RU2378676C1 - Method of determining world (universal) time from pulsar pulses - Google Patents

Abstract

FIELD: measurement techniques.

SUBSTANCE: invention relates to techniques of measuring time and can be used for determining world (universal) time from pulsar pulses. According to the invention, the method of determining world (universal) time from pulsar pulses involves modification of intervals of the pulsar pulses, calculated from corrected observations of values of the period of rotation of the pulsar and derivatives, proportional to the ratio of duration of earth days, measured on the date of observation to duration of earth days, measured on the date of observation of the initial pulsar pulse. From the set of modified and non-modified intervals, the interval difference is determined in the barycentric reference system and in a system with the centre in the phase centre of a radio telescope, and from this difference, world time is determined by correcting readings of atomic clocks by this difference value.

EFFECT: increased accuracy of measurement owing to standardisation of world time values read from a uniform atomic time scale, determined taking into account non-uniformity of rotation of the Earth.

8 cl, 5 dwg

Description

Technical field

The invention relates to the measurement of time in coordinate reference systems using scales and standards of atomic time from observations of periodic astrophysical phenomena, in particular the rotation of the Earth, pulsed radio emission from pulsars - neutron stars - and due to their rotation.

State of the art

As an analogue, the closest system in terms of technical and technological essence to universal time, based on the rotation of the Earth, the essence of which is described in [1], is taken.

Universal time (UT, Universal Time) is associated with the Earth's daily rotation and is defined as the hour angle relative to the Greenwich meridian, recorded at the moment the meridian intersects the observed star by atomic clock in the Coordinated Universal Time (UTC). UTC, by definition, is associated with the International Atomic Time (TAI) International Atomic Time Scale, which is based on the definition of a unit of time - a second of SI compared with the highly stable frequency of emission of a cesium atom during a resonant transition between energy levels.

It is known that the uneven rotation of the Earth violates the uniformity of the UT scale. The uneven rotation of the Earth includes: a) a change in the angular velocity of rotation; b) a change in the position of the axis of rotation relative to the solid Earth, called the movement of the pole. Due to changes in the angular velocity of rotation over one century, the accumulated unevenness of UT will be about 30 seconds. The second component of the uneven rotation of the Earth due to the movement of the pole is many times smaller. The movement of the pole is described by a spiral with a period of about 1.2 years, the maximum size of which does not exceed 15 m. To exclude the influence of the movement of the pole on time measurement, the UT1 world time system was introduced, which determines the universal time of the average Greenwich meridian, determined by the average position of the Earth’s pole, and reflects the actual rotation of the earth.

Thus, the UT (UT1) world time scale with respect to the International Atomic Time Scale TAI, by which the International Coordinated UTC Time Scale is defined, has cumulative unevenness that can be applied to the International Coordinated Time UTC.

In order to maintain the difference in scales within the permissible limits UT1-UTC ≤ ± 0.9 s, from January 1, 1972, a change in the clocks operating in the UTC system was introduced by adding a second on December 31 and (or) June 30. An extra second is added approximately once a year and a half. This means that in a year and a half a difference of 1 s accumulates between the uniform atomic time and the time specified by the rotation of the Earth.

UT1-UTC values are calculated at midnight GMT (0h UT) and are regularly published by the State Service for Time, Frequency and Determination of the Earth's Rotation Parameters in the E Series Bulletin “World Time and Pole Coordinates”.

The considered method for measuring UT has the following disadvantages.

The first drawback of the existing method is that the universal time corrections are determined by measuring the deviations of the duration of the earth's days, which excludes the possibility of comparing the universal and atomic time directly on the atomic time scale.

The second drawback is that universal time is presented in the form of episodic corrections for measuring the non-uniformity of the Earth’s rotation, there is no regular continuum of universal time intervals counted on a uniform atomic time scale.

The third drawback is that the measurement of universal time is limited to the selected coordinate system, the center of which is connected with the Earth, and the definition of universal time in other coordinate systems is not provided.

The fourth drawback is that the measured universal time is characterized by significant variability of the results, which is due to periodic and random variations in the measured duration of the earth's day, comparable or exceeding their systematic (secular) deviations.

A known method of synchronizing an atomic clock by pulsar pulses observed on a radio telescope is based on determining the sequence of moments of the pulsar pulses observed in the coordinate system centered on the phase center of the radio telescope using the local time scale of the measuring standard of a radio telescope synchronized with the International atomic time scale and converting them into barycentric moments of the observed pulses in the coordinate system centered on the barycenter of the solar system [2].

In this method, the set of barycentric moments of the pulsar pulses within the extent determined by the established observation dates is counted as intervals from the initial pulsar pulse within this extent, the observed values of the period of rotation of the pulsar and derivatives are adjusted according to the obtained intervals so that the set intervals calculated from them pulses within the observation length had a minimum value of the rms value of the difference variations observed intervals and calculated by the adjusted values of the period and derivatives, remember the set of intervals of the observed pulses calculated by the adjusted values of the period and derivatives within the observation length, replace the measuring standard with an atomic clock, they additionally accumulate periodic signals of the pulsar radio emission, find a new value for the interval of the observed pulse pulsar relative to the initial atomic clock, determine the difference between the values of the interval in one of which is calculated from the corrected values of the period and the derivatives over the entire set of observed intervals within the observation length and the other measured by an atomic clock, and this difference is corrected reading atomic clock.

The disadvantage of this method is that when determining the correcting difference in the readings of an atomic clock from the totality of pulsar pulse intervals observed in a fixed coordinate system centered in the barycenter of the solar system, the uneven rotation of the Earth is not taken into account. The set of barycentric intervals over which the correction difference is found is determined by the stable parameters of the rotation of the pulsar, which are independent of the uneven rotation of the Earth, which is found in a moving coordinate system centered at the observation point on Earth.

The purpose of the invention is to increase the accuracy of measurement, regularization of the measured values of universal time, determined taking into account the uneven rotation of the Earth and counted on a uniform scale of atomic time.

The problem is solved in that world time is determined in the form of a sequence of intervals specified by the parameters of the rotation of the pulsar, which are modified in proportion to the measured value of the duration of the earth's day and counted on a uniform scale of atomic time.

To this end, the determination of universal (universal) time from the pulsar pulses observed on a radio telescope is carried out using the steps in accordance with which:

A) accumulate periodic pulsar radio emission signals at the set observation date, which determine the moment of the pulsar pulse being observed in the coordinate system centered in the phase center of the radio telescope on the local time scale of the measuring standard of the radio telescope synchronized with the International atomic time scale,

B) convert the moment of the observed pulse of the pulsar into the barycentric moment of the observed pulse in the coordinate system centered in the barycenter of the Solar system,

B) perform the sequence of observations of the pulsar pulses at the set observation dates, get the set of barycentric moments of the pulsar pulses within the observation length determined by the set observation dates,

D) convert the totality of the barycentric moments of the pulsar pulses within the extent determined by the established dates of observation into intervals that are counted from the initial pulse of the pulsar within this extent, adjust the observed values of the period of rotation of the pulsar and derivatives in such intervals so that the values calculated from them the intervals of the set of pulses within the observation length had a minimum value of the rms variation p connectivity observed interval and the corrected values calculated period and derivatives

D) remember the corrected values of the period and derivatives and the set of intervals of the observed pulses calculated from them within the length of the observations, measure the duration of the earth day on the date of observation of the pulsar pulse.

At the same time, the relative deviation of the duration of the Earth days from their duration on the date of observation of the initial pulsar pulse is calculated, each measured barycentric interval is modified proportionally to the ratio of the duration of Earth days on the observation date to the duration of Earth days on the date of observation of the initial pulsar pulse.

Based on the set of modified barycentric intervals counted from the selected initial pulse, the observed values of the period of rotation of the pulsar and derivatives are corrected. Then, the corrected values of the period and derivatives are stored, the intervals of the observed pulses calculated from them within the entire length of the observations, and the values of the duration of the earth days from the growing set of observed barycentric intervals, and the measured moments of the pulsar pulses observed in the coordinate system centered in the phase center of the radio telescope, determined by the established dates of observations, counted in the form of intervals from the selected initial pulse of the pulsar.

