RU2002273C1 - Method for extablishing correspondance between celestial coordinates obtained in optical and radio bands - Google Patents

Abstract

The invention relates to the field of astrometry and is intended to build an accurate inertial coordinate system. The purpose of the invention is to improve the accuracy of determining the relationship of coordinates established in the optical and radio ranges. The radio emission of two point extraterrestrial radio sources with a priori established navigation coordinates is received using a radio interferometer formed by radio telescopes and located in outer space, while photographing from one receiving point another against the background of surrounding stars and determining the NK projections of the base on the celestial sphere in the optical range, which are compared with the navigation coordinates of the projection of the base onto the celestial sphere in the radio range, expressed through the coordinates of the radio sources in in the range. I silt

Description

The invention relates to the field of astrometry, is intended to build an accurate inertial coordinate system and can be used to create a single fundamental coordinate system for solving problems of navigation, geodesy, geodynamics, studying the dynamics and kinematics of the solar system, the galaxy and the universe as a whole.

A known method for determining the relationship of celestial coordinates, which is based on observations in the optical and radio bands of the same astrophysical objects. At the same time, the studied compact extragalactic source (quasar) is photographed with the coordinates set in the radio range, after which the image is linked to the existing fundamental coordinate systems of stars.

However, compact extragalactic radio sources that fix the inertial coordinate system in the radio range have a low luminosity in the optical range, which makes it difficult to obtain their optical images, moreover, the centers of optical and radio brightness of astrophysical objects do not coincide, which makes the optical image of the radio source unreliable . In addition, with the surface position of instruments, the accuracy of optical observations is adversely affected by atmospheric refraction.

The aim of the invention is to increase the accuracy of determining the relationship of celestial coordinates established in the optical and radio bands.

The goal is achieved. that with the method for determining the connection of celestial coordinates established in the optical and radio bands, including setting s the radio frequency range of celestial coordinates C / A. Si and ar, For two compact extraterrestrial radio sources, take the radio emission of these radio sources at two spaced receiving points that are located in outer space, at

-

base 8 determine the mutual time delays p.y., additionally take pictures from one receiving point another against the background of surrounding stars and according to the received

image is determined by celestial

dinates a century SB projection of base 8 on the celestial sphere in the optical range, after

what determine the relationship of celestial coordinates

-

"C, SB projections of base B on the celestial sphere set in the optical range with celestial coordinates" c, SB pro -

projections of base B on the celestial sphere in the radio range in the form

a BP D a b

Ssp fse

In this case, the coordinates D, F of the connection of celestial coordinates established in the optical and radio ranges are determined from the expressions

C t 1 I B t sin Si sin FSs + cos Si -cos F $ B cos (a 1 - D a c)

С T2 i В i -fsinS2sin FSB + cosS2-cos FSe cos (ar Da в) where С is the speed of light.

The inertia property of the celestial coordinate system is due to the immobility of the reference frames of this system on the celestial sphere. Therefore, it is possible to build a highly inertial coordinate system according to observations in the radio range, since in this case extragalactic point sources (quasars), whose proper motions are projected onto the celestial sphere, will become reference points. The existing fundamental coordinate systems are fixed by compact optical sources (stars), recorded in star catalogs compiled from long-term observations. These systems cannot be

inertial. since they rely on optical sources that have some proper motions relative to the galaxies that are stationary on the celestial sphere. In addition, the multifunctional coordinate system in the radio range can be set with high accuracy, since at present radio frequency measurements are 1-2 orders of magnitude superior to terrestrial optical.

With the proposed method, the removal of the receiving points of the radio interferometer into outer space allows you to photograph from one receiving point to another and obtain the coordinates of the projection of the base onto the celestial phase in the optical range, which are then compared with the coordinates of the projection of the base trace onto the celestial sphere, expressed in terms of the coordinates of the two studied radio sources in

radio range. This ensures that a positive effect is achieved - increasing the accuracy of determining the relationship of coordinates established in the optical and radio bands.

The drawing shows a variant of the structural diagram of the device with which the proposed method can be implemented.

The device contains two receiving points 1, 2 each of which includes radio telescopes 3.4, respectively, with independent synchronization. Radio telescopes 3, 4 form a radio interferometer. Reception points 1. 2 are located in outer space on artificial space objects (PPI). One of the receiving points (for example, point f), includes a photographic device 5, and the other receiving point (for example, point 2} is equipped with an optical mask 6. The receiving points 1, 2 are additionally equipped with far-measuring means for determining the relative orientation in space (not shown in the drawing) Radio telescopes 3.4. Photographic device 5 and rangefinder means are connected to the processing unit 7. Using telemetric communication channels 8,9,10, respectively, formed by transmitting and receiving telemetry equipment. Unit 7 can be located on Earth.

