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Let us note some specific features of the microwave-
radiometry method.
The wavelength hand ranges from a few millimeters to a
few decimeters. The penetrating power of these radio waves
(thickness of skin-layer) ranges in most cases from a few
hundredths of a wavelength to a few wavelengths.
The range within which the radio-brightness tempera
tures of most of the natural objects lie is from 130K to
300K (up to the thermodynamic temperature in the case of
absolute black body), which corresponds to the radiation
power of about 0.43 to 1. The sensitivity of the on-board
radiometers used in surveying natural objects is of the or
der of IK and, consequently we can say that the resolution
in terms of signal intensity in the microwave radiometry is
high. In addition, concurrent measurement at a few wave
lengths is possible, where on each wavelength measurements
can, in turn, be accomplished in three polarizations which
in some cases can be independent in terms of independency
of the corresponding radiation-geophysical equations.
The drawback of the materials of the radiometrical
survey is their low resolution of the terrain limited by
the width of the main loke of the antenna radiation pat
tern .
There is every ground to suggest that in the case of
the joint use of the data obtained in the optical and
microwave ranges all the drawbacks inherent to these me
thods shall be to a certain extent compensated.
Let us conduct the assessment of the parameters of the
radiometrical equipment which is recommended to be used for
instance, in refining the boundary ”land-water” of the
shore section of a reeded water reservoir. In the first ap
proximation we shall regard the vegetation layer as a uni
form penetrating layer with the integral penetration-L.
The radio-brightness temperature of the object screened by
the vegetation layer-T^Q, the thermodynamic temperature-T.
The radio-brightness contrast shall be determined from the
following relationship
aT# - T f ~T 2 - dtpT-LT- ( / - jL) Tao , (1)
