RU1768979C - Radio interferometer for finding relative coordinates of space vehicles - Google Patents

Abstract

The invention relates to space navigation, in particular to radio interferometric means for determining the relative coordinates of spacecraft with extra-long bases. The purpose of the invention is to increase the speed of determining the relative coordinates of spacecraft. The device contains two spatially separated receiving channels, each of which contains an antenna, a receiver, an amplitude limiter, as well as a local frequency and time standard, first and second signal filtering units, a subtraction unit, a reference frequency generator, a multiplier, and an integrator. The first inputs of the signal filtering units, the second inputs of which are connected to the output of the amplitude limiter, are connected to the output of the local frequency and time standard, their outputs are connected respectively to the first and second inputs of the subtraction unit, the output of which is connected to the first input of the multiplier, the second input of which is connected with the output of the reference frequency generator, and the output of the multiplier is connected to the input of the integrator, the output of which is connected to the input of the memory unit, the output of which is connected to the input of the processing center. 2 ill. with C

Description

The invention relates to the field of space navigation, in particular, to means for determining the relative coordinates of spacecraft by ultra-long base radio interferometry (VLBI) and can be used to study near and far space.

A radio interferometer is known, comprising two antennas, each of which is connected to a receiver, the first output of which is connected to the first input of the tape recorder, the second input of which is connected to a frequency standard, the output of the tape recorder is connected by plane with its own computer frequency standard, input

which is connected by cable or relay connection to the second output of the receiver.

The specified device has the following disadvantages:

specialized processing systems are used for processing, including recording information on magnetic tape, which increases the time to determine the relative coordinates of spacecraft;

decreased performance due to the complexity of software filtering signals read from magnetic tapes.

An object of the invention is to increase speed.

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This is achieved by the fact that an amplitude limiter, first and second signal filtering units, a subtraction unit, a reference frequency generator, a multiplier, an integrator are introduced into the device, while the output of the receiver is connected to the input of the amplitude limiter, the output of which is connected to the first inputs of the first and second filtering units signals, the second inputs of which are connected to the output of the local frequency and time standard, the outputs of the first and second signal filtering units are connected respectively to the first and second inputs of the subtraction unit, the output of which is connected to the first input of the multiplier, the second input of which is connected to the output of the reference frequency generator, and the output of the multiplier is connected to the input of the integrator, the output of which is connected to the input of the memory unit, the output of which is connected to the input of the processing center.

This goal is also achieved by the fact that each signal filtering unit of the device contains a part period counter selector, a current phase value block, a phase increment register, a period linear modification block, an operation start block, a control counter block, a correlation counter block and a control block, a first output which is connected to the first input of the counter of the part of the period, the second output to the first inputs of the block of the current phase value, the phase increment register, the start block and the second input of the hour meter selector and the period, the third input of which is connected to the output of the device’s amplitude limiter, the fourth input - with the first output of the start block, the fifth input - with the first output of the control counter block, the sixth input - with the output and second input of the current phase value block, the first output of the selector part of the period meter is connected to the first input of the correlation counter unit, and the second output is connected to the first input of the control unit, the third output of which is connected to the second input of the phase increment register, the fourth output is connected to the third input of the register no phase, the fifth output with the first input of the linear period modification block, the sixth output with the second input of the start block, the seventh output with the device subtraction unit, the eighth output with the first input of the control counter block and the second input of the correlation counter block, and the eighth output of the control unit is connected by a bi-directional bus to the second input of the control counter block and the third input of the correlation counter block, the fourth input of which is combined with the third inputs of the control counter block and the block of the current phase value and connected to the second output of the start block, the third and fourth

the inputs of which are connected to the local frequency and time standard of the device, the second output of the control counter block is connected to the second input of the control block, and the third output is connected to the second input of the block

0 linear modification of the period, the first and second outputs of which are connected respectively to the fourth and fifth inputs of the phase increment register, the output of which is connected to the fourth input of the block of the current 5th phase increment.

In FIG. 1 is a schematic diagram of a radio interferometric device for determining the relative coordinates of spacecraft; in FIG.

0 2 - schematic diagram of a signal filtering unit:

1 - antenna; 2 - receiver; 3 - amplitude limiter; 4 - the first block filtering signals; 5 - second filtering unit;

5 6 - local standard of frequency and time; 7 is a subtraction unit; 8 - reference frequency generator. 9 - multiplier; 10 - integrator; 11 is a memory unit; 12 - processing center; 13 - the counter selector of the period; 14 0 block of the current phase value; 15 - phase increment register; 16 - block linear modification of the period; 17 - block start work; 18 is a block of control counters; 19 is a block of correlation counters; 20-block5 laziness.

A radio interferometric device for determining the relative coordinates of spacecraft operates as follows. Signals emitted

0 spacecraft KA1 and KA2 at microwave frequencies with a difference in frequency are received by antenna 1 with a receiver (hereinafter, operation of the device at one receiving point is described), are limited by

5 amplitude and enter blocks 4 and 5 of the filtering signals. In addition to the received signals from spacecraft, second marks and a sinusoidal signal from the local

0 standard frequency and time.

