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04 AIRCRAFT COMMUNICATIONS AND NAVIGATION
20000012180 State Research Center of the Russian Federation-
Central Scientific and Research Inst. Elektropribor, Saint Petersburg,
Russia
SIGNAL PROCESSING USING THE INCREMENTS OF SIGNAL
MULTIPLE INTEGRALS: FROM STRAPDOWN INS TO OTHER
REAL-TIME SYSTEMS
Litmanovich, Yury A., State Research Center of the Russian Federation-Central
Scientific and Research Inst. Elektropribor, Russia;
Lesyuchevsky, Vladimir M., State Research Center of the Russian
Federation-Central Scientific and Research Inst. Elektropribor,
Russia; Gusinsky, Valery Z., State Research Center of the Russian
Federation-Central Scientific and Research Inst. Elektropribor,
Russia; 6th Saint Petersburg International Conference on Integrated
Navigation Systems; October 1999, pp. 8-1 - 8-7; In English; See
also 20000012172
Contract(s)/Grant(s): RFBR-97-01-01134; Copyright Waived; Avail:
CASI; A02, Hardcopy; A03, Microfiche
A new approach to signal processing in strapdown INS is
presented and examined with a view to apply it to the other real-time
systems. The solutions for three problems of the strapdown INS
(Inertial Navigation System) software, which are typical for other
systems are expressed via the increments of the signal multiple
integrals over the iteration interval. The possibility and utility of the
signal multiple integrals generation while the signal pre-processing is
discussed.
Author
Signal Processing; Strapdown Inertial Guidance; Inertial Navigation;
Real Time Operation; Mathematical Models; Measure And
Integration; Computer Programs
20000012181 Scientific and Research Association of Automatics,
Ekaterinburg, Russia
FAULT-TOLERANT STRAPDOWN INERTIAL MEASUREMENT
UNIT: FAILURE DETECTION AND ISOLATION TECHNIQUE
Vodicheva, L. V., Scientific and Research Association of Automatics,
Russia; 6th Saint Petersburg International Conference on Integrated
Navigation Systems; October 1999, pp. 9-1 - 9-9; In English; See
also 20000012172; Copyright Waived; Avail: CASI; A02, Hardcopy;
A03, Microfiche
Familiar and new methods of self-contained failure detection
and isolation technique in respect to sensors of redundant strapdown
Inertial Measurement Unit are analyzed and systematized in the
paper. Conditions of non-sensitivity of FDI (Failure Detection and
Isolation) algorithms to failures are obtained. Measurement unit with
any number of sensors with input axes arbitrary arranged in threedimensional
space is under consideration.
Author
Fault Tolerance; Failure; Strapdown Inertial Guidance; Mathematical
Models; Inertial Navigation; Algorithms; Inertial Platforms
20000012182 Russian Inst. of Radionavigation and Time, Saint
Petersburg, Russia
‘SOYUZ’-‘MIR’ ORBITAL FLIGHT GPS/GLONASS EXPERI-
MENT: FIRST RESULTS
Klyushnikov, Sergey, Russian Inst. of Radionavigation and Time,
Russia; Filatchenkov, Sergey, Russian Inst. of Radionavigation and
Time, Russia; Mikhailov, Nicolai, Soft Nav Ltd., Russia; Pospelov,
Sergey, Soft Nav Ltd., Russia; Vasilyev, Mikhail, Soft Nav Ltd.,
Russia; 6th Saint Petersburg International Conference on Integrated
Navigation Systems; October 1999, pp. 10-1 - 10-10; In English; See
also 20000012172; Copyright Waived; Avail: CASI; A02, Hardcopy;
A03, Microfiche
The combined GPS/GLONASS (Global Positioning System/
Global Navigation Satellite System) receiver ASN-2401P has been
installed on the manned space ship ‘Soyuz-TM28’ and was used to
obtain experimental data during its flight to the space station ‘Mir’ in
August - November 1998. The ASN-2401P receiver is based on the
ASN-22 eighteen-channel C/A-code avionics receiver module: a joint
development of Dasa NFS (Germany, Ulm) and RIRT (Russia,
St.Petersburg). The ASN-22 receiver module is described in brief.
