Remote-Sensing Technologies and Data Processing Algorithms - New Ecoinformatics Tools in Environmental Science: Applications and Decision-making - page 143

Table 2.15 The value of
brightness temperatures
which are typical for the some
land covers

Land cover Wavelength, ʻ (cm)

0.8 1.35

T Tj,min T j,max T Tj,min T j,max

Desert 251 261 245 270

Cultivated steppe 255 268 257 277

Steppe covered by snow 246 261 241 260

The ice covered by snow 247 263 231 253

The ice 239 247 235 254

Sea surface 136 171 110 168

uence of various
atmospheric layers to the receiving signal. The formula ( 2.4 ) makes the expression
( 2.2 ) into a whole. The examples of speci

The weight function Q ðÞ ¼ @ sð u ;1Þ=@ u describes an in fl

c values T j are given in Table 2.15 .
Microwave measurement calibration is important in remote monitoring. Cali-
bration procedure can be de ned as the process of relating signals that can be

extracted from a measurement radiometric system to the physical characteristics of
a target such as its brightness temperature. The main goal of a calibration process is
in getting all measurements to account with a unique scale. In the passive regime
for this aim the objects having known brightness temperature are used (see
Table 2.16 ). Usually it is selected the forest or the freshwater reservoir. In this case
the radiobrightness temperature of forest is equaled to the thermodynamical tem-
perature of the trees canopy, and the radiobrightness temperature of reservoir is
calculated with the known algorithms (Yakimov 1996; Ferm and Hultberg 1999;
Burkov and Krapivin 2009; Krapivin and Shutko 2012).

2.3.1 Remote-Sensing Technologies in the Infrared
and Optical Bands

There exist no less than 10 technologies for remote sensing of the environment.
Between them are those not widely known and not widely applicable for our case,
namely: ultra-sound methods, radar sensing beyond the horizon, solar radiation
sensing and a few others.

Table 2.16 Emission
coef cient for the some
natural and anthropogenic
microwave standards (Shutko
1987)

Land cover Microwave range

Centimetres Decimetres

Dry sand 0.93 ± 0.03 0.93 ± 0.03

Concrete 0.84 ± 0.02 0.82 ± 0.02

Asphalt 0.85 ± 0.03 0.83 ± 0.02

Dense forest 0.95 0.98 0.92 0.96

- -

0.38 ± 0.01 0.36 ± 0.01

Fresh water

Watering soils 0.58 ± 0.03 0.56 ± 0.03