Remote-Sensing Technologies and Data Processing Algorithms - New Ecoinformatics Tools in Environmental Science: Applications and Decision-making - page 166

Fig. 2.22 Averaged spectral
characteristics of different re
zones: 1 — front, 2 — left flank,
3 — right flank, 4 — back, and
5 — faded zone

Plosky Tolbachik E). This map was formed on the base of

radiobrightness temperature spectres represented in the Fig. 2.24 .
In connection with the change climate problem the forest

— 55 ° 49 ′ N, 160 ° 24 ′

fires monitoring gains

speci uence on the

greenhouse gases concentration is impossible for the reliable assessment of the
present and future tendencies in the environment change. That is the reason a global
geoinformation monitoring system has to have built into it a function to effect such
an assessment. For such a function to be brought about there needs to be a model
that can identify the forest state from radiothermal radiation. For such a model to be
created there needs to be knowledge of the dependencies of forest radiothermal
radiation on different wavelengths to reconstruct the moisture content of forest
timber at various layers and its combustibility. Investigations of many authors
shown that application of microwave sensing in the range 0.8

c role in the global ecoinformatics. The forest state and its in fl

÷ 20 cm allows to

estimate the fire-dangerous for the waterlogged forests.

Multi-channel sensing allows using cluster analysis algorithms to distinguish and
classify

fire risk classes. The accuracy of this methodology depends on the detail of
description by the model of the forest structure re fl ecting the canopy state and trees

density. The most dif cult to identify are forest edge fires. In this case the three-

layers model of the flame-smoke-canopy system is effective:

a P ¼ ð 1 exp fj 1 gÞ exp ðj 2 Þ exp ðj 3 Þ;

ʱ P is the emittive ability of the forest near-land ʺ i is the emission

where re hotbed,

relaxation coef flame (i = 1), by the smoke (i = 2), and by the canopy

(i = 3). The emission relaxation coef

cient by the fl

cients are functions of the trees type. It was
established that absorption in the canopy increases with high speed as the wave-
length is decreasing. Consequently, the receipt of emissions and the discovery of
forest near-land

fires become dif cult when trees have a compact structure.

Nevertheless, wavelengths 0.8 1.5 cm enable forest fires to be estimated with high

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