name
IKONOS
GeoEye-1
QuickBird
WorldView-2
Panchromatic
0.450-0.900
0.450-0.800
0.450-0.900
0.450-0.800
Coastal
0.400-0.450
Blue
0.445-0.516
0.450-0.510
0.450-0.520
0.450-0.510
Green
0.505-0.595
0.510-0.580
0.520-0.600
0.510-0.580
Yellow
0.585-0.625
Red
0.632-0.698
0.655-0.690
0.630-0.690
0.630-0.690
Red Edge
0.705-0.745
NIR1
0.757-0.853
0.780-0.920
0.760-0.900
0.770-0.895
NIR2
0.860-1.040
In addition to their high spatial resolution, these satellite sensors offer image data
at 8 times as many gray levels as the 8-bit traditional satellite sensors. Moreover, the
high revisit frequency and fast turnaround time of these high-resolution satellites are
certainly advantages over traditional satellites. These advantages, combined with
their relatively large area coverage and ability to take imagery over any geographic
area, make high-resolution satellite imagery attractive for many applications, includ-
ing precision agriculture.
4.2.6.4 Image Processing and Analysis
Image processing and analysis is an important component of remote sensing technol-
ogy. Different imaging systems provide different types of imagery, and therefore a
variety of techniques need to be used to process and analyze the image data. These
techniques are diverse, ranging from simple visual interpretation to sophisticated
computer processing methods. Image processing and analysis generally involves
image display and enhancements, image registration and rectification, image clas-
sification, accuracy assessment, and more advanced spectral analysis techniques.
Because of limited space, the reader can refer to other textbooks for this special topic
(Campbell, 2002; Richards and Jia, 2005; Lillesand et al., 2007; ERDAS, 2010).
Two other spatial information technologies closely related to remote sensing are
GPS and GIS. GPS data are often required to determine the geographic locations
of airborne imagery and to geometrically correct and georeference the imagery. A
GIS provides a platform for GPS data and remote sensing imagery to be displayed,
analyzed, and integrated with other spatial data. At the same time, remote sensing
imagery and GPS data have become primary data sources for GIS analysis. Indeed,
these technologies have been interrelated to one another, especially for precision
agriculture applications.
