Transcript Document

Keldysh Institute of Applied Mathematics
Orbit determination in "Radioastron" mission
G.K. Borovin, M.V. Zakhvatkin,
Yu.N. Ponomarev, V.A. Stepanyants
Pushino 2012
1
The main tasks of Radioastron navigation
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Perturbations from the jet engines during the
flywheels unload
• Two engines D1 and D2 are not a pair. They provide SC turn
round the Z exes and create the center of masses acceleration
• Two pairs of engines rotate SC round X axes, not disturbing
the center of masses motion
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Antennas of the service radio-system
RT-64, Bear Lakes
RT-70, Ussuriysk
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Antenna RT-22, Pushino
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Telescopes of Scientific system of optical instruments for
astrometric and photometric observation of space object
(NSOI APO)
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International Laser Ranging Service (ILRS)
Observatoire de la Cote d'Azur
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North Caucasus
Special Laser Optical Locator
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The problems identified during the mission
• Measurement of service systems in Ussuriysk and
Bear Lakes contain systematic errors
• Many of laser range station still have not been
able to perform the measurements, despite the
efforts
• Actual disturbance from jet engines of the
stabilisation systen differ significantly from those
of telemetry data
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Laser range successful sessions
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The SC motion model the SC
• Noncentral gravitational field of the Earth model EGM-96
(degree 75x75)
• Gravity of the Moon, Sun and planets (coordinates are
taken from the DE 403)
• Solid Earth tides (Model of Rezos and Stolz, 1985)
• Solar radiation pressure, taking into account the Midel area
changes due to SC orientation
• Earth atmosphere up to a height of 1500 km (dynamic
model)
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Prospects for improving the accuracy of the
orbital parameters
• We are going to continue to calibrate the measurement
system performance and achieve accuracy range of 20 m
and the radial velocity of 1 mm / c
• Currently under revision of the software and hardware at
the laser range station in the North Caucasus.
• There are plans to attract the laser ranging station in
Simeiz (Ukraine). Currently there work carried out for
equipments modification.
• Efforts to begin the work at the Australia laser ranging
station
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The time intervals
where laser range measurements may be
perform by European stations
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Improvement of the dynamic model
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