S. Pasynok, I. Bezmenov, I. Ignatenko, E. Tсyba

e - mail: pasynok@vniiftri.ru, bezmenov@vniiftri.ru, igig@vniiftri.ru, tsyba@vniiftri.ru

1. INTRODUCTION

VNIIFTRI takes participation in Earth’s orientation parameters (EOP) activity as:

1) Russian Main Metrological Center of State Service for Time, Frequencies and Earth orientation parameters

evaluation (MMC SSTF);

2) Analysis Center and regional Data Center for five measurement sites of metrological control of

ROSSTANDART.

Fig. 1. Five sites of metrological control of ROSSTANDART

2. SITES OF METROLOGICAL CONTROL

MDVJ, IRKJ, NOVM – IGS sites, MDVL, IRKL – ILRS sites, MDVJ – EPN site,

Mendeleevo and Irkutsk – sites with colocation of GNSS and SLR [1],

Mendeleevo, Novosibirsk, Irkutsk, Khabarovsk and Petropavlovsk-Kamchatsky – sites of Russian fundamental

astrogeodetic network (FAGN).

Trend of IGS VNIIFTRI station positions

All measurement results are collected in MMC SSTF in hourly mode now.

Moving to sites of new generation:

The station of the "Tochka" type has the instrumental error not exceeding units of millimeters at single

measurement and confirmed the declared characteristics during preliminary tests [2]. A similar station is being

built in Irkutsk.

The both stations meet the requirements SLR2000.

Fig. 2. New SLR2000 stations «Tochka» in Mendeleevo and Irkutsk

2. GNSS ORBITS AND CLOCK DETERMINATION

The only GPS and GLONASS orbits and clock are determined in VNIIFTRI now. The processing has two

modes:

1) Processing about 500 IGS and Russian sites for determination own MMC SSTF orbits and clock

(operative)[3];

2) Combination of orbits and clock of several Russian and IGS centers (a posteriori) [4].

The software of mode 1 is based on BERNESE GNSS Software 5.2 software developed in Astronomical

Institute of the University of Bern (AIUB, Switzerland) and additional program modules developed in MMC

SSTF. The BERNESE GNSS Software 5.2 software shell is used for parameters input for all programs. The

missing software panel files were created.

For mode 2 it was used only VNIIFTRI original software, based on well-known algorithm (Beutler G. et all,1996).

Fig. 3. Comparison results of GLONASS clocks estimated by VNIIFTRI (VNF – estimated values, VNP –

prediction) and other AC with reference values (REF). As reference we used our combination values.

The inter daily jumps in ESA data were removed.

Fig. 4. Main window of software for mode2.

The software for determination deflection of vertical (DOV), geoid heights (GH) and gravity anomalies (GA) also has

developed in VNIIFTRI [5].

3. SATILLITE ALTIMETRY PROCESSING

4. EARTH’S ORIENTATION PARAMETERS EVALUATION

4.1 SLR AND LLR PROCESSING FOR EARTH’S ORIENTATION PARAMETERS

The daily SLR Lageos-1 and Lageos 2 observations processing has been provided in MMC SSTF.

The results of daily processing one can see on Fig. 4.

STD xp ≤ 0,00008

STD yp ≤ 0,00010

Fig. 4. Comparison with EOPC04 of SLR pole coordinates Fig. 5. Main window of LLR UT1 software

4.2 VLBI PROCESSING FOR EARTH’S ORIENTATION PARAMETERS

4.3 GNSS PROCESSING FOR EARTH’S ORIENTATION PARAMETERS

5 EOP COMBINATION

5.2 SINEX EOP COMBINATION

References

[1] Ignatenko I.Yu., Zhestkov A.G., Shlegel V.R., Emelyanov V.A., «Metrologicheskie aspekty lazerno-lokacionnykh izmerenij» // «Metrologiya vremeni i prostranstva. Materialy VIII Mezhdunarodnogo simpoziuma», Abstracts book, ISBN 978-5-903232-63-5, 14-16 September 2016, S. Peterburg.-

Mendeleevo: FSUE "VNIIFTRI", 2016, P. 192 (In Russia).

[2] Baryshnikov M.V., Blinov I.Yu., Bondarev N.N., Borisov B.A., Donchenko S.I., Kolychev A.M., Nekrasov Y.V., Martynov S.V., Sadovnikov M.A., Shargorodsky V.D., Rezul'taty ispytanij rossijskoj lazernoj stancii novogo pokoleniya «TochkA» // Book of abstarcts of 8-th All-Russian conference

«Fundamental’noye i prikladnoye koordinatno-vremennoye i navigatsionnoye obespecheniye» (KVNO-2019) which took place in St. Petersburg from 15 to 19 April 2019 in IAA RAS. 2019. P. 18 (In Russia).