According to the data obtained, the values of the rotation period of the pulsar and its derivatives are corrected, according to which the intervals of the pulsar pulses are calculated within the observation length. The adjusted values of the period of rotation of the pulsar and derivatives and the intervals of pulses calculated from them within the entire length of the observations are remembered. Each calculated interval is modified in proportion to the ratio of the duration of the earth day, measured at the date of observation to the duration of the earth day, measured at the date of observation of the initial pulse of the pulsar. Observations of pulsar pulses are repeated with regular measurements of the duration of the earth's day.

Based on the modified intervals, the values of the rotation period of the pulsar and its derivatives are corrected, according to which the world time intervals are calculated, the corrected values of the period and derivatives are calculated, the intervals of the observed pulses calculated from them within the entire length of the observations and the relative magnitude of the earth's day over the growing set of observed intervals are stored.

Then, from the totals of the modified and unmodified intervals calculated from the adjusted values of the period of rotation of the pulsar and its derivatives, the difference of the intervals in the barycentric reference system and in the system centered in the phase center of the radio telescope is determined, and world time is determined from this difference by adjusting the atomic readings for this difference hours.

In this case, the intervals from the selected initial pulsar pulse are selected in the range from several hours to several years according to the growing set of measurements of the moments of the observed pulsar pulses with a step between measurements in the range from day to several days.

Another aspect of the invention is that the duration of an earth day is determined by the satellite laser ranging method (SLR-Satellite Laser Ranging), or the radio-technical observations of the satellite by the GPS navigation system, or by the method of radio interferometry with extra-long bases (VLBI), or a combination thereof, and the range of deviations of the duration Earth days from the accepted calculated value of 86400 s, measured over the observation length of 1980-2000, is approximately from 0 to 4 ms [1].

Another aspect of the invention is that the duration of the Earth’s day is determined every day at the state at 0h UT using the satellite observation method of the satellite, at 12h UT using the GPS navigation system and on average once a day (there are dates with missing observations, there are two -, more rarely, three-time observations on one date) by the VLBI method with the MJD of the observation date with an accuracy of 0.01 s. The error in determining the duration of Earth days is 20-30 μs. Variations in the measured values of the duration of the Earth's day of the same order as the measured deviations, which are approximately 3-4 ms.

The next aspect of the invention is that the length of the observations is selected from several days to several years or more, while the dates of observation of the pulsar pulses and measurements of the duration of the earth day are chosen either coinciding or differing by an integer number of days, or, if these conditions are not met, lead to them, for example, by interpolating the measured values of the duration of the earth's day.

A further aspect of the invention is that the length of the observations is counted from the selected initial pulse of the pulsar to the last observed pulse of the pulsar and the entire set of intervals contained within the boundaries of the length of the observations is calculated from the adjusted values of the period and derivatives. In this case, the error in measuring the intervals of pulsar pulses is 50-100 ns within the boundaries of the observation length.

Another aspect of the invention is that the intervals of the pulsar pulses are modified proportionally to the ratio of the duration of the earth day on the date of observation, which is measured with an error of 20-30 μs, to the duration of the earth day on the date of observation of the initial pulse of the pulsar, the observed values of the period of rotation of the pulsar and its derivatives are corrected within the length of the observations and calculate from them the intervals of the pulsar pulses, the error of which is 50-100 ns within this length.

The next aspect of the invention is that the moments measured in the coordinate system with the beginning in the phase center of the radio telescope are converted into the coordinate system with the beginning in the barycenter of the Solar system, they are converted into intervals that are counted from the moment of the initial pulse, the rotation parameters are adjusted, and barycentric intervals are calculated from them , which are counted into the coordinate reference system with the beginning in the phase center of the radio telescope.

List of drawings

Figure 1 shows the pulse profile of the pulsar In 1937 + 21 (J1939 + 2134) after accumulation.

Figure 2 shows the deviation of the relative magnitude of the adjusted period of rotation of the pulsar deviation and barycentric intervals, where

2a) deviations of the relative magnitude of the adjusted rotation period,

2b) deviation of the barycentric intervals of the pulsar pulses.

Figure 3 shows the time-varying difference of the intervals observed in the barycenter of the Solar system and the phase center of the radio telescope within an approximately 8-year extent, with a pronounced annual cycle of these changes.

Figure 4 shows the deviations of the unmodified intervals calculated by the adjusted parameters of the rotation of the pulsar in the barycenter of the Solar System (TV chart) and the phase center of the radio telescope (CT chart). Note. The values of the corrected parameters of the rotation of the pulsar in the barycenter of the solar system and the phase center of the radio telescope coincide.

Figure 5 shows the simulated difference values of the modified and unmodified intervals by the adjusted parameters of the rotation of the pulsar observed in the barycenter of the Solar System (TV plot) and in the phase center of the radio telescope (TT plot). Note. The difference in the graphs in FIG. 5 is much, approximately 5 orders of magnitude, less than the absolute value of the difference between the modified and unmodified intervals, which is determined by the uneven rotation of the Earth. Therefore, the graphs of the difference between the modified and unmodified intervals in the barycenter of the Solar system and the phase center of the radio telescope in Figure 5 are practically indistinguishable.

Terms and abbreviations

The time scale is a continuous sequence of time intervals of a certain duration, counted from the initial moment [8].

Atomic time - time on a scale in which the unit of time is equal to a second of the International System of Units [8].

A second is a period of time consisting of 9 192 631 770 periods of radiation corresponding to a transition between two ultrathin levels of the ground state of a cesium atom 133 [4].

The international atomic time scale TAI is the atomic time scale calculated by the International Bureau of Weights and Measures [8].

The international coordinated time scale UTC is a time scale calculated so that the offset relative to the International atomic time scale is an integer number of seconds, and relative to the universal time scale, it does not exceed 0.9 s [8].

World time is the general value of time scales based on the rotation of the Earth around its axis [8].

Measurement of the time interval - experimental determination of the duration of the measured time interval in accepted units [8].

Modified time interval - a measured interval that is changed in proportion to some set value.

Secondary standard of units of time and (or) frequency - a measuring instrument designed to store and transmit units of time and (or) frequency and time scales with the accuracy highest for a specific region or industry. The sizes of time units and (or) frequencies stored by secondary standards are determined by standardized methods of comparisons with the state standard [8].

Clock - a device for measuring and displaying time [8].

Clock Correction - the value of the time interval, which is added to the clock to obtain the actual time in this scale.

Julian date - a form of recording on a time scale that counts down in days from the initial moment corresponding to 12 h January 1, 4713 BC according to the Julian calendar. The modified Julian date is equal to the Julian date minus 2400000.5 days [8].

Modified Julian date of observation: a decimal number for which the integer part determines MJD (in days), and a decimal fraction that defines the part of the day (the length of the day is 86,400 s) at the date of observation, measured from their beginning to the observed event. For example: MJD = 46053.7825072939094 corresponds to the calendar date 12/19/1984 with the time of the event 86400 with 0.7825072939094 = 67608.63019377 s from the beginning of the day on this date.

The length of observations is the time interval between the initial and last observed events in a given series (sequence) of events.

Local time scale - a time scale counted by a measuring standard on a radio telescope.

Timing of pulsars - measuring the time of arrival of pulsar pulses in a certain coordinate frame of reference.

Pulsar rotation parameters - period (or frequency) and their derivatives.

MPI of the pulsar - the moment of arrival of the pulsar pulse: the numerical value of the moment of the event (era) in any time scale.

The barycentric MPI of a pulsar is the MPI of a pulsar recounted using ephemeris into the barycenter of the Solar System, measured from observations in the phase center of a radio telescope [3].

AES - artificial satellite of the Earth.

12h UT - 12 hours UTC

TV - a barycentric interval of pulsar time.

TT is the pulsar time interval in the phase center of the radio telescope.

