Results of comparing astronomical-geodetic and navigational-geodetic methods of determining the components of the deflection of vertical

2021 ◽  
Vol 975 (9) ◽  
pp. 2-10
Author(s):  
M.M. Murzabekov ◽  
D.S. Bobrov ◽  
R.A. Davlatov ◽  
V.P. Lopatin ◽  
I.N. Pchelin
Keyword(s):  
High Precision ◽  
Relative Method ◽  
Confidence Bounds ◽  
Satellite Navigation System ◽  
Geodetic Coordinates ◽  
Camera Systems ◽  
Normal Heights ◽  
Local Direction ◽  
Star Catalogs ◽  
Deflection Of Vertical

The authors present the results of comparing the components of deflection of vertical obtained through astronomical-geodetic and navigational-geodetic methods. The first one is based on comparing astronomical and geodetic coordinates of a location. This method has recently been widely implemented in a digital zenith camera systems using a small-sized digital telescope with an astronomical camera based on CCD or CMOS technologies, a high-precision inclinometer and satellite navigation system receiver. In this case, the combination of a telescope, an astronomical camera and an inclinometer enables determining the local direction of the plumb line, expressed by astronomical coordinates, from observations of stars at the zenith and using high-precision star catalogs. The navigational-geodetic method is based on comparing the results of the normal heights’ increments, defined through geometric leveling, and geodetic heights, computed with the relative method of satellite coordinate determinations. For each method, random and systematic components of the error and its confidence bounds were calculated; the absolute values of the deflection of vertical components at two geographically separated points were compared.

Analysis of Influence of Ephemeris-Time Information on Accuracy of Solving a Navigation Problem by Signals of GLONASS System

2020 ◽  
Vol 25 (5) ◽  
pp. 465-474
Author(s):  
V.O. Zhilinskiy ◽  
◽  
D.S. Pecheritsa ◽  
L.G. Gagarina ◽  
◽  
...  
Keyword(s):  
High Precision ◽  
Satellite Navigation ◽  
Satellite System ◽  
Navigation Systems ◽  
Navigation Problem ◽  
Satellite Navigation System ◽  
Study Results ◽  
Accuracy Of Measurements ◽  
Huge Impact ◽  
Time Information

The Global Navigation Satellite System has a huge impact on both the public and private sectors, including the social-economic development, it has many applications and is an integral part of many domains. The application of the satellite navigation systems remains the most relevant in the field of transport, including land, air and maritime transport. The GLONASS system consists of three segments and the operation of the entire system depends on functioning of each component, but primarily, the accuracy of measurements depends on the basis forming of the control segment and management, responsible for forming ephemeris-time information. In the work, the influence of ephemeris-time information on the accuracy of solving the navigation problem by the signals of the GLONASS satellite navigation system has been analyzed. The influence of both ephemeris information and the frequency information, and of the time corrections has been individually studied. The accuracy of the ephemeris-time information is especially important when solving the navigation problem by highly precise positioning method. For the analysis the following scenarios of the navigation problem solving have been formed: using high-precision and broadcast ephemeris-time information, a combination of broadcast (high-precision) ephemeris-time information, and high-precision (broadcast) satellite clock offsets and two scenarios with simulation of the calculation of the relative correction to the radio signal carrier frequency. Based on the study results it has been concluded that the contribution of the frequency-time corrections to the error of location determination is of the greatest importance and a huge impact on the error location, while the errors of the ephemeris information are insignificant

The model is integrated satellite gyroscopic system operational determination of high-precision bearing

2017 ◽  
Vol 925 (7) ◽  
pp. 2-8
Author(s):  
I.V. Chernov
Keyword(s):  
High Precision ◽  
High Efficiency ◽  
Rapid Determination ◽  
A Priori ◽  
High Accuracy ◽  
Satellite Observations ◽  
Relative Method ◽  
Gyroscopic System ◽  
Joint Processing

The article considers the possibility of rapid determination of azimuth directions with high accuracy. It is shown that the gyroscopic method and the relative method of space geodesy with high efficiency, allows to obtain the azimuths of the directions with high precision and Autonomous. To achieve high accuracy of orientation with the use of satellite geodetic equipment are encouraged to design observations with regard to the length and azimuth direction, and time of observation. This will allow to abandon the use of the original geodetic framework that will increase efficiency. To improve the reliability of the obtained azimuth directions, it is proposed to integrate the gyroscopic observations and satellite observations without using the original geodesic Foundation. Considered by the joint processing of satellite and gyro measurements as a dual and unequal dimensions. In conclusion, the a priori calculation of observing time and accuracy of the resulting values of azimuth directions.

