Holographic Calibration of Phased Array Telescopes

Abstract

In radio astronomy, holography is a commonly used technique to create an image of the electric field distribution in the aperture of a dish antenna. The image is used to detect imperfections in the reflector surface. Similarly, holography can be applied to phased array telescopes, in order to measure the complex gains of the receive paths of individual antennas. In this paper, a holographic technique is suggested to calibrate the digital beamformer of a phased array telescope. The effectiveness of the technique was demonstrated by applying it on data from the Engineering Development Array 2, one of the prototype stations of the low frequency component of the Square Kilometre Array. The calibration method is very quick and requires few resources. In contrast to holography for dish antennas, it works without a reference antenna. We demonstrate the utility of this technique for initial station commissioning and verification as well as for routine station calibration.

arXiv comment14 pages, 10 figures. Accepted for publication in Radio Science

References in corpus (14)

• LOFAR: The LOw-Frequency ARray
• The Murchison Widefield Array: the Square Kilometre Array Precursor at low radio frequencies
• The Precision Array for Probing the Epoch of Reionization: 8 Station Results
• The LWA1 Radio Telescope
• Understanding Instrumental Stokes Leakage in Murchison Widefield Array Polarimetry
• Characterization of a Low-Frequency Radio Astronomy Prototype Array in Western Australia
• Calibration and Stokes Imaging with Full Embedded Element Primary Beam Model for the Murchison Widefield Array
• Measuring Phased-Array Antenna Beampatterns with High Dynamic Range for the Murchison Widefield Array using 137 MHz ORBCOMM Satellites
• Fast and Accurate Simulation Technique for Large Irregular Arrays
• In situ measurement of MWA primary beam variation using ORBCOMM
• Signal Processing Firmware for the Low Frequency Aperture Array
• The Engineering Development Array: A low frequency radio telescope utilising SKA precursor technology
• Main Beam Modeling for Large Irregular Arrays: The SKA1-LOW telescope case
• Tied-array holography with LOFAR

Cited by in corpus (4)

• Exploring the cosmic dawn and epoch of reionization with 21cm line
• Optimization and Commissioning of the EPIC Commensal Radio Transient Imager for the Long Wavelength Array
• Calibration of an SKA-Low Prototype Station Using Holographic Techniques
• Beamforming approaches toward detecting the 21-cm global signal from Cosmic Dawn with radio array telescopes