Description of the invention

In accordance with the proposed method, the determination of universal (universal) time from the pulsar pulses observed on a radio telescope is carried out using the steps in which:

A) accumulate periodic pulsar pulsar radio emission signals at the set observation date, which determine the moment of the pulsar pulse being observed in the coordinate system centered in the phase center of the radio telescope on the local time scale of the measuring standard of the radio telescope, synchronized with the international atomic time scale taking into account orbital motion and daily Earth rotation

B) convert the moment of the observed pulse of the pulsar into the barycentric moment of the observed pulse in the coordinate system centered in the barycenter of the Solar system,

B) sequentially observe the pulsar pulses according to the established observation dates, obtain a set of barycentric moments of the pulsar pulses within the observation length determined by the established observation dates,

D) they process the entire set of barycentric moments of the pulsar pulses within the extent determined by the established observation dates, count in the form of intervals from the initial pulse of the pulsar within this extent, the observed values of the period of rotation of the pulsar and its derivatives are corrected in such intervals so that the values calculated from them the intervals of the set of pulses within the observation length had a minimum value of the rms value of the difference variations observed intervals and calculated from the adjusted values of the period and derivatives,

D) remember the corrected values of the period and derivatives and the set of intervals of the observed pulses calculated from them within the length of the observations, measure the duration of the earth day on the date of observation of the pulsar pulse.

Moments of arrival of pulses (MPI) of a pulsar are measured in a coordinate system centered in the phase center of the radio telescope. The obtained MPI values with reference to the phase center of the radio telescope can be transformed to any point in space by converting them using numerical models to another coordinate system in 4-dimensional space-time. As such a point, the center of mass (barycenter) of the solar system is usually chosen — its fixed point, at which the moment of arrival of pulses is determined only by the parameters of the rotation of the pulsar and, in contrast to the results of MPI measurements directly on the radio telescope, are independent of the motion of celestial bodies in the solar system taken into account by the ephemeris, including rotation (without taking into account unevenness) and orbital motion of the Earth.

When choosing the origin at the center of mass of the solar system, the barycentric moment t _{n of the} observed pulse with number N is determined by the polynomial [3]:

where t ₀ is the initial moment of measurement,

- период вращения пульсара в начальный момент и его производная,P ₀

- the period of rotation of the pulsar at the initial moment and its derivative,

R _appr - approximation error due to a finite number of members of the polynomial.

Physical parameters of pulsars [7]

Rotation period: from a few milliseconds (the shortest period known for the pulsar B1937 + 21, is about 1.56 s) to several seconds (about 4.3 s for the pulsar B1845-19);

Derivative of the period: from 1.78 × 10 ^-20 s / s (pulsar B1855 + 09) to 1.2 × 10 ^-11 s / s (J0437-47); The second derivative of the period: the catalogs contain information only for some pulsars. The influence of the second derivative on the measured moments of the pulsar pulses due to their smallness is insignificant compared with the measurement error. For the pulsar taken here as an example, B1937 + 21 is 3.7 × 10 ⁻³² s ⁻¹ ;

The pulsar radiation flux density at frequencies of 400 MHz (S400) and 1400 MHz (S1400) is in the range from several thousandths to several units of Jansky (Jy).

For the pulsar B1937 + 21: S400 = 240 mJy, S1400 = 16 mJy;

The width of the average radiation profile of the pulsar pulse is from 0.1 to 0.5 or more of the duration of the rotation period. The radiation profile can be two-component, as in the pulsar B1937 + 21;

The signal-to-noise ratio of the pulsar at the input of the amplifier of the radio telescope depends on the radiation flux density and ranges from 10 ^-1 to 10 ^-3 and even less for weak pulsars.

с/с, а вторая производная составляет

с^-1) погрешность аппроксимации достигнет величины, сопоставимой с периодом вращения пульсара (1,56 мс) на протяженности наблюдений только приблизительно через 10⁴ лет, если в полиноме (1) учитывать только период и первую производную.In expression (1), only the first derivative of the period of rotation of the pulsar is taken into account, which is sufficient given the achievable accuracy of timekeeping. The value of the root-mean-square error of determining the angular momenta is usually 50-100 ns, and the approximation error over the observation length of several years fits into the same limits if only the first derivative is taken into account. The use of second-order derivatives may be required with an increase in the accuracy of determining the angular momenta with an observation length of the order of tens of years. Due to the extreme smallness and high stability of the absolute values of the derivatives (for example, for the pulsar PSR B1937 + 21, the first derivative

s / s, and the second derivative is

s ^-1 ) the approximation error will reach a value comparable to the period of rotation of the pulsar (1.56 ms) over the observation period only after about 10 ⁴ years, if only the period and the first derivative are taken into account in polynomial (1).

определяют барицентрический момент наблюдаемого импульса пульсара с номером N с погрешностью аппроксимации R_appr.According to the known, for example, previously obtained from observations values of the rotation period of the pulsar P ₀ and the derivative

determine the barycentric moment of the observed pulse of the pulsar with the number N with an approximation error R _appr .

If the barycentric moments t _{n are} counted from some pulse selected as the initial one, then expression (1), taking into account the fact that t ₀ vanishes, determines the intervals between the observed pulses counted from the selected initial one:

This expression with a known error determines the intervals of the observed pulses within the entire length of the observations, which, as a rule, is at least several years.

A radio telescope is pointed at a pulsar - a rotating neutron star - and its radio emission is received and recorded in the form of a periodic sequence of pulses [2]. The reception and registration of the pulsar radio emission is carried out in the process of observations of the pulsar at predetermined dates that determine the year, month, number and time of the beginning of observations. The time interval between the dates of observations is established, depending on the required accuracy of the approximation of the observed intervals of the pulsar pulses, ranging from several hours to several weeks. Since the level of the received pulsar signal is many times smaller than the noise level, then for the registration of pulsar pulsar use the accumulation of weak periodic signals using a synchronous drive. The launch of the storage ring is synchronized according to previously obtained from observations values of the rotation period of the pulsar and its derivatives, which are determined for the barycenter of the Solar System for a fixed observation era. A sequence of starts of the drive with a constant period is achieved until the set number of accumulated pulses is reached, which is determined so that the offset of the accumulated pulse due to a change in the observed period of rotation of the pulsar on the radio telescope during this sequence of starts of the drive, taking into account its derivative, does not exceed the permissible value. If, upon reaching the set number of accumulated pulses, the level of the accumulated pulse has not yet reached a sufficient value, a new period value is set, accumulation is continued, and so on until the ratio of the accumulated pulse level reaches a value sufficient to reliably identify the pulse profile by which to measure the angular momentum relative to the moment the synchronous drive is started.

The pulsar pulse moments and the moments of the synchronous drive start are counted by the measuring atomic standard, which is part of the radio telescope tools, which is synchronized with the State standard of time and frequency by comparing the time several times a day and making appropriate corrections of the measuring standard time according to the refinement of the State standard. The state standard, in turn, is synchronized with the International Atomic Time Scale.

The pulse accumulation takes time from several minutes to several hours, depending on the pulsar radiation flux density and the sensitivity of the radio telescope. During this time, the radio telescope receives from several thousand to several tens or even hundreds of thousands of pulsar pulses. The pulse profile highlighted as a result of accumulation can equally be compared with any of the pulses taken during the accumulation. In this case, the difference in the numerical values of the moments is an integer number of periods that separate the moments when the drive starts.

The moment of arrival of the pulsar pulse, measured in the phase center of the radio telescope, is calculated on the basis of the ephemeris at the barycentric moment of the pulse, counted in the coordinate system centered on the barycenter of the solar system.

The described process of accumulating pulsar radio emission signals, determining the angular momentum observed in the phase center of a radio telescope, converting it to a barycentric moment is repeated according to the established observation dates, and a set of barycentric pulsar pulse moments is obtained within the observation length determined by the established observation dates.

и таким образом определяют наблюдаемые параметры вращения пульсара

,

. По скорректированным параметрам вращения пульсара определяют интервалы импульсов относительно начального в пределах всей протяженности:The entire set of barycentric moments of the pulsar pulses within the observation length, which is determined by the established observation dates, is counted relative to the initial pulse of this length in the form of observed intervals. According to the observed intervals, the barycentric values of the period of rotation of the pulsar P ₀ and the derivative are obtained earlier from previous observations.

and thus determine the observed rotation parameters of the pulsar

,

. The adjusted parameters of the rotation of the pulsar determine the intervals of the pulses relative to the initial within the entire length:

where TB _i is the barycentric interval of the observed pulse, measured relative to the initial pulse,

N _B is the number of emitted pulses within the i-th observed interval in the barycentric reference system,

i is the serial number of the observed interval at the set date within the length of the observations.

