About the design of the orbital infrared telescope
The telescope was built according to the "broken" beam pattern: the radiation fell on the 57-centimeter main mirror, then a small secondary mirror directed it through the central hole of the main mirror into the focal plane. The three devices it focused on included IR-sensitive semiconductor receivers. The telescope was placed inside an insulated tank filled with 457 liters of liquid helium before launch. The refrigerant kept the telescope tube and mirrors at a temperature of about 10K. The receivers were cooled to a temperature of approximately 2K. The refrigerant was maintained at this temperature (below the boiling point) due to its slow evaporation.
Photoconductive detectors with specially selected filters were used as receivers; they were sensitive to certain bands of the infrared spectrum. Their sensitivity was so high that the telescope could "spot" a speck of dust at a distance of 2 or 3 km. The main survey instrument consists of a set of 62 detectors that almost completely cover the IR spectrum from 8 to 120 microns with four bands centered at 12, 25, 60, and 100 microns. (The visible part of the spectrum occupies an area of up to 0.7 microns, and the radio range begins at about 1000 microns.) Two more instruments were mounted in the focal plane: a spectrometer for recording the IR spectrum of bright sources and a photometer with a higher spatial resolution (than survey detectors could provide) for measuring selected sources.
Each element of the survey detector set scanned a strip of sky five arcminutes (5’) wide and generated a signal proportional to the total flux of radiation incident on it. In machine processing on Earth, discrete sources were isolated from a continuous stream of data and multiple registrations of each source were combined for joint processing. Discrete sources in this procedure were considered "point sources" (smaller than a few arc minutes in size).
The satellite's orbit at an altitude of 900 km was circumpolar. The plane of the orbit made a precession of about 1 ° per day, which just compensated for the orbital motion of the Earth around the Sun. Due to this, the spacecraft was constantly kept close to the Earth's terminator (the boundary between the day and night zones) and maintained a direction at an angle of 90 ° from the Sun.
The high sensitivity of the detectors led to the fact that dust and solid particles near the satellite, as well as cosmic rays and other charged particles, generated numerous false signals. This background noise was filtered out from astronomical signals — each signal recognized as a source was confirmed by subsequent observations with repetitions over different time periods. 1xBet provides a wide range of betting markets for Indian players. Players can choose to bet on any sports match of their preference. In India, with cricket being the most popular sport, 1xbet offers various bonus options for prominent events such as the Indian Premier League and T20 World Cup. The promo code for 1xbet get vip sports bonus of 100% up to €/$130 (or the equivalent in your local currency). To claim this offer, use the code during registration and select the bonus. This code applies to all four deposits, and be sure to meet the wagering requirements for maximum benefits.