The signal filtering units (4 and 5) carry out narrow-band filtering of the signal from each spacecraft. The signals from the outputs of the signal filtering blocks are Fourier transform in blocks 7-10 and transmitted through the memory block 11 to the processing center 12.

This data is then transmitted over the simplest communication line (e.g., over the telephone channel) to the processing center 12.

In the processing center, after subtracting the data recorded at various reception points and subtracting the data received in the difference signal, it carries information on the relative position of KA1 and KA2, compensating for the influence of the frequency drift of the transmitters of spacecraft.

An input sinusoidal analog signal is installed from KA1 and KA2, clipped in an amplitude limiter, time-sliced and processed in a filtering unit.

Signal filtering units 4 and 5 provide real-time determination of the correction coefficients of the input signal from KA1 or KA2 with sinusoidal and cosine reference signals of the frequency and phase previously known at each given moment and coming from the local frequency and time standard.

The incoming signal is clipped into two levels and quantized in time. The reference signal period from the local frequency and time standard is divided into N parts.

According to the phase of the reference signal, a clipped value is added to one of the N accumulation counters. The value of each and: counters after the accumulation time has expired, is then multiplied by the value of the required trigonometric functions and integration.

The period of the reference signal is set by writing to the register 15 the phase increment for the interval A t D. A linear change in the frequency of the reference voltage is provided by setting the number of intervals Ar, through which the value of D must be changed by one, and the direction of the change.

The period portion counter selector 13 consists of a programmable counter for determining the accumulation time, the contents of which are reduced by one per Ar (after the set accumulation time has expired, an interrupt signal is generated), as well as an additional programmable counter for determining the time.

The current phase value block 14 includes an adder of the current phase value (SAXX) with a phase increment value (SBXX) and storing the obtained value in the output register. The current phase value (SAXX), the mode select signal R8, and the signal 2 At are fed to the input of the counter selector of part of period 13, which, at a unit value of the incoming data, KLDATA generates the corresponding

a GATE signal for one of the counters of the correlation counter block 19.

The phase increment register 15 stores the current SBXX phase change value for

At, and changes it depending on the signals C + and C. The value of the phase increment register 15 is reset by the RESET signal, the initial phase increment POO-P19 is entered from the control unit (signal NEW,

ROO-R1E data).

The block of linear modification of period 16 on the STEP signal generates signals O and C - change the register RDF one step in the right direction to change

period depending on the direction set by the direction control unit UP.

The start-up unit 17 generates a start-up signal START from the start-up signal ON from the control unit and external signals fb and Tn, and also generates a signal Ar.

The correlation counter block 19 includes accumulating counters. The value of each counter decreases by one at

the presence of the corresponding GATE signal for 2 At.

Claims (2)

The claims A radio interferometric device for determining the relative coordinates of spacecraft, containing two spatially separated receiving channels, each of which contains an antenna, the output of which is connected to the input of the receiver, a local frequency and time standard, a memory unit and a processing center, characterized in that. in order to improve performance, it additionally contains an amplitude limiter, a first and second signal filtering unit, a subtraction unit, a reference frequency generator, a multiplier, an integrator, while the output of the receiver is connected to the input of the amplitude limiter, the output of which is connected to the first inputs of the first and second filtering units signals, the second inputs of which are connected to the output of the local frequency and time standard, the outputs of the first and second signal filtering units are connected respectively to the first and second inputs of the bl subtraction window, the output of which is connected to the first input of the multiplier, the second input of which is connected with the output of the reference frequency generator, and the output of the multiplier is connected to the input of the integrator, the output of which is connected to the input of the memory unit, the output of which is connected to the input of the processing center 2. The device pop. 1, characterized in that each of the signal filtering units comprises a period part counter selector, a current phase value unit, a phase increment register, a period linear modification unit, a start operation unit, a control counter unit, a correlation counter unit and a unit control, the first output of which is connected to the first input of the period part counter selector, the second output - with the first inputs of the current phase value block, phase increment register, the start of operation block and the second input of the period part counter selector, the third input to It is connected to the output by the limiter of the device amplitudes, the fourth input - with the first output of the start block, the fifth output - with the first output of the control counter block, the sixth input - with the output and the second input of the current phase value block, the first output of the period part counter selector connected to the first input of the correlation counter block, and the second output to the first input of the control unit, the third output of which is connected to the second input of the phase increment register, the fourth output is with the third input of the phase increment register, the fifth output is the first input of the linear period modification block, the sixth output - with the second input of the start block, the seventh output - with the device subtraction unit, the eighth output - with the first input of the control counter unit and the second input of the correlation counter unit, and the eighth output of the control unit is connected by a bi-directional bus with the second input of the control counter block and the third input of the correlation counter block, the fourth input of which is combined with the third inputs of the control counter block and the block of the current phase value and connected to the second output ohm of the start-up block, the third and fourth inputs of which are connected to the local frequency and time standard of the device, the second output of the control counter block is connected to the second input of the control block, and the third output is with the second input of the period linear modification block, the first and second outputs of which are connected respectively, with the fourth and fifth inputs of the phase increment register, the output of which is connected to the fourth input of the block of the current phase increment, KA1 KA2 KLDATA I am ata Gate