[3] Bezmenov I.V., «Vychislenie v GMC GSVCh orbit i popravok chasov KA GNSS v operativnom rezhime po dannym izmerenij» // Proceedings of IX International Simposium «Metrologiya vremeni i prostranstva», Mendeleevo 2018, FSUE “VNIIFTRI", 2018. P. 206-210. (In Russia).

[4] I.V. Bezmenov, S.L. Pasynok, GLONASS orbit\clock combination in VNIIFTRI, Proceedings of the Journees 2014 "Systemes de reference spatio-temporels", Z. Malkin and N. Capitaine (eds), Pulkovo observatory, 2015, ISBN 978-5-9651-0873-2 & ISBN 978-2-901057-70-3, pp. 215-216.

[5] Tcyba E.N., «Predvaritel`nye rezul`taty postroeniya modeli geoida akvatorii Mirovogo okeana po dannym sputnikovoj al`timetrii v GMC GSVCh» // Book of abstarcts of 8-th All-Russian conference «Fundamental’noye i prikladnoye koordinatno-vremennoye i navigatsionnoye obespecheniye» (KVNO-

2019) which took place in St. Petersburg from 15 to 19 April 2019 in IAA RAS. 2019. P. 191 (In Russia).

[6] Efim TCYBA, O. Volkova: Determination of Earth Orientation Parameters by SLR in MMC SSTF FSUE VNIIFTRI // Journees 2019, This poster session.

[7] Zharov V.E., Osnovy radioastrometrii // M: Fizicheskiy fakul’tet MGU im. M. V. Lomonosova. Moskva. 2011. S. 208 - 224 (In Russia).

[8] Kaufman, M., Pasynok S., 2010, "Russian state time and Earth rotation service: observation, EOP series, prediction", Artificial Satellites, Vol. 45, No. 2, pp. 81-86.

Fig. 6. Comparison of results of ARIADNA UT1 evaluation from VLBI processing in VNIIFTRI and some

other AC

For VLBI data analysis VNIIFTRI uses the ARIADNA software package developed by V. Zharov [7].

Version 4.11 of this software was finished and tested at the end of 2018 as a part of common activities SAI

-VNIIFTRI AC.

The daily processing IVS VLBI sessions data for EOP evaluation are provided in VNIIFTRI now.

The comparison with other AC is showed on fig. 6.

For GNSS data analysis VNIIFTRI uses the BERNESE software package.

The GNSS processing of measurements and EOP evaluations are carried out using the BERNESE GNSS

software developed in Astronomical Institute of the University of Bern (AIUB, Switzerland). The actual

algorithm was entered in 2006 [8] with some changes. It is based on the so-called method of Precise Point

Positioning (PPP). This method is based on use phase measurements for the navigating task solution with

known precise satellites coordinates and onboard clocks biases. Then the values of UT1 and pole

coordinates are calculated using the calculated instantaneous coordinates of stations and their catalogue

values. Processing is carried out separately for each daily session of measurements.

Fig. 7. The Earth pole coordinates (trend removed). Solid line – USNO,

squares – time raws combination, circles – SINEX combination results.

5.1 RAWS EOP COMBINATION

Combination for operative EOP evaluation has been provided in VNIIFTRI since 1955.

Now two types of EOP combination are maintained in VNIIFTRI: combination on time raws level and

combination on normal equation level.

Combination EOP on time raws level are calculated in VNIIFTRI by the combination of the nine

independent individual EOP series provided by following Russian analysis centers:

VNF (VNIIFTRI), IAA (Institute of Applied Astronomy), IAC (Information-Analytical Center of Russian Space

Agency) and SVOEVP (Russian Space Agency).

Combination EOP on observations level are calculated in VNIIFTRI by the combination of the SINEX

files, mainly international.

The core of SINEX combination program - SINCom software package developed in Institute of Applied

Astronomy. The Perl scripts for automatization of data preparing, realizing of calculation strategy, prediction

and forming results were developed in VNIIFTRI.

The modern program of UT1 evaluation based on Lunar Laser Ranging measurements were created in the

MATLAB environment [6].

Now ILRS LLR data are processed only, but program ready for processing the Altay LLR station measurements

too. The main window of software is showed on Fig. 5.