The receiver used in the experiment together with the antenna will
become core elements of navigation system of Russian module of
International Space Station ‘Alpha’ and Russian space ships. Raw
pseudorange and carrier phase measurements, along with the
position, velocity and time (PVT) results have been recorded during
the autonomous flight of ‘SoyuzTM28’, rendezvous operations, as
well as during the docked to ‘Mir’ flight. The receiver installation,
18
space ship attitude orientation modes, receiver control and data
recording are described. Analysis of flight data is presented in the
paper.
Author
Global Positioning System; Mir Space Station; Soyuz Spacecraft;
International Space Station; Space Rendezvous; Glonass; Flight
Tests
20000012183 Quebec Univ., Ecole de Technologie Superieure,
Montreal, Quebec Canada
NEW TECHNIQUE TO IMPROVE GPS RECEIVER PERFOR-
MANCES BY ACQUISITION AND TRACKING THRESHOLDS
REDUCTION
Landry, Rene, Jr., Quebec Univ., Canada; 6th Saint Petersburg
International Conference on Integrated Navigation Systems; October
1999, pp. 11-1 - 11-11; In English; See also 20000012172; Copyright
Waived; Avail: CASI; A03, Hardcopy; A03, Microfiche
This paper proposes a robust method for threshold’s reduction
taking into account features both concerning GPS receiver modification
and real gain on the performances improvement. This method
involves two steps. The aim is to use the strong channels of the GPS
(Global Positioning System) receiver which are actually tracking
satellites for velocity aiding the other channel trying to acquire or
track satellites presenting a low signal over noise ratio due to lower
elevation or masking conditions. Second, according to the theory
and the characteristics of the digital internal loops of the GPS
receiver, the predetection bandwidth is reduced to the lowest value
permitted by the velocity aiding accuracy. This technique allows to
improve the GPS accuracy and robustness. The paper shows first a
large panorama of all potential threshold’s reduction techniques both
for acquisition and tracking processes. It proposes and identifies the
automatic model of a velocity aided loop. Furthermore, to allow the
validation of the described tracking threshold reduction, the technique
is proposed to be inserted and validated into the new GPS
simulator which is a generic digital MATLAB GPS receiver model.
This work is intended to be used for space and aeronautical
applications.
Author
Applications Programs (Computers); Global Positioning System;
Computerized Simulation; Mathematical Models; Autonomy; Target
Acquisition
20000012184 Stanford Telecommunications, Inc., Reston, VA USA
ANALYSIS OF TRACKING PERFORMANCE OF A DELAY
LOCKED LOOP FOR NEWLY PROPOSED GPS SIGNAL WAVE-
FORMS
Draganov, Alexandr, Stanford Telecommunications, Inc., USA;
Stafford, James, Stanford Telecommunications, Inc., USA; 6th Saint
Petersburg International Conference on Integrated Navigation
Systems; October 1999, pp. 12-1 - 12-10; In English; See also
20000012172; Copyright Waived; Avail: CASI; A02, Hardcopy; A03,
Microfiche
Recently, several new GPS waveforms have been suggested to
enhance the GPS signal. This paper presents a comparative theoretical
analysis of Delay Locked Loop (DLL) tracking performance for
different waveforms in the presence of the ambient white noise, and
band-limited, shaped spectrum noise. Incoherent (power) DLL is
selected as a baseline design. For the purposes of comparative
analysis, gain is treated as an arbitrary parameter and is selected to
provide desired (and uniform) dynamic tracking capabilities of the
DLL for different waveforms. The dynamic differential equation for
the code phase being tracked by the DLL is examined by a means of
the Fokker-Planck formulation. The Fokker-Planck equation is a
partial differential equation describing the evolution of statistical
characteristics of the tracking error. Coefficients for the Fokker-
Planck equation are derived analytically for all waveforms under
consideration. The tracking performance is linked to eigenvalues and
eigenvectors of the Sturm-Liouvile problem for the Fokker-Planck
equation. Eigenvalues and eigenvectors are found numerically yielding
two major results: the average time to lose lock and the root
mean squared (RMS) tracking error. Results for different waveforms
and different signal to noise (SNR) ratios are presented. They show
superior tracking capabilities for P(Y) and C/A signals as compared
to more complicated subcarrier modulated waveforms, if the latter
are tracked using a typical ‘early squared minus late squared’ DLL.
Tracking of subcarrier modulated waveforms can be improved
substantially if the subcarrier is tracked separately, using a PLL-type