According to expression (3), the taken into account values of the period and the first-order derivative are corrected, which is sufficient for the length of observation in several years. In the case of observations of a greater extent (several tens of years), it may be necessary to take into account and accordingly correct also the second-order derivative. The number of adjusted derivatives of the period is selected according to the value of the allowed variation of the intervals calculated from the adjusted values of the period and derivatives, so that the variations of the intervals when changing the length of the observations do not exceed the achievable measurement error of the intervals. The number of adjusted derivatives is kept constant within the observation length.

,

определяют коррекцией параметров

таким образом, чтобы вычисленные по ним интервалы в пределах всей протяженности наблюдений имели минимальное значение среднеквадратичной величины разности наблюдаемых интервалов TB_i и вычисленных по скорректированным значениям периода и производной

по всем наблюдаемым моментам протяженности.The values of the observed rotation parameters of the pulsar

,

determined by correction of parameters

so that the intervals calculated from them within the entire length of the observations have a minimum value of the rms difference between the observed intervals TB _i and calculated from the adjusted values of the period and derivative

for all observed moments of extent.

запоминают вычисленные по скорректированным значениям периода и производных барицентрические интервалы наблюдаемых импульсов в пределах всей протяженности. Коррекцию параметров вращения пульсаров выполняют каждый раз после измерения очередного интервала в результате наблюдения очередного импульса на установленную дату наблюдений.As a result of this correction, the numerical values of the rotation parameters of the pulsar are determined

remember the barycentric intervals of the observed pulses calculated from the adjusted values of the period and derivatives within the entire length. The correction of the rotation parameters of the pulsars is performed each time after measuring the next interval as a result of observing the next pulse at the set observation date.

In the proposed method, the above disadvantages of the existing method are proposed to be eliminated by introducing additional and changing existing technological operations, in accordance with which:

1. Take the measured duration of the Earth day on the date of observation of the pulsar pulse, calculate the relative deviation of the Earth day from their duration, measured on the date of observation of the initial pulse of the pulsar.

The duration of the earth day is determined taking into account the uneven rotation of the Earth:

where ΔLOD _i is the deviation of Earth days from their duration on the date of observation of the initial pulse of the pulsar LOD ₀ : ΔLOD _i = LOD _i -LOD ₀

- относительное отклонение земных суток на дату наблюдения.

- relative deviation of Earth days on the date of observation.

и производной

таким образом, чтобы вычисленные по ним интервалы в пределах всей протяженности наблюдений в соответствии с (3) имели минимальное значение среднеквадратичной величины разности наблюдаемых интервалов TB_i и вычисленных по скорректированным значениям периода и производной с учетом неравномерности вращения Земли:The calculated barycentric intervals of the observed pulses are modified proportionally to the value (1 + δ _i ) - the relative value of the duration of the Earth day calculated in accordance with (4), taking into account the uneven rotation of the Earth. The set of modified intervals corrects the barycentric values of the period of rotation of the pulsar

and derivative

so that the intervals calculated from them within the entire length of the observations in accordance with (3) have a minimum value of the rms difference between the observed intervals TB _i and calculated from the corrected values of the period and derivative taking into account the uneven rotation of the Earth:

и

и вычисленные по ним наблюдаемые интервалы с учетом неравномерности вращения Земли, величина которой учитывается коэффициентом (1+δ_i) по всем наблюдаемым интервалам в пределах протяженности.This determines the observed rotation parameters of the pulsar

and

and the observed intervals calculated from them, taking into account the uneven rotation of the Earth, the value of which is taken into account by the coefficient (1 + δ _i ) for all observed intervals within the extent.

и

запоминают вычисленные по скорректированным значениям периода и производных интервалы наблюдаемых импульсов в пределах всей протяженности и значения коэффициентов (1+δ_i) в выражении (5) по нарастающей совокупности барицентрических интервалов.The correction of the rotation parameters of the pulsars is performed each time after measuring the next interval as a result of observing the next pulse at the set observation date. As a result of this correction, the numerical values of the rotation parameters of the pulsar are determined

and

the intervals of the observed pulses calculated from the corrected values of the period and derivatives are stored within the entire length and the values of the coefficients (1 + δ _i ) in expression (5) are taken from the growing set of barycentric intervals.

2. The measured moments of the pulsar pulses observed in the coordinate system centered in the phase center of the radio telescope are counted in the form of intervals from the selected initial pulsar pulse. Using them, the corrected values of the rotation period of the pulsar and its derivatives are found so that the intervals calculated over them within the entire observation length have a minimum value of the mean-square difference of the intervals observed in the phase center of the radio telescope and calculated from the corrected values of the period and derivative.

The intervals of events observed in two arbitrary reference systems are calculated by the four coordinates X, Y, Z, T and X ', Y', Z ', T', respectively. When moving from one coordinate system to another, the space-time geometry does not change, and the indicated 4-dimensional coordinates are related by the relation [5]

where J is a constant value independent of the chosen reference frame,

c is the speed of light.

In relation to the measurement of intervals, expression (6) is presented in equivalent differential form [5]:

where the interval dσ is also independent of the chosen reference frame.

и

значения коэффициентов (1+δ_i), по которым производится модификация наблюдаемых интервалов с учетом относительных отклонений земных суток, также одинаковы в обеих системах отсчета.This means that in relation to the observed intervals of pulsar pulses, taking into account relations (6) and (7), the adjusted values of the parameters of rotation of the pulsar

and

the values of the coefficients (1 + δ _i ) over which the observed intervals are modified taking into account the relative deviations of the Earth's day are also the same in both reference systems.

и производной

таким образом, чтобы вычисленные по ним интервалы в пределах всей протяженности наблюдений имели минимальное значение среднеквадратичной величины разности наблюдаемых интервалов TT_i и вычисленных по скорректированным значениям периода и производной с учетом неравномерности вращения Земли:From the measured in the phase center of the radio telescope, the pulsar pulses for the specified dates calculate the intervals of the observed pulses relative to the initial pulse. The calculated intervals of the observed pulses are modified proportionally to the value (1 + δ _i ) - the relative value of the measured duration of the earth's day, taking into account the uneven rotation of the Earth. The set of modified intervals corrects the values of the observed period of rotation of the pulsar

and derivative

so that the intervals calculated from them within the entire length of the observations have a minimum value of the rms difference between the observed intervals TT _i and calculated from the adjusted values of the period and derivative taking into account the uneven rotation of the Earth:

where N _T is the number of emitted pulsar pulses in the reference system with the beginning in the phase center of the radio telescope within the observation length.

и

вычисленные по ним наблюдаемые интервалы с учетом неравномерности вращения Земли, величина которой учитывается коэффициентом (1+δ_i) по всем наблюдаемым интервалам протяженности.This determines the observed rotation parameters of the pulsar

and

the observed intervals calculated from them, taking into account the unevenness of the Earth's rotation, the value of which is taken into account by the coefficient (1 + δ _i ) over all observed intervals of extent.

The correction of the rotation parameters of the pulsars is performed each time after measuring the next interval as a result of observing the next pulse at the set observation date. As a result of this correction, numerical

и

запоминают вычисленные по скорректированным значениям периода и производных интервалы наблюдаемых импульсов в пределах всей протяженности и значения коэффициентов (1+δ_i) в выражении (8) по нарастающей совокупности интервалов, наблюдаемых в фазовом центре радиотелескопа.values of pulsar rotation parameters

and

the intervals of the observed pulses calculated from the corrected values of the period and derivatives are stored within the entire length and the coefficient values (1 + δ _i ) in expression (8) are taken from the growing set of intervals observed in the phase center of the radio telescope.

