Agriculture Reference
In-Depth Information
bands for MSS with a spatial resolution of approximately 80 m in the visible to
the near-infrared (NIR) region: 0.5 to 0.6
μ
m (band 4), 0.6 to 0.7
μ
m (band 5), 0.7
to 0.8
μ
m (band 6), and 0.8 to 1.1
μ
m (band 7). A thermal infrared (TIR) band
(10.4 to 12.5
m) with a spatial resolution of 240 m is used in the MSS mounted on
Landsat 3. The Thematic Mapper (TM) is an optical sensor installed on Landsat 4
and Landsat 5, which has seven bands: 0.45 to 0.52
μ
μ
m (band 1), 0.52 to 0.60
μ
m
(band 2), 0.63 to 0.69
μ
m (band 3), 0.76 to 0.90
μ
m (band 4), 1.55 to 1.75
μ
m (band
5), 10.40 to 12.50
m (band 7). The spatial resolution
is 30 m for these bands, except for band 6, which has a spatial resolution of 120 m.
The Enhanced Thematic Mapper Plus (ETM+), a sensor installed on Landsat 7 and
launched in 1999, is an improved version of the TM sensor on Landsat 4 and 5.
The Hyperion, installed on Earth Observing-1 (EO-1), was launched in 2000. It is a
high-resolution hyperspectral imager capable of resolving 220 spectral bands (0.4 to
2.5
μ
m (band 6), and 2.08 to 2.35
μ
m) with a 30-m spatial resolution. The Advanced Spaceborne Thermal Emission
and Reflection Radiometer (ASTER) is an optical sensor installed on EOS AM-1,
which was launched in 1999. The ASTER with three bands (0.52 to 0.86
μ
μ
m) has a
spatial resolution of 15 m; meanwhile, the one with six bands (1.60 to 2.43
μ
m) has a
spatial resolution of 30 m, and the one with five bands (8.125 to 11.65
m) has a spa-
tial resolution of 90 m. The High-Resolution Visible (HRV) sensor is an optical sen-
sor installed on SPOT 1 (launched in 1986), SPOT 2 (launched in 1990), and SPOT 3
(launched in 1993), and the High-Resolution Visible Infrared (HRVIR) is installed
on SPOT 4 (launched in 1998). The SPOT was designed by the Centre National
d'Etudes Spatiales, France. There are two modes for the HRV on SPOT 1 to 3: mul-
tispectral and panchromatic modes. There are three bands of 0.50 to 0.59
μ
μ
m (band
1), 0.61 to 0.68
m (band 3) with the spatial resolution
of 20 m in the multispectral mode, whereas the spatial resolution is 10 m of 0.51 to
0.73
μ
m (band 2), and 0.79 to 0.89
μ
m wavelength in the PAN mode. The IKONOS, an earth-observation satellite
launched by Space Imaging/EOSAT in 1999, has the major advantage of measuring
high spatial resolution images, which can be used for applications in urban, forest,
and agricultural areas. The QuickBird of DigitalGlobe, launched in 2001, has similar
spectral bands to those of IKONOS, but with higher spatial resolution. Specifically,
the spatial resolutions are 0.61 and 2.44 m for PAN (0.45 to 0.90
μ
μ
m) and multispec-
tral [0.45 to 0.52
μ
m (blue), 0.52 to 0.60
μ
m (green), 0.63 to 0.69
μ
m (red), and 0.76
to 0.90
m (near-IR)] bands, respectively. Both NOAA and TIROS-N satellites are
installed with the Advanced Very High Resolution Radiometer (AVHRR), which
provides spatial resolution of approximately 1.1 km and a swath 2399 km wide. There
are five bands for the current AVHRR, which are 0.58 to 0.68
μ
μ
m (band 1), 0.725 to
1.1
μ
m (band 2), 3.55 to 3.93
μ
m (band 3), 10.3 to 11.3
μ
m (band 4), and 11.5 to 12.5
μ
m (band 5). The Moderate Resolution Imaging Spectroradiometer (MODIS) is an
optical sensor installed on EOS AM-1 and PM-1, which were launched in 1999 and
2002, respectively. The MODIS has 21 bands in 0.4 to 3.0
μ
m and 15 bands in 3.0
to 14.5
m. Its spatial resolutions are 250 m (2 bands), 500 m (5 bands), and 1000 m
(29 bands), and as an active sensor the Synthetic Aperture Radar (SAR) is used to
observe the physical properties, roughness, and inclination of the ground level using
microwaves. The main advantage of SAR is its ability to operate under almost all
weather conditions. Therefore, SAR is available for observation through clouds, and
μ