scholarly journals Analysis of Deflection of Vertical Compensation for Inertial Navigation System

2020 ◽  
Vol 2020 ◽  
pp. 1-15
Author(s):  
Shiwen Hao ◽  
Zhili Zhang ◽  
Zhaofa Zhou ◽  
Junyang Zhao ◽  
Zhenjun Chang ◽  
...  
Keyword(s):  
High Precision ◽  
Spherical Harmonic ◽  
Inertial Navigation System ◽  
Inertial Navigation ◽  
Harmonic Coefficient ◽  
Calculation Error ◽  
Harmonic Model ◽  
Spherical Harmonic Coefficient ◽  
Deflection Of Vertical ◽  
Spherical Harmonic Model

With the development of high-precision inertial navigation systems, the deflection of vertical (DOV), gravity disturbance, is still one of the main error sources that restrict navigation accuracy. For the DOV compensation of the Strapdown Inertial Navigation System (SINS) problem, the influences of the calculation degree of the spherical harmonic coefficient and the calculation error of the DOV on the compensation effect were studied. Based on the SINS error model, the error propagation characteristics of the DOV in SINS were analyzed. In addition, the high-precision global gravity field spherical harmonic model EIGEN-6C4 was established and the influence comparative analysis of the calculation degree of the spherical harmonic coefficient on the DOV compensation of SINS in different regions was carried out. Besides, the influence of the calculation error of the DOV on the compensation was emphatically analyzed. Finally, the vehicle experiment verified the feasibility of compensation in SINS based on the gravity field spherical harmonic model. The simulation and experiment results show that it is necessary to consider the influence of the calculation degree and the calculation error of the DOV on the compensation for long-time high-precision SINS with the position accuracy of 0.3 nm/h, while the SINS with general requirements for position accuracy can ignore the impact.

ANALYSIS OF THE IMPACT OF CELESTIAL BODIES ON DIFFERENCES IN MEASURED HEIGHT / DANGAUS KŪNŲ ĮTAKOS IŠMATUOTAM AUKŠČIŲ SKIRTUMUI TYRIMAS / АНАЛИЗ ВЛИЯНИЯ НЕБЕСНЫХ ТЕЛ НА ИЗМЕРЕННУЮ РАЗНИЦУ ВЫСОТ

2011 ◽  
Vol 37 (3) ◽  
pp. 101-104
Author(s):  
Darius Popovas
Keyword(s):  
High Precision ◽  
Lunar Phase ◽  
Height Difference ◽  
Correction Rate ◽  
Celestial Bodies ◽  
The Impact ◽  
Deflection Of Vertical

Under the effect of celestial bodies, the deflection of vertical induces changes in the levelled height difference. Therefore, it is necessary to evaluate the produced effect on high-precision levelling data. The article analyses the dependency of lunisolar correction on the lunar phase and azimuth of the levelling line and correction rate of changes. The paper also revises formulas for calculating lunisolar correction derived from using tide generating potential. Santrauka Straipsnyje analizuojama vertikalės nuokrypio dėl dangaus kūnų įtaka išmatuotam aukščių skirtumui. Šią įtaką būtina įvertinti apdorojant precizinės niveliacijos matavimų duomenis. Įvertinta potvynio pataisos priklausomumas nuo Mėnulio fazių ir niveliacijos linijos azimuto bei pataisos kitimo greitis. Taikant potvynio potencialo išraišką, gautos patikslintos išmatuoto aukščių skirtumo vertinimo formulės. Резюме Под влиянием небесных тел отклонение вертикали вызывает изменения в разнице высот, полученной нивелированием. Необходимо оценить этот эффект в данных высокоточной нивеляции. Были проанали зированы зависимость лунно-солнечных поправок от лунных фаз, азимута линии нивеляций и скорости изменения поправки. Получены уточненные формулы для расчета лунно-солнечной поправки с использованием приливного потенциала.