3. Using the difference values of the modified and taking into account the non-uniform rotation of the Earth and unmodified intervals measured in the reference system centered on the phase center of the radio telescope, the world time is determined in the form of a correction for the value of this difference in the readings of the atomic clock, over which the observed intervals were calculated. The correction value is determined in accordance with expression (8) for any emitted pulse N _T within the observation length. At the same time, the rotation parameters by which the time intervals are calculated are corrected after each new measurement of the observed interval and its modification is proportional to the magnitude of the relative duration of the Earth day, taking into account the uneven rotation of the Earth.

,

δ_i в обеих системах отсчета, то всемирное время, которое определяют как поправку показаний атомных часов по разности модифицированных и немодифицированных интервалов в системе отсчета с центром в фазовом центре радиотелескопа, точно так же определяют и в барицентрической системе отсчета. Отличие состоит только в том, что в соответствии с выражением (5) вычисленная разность модифицированных и немодифицированных барицентрических интервалов не связана непосредственно с показаниями атомных часов на Земле. Эта разность представляет собой поправку, с помощью которой интервалы пульсарного времени, измеренные по атомным часам в фазовом центре радиотелескопа и пересчитанные в барицентр, корректируют с учетом неравномерности вращения Земли и таким путем определяют всемирное время в барицентре Солнечной системы.Since, in accordance with expression (7), both reference frames are equivalent, and in accordance with expressions (5) and (8), the measured intervals are determined by the same parameter values

,

δ _i in both reference systems, the universal time, which is defined as the correction of the atomic clock readings by the difference between the modified and unmodified intervals in the reference system with the center in the phase center of the radio telescope, is also determined in the barycentric reference system. The only difference is that, in accordance with expression (5), the calculated difference between the modified and unmodified barycentric intervals is not directly related to the readings of the atomic clock on Earth. This difference is a correction with the help of which the pulsar time intervals measured by the atomic clock in the phase center of the radio telescope and recalculated into the barycenter are corrected taking into account the uneven rotation of the Earth and thus determine the world time in the barycenter of the Solar System.

Thus, according to the revealed difference between the modified and unmodified intervals of the pulsar pulses, the world time is determined by adjusting the atomic clock readings by the value of this difference, by which the intervals of the pulsar pulses observed in the phase center of the radio telescope are counted. They also determine the correction of the pulsar time intervals in the barycentric reference system. With this correction, the barycentric intervals of the pulsar time are converted to the intervals that determine the universal time in the barycentric reference frame.

The non-obviousness of the technical solution is due to the fact that improving the accuracy of measurement, regularizing the measured values of universal time, determined taking into account the uneven rotation of the Earth and counted on a uniform scale of atomic time, are possible only in the aggregate of all the features given in the method.

The task of determining universal time in the form of a sequence of intervals was solved by modifying the intervals of the pulsar pulses calculated from the adjusted observable values of the period of rotation of the pulsar and derivatives, in proportion to the ratio of the duration of the earth day measured on the date of observation to the duration of the earth day measured on the date of observation of the initial pulse of the pulsar. Then, the intervals of the pulsar pulses as a result of the modification receive an additional increment, which is determined by the uneven rotation of the Earth, expressed in the form of the measured relative magnitude of the duration of the earth day on the observation date. As a result of the modification, the intervals of the pulsar pulses calculated from the corrected observed values of the period of rotation of the pulsar and derivatives taking into account the uneven rotation of the Earth are transformed into a set of universal time intervals, and thus universal time is determined in the same form as regular sequences of intervals of International Atomic Time and the pulsar time associated with it. This technical solution is not obvious in order to increase the measurement accuracy, to regularize the measured values of universal time, determined taking into account the uneven rotation of the Earth and measured on a uniform atomic time scale, in which a combination of data on modified and unmodified pulsar pulse intervals is used. This combination is absent in the known literature and patent sources.

The following is an example implementation of the proposed method.

Using a radio telescope, at a predetermined date of observation, the pulsar radio emission is received and recorded in the form of a periodic sequence of pulses. To register pulsar pulses, the accumulation of signals using a synchronous drive is used, the launch of which is synchronized according to the values of the rotation period of the pulsar and its derivatives, previously obtained from observations. The pulsar pulse moments and the synchronization drive start times are counted by the atomic measurement standard, which is part of the radio telescope tools, which is synchronized with the State standard of time and frequency, and that, in turn, with the International atomic time scale. During the pulse accumulation, the radio telescope receives from several thousand to several tens or even hundreds of thousands of pulses.

Figure 1 shows the pulse profile of the pulsar B1937 + 21 (J1939 + 2134) after accumulation. The x-axis represents the time equal to the period of rotation of the pulsar (approximately 1.56 ms for this pulsar). The pulse allocated as a result of the accumulation in such a way that the signal-to-noise ratio is not less than 10 is compared with one of the pulses taken during the accumulation time and its moment is determined in the coordinate reference system with the center in the phase center of the radio telescope. In this case, the difference in the numerical values of the moments of other pulses taken during the accumulation of time will be an integer number of periods that separate the moments when the drive starts.

The moment measured in the phase center of the radio telescope is calculated on the basis of the ephemeris at the barycentric moment of the pulse observed in a fixed coordinate system centered on the barycenter of the solar system, in which its numerical value does not depend on the orbital and diurnal motion of the Earth.

By repeating, according to the established dates of observations, the process of accumulation of pulsar radio emission signals, determining the angular momentum in the phase center of the radio telescope, converting it to the barycentric moment, we obtain a set of barycentric angular momenta of the pulsar within the increasing length of observations of several years.

The obtained barycentric moments of the entire set of pulses within the observation length are counted in the form of intervals from the initial pulse of this set. Based on the obtained intervals, the observed values of the period of rotation of the pulsar and derivatives are corrected and the intervals of the set of pulses are calculated from them within the length of the observations. As a result of the correction, the minimum value of the rms value of the difference between the observed intervals and calculated from the adjusted values of the period and derivatives is achieved. The intervals of the set of observed pulses calculated from the corrected values of the period and derivatives within the length of the observations are remembered.

For example, the timing of the pulsar PSR B1937 + 21 on the Arecibo radio telescope (USA) over an 8-year length 1984-1992. at a frequency of 2.3 GHz [6], barycentric intervals of pulses measured during this time were obtained relative to MJDo = 46053.7796041243972 selected as the starting date in the reference system centered at the phase center of the radio telescope, which corresponds to the initial reference time TVo = 86400s · 0.7796041243972 = 67357.79634792 s, recalculated on this date in the reference system centered in the barycenter of the Solar System, and as a result of the correction, the following measured from observations values of the period at the initial moment and the derivative for the barycenter of the Solar System are obtained from these data nym:

.P ₀ = 0.00155780645568484 s;

.

For comparison, we present the calculated values of these parameters:

a) from the catalog [7], 1993:

P ₀ = 0.00155780644887275 s;

b) according to [6], 1994:

.P ₀ = 0.001557806468819794 s;

.

следует, что полученные в результате коррекции величины периода вращения пульсара и его производной с высокой точностью согласуются с ранее установленным значениям по обоим источникам приблизительно на одну и ту же эпоху наблюдений, отличия не превышают разности оценок в источниках. Значение производной периода совпадает с величиной, приведенной в работе [6], и его сохраняют неизменным в пределах всей протяженности наблюдений.From the given values of the parameters P ₀ ,

it follows that the values of the rotation period of the pulsar and its derivative obtained as a result of correction are highly consistent with the previously established values for both sources by approximately the same observation era, the differences do not exceed the difference in the estimates in the sources. The value of the derivative of the period coincides with the value given in [6], and it is kept unchanged within the entire length of the observations.

Figure 2 shows the deviations of the relative magnitude of the adjusted rotation period (Figure 2a) and barycentric intervals (Figure 2b), which are calculated by the adjusted rotation parameters within the observation length in accordance with formula (2). Deviations of barycentric intervals are caused by changes in the adjusted period according to the results of its measurement within the observation length and do not exceed 10 μs within the 8-year interval.

