Mediaspace scheduled maintenance: Aug 25, 2026 07:00 - 12:00 AM. During this time, videos will be temporarily unavailable. Check status updates.

Lecture

Calibration and Self-calibration

Description

This lecture covers the concepts of calibration and self-calibration in radio astronomy, focusing on techniques such as bandpass, gain, and delay calibration using calibrators. It also delves into self-calibration strategies, including the use of known parameters to compute corrections and the elimination of the need for calibrators under certain conditions.

In MOOC

The Radio Sky II: Observational Radio Astronomy

Official source

Related concepts (30)

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.

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 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.

Radio spectrum

The radio spectrum is the part of the electromagnetic spectrum with frequencies from 3 Hz to 3,000 GHz (3 THz). Electromagnetic waves in this frequency range, called radio waves, are widely used in modern technology, particularly in telecommunication. To prevent interference between different users, the generation and transmission of radio waves is strictly regulated by national laws, coordinated by an international body, the International Telecommunication Union (ITU).

History of radio

The early history of radio is the history of technology that produces and uses radio instruments that use radio waves. Within the timeline of radio, many people contributed theory and inventions in what became radio. Radio development began as "wireless telegraphy". Later radio history increasingly involves matters of broadcasting. Invention of radio In an 1864 presentation, published in 1865, James Clerk Maxwell proposed theories of electromagnetism, with mathematical proofs, that showed that light and predicted that radio and x-rays were all types of electromagnetic waves propagating through free space.

Related lectures (40)

Radio Interferometry: The Universe At Radio Wavelengths MOOC: The Radio Sky II: Observational Radio Astronomy

Explores radio interferometry, MeerKAT telescope, imaging vs. single measurement, and Fourier transform in radio astronomy.

The Incredible Diversity of Radio Telescopes MOOC: The Radio Sky II: Observational Radio Astronomy

Explores the incredible diversity of radio telescopes and covers primary beam patterns, sensitivity calculations, and historical significance.

Untitled

Radio Interferometry Measurement Equation: Correlation Matrix and Geometric Delay MOOC: The Radio Sky II: Observational Radio Astronomy

Explores the correlation matrix, geometric delay, averaging, smearing, fringe stopping in radio interferometry.

Data Inspection: Visibility Data and CASA Software MOOC: The Radio Sky II: Observational Radio Astronomy