scholarly journals New precise positions in 2013–2019 and a catalog of ground-based astrometric observations of 11 Neptunian satellites (1847–2019) based on Gaia-DR2

2021 ◽  
Vol 645 ◽  
pp. A48
Author(s):  
Ye Yuan ◽  
Fan Li ◽  
Yanning Fu ◽  
Shulin Ren
Keyword(s):  
High Precision ◽  
Reference System ◽  
Star Catalog ◽  
Relative Coordinates ◽  
Ccd Observations ◽  
Total Observation ◽  
Celestial Reference System ◽  
Star Catalogs ◽  
Gaia Dr2

Context. Developing high-precision ephemerides for Neptunian satellites requires not only the continuation of observing campaigns but also the collection and improvement of existing observations. So far, no complete catalogs of observations of Neptunian satellites are available. Aims. We aim to provide new, precise positions, and to compile a catalog including all available ground-based astrometric observations of Neptunian satellites. The observations are tabulated in a single and consistent format and given in the same timescale, the Terrestrial Time (TT), and reference system, the International Celestial Reference System (ICRS), including necessary changes and corrections. Methods. New CCD observations of Triton and Nereid were made at Lijiang 2.4-m and Yaoan 0.8-m telescopes in 2013–2019, and then reduced based on Gaia-DR2. Furthermore, a catalog called OCNS2019 (Observational Catalog of Neptunian Satellites (2019 version)) was compiled, after recognizing and correcting errors and omissions. Furthermore, in addition to what was considered for the COSS08 catalog for eight main Saturnian satellites, all observed absolute and relative coordinates were converted to the ICRS with corrections for star catalog biases with respect to Gaia-DR2. New debiasing tables for both the modern and old star catalogs, which were previously not provided based on Gaia-DR2, are developed and applied. Treatment of missing positions of comparison bodies in conversions of observed relative coordinates are proposed. Results. OCNS2019 and the new debiasing tables are publicly available online. OCNS2019 includes 24996 observed coordinates of 11 Neptunian satellites obtained over 3741 nights from 1847 to 2019. All observations are given in TT and ICRS. The star catalog biases are removed, which are significant for Nereid and outer satellites. We obtained 880 (5% of total now available) new coordinates for Triton over 41 nights (1% of total observation nights so far), and 790 (14%) for Nereid over 47 nights (10%). The dispersions of these new positions are about 0.″03 for Triton and 0.″06 for Nereid. Conclusions. OCNS2019 should be useful in improving ephemerides for the above-mentioned objects.

High-Precision Kinematic Satellite and Doppler Aided Inertial Navigation System

2010 ◽  
Vol 64 (1) ◽  
pp. 91-108 ◽  
Author(s):  
Ranjan Vepa ◽  
Amzari Zhahir
Keyword(s):  
High Precision ◽  
Navigation System ◽  
Carrier Phase ◽  
Inertial Navigation System ◽  
Unscented Kalman Filter ◽  
Inertial Navigation ◽  
Satellite Navigation ◽  
Initial Alignment ◽  
Phase Measurements ◽  
Satellite Navigation System

In this paper an adaptive unscented Kalman filter based mixing filter is used to develop a high-precision kinematic satellite aided inertial navigation system with a modern receiver that incorporates carrier phase smoothing and ambiguity resolution. Using carrier phase measurements with multiple antennas, in addition to a set of typical pseudo-range estimates that can be obtained from a satellite navigation system such as GPS or GLONASS, the feasibility of generating high precision estimates of the typical outputs from an inertial navigation system is demonstrated. The methodology may be developed as a stand-alone system or employed in conjunction with a traditional strapped down inertial navigation system for purposes of initial alignment. Moreover the feasibility of employing adaptive mixing facilitates the possibility of using the system in an interoperable fashion with satellite navigation measurements.

scholarly journals Creating and updating of topographic maps height base in the new national spatial coordinate system: case Fergana valley

2021 ◽  
Vol 27 (2) ◽  
pp. 155-164
Author(s):  
Dilbarkhon Fazilova ◽  
Khasan Magdiev
Keyword(s):  
Coordinate System ◽  
High Precision ◽  
Tide Gauge ◽  
Topographic Maps ◽  
Geopotential Model ◽  
Normal System ◽  
Topographic Map ◽  
Coordinate Systems ◽  
Gps Measurements ◽  
Normal Heights

