Radio Astronomy Data Acquisition Through HTTP Requests

Radio astronomy is a field that deals with recording astronomical objects in different radio frequencies. Radio astronomy often requires large and expensive instruments to achieve a high resolution, which is particularly important for research. Due to these criteria, individuals and research groups often rely on different observatories worldwide for open-source data. The National Radio Astronomy Observatory's (NRAO) Very Large Array (VLA) in New Mexico contains 27 radio antennas in a Y-shaped configuration. It has a resolution ranging from 0.2 arcseconds to 0.04 arcseconds. The data from VLA are available based on different surveys, such as the Faint Images of the Radio Sky at Twenty-Centimeters (FIRST) and the NRAO VLA Sky Survey. The data from both surveys can be easily downloaded through their simplified webpage or access to their file transfer protocol (FTP) servers. These resources to obtain data are an excellent choice for research needs as they are simple and quick. However, challenges arise when the data required is large in quantity. In this paper, we discuss developing and using a simple tool called Radio Astronomy Data Acquisition Tool (RADAT) that makes it easy to obtain multiple radio sources from multiple surveys. The Python programming language is a popular choice among researchers given its ease of use and large packages available on the internet for the purposes of astronomy-related research. The approach used to design RADAT is through a particular library of Python named requests and astronomy in a Python package called Astropy. RADAT makes utilization of the HTTP requests function, which is a library for Python. It connects to the website of NRAO or FIRST through a URL. It then fills in the necessary information in the forms and gathers the required data. The data can be in raw Flexible Image Transport System (FITS) or processed FITS files. The package Astropy collects these data and provides the completed file to the user. This file is saved to allow the user to use any FITS-compatible software for further processing. This process can be repeated over several files per the user's requirement. This process can be automated for bulk files by creating an input file that contains the Right Ascension and Declination of radio sources, and the tool continues to download the files of the sources in the input file.