urn:nasa:pds:context:instrument:dushanbe.rcc.sanglok 1.4 1.25.0.0 Product_Context 2026-07-07 1.4 Removed duplicate Internal_Reference entries from Reference_List. 2025-12-24 1.3 Adding missing "telescope" references. 2025-12-24 1.2 Updated schema version. Adding missing "telescope" references. 2025-01-02 1.1 Updated schema version. Update instrument type/subtype to use valid CTLI LDD. 2020-02-18 1.0 Initial export from OLAF urn:nasa:pds:context:telescope:dushanbe.rcc instrument_to_telescope Kayumov V.V., N.N. Kiselev, P.A. Pushnin, V.Yu. Rakhimov, V.I. Siklitskij, K.V. Tarasov, G.P. Chernova, and V.N. Yakutovich, The investigation of the photometer-polarimeter of the 1-m RCC telescope. Bull. Inst. Astrophyz. Tadjik Acad. Sci. No. 78, p. 10-16 (in Russian), 1989. Sanglok Observatory Photometer-Polarimeter Polarimeter The single-channel photometer-polarimeter at Sanglok Observatory was built at the Institute of Astrophysics of Tadjik Academy of Sciences. It allowed quasi-simultaneous photometric and polarimetric observations. The useble wavelength range was 0.35-0.75 microns. The polarimeter worked on the modulation principle with a rapidly-rotating polarizer as the analyzer. The rotation frequency of the polarizer was about 33 revolutions per second. Four impulse counters were used to registrate impulses during each quarter of a polarizer revolution. The total number of impulses in four positions of the polarizer allow the derivation of the values of the Stokes Q and U parameters and hence the value of the degree of linear polarization and the position angle. The observing procedure included consecutive measurements of an object and a sky background near the object with the same diaphragm. To control the stability of instrument operation the measurements of a built-in signal generator were used. For more information, see Kayumov V.V., Kiselev N.N., Pushnin P.A., Rakhimov V.Yu., Siklitskij V.I., Tarasov K.V., Chernova G.P., Yakutovich V.N. The investigation of the photometer-polarimeter of the 1-m RCC telescope. Bull. Inst. Astrophyz. Tadjik Acad. Sci No. 78, p. 10-16, 1989 (in Russian).