The use of high-precision technology of the global navigation satellite system (GNSS) has put forward the task of developing the methods for the creation and the use of a new national open coordinate system in the Republic of Uzbekistan. In the country, up to now the CS42 coordinate system, based on the Krasovsky ellipsoid used for geodetic works. The Baltic normal system of heights (1977), tied to the mean sea level with the zero mark of the Kronstadt tide gauge, was adopted as a height datum. Due to lack geoid information for the territory of the country determined by modern methods, the realization of a height reference datum becomes an urgent task. The results of GPS measurements usually presented in a coordinate system relative to the WGS-84 ellipsoid, and have to convert to national, local coordinate systems to solve practical problems. The horizontal GPS coordinates can directly use for computational work, but the geodetic heights have to convert to orthometric (or normal) heights for a given area using geoid information. In this work, a study was made of methods for updating the height reference datum of topographic maps at a scale of 1:200,000 using a deformation matrix between two reference coordinate systems for the territory of the Fergana Valley. To convert between geodetic and normal heights between the CS42 and WGS84 coordinate systems, a vertical deformation matrix in the GTX format of the National oceanic and Atmospheric Administration of Canada (NOAA) have created. To create a file of elevation displacements, the results of classical leveling and satellite GPS measurements have used at 144 “common” points of the entire network of the country with known coordinates in two systems. The difference between the “real” values of geodetic heights obtained from GPS measurements and “modeled” ranges from -0.13 m to 0.67 m. It has revealed that the maximum differences in heights are in the area of the Fergana basin itself and may be a consequence of both an anomalous gravitational field in this part of the territory, and an insufficient density of stations of the GPS network in the northeastern part of the area. The normal height values for the updated topographic map in WGS84 have computed using the EGM2008 high precision geopotential model. The discrepancy between the values of heights in CS42 and WGS84 is in the range of -3.93 m and 0.31 m.

Optical stimulator for vision-based sensors

2014 ◽  
Vol 3 (2) ◽  
Author(s):  
Dirk Roessler ◽  
David A.K. Pedersen ◽  
Mathias Benn ◽  
John L. Jørgensen
Keyword(s):  
Computer Simulations ◽  
High Precision ◽  
Test Bench ◽  
Efficient Tool ◽  
Ground Testing ◽  
Planetary Rovers ◽  
Long Term Stability ◽  
Camera Systems ◽  
Different Types

AbstractWe have developed an optical stimulator system for vision-based sensors. The stimulator is an efficient tool for stimulating a camera during on-ground testing with scenes representative of spacecraft flights. Such scenes include starry sky, planetary objects, and other spacecraft. The optical stimulator is used as a test bench to simulate high-precision navigation by different types of camera systems that are used onboard spacecraft, planetary rovers, and for spacecraft rendezvous and proximity maneuvers. Careful hardware design and preoperational calibration of the stimulator result in high precision and long-term stability. The system can be continuously used over several days. By facilitating a full camera including optics in the loop, the stimulator enables the more realistic simulation of flight maneuvers based on navigation cameras than pure computer simulations or camera stimulations without the involvement of the actual optics.

Solving the Grid-to-Ground Problem when Using High Precision GNSS in Archaeological Mapping

2014 ◽  
Vol 2 (2) ◽  
pp. 138-143 ◽  
Author(s):  
William (Fred) Limp ◽  
Adam Barnes
Keyword(s):  
Real Time ◽  
High Precision ◽  
Global Positioning System ◽  
Navigation System ◽  
Survey Methods ◽  
Archaeological Sites ◽  
Positioning System ◽  
Global Satellite Navigation System ◽  
Satellite Navigation System ◽  
Global Positioning

AbstractIncreasingly, high-precision GPS/GNSS (global positioning system/global satellite navigation system) based real-time-kinematic methods are being used in the mapping of archaeological sites. However, when utilizing high-precision satellite-based methods for archaeological location purposes, there is a significant but usually unanticipated problem that must first be addressed if accurate measurements are to be made. Simply put, unless proper correction methods are used, horizontal distances between two locations determined by the GNSS method will differ from the measurements that are made by traditional survey methods. This difference between the two measurements is often referred to as the grid-to-ground problem. This article provides a process to address this problem.

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