SU1318803A1 - One=channel photometer for observing astronomical objects - Google Patents

Abstract

The invention relates to photometry, and specifically to devices for measuring photometric quantities, in particular the power of optical radiation, and can be used to observe astronomical objects. The aim of the invention is to provide simultaneous registration of signals from the object and from the sky background. In a single-channel photometer, a field diaphragm is used to observe astronomical objects, the area of which varies periodically with time. Measuring changes in the recorded flux caused by the modulation of the aperture area of the field, allows us to determine the brightness of the sky background without losing information about the brightness of the observed object. The use of a diaphragm of a field of variable area allows continuous measurement of the entire light flux coming from the object under study and the signal from the sky background, which changes the field depending on the area of the diaphragm. 1 il. (O O)

Description

The invention relates to photometry, to devices for measuring photometric quantities, in particular the power of optical radiation, and can be used to observe astronomical objects, and more specifically, satellites.

The purpose of the invention is to increase accuracy by providing simultaneous registration of signals from the object and from the sky background.

The drawing shows a block diagram of a single-channel photometer for observing astronomical objects.

A single-channel photometer for observing astronomical objects contains successively located aperture 1 field, a photodetector 2 and a 3 photon counter. Diaphragm 1 is connected via modulator 4 to a synchronization block 5 connected to the subtraction scheme 6, the output of which is connected to dividing circuit 7. The key circuit 8 is connected via switch 9 to a memory cell 10, which is connected to adder 12 through multiplication circuit 7 and multiplication unit 11, another one. the input of which is connected via key circuit 8 with a 3-photon counter.

The device works as follows

The imaging of a portion of the sky through the aperture diaphragm 1 field is focused on the photodetector 2, which converts the optical signal into an electrical one and operates in single photon mode. The number of photons is registered by the counter 3. The synchronization unit 5, made in the form of a clock generator, generates a sequence of pulses. The odd signal of the synchronization unit coming into the modulator 4 will correspond to setting controlled aperture 1 in a position in which its opening will be equal to a given area S. The even value of the signal C of the synchronization unit 5 will correspond to the modulator 4 setting the aperture value 1 corresponding to square S.

Simultaneously, the clock pulses from the other output of the synchronization unit 5 are fed to the inputs of the subtraction circuit 6, the key circuit 8 and the switch 9. As a result, the odd signal of the synchronization unit 5 from the output of the photon counter 3 signals A and A is proportional to

3 signals A and A., which are the number of photons or diaphragm

area S and S, respectively, form the difference (A - Ajj) in the subtraction circuit 6. This difference is fed to the input of dividing circuit 7, which divides the difference (A – Ag) by the value of the area difference (S, –S) recorded in memory cell 10. The output signal from dividing circuit 7 is fed to one of the inputs of multiplication circuit 11, to the other input of which the value S comes from memory cell 10 through switch 9 for each odd pair of pulses of synchronization unit 5. The result of the multiplication in block 11 is fed to one of the inputs of the adder 12, to the other input of which signal A comes from the 3-photon counter through key circuit 8 for each odd pair of pulses of the synchronization block 5. For an even pair, the key circuit 8 will supply the input of the adder 12, respectively, the value A, and the switch 9 to the multiplication unit 11 from the memory cell 10 will receive a signal proportional to the value S. At the output of block 12 for odd and even pairs, respectively, we will have signal values that will be proportional to the magnitude of the light

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The invention makes it possible to measure the sky background directly at the location of the object being studied and excludes errors of the sky background offset. This is especially important when observing artificial satellites moving against the background of stars and the Milky Way.

Claims (1)

45 claims 50 A single-channel photometer for observing astronomical objects, containing a diaphragm of a field and a photodetector successively installed next to each other, to which a photon counter is connected, characterized in that, in order to improve the accuracy by providing simultaneous recording of signals from the object and from the background a modulator, a synchronization unit, a subtraction circuit, a division circuit, a multiplication circuit, a switch, a memory cell. 3 13 a key circuit and an adder, wherein one of the outputs of the synchronization block is connected via a modulator to the aperture input of the field and the other output is connected to one of the inputs of the key circuit, subtraction unit and switch, the output of the photon counter is connected to another input of the subtraction circuit key schema whose output is connected to one of the inputs of the adder. 188034 the output of the subtracting circuit is connected to one of the inputs of the division circuit, the other input of which is connected to one of the outputs of the memory cell, the second output of which is connected to the second input of the commutator, the output of which is connected to one of the inputs of the multiplication circuit the second input of which is connected to the output cxeNai division, and its output is connect} 0 nen with the second input of the adder. Compiled by A, Churbakov Editor N. Egorova Tehred V. Kadar, Order 2498/32 Circulation 776 Subscription VNII1Sh State Committee of the USSR for inventions and discoveries 113035, Moscow. Zh-35, Raushsk nab. 4/5 Production and printing company, Uzhgorod, st. Project, 4 Proofreader A.Ilyin