The measured moments of the pulsar pulses observed in the coordinate system centered in the phase center of the radio telescope are counted as intervals from the selected initial pulsar pulse. Based on the obtained intervals, the observed values of the rotation period of the pulsar and derivatives are corrected so that the intervals of the set of pulses calculated from them within the observation length have a minimum value of the rms value of the difference between the observed intervals and calculated from the corrected values of the period and derivatives. Based on the adjusted values of the period and derivatives, the intervals of the set of pulses relative to the initial within the length of the observations are calculated. As a result of the correction, the following values of the period for the epoch of the initial impulse and derivative in the coordinate system centered in the phase center of the radio telescope were obtained from these data:

.P ₀ = 0.00155780645568484 s;

.

The adjusted parameters of the rotation of the pulsar in both reference systems coincide. They calculate the intervals of the set of pulses relative to the initial within the observation length.

As the initial in the coordinate system centered in the phase center of the radio telescope, the date MJDo = 46053,7825072939094 is chosen, the same as in the barycentric system. This date in the coordinate system centered in the phase center of the radio telescope corresponds to the initial moment ТТо = 86400 s · 0.7825072939094 = 67608.63019377 s for this date.

The intervals of the totality of the pulses observed in both systems, calculated from the adjusted values of the period and derivatives, are remembered within the observation length.

We note that the initial moments TVo = 67357.79634792 s and TTo = 67608.63019377 s and the pulse intervals related to the same pulsar pulses, but observed in two different systems, do not coincide in magnitude due to the mutual displacement of their centers due to rotation and orbital motion of the Earth relative to the barycenter of the solar system.

Figure 3 shows the time-varying difference of the intervals observed in the barycenter of the solar system and the phase center of the radio telescope within an 8-year length with a pronounced annual cycle of these changes. This difference in intervals, determined by relation (7), is due to the dependence of the values of T and T 'in (6) on the change in the spatial coordinates of X, Y, Z due to the displacement of the phase center of the radio telescope relative to the barycenter of the Solar system. However, despite this changing difference in time intervals counted in the 4-dimensional metric (7) in both systems, due to the coincidence of the adjusted values of the pulsar rotation parameters and the calculated pulse intervals observed in each system, the deviations of the intervals calculated according to the corrected rotation parameters in the barycenter of the Solar system and the phase center of the radio telescope, also turn out to coincide with high accuracy, limited mainly by the error in the conversion of the moment ntov observed pulses from one coordinate frame to another, which is determined by the accuracy ephemeris.

Figure 4 shows the deviations of the intervals calculated by the adjusted rotation parameters in the barycenter of the solar system and the phase center of the radio telescope. The standard deviation of their difference TB _i -TT _i does not exceed 0.31 μs within the same 8-year observation length, which is comparable to the maximum achievable accuracy of measuring the intervals of pulsar radiation pulses in various coordinate systems. The values of the corrected parameters of the rotation of the pulsar in the barycenter of the solar system and the phase center of the radio telescope coincide.

To determine the universal (universal) time from the pulsar pulses observed on a radio telescope, the following actions are performed. Using the method described above, the next moment of the observed pulsar pulse is measured in the coordinate system centered on the phase center of the radio telescope according to the local time scale of the measuring standard of the radio telescope synchronized with the International Atomic Time Scale, it is counted as an interval from the initial pulse, added to the set of intervals within the extent observations and transform it into the barycentric moment of the observed pulse in the coordinate system centered in the barycenter of the solar system. The barycentric moment is counted as an interval from the initial pulse and added to the set of intervals within the observation length. Based on the totality of barycentric intervals, including the next, the observed values of the rotation period of the pulsar and derivatives are corrected, the adjusted values of the period and derivatives and the pulse intervals calculated from them are stored within the observation length. The duration of Earth days is measured on the date of observation of the next pulse of the pulsar, the relative deviation of Earth days from their duration on the date of observation of the initial pulse of the pulsar is calculated. Each measured barycentric interval is modified in proportion to the ratio of the duration of the Earth day on the date of observation to the duration of the Earth day on the date of observation of the initial pulse of the pulsar. Based on the set of modified barycentric intervals counted from the selected initial pulse, the observed values of the period of rotation of the pulsar and derivatives are corrected. The corrected values of the period and derivatives, the intervals of the observed pulses calculated from them within the entire length of the observations, and the values of the duration of the Earth's days along the growing set of observed barycentric intervals are remembered.

The measured moments of the pulsar pulses observed in the coordinate system centered in the phase center of the radio telescope according to the set dates are counted in the form of intervals from the selected initial pulsar pulse. Based on the set of intervals, including the next, the values of the rotation period of the pulsar and its derivatives are corrected, by which the intervals of the pulsar pulses are calculated within the observation duration, the adjusted values of the period and derivatives are calculated, the intervals of the observed pulses calculated from them within the entire observation duration are stored. Each calculated interval is modified in proportion to the ratio of the duration of the earth day, measured at the date of observation to the duration of the earth day, measured at the date of observation of the initial pulse of the pulsar. Observations of pulsar pulses are repeated after a set period of time with the regularity of measurements of the duration of earthly days. Based on the modified intervals, the values of the rotation period of the pulsar and its derivatives are corrected, according to which the world time intervals are calculated, the corrected values of the period and derivatives are calculated, the intervals of the observed pulses calculated from them within the entire length of the observations and the relative magnitude of the earth's day over the growing set of observed intervals are stored.

From the sets of modified and unmodified intervals calculated from the adjusted values of the period of rotation of the pulsar and its derivatives, the difference in the intervals in the barycentric reference system and in the system centered in the phase center of the radio telescope is determined, and world time is determined by this difference by adjusting the value of the difference in the readings of the atomic clock .

The intervals from the selected initial pulse of the pulsar are selected in the range from several hours to several years according to the growing set of measurements of the moments of the observed pulses of the pulsar with a step between measurements in the range from day to several days.

The duration of Earth days is determined by the method of laser light-ranging observations of a satellite, or by radio-technical observations of a satellite by the GPS navigation system, or by the method of radio interferometry with extra-long bases (VLBI), or a combination thereof.

The duration of Earth days is determined every day according to the state on Oh UT by the method of laser observations of the satellite, as of 12h UT using the GPS navigation system and, on average, once a day by VLBI with the modified Julian date of observation (MJD) with an accuracy of 0.01 s and the error in determining the duration of Earth days in the range of 20-30 μs.

The length of the observations is chosen from several days to several years or more, while the dates of observation of the pulsar pulses and measurements of the duration of the earth's days are chosen either to coincide or differ by an integer number of days, or, if these conditions are not met, lead to them, for example, by interpolation measured values of the duration of the earth day.

The length of the observations is counted from the selected initial pulse of the pulsar to the last observed pulse of the pulsar and calculated from the adjusted values of the period and derivatives of the entire set of intervals contained within the boundaries of the length of the observations, with an error of 50-100 ns for all intervals of the pulsar pulses within the limits of the length of the observations.

The intervals of the pulsar pulses are modified in proportion to the ratio of the duration of the earth day on the observation date, which is measured with an error of 20-30 μs, to the duration of the earth day on the date of observation of the initial pulse of the pulsar, the observed values of the period of rotation of the pulsar and derivatives are corrected for them within the observation length and calculated by the intervals of the pulsar pulses, the error of which is 50-100 ns within this length.

The moments measured in the coordinate system with the beginning in the phase center of the radio telescope are converted into the coordinate system with the beginning in the barycenter of the Solar system, they are converted into intervals that count from the moment of the initial pulse, the pulsar rotation parameters are corrected, and barycentric intervals are calculated from them, which are converted into the coordinate system reference point with the beginning in the phase center of the radio telescope.

To illustrate the determination of world time and the identification of corrective corrections of the atomic clock from the measured intervals of pulsar pulses observed on a radio telescope, taking into account the uneven rotation of the Earth, the same sequence of measured moments over an 8-year length was used according to observations in Arecibo (1984-1992). After correcting the parameters of the rotation of the pulsar and calculating the intervals of the observed pulses from the adjusted values of the parameters of rotation of the pulsars in the barycentric reference frame and in the system centered on the phase center of the radio telescope, the obtained sets of intervals of pulses observed in both coordinate systems were modified in proportion to the value simulating the change in the duration of the Earth’s day by date of observation. This simulated the unevenness of the Earth's rotation, taking into account which the totality of the world time intervals was determined and the deviations of the observed intervals in both reference systems due to the uneven rotation of the Earth, according to which the atomic clock readings are corrected.

