The Ionospheric Spectral Imager (ISI):A digital spectrometric Riometer.

Abstract

Radiometric systems’ theory and application are fundamental to human progress, holding significance in telecommunications, electronics, medical devices, and beyond. In our investigation, they play a vital role in studying the universe, characterizing planetary atmospheres, and investigating the space weather of our solar system. This document thoroughly delves into these aspects to provide a comprehensive understanding of their application across these three topics. Beginning with the subject’s importance, the introduction delves into the characteristics and behavior of cosmic radiation, the Earth’s ionosphere, their interplay, and their reliance on local space weather conditions. The discussion also encompasses the current state-of-the-art radiometric system designed for studying this phenomenon, referred to as the RIOMETER (Relative Ionospheric Opacity Meter for Extra-Terrestrial Emissions of Radio Noise). This system is capable of generating an intensity map of Relative Ionospheric Opacity using cosmic radiation at 38 MHz. Around 2004, roughly twelve instances of this system were set up in South America as part of the South America Riometer Network (SARINET). This aimed to study the South Atlantic Magnetic Anomaly (SAMA), where Earth’s magnetic field strength significantly reduces, creating a gradient. One instance was implemented at Universidad de Concepción, operational but limited in producing sensitive ionospheric information. Building on the theoretical framework, I proposed upgrading RIOMETER’s data generation. Shifting from a total power receiver, the proposal involves a spectrometric system enabling multi-spectral image creationan advancement known as ISI-RIOMETER. This involves an overall upgrade of electric and electronic components using modern tech like surface-mount devices and fieldprogrammable gate arrays. It enhances ionospheric understanding, space weather insights, and opens new exploration dimensions. Analyzing ISI generated data for three weeks confirms its operational capability and capacity to produce a multi-spectral image using radio noise signals across 87 different pixels. Theoretical calculations and simulations project an expected 25-degree angular resolution and sensitivity near 0.01 dB.