RU2760829C1 - Space geodesy colocation station - Google Patents

Abstract

FIELD: radio measurements.

SUBSTANCE: invention relates to a technique for radio measurements and can be used in a measurement system by methods of space geodesy. To achieve the effect, the colocation station contains a radio telescope, a receiver for signals from spacecraft (SC) of global navigation satellite systems (GNSS), and a laser ranging (LR) system.

EFFECT: increasing the accuracy of measurements of local geophysical parameters by combining measuring instruments into a single colocation station and increasing the stability of solutions obtained as a result of processing their measurements.

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Description

The invention relates to measuring instruments using space geodesy methods, which are combined into a single colocation station, and the stations, in turn, into a network of stations to improve the accuracy and stability of solutions obtained as a result of processing their measurements using space geodesy methods for fundamental and applied coordinate-time provision; measuring instruments are collocated at the spatial level with the help of linkage within the local geodetic network (LGS) and at the time level due to the linkage to the unified time-frequency synchronization system (SFCS) of the colocation station. Through local communications and observation of space objects, binding to global time scales and coordinate systems is carried out.

The considered measuring instruments include:

1. Radio telescope (RT), designed to register the radiation of extragalactic sources in the mode of radio interferometry with very long baselines (VLBI);

2. Receiver of signals from spacecraft (SC) of global navigation satellite systems (GNSS);

3. A laser ranging system (LD), designed to register its own signal reflected from corner reflectors installed on the spacecraft or the Moon.

FIG. 1 shows a block diagram of a colocation station for space geodesy, where numbers indicate: 1 - GNSS receiver; 2 - RT; 3 - LD; 4 - SCHVS; 5 - LGS; 6 - GNSS; 7 - extragalactic radio sources; 8 - spacecraft equipped with corner reflectors; 9 - Corner reflectors mounted on the Moon.

The observed values of all measuring instruments are signal delays. For a radio telescope operating in the VLBI mode, the plane wave registration delay between the network stations is measured, for the GNSS receiver and for the LD, the delay between the signal emission time and the moment of its registration is measured.

As a result of processing observations carried out by means of space geodesy, the following main parameters are determined:

1. Coordinates of the celestial pole and Universal Time (VLBI);

2. Coordinates of the earth's pole and the duration of the day (VLBI, GNSS, LD);

3. Coordinates of the station (RSDB, GNSS, LD);

4. Errors SCHVS (RSDB, GNSS, LD);

5. Orbits of the observed spacecraft (GNSS, LD);

6. Clock corrections of the observed spacecraft (GNSS);

7. Tropospheric delay of the recorded signal (VLBI, GNSS);

8. Electronic content of the local ionosphere (GNSS, VLBI).

The partial derivatives of the measured signal delays with respect to the parameters of the reduction models allow one to estimate these parameters using the least squares method. Common parameters allow combining at the level of conditional or normal equations, thereby improving the stability of solutions and the accuracy of the parameters being determined.

The provision of high accuracy in determining the main parameters is carried out by fulfilling the following requirements for the colocation station facilities:

1. Requirements for RT:

- The sensitivity of the receiving system should be sufficient to register a signal from extragalactic radio sources within the coherence time of the SFS;

- Simultaneous registration of several frequency ranges;

- Possibility of continuous work.

2. Requirements for the GNSS receiver:

- The GNSS receiver must be of a geodetic class, dual-frequency and multi-system;

- The antenna of the GNSS receiver must be calibrated and installed on specially prepared stable bases;

- The GNSS receiver must be able to connect to an external SCHVS.

3. Requirements for LD:

- Possibility of observing spacecraft of various orbital constellations or the Moon;

- Carrying out observations at night and daytime;

- Availability of technical means for determining the calibration correction.

When choosing a SCWS, it is preferable to use a cesium frequency standard or a hydrogen maser. The stability of the local time scale should be no worse than 1 ns / day. Geodetic tools for constructing the LGS must ensure the mutual referencing of the main tools with an error of no more than 1 mm. The LGS should include at least three mutually visible reference geodetic markers for each instrument.

The application of the invention leads to an improvement in the accuracy and stability of the results of combined processing of measurements of space geodesy means, which is confirmed by works on the analysis of similar measurements [1] and mathematical modeling [2]. The invention was created using the scientific equipment of the UNU "Radio interferometric complex" KVAZAR "of the Federal State Budgetary Institution of Science Institute of Applied Astronomy of the Russian Academy of Sciences.

Literature

1. Shuygina, N .; Ivanov, D .; Ipatov, A .; Gayazov, I .; Marshalov, D .; Melnikov, A .; Kurdubov, S .; Vasilyev, M .; Ilin, G .; Skurikhina, E .; Surkis, I .; Mardyshkin, V .; Mikhailov, A .; Salnikov, A .; Vytnov, A .; Rakhimov, I .; Dyakov, A. & Olifirov, - V. Russian VLBI network “Quasar”: Current status and outlook, - Geodesy and Geodynamics, Elsevier BV, 2019, 10, 150-156

2. Ivanov D.V., Uratsuka M.-R., Ipatov A.V., Marshalov D.A., Shuigina N.V., Vasiliev M.V., Gayazov I.S., Ilyin G.N. , Bondarenko Yu.S., Melnikov A.E., Suvorkin V.V. Russian-Cuban colocation station for radio astronomical observations and monitoring of near-Earth space // Astrophysical Bulletin. 2018. No. 2.

Claims (1)

A colocation station for space geodesy means, containing a radio telescope located on a site equipped with measuring systems, a signal receiver for spacecraft (SC) global navigation satellite systems (GNSS), a laser ranging system (LD), characterized in that the GNSS receiver, a laser ranging system and a radio telescope are connected to a unified time-frequency synchronization system (SCHSS) and are interconnected into a local geodetic network (LGS) for mutual coordinate referencing of the reference points of the measuring instruments used, while the antenna of the GNSS receiver is installed on a stable base of the site, the receiver is made with the ability to register signals from several GNSS spacecraft constellations in two frequency ranges simultaneously, the radio telescope is designed for continuous operation and simultaneous registration of several frequency ranges of extragalactic radio sources in the radio interferometry mode with ultra-long baselines within the time system, and the laser ranging system is made with the ability to observe the orbital constellations of spacecraft equipped with corner reflectors or the Moon in the daytime and at night and includes means for determining the calibration correction, while the GNSS receiver, radio telescope and the laser ranging system are connected in space and time by means of LGS and SCHVS for the possibility of joint processing of long observation series.

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