When modeling, it was assumed that the duration of the earth's day varies according to a linear law:

where t _i are the moments of the observed pulses of the pulsar, counted from the initial pulse.

The coefficient δ in (9) was calculated according to the method described in [1]. The accumulated time unevenness UT in the interval τ is determined

where Ω ₀ is the angular velocity of the Earth at the beginning of the gap.

The dependence of the duration of the earth day on the angular velocity of rotation of the Earth:

Change in the length of the day, taking into account that δΩ << 1:

where LOD ₀ = 2π / Ω ₀ is the duration of Earth days at the beginning of the interval (on the date of observation of the initial pulse of the pulsar). The value of the coefficient δ is determined from the relation

Considering that over one century, the accumulated unevenness of UT is approximately 30 s, and the estimated duration of Earth days is 86,400 s, we find

Using the found value of the coefficient δ, which is a constant in accordance with (9) within the entire length of the observations, the value is calculated

(1 + δ · t _i ), equal to the ratio of the duration of Earth days on the date of observation to the duration of Earth days on the date of observation of the initial pulse of the pulsar. This value is used to modify the pulsar pulse intervals measured in the barycentric reference system and in the system centered in the phase center of the radio telescope. As the values of t _i taken values of the intervals of pulses observed in each system and counted from the initial pulse.

Figure 5 shows the simulated difference values of the modified and unmodified intervals for the adjusted parameters of the rotation of the pulsar observed in the barycenter of the solar system and in the phase center of the radio telescope. The results were obtained at increasing intervals within the 8-year observation length. On the graph, both difference sequences practically coincide, their standard deviation within the entire length does not exceed 0.59 μs, they are of the same order as for unadjusted intervals in both coordinate frames (standard deviation is 0.31 μs) shown in FIG. four.

Meanwhile, the absolute deviations of the modified and unmodified intervals differ from each other due to the influence of the uneven rotation of the Earth, by about 5 orders of magnitude. From this it follows that the accuracy of determining universal time in absolute terms and the difference between the modified and unmodified intervals, due to the uneven rotation of the Earth, is close to the maximum achievable when measured using an atomic clock, does not depend on the selected coordinate frame of reference, and is mainly limited only by the accuracy of moment conversion pulsar pulses from one coordinate system to another.

Thus, the proposed method for determining world time by measuring the sequence of intervals of pulsar pulses on an atomic time scale, modifying their duration in proportion to the change in the duration of Earth days due to uneven rotation of the Earth, solves the problem of measuring and counting on a scale of atomic time a sequence of intervals of universal time over the entire length measurements. Thus, a direct comparison of world and atomic time is achieved according to the readings of the same atomic clock.

Instead of episodic corrections, determined by measuring the irregularity of the Earth’s rotation with a random sample, universal time is determined as a regular continuum of intervals of the emitted pulsar pulses, which are corrected for the detected changes in the duration of the Earth day due to the uneven rotation of the Earth and are counted on a uniform atomic scale.

The invariance of universal time, measured by pulsar pulse intervals in a barycentric reference frame with a fixed center and in the phase center of a radio telescope that rotates and orbits with the Earth, allows you to determine universal time in any other coordinate frame of reference with an arbitrarily chosen center within the solar system and thereby realize its versatility.

World time, measured by the intervals of pulsar pulses, which are determined by the adjusted parameters of the rotation of the pulsar, have a high order of 10 ^-15 , long-term stability and are insensitive to periodic and random variations of the measured values. Therefore, despite the significant variability of the measured deviations of the Earth's day, comparable with the magnitude of these deviations, the universal time, determined from the intervals of pulsar pulses, has the same resistance to variations and has long-term stability of the same order as the intervals of pulsar pulses, which are determined by the adjusted parameters rotation of the pulsar.

Therefore, the proposed method for determining universal time solves the problem of comparing time scales based on the rotation of the Earth around its axis, using highly stable regular intervals of the emitted pulsar pulses in any coordinate reference system with an arbitrarily chosen center within the solar system. Due to the universality of the definition of universal time in space and the long-term stability of the measured intervals, the proposed method is focused on the use in high-precision global coordinate-time measurement systems, for example, GLONASS, where the uneven rotation of the Earth should be taken into account.

Summarizing, we note that the proposed method for determining the universal (universal) time for pulsar pulses includes the accumulation of periodic pulsar radio signals from the pulsar at the set observation date, which determine the moment of the pulsar pulse observed in the coordinate system centered in the phase center of the radio telescope using the local time scale of the measuring standard of the radio telescope synchronized with the scale of international atomic time, taking into account the orbital motion and daily rotation of the earth , and transform it into the barycentric moment of the observed pulse in the coordinate system centered in the barycenter of the solar system. A sequence of observations of pulsar pulses is carried out according to the established observation dates, and a set of barycentric moments of the pulsar pulses is obtained within the observation length determined by the established observation dates. The entire set of barycentric moments of the pulsar pulses within the extent determined by the established observation dates is converted into intervals that are counted from the initial pulse of the pulsar within this extent. Based on the obtained intervals, the observed values of the rotation period of the pulsar and derivatives are corrected so that the intervals of the set of pulses calculated from them within the observation length have a minimum value of the rms value of the difference between the observed intervals and calculated from the corrected values of the period and derivatives. The corrected values of the period and derivatives and the set of intervals of the observed pulses calculated from them are stored within the limits of the observation length. The duration of the earth day on the date of observation of the pulsar pulse is measured. The relative deviation of Earth days from their duration on the date of observation of the initial pulsar pulse is calculated, each measured barycentric interval is modified proportionally to the ratio of the duration of Earth days on the observation date to the duration of Earth days on the date of observation of the initial pulsar pulse. Based on the set of modified barycentric intervals counted from the selected initial pulse, the observed values of the period of rotation of the pulsar and derivatives are corrected. The corrected values of the period and derivatives, the intervals of the observed pulses calculated from them within the entire length of the observations, and the values of the duration of the Earth's days along the growing set of observed barycentric intervals are remembered. The measured moments of the pulsar pulses observed in the coordinate system centered in the phase center of the radio telescope, determined by the established observation dates, are counted in the form of intervals from the selected initial pulsar pulse, the values of the rotation period of the pulsar and its derivatives are corrected according to which the pulsar pulse intervals are calculated within length of observations. The corrected values of the period and derivatives are stored, the intervals of the observed pulses calculated from them within the entire length of the observations are modified, each calculated interval is modified in proportion to the ratio of the duration of the earth's day, measured on the date of observation to the duration, measured on the date of observation of the initial pulse of the pulsar. Observations of pulsar pulses are repeated with regular measurements of the duration of the earth's day. Using the modified intervals, the values of the rotation period of the pulsar and its derivatives are corrected, according to which the world time intervals are calculated. The adjusted values of the period and derivatives, the intervals of the observed pulses calculated from them within the entire length of the observations, and the values of the relative magnitude of the Earth's days along the growing set of observed intervals are remembered. From the sets of modified and unmodified intervals calculated from the adjusted values of the period of rotation of the pulsar and its derivatives, the difference in the intervals in the barycentric reference system and in the system centered in the phase center of the radio telescope is determined, and world time is determined by this difference by adjusting the value of the difference in the readings of the atomic clock .

The intervals from the selected initial pulse of the pulsar are selected in the range from several hours to several years according to the growing set of measurements of the moments of the observed pulses of the pulsar with a step between measurements in the range from day to several days.

The duration of Earth days is determined by the method of laser light-ranging observations of a satellite, or by radio-technical observations of a satellite by the GPS navigation system, or by the method of radio interferometry with extra-long bases (VLBI), or a combination thereof.

The duration of Earth days is determined every day according to the state on Oh UT by the method of laser observations of the satellite, as of 12h UT using the GPS navigation system and, on average, once a day by VLBI with the modified Julian date of observation (MJD) with an accuracy of 0.01 s and the error in determining the duration of Earth days in the range of 20-30 μs.

The length of the observations is chosen from several days to several years or more, while the dates of observation of the pulsar pulses and measurements of the duration of the earth's days are chosen either to coincide or differ by an integer number of days, or, if these conditions are not met, lead to them, for example, by interpolation measured values of the duration of the earth day.

