**
Lunar Research. Publications**

*Velikodsky Yu.I.* (2002) **The Influence of Albedo and
Relief on the Law of Brightness Distribution over Lunar Disk**
// Thesis for a degree of candidate of physical and mathematical
sciences (Ph.D.). -Kharkov. In Russian.

The dissertation is devoted to the experimental
study of the law of light reflection by the Moon. The empirical
formula of phase dependence of the smoothness factor of lunar
surface in an interval of phase angles 0-135° is obtained,
that permits to perform the comparative analysis of optical properties
of the all lunar disk. Using a theory describing light scattering
by porous surfaces, absence of essential influence of albedo on
latitude dependence of brightness of a lunar surface is proved.
It is shown, that at phase angles, at least, up to 142°, the
smoothness factor q is determined only by a relief practically
for all surface of the Moon. On the basis of the space data it
is shown, that the smoothness factor of some flat mare areas,
as against the rest of lunar surface, depends on albedo. It is
related to low degree of a roughness of these areas.

**Full
text (html, in Russian)**

*Yu.I.Velikodsky, L.A.Akimov, and V.V.Korokhin (2002).*
**The Latitude Dependance of Brightness of the Lunar Surface**
// Lunar and Planet. Sci. 33-rd. Abstract #1860. LPI. Houston.

It was obtained values of parameter of
empirical Akimov's formula for different types of the lunar surface.
Spectral dependance of this parameter was studied.

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text (pdf)**

Akimov
L.A., Velikodsky Yu.I., and Korokhin V.V. *(2000)***
Dependence of Latitude Brightness Distribution Over the Lunar
Disk on Albedo and Relief **"Kinematika i fisika nebesnykh tel.",
in press., in Russian.

Results
of brightness distribution measurements of the lunar disk and
laboratory samples at different phase angles in blue and red spectral
bands are presented. It is shown for the Moon that brightness
falling with photometric latitude is formed mainly by micro- and
mesorelief of its surface. Small decreasing of brightness falling
with wavelength is due to not so much albedo changing as changing
of microrelief size range which has an influence on the law of
light reflection by the Moon.

Akimov
L.A., Velikodsky Yu.I., Korokhin V.V.*
(1999)* **Dependence
of Lunar Highlands Brightness on Photometric Latitude** // Kinematika
i fisika nebesnykh tel. -1999. -V.15, No 4. -P.304-309. In Russian.

Results
of photometric measurements of the Moon at different phase angles
are presented. Brightness distribution as the function of photometric
latitude has been studied. It is shown that brightness falling
to poles increases with phase angle a,
and at a~120° the Moon reflects
nearly by the Lambert's law. The origin of such phenomenon is
discussed.

*V.V.Korokhin,
L.A.Akimov (1994) ***MAPPING OF THE PHASE DEPENDENCE OF LUNAR
SURFACE BRIGHTNESS: REDUCTION OF THE OBSERVATIONS TO STANDARD
CONDITIONS, CONSTRUCTION OF THE EQUIGONAL ALBEDO MAPS**. Kinematika
Fizika Nebeshykh Tel, 1994, v.10, No 2, pp.56-64

The
procedure is described of Lunar surface brightness observations
using the photopolarimeter with one-dimensional CCD and personal
computer. The algorithms are developed for initial processing
of measurements, reduction of observations to standard conditions
and construction of equigonal albedo maps. The maps will be used
to construct the parameters maps of phase dependence of lunar
surface brightness.

*V.V.Korokhin,
L.A.Akimov (1997-1)*** ****MAPPING OF THE PHASE PARAMETERS
OF THE LUNAR SURFACE BRIGHTNESS **Astronomicheskii Vestnic,
1997, v.31, No 2, pp.143-152 [Solar System Research (Engl. transl.),
1997, v.31, No 2, pp.128-136]

A
tecnique for mapping the parameters of the phase dependence of
lunar-surface brightness is described. The effect of the lunar
relief on the brightness phase dependence is considered and a
method for eliminating such an influence is proposed. The possibility
of revealing the lunar relief from photometric observations is
pointed out. The dependence of the so-called effective roughness
coefficient on albedo is investigated. The possibility to determine
the relative age of lunar formations from the analysis of roughness
is demostrated.

*V.V.Korokhin
(1997-2) ***ZONING
OF THE LUNAR SURFACE BY PARAMETERS OF BRIGHTNESS-PHASE RELATION.
**Kinematika
i Fisika Nebeshykh tel, 1997, v.31, No 6, pp.484-490 [Solar System
Research (Engl. transl.), 1997, v.31, No 6, pp.430-435]

An
analysis is done for distribution of parameters of brightness-phase
relation over the lunar. For this purpose two-dimensional histogram
(correlation diagram) diffuse albedo - effective roughness coefficient
is constructed and analyzed. On the base of claster analysis of
this histogram, two-parameter zoning of the Moon's visible hemisphere
is carried out. Also, the regions of lunar surface with extreme
values of diffuse albedo and effective roughness coefficient are
visualized. A possibility to estimate the degree of lunar-soil
maturity from the analysis of the parameters of the brightness-phase
relation is pointed out.

*Yu.G.Shkuratov,
D.G.Stankevich, A.A.Ovcharenko and V.V.Korokhin (1997) ***A
STUDY OF LIGHT BACK SCATTERING FROM PLANETARY-REGOLITH- TYPE SURFACES
AT PHASE ANGLEG 0.2-3.5 DEGREES**. Astronomicheskii Vestnic,
1997, v.31, No 1, pp.56-63 [Solar System Research (Engl. transl.),
1997, v.31, No 1, pp. - ]

This
work is devoted to studying the photometric properties of disperse
samples, which are structural analogs of the surfaces of atmosphereless
celestial bodies at extremely small phase angles. The phase dependences
of brightness were measured with a laboratory small-phase-angle
photometer designed and built at the Astronomical Observatory
of Kharkov State University. The majority of dielectric materials
exhibited the opposition spike with an amplitude of about 20%
at phase angles ranging from 0.2 to 3.5 degrees. Palagonite, which
is a spectral analog of the Martian soil, showed the so-called
anomalous opposition color revealed earlier measurements of the
lunar soil. It is shown that the opposition brightness spike of
the Moon discovered by spacecraft Clementine is likely a consequence
of incorrect data analysis, since the width of this spike is less
then the angular size of the light source (the Sun). The phase
dependence of brightness for an ash sample is presented and considered
to be a model for the lunar phase curve in the phase-angle range
0.2-30 degrees. The amplitude of the opposition spike of this
"moon" is 1.35 in the phase-angle interval 0.2-5.0 degrees.

*Yu.I.Velikodsky,
L.A.Akimov, and V.V.Korokhin. (2000) ***Two-parameter Empirical
Photometric Function in Analysis of Earth-based Observations of
the Moon** // Lunar and Planet. Sci. 30-th. Abstract #1391.
2000. LPI. Houston.

Improved
empirical Akimov's formula is presented. This photometric function
gives a good fit to Earth-based and Clementine observational data.
An influence of albedo and relief on the disk brightness distribution
is discussed.

2003/01/19