Lecture

Self Calibration: Sphe-SelfCal

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Description

This lecture covers the concept of self-calibration in radio astronomy, focusing on the iterative process of improving gains and models using available information. The instructor explains how to make a model using 1GC data, flag residual data, estimate gains model, apply gains, and repeat the process until satisfied. The lecture also includes practical examples of scripting in CASA for self-calibration activities.

In MOOC

The Radio Sky II: Observational Radio Astronomy

The first part of the course introduces the different types of telescope technologies available to astronomers, with a particular focus on single-dish radio telescopes and radio interferometers. Optical, UV, X-ray, Gamma, neutrino, and gravitational wave telescopes will also be briefly covered, as well as a foray into Search for Extraterrestrial Intelligence. We, then, dive deep into the principles of observational radio astronomy, covering the observables (flux, luminosity, brightness temperature), and th

Official source

Related concepts (32)

Radio telescope

A radio telescope is a specialized antenna and radio receiver used to detect radio waves from astronomical radio sources in the sky. Radio telescopes are the main observing instrument used in radio astronomy, which studies the radio frequency portion of the electromagnetic spectrum emitted by astronomical objects, just as optical telescopes are the main observing instrument used in traditional optical astronomy which studies the light wave portion of the spectrum coming from astronomical objects.

Radio astronomy

Radio astronomy is a subfield of astronomy that studies celestial objects at radio frequencies. The first detection of radio waves from an astronomical object was in 1933, when Karl Jansky at Bell Telephone Laboratories reported radiation coming from the Milky Way. Subsequent observations have identified a number of different sources of radio emission. These include stars and galaxies, as well as entirely new classes of objects, such as radio galaxies, quasars, pulsars, and masers.

Spectral density estimation

In statistical signal processing, the goal of spectral density estimation (SDE) or simply spectral estimation is to estimate the spectral density (also known as the power spectral density) of a signal from a sequence of time samples of the signal. Intuitively speaking, the spectral density characterizes the frequency content of the signal. One purpose of estimating the spectral density is to detect any periodicities in the data, by observing peaks at the frequencies corresponding to these periodicities.

Radio wave

Radio waves are a type of electromagnetic radiation with the longest wavelengths in the electromagnetic spectrum, typically with frequencies of 300 gigahertz (GHz) and below. At 300 GHz, the corresponding wavelength is 1mm, which is shorter than the diameter of a grain of rice. At 30 Hz the corresponding wavelength is ~, which is longer than the radius of the Earth. Wavelength of a radio wave is inversely proportional to its frequency, because its velocity is constant.

Astronomy

Astronomy is a natural science that studies celestial objects and phenomena. It uses mathematics, physics, and chemistry in order to explain their origin and evolution. Objects of interest include planets, moons, stars, nebulae, galaxies, meteoroid, asteroid, and comets. Relevant phenomena include supernova explosions, gamma ray bursts, quasars, blazars, pulsars, and cosmic microwave background radiation. More generally, astronomy studies everything that originates beyond Earth's atmosphere.

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