The length of the observations is counted from the selected initial pulse of the pulsar to the last observed pulse of the pulsar and calculated from the adjusted values of the period and derivatives of the entire set of intervals contained within the boundaries of the length of the observations, with an error of 50-100 ns for all intervals of the pulsar pulses within the limits of the length of the observations.

The intervals of the pulsar pulses are modified in proportion to the ratio of the duration of the earth day on the observation date, which is measured with an error of 20-30 μs, to the duration of the earth day on the date of observation of the initial pulse of the pulsar, the observed values of the period of rotation of the pulsar and derivatives are corrected for them within the observation length and calculated by the intervals of the pulsar pulses, the error of which is 50-100 ns within this length.

The moments measured in the coordinate system with the beginning in the phase center of the radio telescope are converted into the coordinate system with the beginning in the barycenter of the Solar system, they are converted into intervals that count from the moment of the initial pulse, the pulsar rotation parameters are corrected, and barycentric intervals are calculated from them, which are converted into the coordinate system reference point with the beginning in the phase center of the radio telescope.

Thus, the proposed method eliminates the above disadvantages of the existing method and the goal of the invention is achieved - improving the accuracy of measurement, regularizing the measured values of universal time, determined taking into account the uneven rotation of the Earth and counted on a uniform atomic time scale.

Information sources

1. V.E. Zharov. Spherical astronomy. Ed. "Century 2", Fryazino, 2006, p.170-181.

2. A.E. Avramenko, A.E. Rodin. A method for synchronizing atomic clocks by pulsar pulses observed on a radio telescope. Patent No. 2316034 RU. 2008, Bull. Number 3.

3. OV Doroshenko, S. M. Kopeikin Algorithm for high-precision phase analysis of observations of single pulsars. Astronomical Journal, 1990, 67, 5, pp. 986-998.

4. K. Oduan, B. Gino. Time measurement. GPS basics. Per. from English under the editorship of V.M. Tatarenkova. M., TECHNOSPHERE, 2002, p. 73.

5. A.A. Logunov. Lectures on the theory of relativity. Ed. “Science”, Moscow, 2002, p. 39-52.

6. V. M. Kaspi, J. H. Taylor, and M. F. Ryba. High Precision Timing of Millisecond Pulsars. III. Long-Term Monitoring of PSRs B1855 + 09 and B1937 + 21. The Astrophysical Journal, 428: 713-728, 1994, June 20.

7. J.H. Taylor, R.N. Manchester, and A.G. Lyne. Catalog of 558 Pulsars. The Astrophysical Journal Supplement Series, 88: 529-568, 1993. October.

8. GOST 8.567-99. Interstate standard “Measurements of time and frequency. Terms and Definitions".

Claims (8)

1. A method for determining the universal (universal) time from pulsar pulses, including the accumulation of periodic pulsar pulsed radio emission signals at a specified observation date, which determine the moment of the pulsar pulse being observed in the coordinate system centered in the phase center of the radio telescope using the local time scale of the measurement standard of the radio telescope synchronized with the International Atomic Time Scale, taking into account the orbital motion and daily rotation of the Earth, and convert it into a barycenter the moment of the observed pulse in the coordinate system centered on the barycenter of the solar system, a sequence of observations of pulsar pulses is carried out according to the established observation dates, a set of barycentric moments of the pulsar pulses is obtained within the observation length determined by the established observation dates, the whole set of barycentric pulsar pulses within the length, determined by the established dates of observations are converted into intervals that count about t of the initial pulse of the pulsar within this length, the observed values of the period of rotation of the pulsar and derivatives are adjusted according to the obtained intervals so that the intervals of the set of pulses calculated from them within the length of the observations have a minimum value of the rms value of the difference between the observed intervals and calculated from the corrected values of the period and derivatives, remember the adjusted values of the period and derivatives and the totality of the observed pulse pulses within the observation length, measure the duration of Earth days on the date of observation of the pulsar pulse, characterized in that the relative deviation of Earth days from their duration on the date of observation of the initial pulse of the pulsar is calculated, each measured barycentric interval is modified proportionally to the ratio of the duration of Earth days on the observation date to the duration of Earth days on the date of observation of the initial pulse of the pulsar, collectively modified barycentric intervals counted from the selected initial pulse, correct the observed values of the period of rotation of the pulsar and derivatives, remember the corrected values of the period and derivatives, the intervals of the observed pulses calculated from them within the entire length of the observations and the values of the duration of the earth day from the growing set of observed barycentric intervals, measured moments of pulsar pulses observed in a coordinate system centered in the phase center of a radio hotel the cop determined by the established dates of observations is counted in the form of intervals from the selected initial pulse of the pulsar, the values of the period of rotation of the pulsar and its derivatives are corrected according to which the intervals of pulses of the pulsar are calculated within the length of the observations, the adjusted values of the period of rotation of the pulsar and derivatives calculated by the intervals of the observed pulses within the entire length of the observations, each calculated interval is modified in proportion to the ratio of of the earth day’s intensity, measured on the observation day to the earth’s day, measured on the observation date of the initial pulsar pulse, the pulsar pulse observations are repeated with the regularity of measurements of the earth’s day, the values of the rotation period of the pulsar and its derivatives are corrected at modified intervals, according to which the world time intervals are calculated , remember the corrected values of the period and derivatives, the intervals of the observed pulses calculated from them within the entire extended the observational values and the values of the relative magnitude of Earth days from the growing set of observed intervals, from the sets of modified and unmodified intervals calculated from the adjusted values of the rotation period of the pulsar and its derivatives, determine the difference in the intervals in the barycentric reference system and in the system centered in the phase center of the radio telescope, and world time is determined by this difference by adjusting the value of the difference in the readings of atomic clocks. 2. The method according to claim 1, characterized in that the intervals from the selected initial pulse of the pulsar are selected in the range from several hours to several years according to the growing set of measurements of the moments of the observed pulses of the pulsar with a step between measurements ranging from one day to several days. 3. The method according to claim 1, characterized in that the duration of the earth day is determined by laser light-ranging observations of artificial Earth satellites (AES), or by radio-technical observations of a satellite by the GPS navigation system, or by radio-interferometry with extra-long bases (VLBI), or a combination thereof. 4. The method according to claim 3, characterized in that the duration of the Earth’s day is determined every day at a state of 0h UT using the satellite observation method, at 12h UT using a GPS navigation system and, on average, once a day by VLBI method indicating modified Julian date of observation (MJD) with an accuracy of 0.01 s and an error in determining the duration of Earth days in the range of 20-30 μs with their measured variations of approximately 3-4 ms. 5. The method according to claim 1, characterized in that the length of the observations is selected from several days to several years or more, while the dates of observation of the pulsar pulses and measurements of the duration of the Earth day are chosen either coinciding or differing by an integer number of days, or if these conditions are not met, lead to them, for example, by interpolating the measured values of the duration of the earth's day. 6. The method according to claim 5, characterized in that the length of the observations is counted from the selected initial pulse of the pulsar to the last observed pulse of the pulsar and calculated from the adjusted values of the period and derivatives of the entire set of intervals contained within the boundaries of the length of the observations, with an error in the range of 50-100 ns for all pulsar pulse intervals. 7. The method according to claim 5, characterized in that the intervals of the pulsar pulses are modified proportionally to the ratio of the duration of the earth day on the date of observation, which is measured with an error of 20-30 μs, to the duration of the earth day on the date of observation of the initial pulse of the pulsar, the observed values are corrected by them the rotation period of the pulsar and derivatives within the observation length and calculate the intervals of the pulsar pulses, the error of which is 50-100 ns within this length. 8. The method according to claim 1, characterized in that the moments measured in the coordinate system with the beginning in the phase center of the radio telescope are recounted with the help of ephemeris into the coordinate system with the beginning in the barycenter of the Solar system, they are converted into intervals that are counted from the moment of the initial pulse, correct the parameters of the rotation of the pulsar, they calculate the barycentric intervals, which are converted into a coordinate reference system with the beginning in the phase center of the radio telescope.

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