of gravimeter sensitivity axis along the Earth gravitational field direction to define
gravitational vertical direction. Gravitational field distortion takes place in the regions
of gravitational abnormalities. This causes additional methodical errors.
AGS
stabilization system. Utilization of 1asers in the capacity of AGS
accelerometer - gravimeter is one of their possible outlook application. Efficacy of
aviation
gravimetric
measurements depends not only from the improvement of
accuracy characteristics, modernization of already existence gravimeters types but
from the development of gravimeters based on new measurement methods on principle.
Main advantage of laser gravimeters is possibility to receive higher accuracy
measurements of gravimetry acceleration abnormalities [5].
Given article aim is to show the possibility of laser application in the capacity of
AGS gravimeter.
Motion equations and block diagrams of main AGS subsystems are given to
widen representation what place takes gravimeter into AGS and what way it connects
with other system components.
Present work has comparative analysis of some AGS gravimeters developed in
the USSR and USA because literature has no any generalized comparative analysis of
aviation gravimeters characteristics.
AGS stabilization system (SS) purpose is to ensure coincidence of gravimeter
sensitive axis with inquiry vertical. Output signals expressions of linear
accelerometers, which sensitivity axis are directed to the north and east accordingly,
placed on the horizontal stabilized platform (HSP) orientated in the geographic
coordinate system have been received:
(
)
(
)
),
cos(
)
cos(
2
)
sin(
2
)
sin(
2
)
sin(
)
cos(
)
sin(
)
cos(
2
)
sin(
)
cos(
2
3
3
3
2
C
C
C
C
C
C
y
C
C
C
C
C
x
r
r
r
r
g
f
r
r
r
r
r
r
g
f
−
−
+
+
−
=
−
−
−
−
+
+
−
=
(1)
where g - gravity; r - moving system position radius; x,y - angles between
normal’s to ellipsoid and geoid in the meridian section and plane of section, which is
perpendicular to the meridian plane accordingly; φ, φ
C
- geographic and geocentric
latitudes accordingly ; θ - deviation from vertical; ω
3
- Earth rotation angular velocity;
λ - place longitude.
When platform is adjusted in the vertical position exactly in absolute horizontal
components of gravity acceleration will be equal to zero. Putting θg=-νg=0 we can
rewrite equation (1) in the form:
(
)
(
)
)
cos(
)
cos(
2
)
sin(
2
)
sin(
2
),
sin(
)
cos(
)
sin(
)
cos(
2
)
sin(
)
cos(
2
3
3
2
C
C
C
C
C
C
y
C
C
C
C
C
x
r
r
r
r
f
r
r
r
r
r
r
f
−
−
+
=
−
−
−
−
+
+
−
=
(2)
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