As radio telescopes 3, 4, radio telescopes of the KRT-10 type can be used. As the optical mask 6, a laser with an appropriate radiation power can be used. Photographic device 5 may be an optical telescope used in the Hubble project. As a processing unit 7, any standard computer with a corresponding memory object, for example, BESM-6, can be used.

The construction of telemetric communication channels 8, 9, 10 is known.

A method for determining the communication of coordinate systems using a device whose structural diagram is shown in the drawing is carried out as follows.

With some fixed sex -

live base In the radio interferometer. the length of which is determined by means of rangefinding means, the radio emission from two studied radio sources is received using radio telescopes 3, 4, the mutual delays are determined by 1. 1 2 signals received by radio telescopes 3, 4 from each radio source and transmitted to the processing unit 7 by telemetry communication channels 8. 9, respectively. Using the photographic device 5 from the receiving point 1, they photograph the optical mask 6 of the receiving point 2 on the background of surrounding stars and the telemetry image

communication channel 10 is transmitted to block 7. In processing block 7, the resulting image is identified with a portion of the starry sky map and a point corresponding to the image of optical mask 6 in this portion of the map is determined. Then the coordinates of the indicated point are determined from the map of the starry sky а в. SB - base projection coordinates

Yu B to the heavenly sphere.

Unknown celestial

coordinates

fifteen

about. BP, 5B projection of base B on the celestial sphere in the radio range is determined by the relations

Avr O "in SBP FSe,

(1)

where D, F are the coupling coefficients of the indicated coordinates, defined as follows.

-

Base vector B can be written in a Cartesian coordinate system

- In BcosSe COSOB

In (By (BCOSSB SllUTB (2)

 O- GelnCr, /

IN 2

Bslnse

thirty

delay t tz

r Ј (B. Si): (B, S2). (3)

where C is the speed of light;

-

Si. $ 2 are the unit direction vectors to the first and second studied radio sources with coordinates t, Si and as, Sz. respectively:

- S xicosSi cosai

S {Syi) C cosSt slnai (4)

 WITH . f elnC./

Sri

Sinsy

- Sx2cosSa cosoa

S2 {Sy2 - (COS $ 2 Slndi

sinSa

In this way

riC (B, Si) Bxcos Stcos "1 +

+ Bycos5is nai + BzSinSt

- IB I slnSt - slnSsp + cosSi x

x cosSep cos (ai - D "BP); - -

Z5C (V, S2) BxCosSacosos +

4- By cosSasln "2 + BzsinS2

-

 I to I slmfc sindep +

+ cosS2CosSBpCos (ai - Oovr).

After substituting into expression (5), align (1) we get

ъ С I В (sin Si sin FSB + cos S

FSe -cos (a 1 - DaB)} -

G2 C I 8 I Sin S2 Sin FSB + COS S2

FSe -cos {05-Dae)

(6) - a system of two equations with two unknown D, F coupling coefficients of celestial coordinates. Using processing unit 7, a solution to system (6) is found and

Thus, a connection is determined in the form of (1) celestial coordinates set in the optical and radio bands.

The proposed method allows to increase the accuracy of measurements in comparison with

terrestrial measurements in three orders of magnitude. (56) Kulikova I.I. Some results of determining the optical positions of extragalactic radio sources. The tasks of modern astrometry in creating

inertial coordinate system. Proceedings of the XXI Astrometric Conference of the USSR. Tashkent, FAN, 1981, p. 282.

Claims (1)

Claims METHOD FOR DETERMINING THE LINK OF CELESTIAL COORDINATES ESTABLISHED BY THE OPTICAL. AND RADIO BANDS, including the installation in the radio range of the celestial coordinates "1, Si and a2, S2 of two compact extraterrestrial radio sources and photographing, characterized in that, in order to improve accuracy, receive radio emission from these radio sources at two separated reception points that have in outer space, with base B determines the mutual time delays r, tg of radio signals, additionally photograph from one receiving point another against the background of surrounding stars, and from the received image determine the celestial coordinates of sowing, 5th projection base B to the celestial sphere in the optical 17 range, after which the connection of celestial coordinates is determined; In the celestial sphere, installed in the optical range, with the celestial coordinates abr, SBP, the projection of base B on the celestial sphere in the radio range in the form "VR D" B, SBP FSe, wherein the coupling coefficients D, F of the celestial coordinates established in the optical and radio ranges are determined from the expressions ps sinSisinFSe + cosSi cosFSB cosfai - Das); GZS IBl sinS2SinFSe + cosSi cosFSe cosfai - Das) -. where c is the speed of light.