# Estimating solar flux density at low radio frequencies using a sky brightness model

## TL;DR

This paper presents a new method to estimate solar flux density at low radio frequencies using sky brightness models and interferometric data, enabling efficient and robust calibration of solar observations with minimal computational resources.

## Contribution

The authors extend sky model calibration from single antennas to two-element interferometers, allowing for reliable solar flux estimation with less computational effort.

## Key findings

- Successfully applied to Murchison Widefield Array data
- Provides robust absolute solar flux calibration
- Offers a computationally efficient calibration method

## Abstract

Sky models have been used in the past to calibrate individual low radio frequency telescopes. Here we generalize this approach from a single antenna to a two element interferometer and formulate the problem in a manner to allow us to estimate the flux density of the Sun using the normalized cross-correlations (visibilities) measured on a low resolution interferometric baseline. For wide field-of-view instruments, typically the case at low radio frequencies, this approach can provide robust absolute solar flux calibration for well characterized antennas and receiver systems. It can provide a reliable and computationally lean method for extracting parameters of physical interest using a small fraction of the voluminous interferometric data, which can be prohibitingly compute intensive to calibrate and image using conventional approaches. We demonstrate this technique by applying it to data from the Murchison Widefield Array and assess its reliability.